Как настроить градусник электронный: Как правильно пользоваться электронным градусником

Как набить температуру на градуснике (ртутном и электронном) в домашних условиях и у врача? — ХеХе Клуб — развлекательный портал

Существует множество случаев, когда людям хочется узнать, как набить температуру тела. К примеру, ребенок не хочет идти в школу и пытается убедить своих родителей, что заболел. Или студенту предстоит важный экзамен, к которому он не готов, и теперь хочет пропустить его по причине якобы болезни. Возможно, человеку надоела работа, и он хочет провести неделю дома на больничном. Безусловно, лучший способ доказать кому-то наличие болезни – это повышенная температура. Но как быстро набить температуру тела, когда это необходимо?

Интересуясь хотя бы раз имитацией болезни, в голове наверняка появлялся вопрос, как набить температуру до 38 градусов. Это весьма парадоксально, но многие люди посещают сайты о здоровье человека не только для того, чтобы найти ответ на вопрос, как сбить температуру, но и чтобы найти там информацию о том, как можно быстро вызвать у себя болезнь. Итак, есть несколько основных способов, как набить температуру в домашних условиях. Повысить температуру тела можно с помощью следующих средств:

Йод.
Канцелярский клей.
Кофе.
Грифель.
Лук или чеснок.

Как набить температуру при помощи йода?

Для поднятия температуры йодом необходимо небольшое количество его раствора капнуть на хлеб или сахар, и съесть его.

Также можно добавить йод в стакан с водой и выпить. В результате температура быстро повышается до 38 градусов, а иногда и еще выше, и держится в течение нескольких часов.

Недостаток способа состоит в способности йода сжечь слизистую, поэтому сто раз подумайте, прежде чем решаться на такой шаг.

Как повысить температуру канцелярским клеем?

Для этого необходимо взять обычный канцелярский клей и нанести его на внутреннюю часть ноздрей. Преимущество данного способа заключается в том, что кроме повышения температуры, появляются и другие симптомы болезни, например, насморк и чихание.

Кофе, как способ поднять температуру

Еще один способ искусственного повышения температуры – кофе. Только в этом случае его нужно не пить, а есть. Съешьте пару ложек обычного растворимого кофе, и температура тела заметно увеличится. Конечно, если кушать кофе всухомятку, оно обладает довольно неприятным вкусом, поэтому его можно закусить небольшим количеством сахара.

Однако стоит отметить, что данный способ помогает не всем желающим.

Как поднять температуру при помощи грифеля?

Следующий способ набивания температуры связан с грифелем. Он является самым распространенным ответом на вопрос, как набить температуру в школе. Возьмите обычный карандаш, извлеките оттуда грифель, и съешьте небольшой кусочек. Спустя небольшое время можно почувствовать повышение температуры, которая иногда достигает 40 градусов и держится 3-4 часа.

Повышение температуры при помощи чеснока или лука

Чеснок и лук также могут искусственно вызвать повышение температуры. Для этого необходимо взять лук или чеснок, и натирать им подмышки в течение 10 минут. Помимо перечисленных продуктов также подойдут соль или перец.

Недостатком этого способа является то, что он может привести к раздражению кожи.

К тому же, запах вам вряд ли удастся скрыть, а поскольку такой способ был придуман давно – все врачи знают, как уличить человека в подобном мошенничестве.

Практически все способы объединяет неоправданный риск здоровья человека. Это значит, что не следует необдуманно принимать йод, грифель или кофе, даже будучи уверенным, что это не нанесет вред организму.

Другие способы повышения температуры на градуснике

Кроме перечисленных способов набивания температуры существуют и другие:

Целый день, занимаясь физическими нагрузками, можно увеличить температуру тела на пару градусов.
При необходимости повысить температуру наутро, лягте спать в мокрой пижаме и таких же носках.
Один из интересных способов поднятия температуры заключается в том, что нужно ходить в носках с коркой от апельсина внутри. Конечно, звучит это довольно странно, но этот способ работает на самом деле.
Можно съесть сырое яйцо, а потом выпить небольшое количество молока. В этом случае температура также поползет вверх.
Сделайте четыре глубоких вдоха, наберите воздух в легкие и напрягите пресс вместе с диафрагмой так, будто пытаясь внутри раздавить воздух. Задержите дыхание на время от 15 до 45 секунд. Пять раз выполните данное упражнение, после чего температура начнет повышаться.

Как повысить температуру на ртутном градуснике?

В случаях, когда температура измеряется без наблюдения, пригодятся знания того, как набить температуру на градуснике.

В первую очередь следует отметить такой эффективный способ, как соприкосновение градусника и чего-то горячего. Его можно поднести к батарее или лампочке, опустить в горячий чай.

Будьте предельно осторожны, поскольку температура будет повышаться очень быстро.

Второй способ, не менее известный, занимает немного больше сил и времени. Он является оптимальным решением при отсутствии рядом горячих предметов. В этом случае применяйте трение. Потрите градусник об джинсы, диван (главное, чтобы он был не кожаный), ковер, одеяло или другие предметы. Главное не перестараться и не получить слишком высокий результат – температуру выше 40 градусов. Иначе это станет поводом для направления в стационар или вызовет удивление врача, после чего он, скорее всего, предложит повторно измерить температуру. В этом случае доктор будет внимательней следить за измерением, так что повторить натирание термометра вряд ли удастся.

Как обмануть электронный градусник?

Зная способы повышения температуры на ртутном градуснике, вопросов о том, как набить температуру на электронном градуснике возникать не должно. Электронный градусник работает на тепловом датчике, поэтому для него подойдут все те же способы, что и для ртутного. Кроме того, можно подержать его под горячей водой или погреть в руках. Еще один способ нагреть градусник, особенно если за измерением температуры наблюдают, заключается в том, чтобы поставив градусник, постараться нагреть его при помощи работы мышц. Известно, что при работе мышц к ним приливает кровь, что способствует повышению температуры.

Что делать, если температура измеряется под присмотром?

Планируя повысить температуру искусственным путем необходимо подумать о том, как набить температуру у врача. На самом деле вариантов не так уж много.

Заранее вычислите, какой термометр будет предложен для измерения температуры и купите абсолютно такой же. При помощи перечисленных способов повысьте дома показания градусника и придите к врачу с готовым термометром подмышкой. Конечно, здесь понадобится ловкость рук и хорошая выдержка. Лучше всего заранее потренируйтесь дома. Обратите внимание, что одежда нужна свободная, а вот майку рекомендуется заправить, чтобы избежать падения градусника на пол. Не забывайте, что при нарушении целостности термометра наружу выпадают капли ртути, которая является сильно ядовитым веществом. Чтобы этого не случилось, старайтесь более тщательно планировать свои действия.

Второй способ – изготовление небольшой грелки. В качестве примера можно использовать следующий вариант конструкции:

Необходимо взять горчичник и подержать его несколько секунд в горячей воде.

После чего вытащите его и положите в полиэтиленовый пакет. Это делается для того, чтобы измеряя температуру, термометр не соприкасался с горчичником.

Эту грелку закрепите подмышкой, используя, например, скотч. Сложность этого способа заключается в необходимости добиться того, чтобы грелка повышала температуру до необходимой величины, не превышая ее. Достичь желаемого результата можно лишь поэкспериментировав над этим дома.

А для того чтобы грелка дольше оставалась теплой, ее нужно утеплить при помощи мягкой ткани.

Существует еще один вариант, как повысить температуру тела. Он подразумевает использование специальных пакетов, согревающих руки. Принцип их работы основывается на смешивании некоторых определенных веществ, что способствует выделению тепла. В инструкции к грелке написано, что она нагревается почти до 50 градусов, удерживая ее несколько часов. Конечно, 50 градусов для градусника это очень много. Однако грелку можно завернуть в носовые платочки, тогда температура на ее поверхности будет несколько ниже. Прежде чем использовать этот метод у врача, потренируйтесь сначала в домашних условиях.

Следует помнить о том, что показания градусника можно сохранить лишь осторожно обращаясь с ним. Сброс показаний термометра может произойти при любой неосторожной встряске, что порой приводит к показателям, абсолютно не соответствующим температуре как больного человека, так и здорового.

90000 Building a Digital Thermometer — How Microcontrollers Work 90001 90002 Now that you understand a little bit about your Stamp and the LCD, we can add another component and create a digital thermometer. To create a thermometer, we will use a chip called the DS1620. This chip contains: 90003 90004 90005 A 90006 temperature-sensing device 90007 90008 90005 An 90006 analog-to-digital (A / D) converter 90007 for the temperature-sensing device 90008 90005 A 90006 shift register 90007 to read the data out of the A / D converter 90008 90005 A little 90006 EEPROM 90007 (electrically erasable programmable read-only memory) to remember settings 90008 90021 90002 The DS1620 has two modes: In one mode, it acts as a stand-alone thermostat chip, and in the other mode you hook it up to a computer and use it as a thermometer.The EEPROM remembers the current mode as well as the set temperatures for the thermostat. 90003 90002 Hooking up the DS1620 to the Stamp is very easy. The DS1620 comes in an 8-pin chip. Supply +5 volts from the Stamp to pin 8 of the DS1620. Supply ground to pin 4 of the DS1620. You then use three I / O pins from the Stamp to drive three pins on the DS1620: 90003 90004 90005 Pin 1 on the DS1620 is the data pin. You read and write data bits on this pin.90008 90005 Pin 2 on the DS1620 is the clock pin. You clock data in and out of the shift register with this pin. 90008 90005 Pin 3 on the DS1620 is the reset / select pin. You set pin 3 high to select the chip and communicate with it. 90008 90021 90002 For this example code, it is assumed that: 90003 90004 90005 The data pin goes to I / O pin 2 on the Stamp. 90008 90005 The clock pin goes to I / O pin 1 on the Stamp. 90008 90005 The reset / select pin goes to I / O pin 0 on the Stamp.90008 90021 90002 The completed wiring looks like this: 90003 90002 You can get a DS1620 either from Jameco (part number 146456) or Parallax (part number 27917) in an «application kit» that includes the chip, the capacitor, some good documentation and sample code. Or you can buy the chip on its own from Jameco (part number 114382). I would suggest getting the application kit the first time you try using the DS1620 because the documentation is very useful. 90003 90002 You can assemble the DS1620 in the prototype area of ​​the Stamp carrier board or on a separate breadboard.Once you have assembled it, hook your LCD display up to I / O pin 3 of the Stamp, and then load and run the following program: 90003 90050 symbol RST = 0 ‘select / reset line on 1620 symbol CLK = 1 ‘clock line for shift registers on 1620 symbol DQ = 2 ‘data line on 1620 symbol DQ_PIN = pin2 ‘pin representation for DQ symbol LCD = 3 ‘data line for LCD begin: low RST ‘deselect the 1620 unless talking to it high CLK ‘clock pin on 1620 should default high pause 1000 ‘wait for the thermometer and LCD to boot setup: high RST ‘select the 1620 b0 = $ 0C ‘$ 0c is the 1620 command byte ‘Saying «Write Config» gosub shift_out ‘send it to the 1620 b0 =% 10 ‘% 10 is the 1620 command byte ‘To set thermometer mode gosub shift_out ‘send it to the 1620 low RST ‘deselect the 1620 pause 50 ‘delay 50ms for EEPROM start_convert: b0 = $ EE ‘$ EE is the 1620 command byte ‘To start conversions high RST ‘select the 1620 gosub shift_out ‘send it to the 1620 low RST ‘deselect the 1620 ‘This is the main loop ‘- reads and displays temperature every second main_loop: high RST ‘select the 1620 b0 = $ AA ‘$ AA is the 1620 command byte ‘For reading temperature gosub shift_out ‘send it to the 1620 gosub shift_in ‘read the temperature ‘From the 1620 low RST ‘deselect the DS1620.gosub display ‘display the temp in degrees C pause 1000 ‘wait a second goto main_loop ‘The shift_out subroutine sends whatever is in ‘The b0 byte to the 1620 shift_out: output DQ ‘set the DQ pin to ‘Output mode for b2 = 1 to 8 low CLK ‘prepare to clock the bit ‘Into 1620 DQ_PIN = bit0 ‘Send the data bit high CLK ‘latch data bit into 1620 b0 = b0 / 2 ‘shift all bits right ‘Toward bit 0 next return ‘The shift_in subroutine gets a 9-bit ‘Temperature from the 1620 shift_in: input DQ ‘set the DQ pin to ‘Input mode w0 = 0 ‘clear w0 for b5 = 1 to 9 w0 = w0 / 2 ‘shift input right.low CLK ‘ask 1620 for next bit bit8 = DQ_PIN ‘read the bit high CLK ‘toggle clock pin next return ‘Displays the temperature in degrees C display: if bit8 = 0 then pos ‘if bit8 = 1 ‘Then temp is negative b0 = b0 & / b0 ‘invert b0 by NANDing it ‘With itself b0 = b0 + 1 pos: serout LCD, n2400, (254, 1) ‘clear the LCD serout LCD, n2400, ( «Temp =») ‘display «Temp =» ‘On the display bit9 = bit0 ‘save the half degree b0 = b0 / 2 ‘convert to degrees if bit8 = 1 then neg ‘see if temp is negative serout LCD, n2400, (# b0) ‘display positive temp goto half neg: serout LCD, n2400, ( «-«, # b0) ‘display negative temp half: if bit9 = 0 then even serout LCD, n2400, ( «.5 C «) ‘display the half degree goto done even: serout LCD, n2400, ( «.0 C») ‘display the half degree done: return 90051 90002 If you run this program, you will find that it displays the centigrade temperature with an accuracy of one-half degree. 90003 90002 The DS1620 measures temperatures in centigrade half-degrees. It returns the temperature in a 9-bit 2s-complement number with a range of -110 to 250 F (-55 to 125 C). You divide the number you receive by 2 to get the actual temperature.90006 2s-complement binary numbers 90007 are a convenient way to represent 90006 negative values ​​90007. The following list shows the values ​​for a 4-bit 2s-complement number: 90003 90050 0111: 7 0110: 6 0101: 5 0100: 4 0011: 3 0010: 2 0001: 1 0000: 0 1111: -1 1110: -2 Тисяча сто один: -3 1100 -4 1011: -5 1010: -6 1001 -7 1000: -8 90051 90002 You can see that instead of the 4 bits representing values ​​from 0 to 15, the 4 bits in a 2s-complement number represent the values ​​-8 to 7.You can look at the left-most bit to determine if the number is negative or positive. If the number is negative, you can invert the bits and add 1 to get the positive representation of the number. 90003 90002 Here’s what goes on with the digital thermometer program shown here: 90003 90066 90005 It uses the 90006 symbol 90007 keyword to set up several constants that make the program slightly easier to read (and also make it easy for you to move the chip to different I / O pins on the Stamp).90008 90005 It sets the CLK and RST pins on the DS1620 to their expected values. 90008 90005 It writes a command byte to the EEPROM on the DS1620 to tell the chip to operate in «thermometer mode.» Because the mode is stored in EEPROM, you only have to do it once, so you could technically take this section of the code out of the program after you run the program once (to save program space). 90008 90005 The program sends the command 90006 $ EE 90007 ( «$» means «hexadecimal number» — $ EE is 238 in decimal) to tell the thermometer to start up its conversion process.90008 90079 90002 The program then enters a 90006 loop 90007. Every second, it sends a command to the DS1620 telling the DS1620 to return the current temperature, and then it reads the 9-bit value that the DS1620 returns into the w0 variable. The Stamp sends and receives data 1 bit at a time by toggling the CLK line on the DS1620. Remember that the w0 (16-bit) variable overlays the b0 / b1 (8-bit) variables, which overlay the bit0 / bit1 /…/ bit15 (1-bit) variables, so when you insert a bit from the DS1620 into bit 8 and divide w0 by 2, what you are doing is shifting each bit to the right to store the 9-bit temperature from the DS1620 into w0.Once the temperature has been saved in w0, the display subroutine determines whether the number is positive or negative and displays it appropriately on the LCD as a centigrade temperature. The conversion from degrees C to degrees F is: 90003 90002 At this point, we have succeeded in creating an extremely expensive thermometer. What might you do with it? Here’s one idea. Let’s say you work for a drug company and you are shipping expensive drugs across the country that MUST remain at a certain temperature the entire way or the drugs will spoil.What you can do with a Stamp is create a 90006 data logging thermometer 90007. Both Jameco (part number 143811) and Parallax (part number 27960) sell a device called the «RAM Pack module.» It contains a low-power 8-kilobyte (or optionally 32-kilobyte) RAM chip with a serial interface. You could add this component (or something similar) to your Stamp and write code that saves temperature readings to the RAM every minute. You could then slip your Stamp into the drug shipment, and at the other end of the trip retrieve the Stamp.The RAM module would contain the temperature history of the entire trip and you would know whether or not the drugs ever thawed out. 90003 90002 There are all kinds of neat, useful devices like this that you can build with a Stamp now that you know how microcontrollers work! 90003 90002 For more information on microcontrollers and related topics, check out the links below. 90003 90092 Related Articles 90093 90092 BASIC Stamp Links 90093 90092 PIC Links 90093 90092 FAQs 90093 90092 Other Links 90093 .90000 How To Change The Temperature On Your Electric Water Heater 90001 90002 If you are 90003 running out of hot water 90004 when taking a shower, you may want to 90003 turn the temperature on your electric water heater up 90004. Increasing the temperature on your water heater will increase your electric bill but only in the slightest. For each 10 ° degrees you go up (meaning hotter), your electricity usage may go up 3% to 5% percent. For each 10 ° degrees you go down (meaning cooler), your electricity usage may go down 3% to 5% percent.So consider the cost benefits when increasing or decreasing your 90003 water heater temperature 90004. 90009 90002 90011 90009 90002 90003 FACT Lowering the thermostat on your hot water heater can save 3-5% operating cost for each 10 ° degrees lower you go. 90004 90009 90002 90018 90003 Here is how to safely increase or decrease the water temperature on your electric water heater. 90004 90021 90009 90002 90003 TOOLS NEEDED TO INCREASE OR DECREASE TEMPERATURE ON YOUR ELECTRIC WATER HEATER: 90004 90009 90027 90028 Flat screwdriver 90029 90028 Phillips screwdriver 90029 90028 Flashlight 90029 90028 Gloves 90029 90036 90002 90003 Step 1: 90004 90040 For safety, turn off circuit breaker to your water heater and make sure the power is shut off to your water heater before adjusting the temp.90009 90002 90043 90009 90002 90003 Step 2: 90004 90040 Remove thermostat / element covers. 90040 90018 (usually 2 covers — one on the top for the top element and one on the bottom for the bottom element.) 90021 90040 After removing the covers, save the screws in a safe place. 90040 Pull out insulation to access the thermostat control. 90040 Do not touch or move wires. 90009 90002 90057 90009 90002 90003 Step 3: 90004 90040 Use a flat tip screwdriver to adjust the top and bottom thermostats to about 120 ° degrees.90040 The temperature of 120 ° degrees is good for most homes however if you are running out of hot water frequently, adjust the temp higher. 90040 For homes that use more hot water, set only the top thermostat 5 ° to 10 ° degrees higher. 90009 90002 90067 90009 90002 90003 Step 4: 90004 90040 Once you have the temperature settings as needed, replace the insulation. 90040 Next put the top and bottom metal covers back in place with the screws you removed earlier. 90040 Turn power back on to the water heater and enjoy your new water temperature settings.90009 90002 90003 90078 90079 90040 How to Adjust Hot Water Heater Temperature 90004 90009 90002 90003 90085 90079 90040 How To Reset The Reset Button On a Electric Hot Water Heater 90004 90009 90002 90091 90009 90002 90018 Please note: All water heater thermostat settings are approximate. It is best to test the actual temperature of the water the at faucet with a thermometer. 90021 90009 90002 90018 90003 Safety Notes: 90004 90021 Never touch a wet water heater for safety reasons.If your water heater is making strange noises here are ways to fix it. If you need to know the correct temperature to set your water heater, here is the info you need. 90009 90002 90003 If water is on the floor leaking from the water heater, shut-off the water and power and find the problem immediately. 90004 90009 90002 90003 90109 90079 90040 What do I do when my water heater is leaking? 90004 90009 90002 If you find that you have a burned or bad thermostat on your electric water heater, here is 90003 how to replace the thermostat in your water heater 90004.90009 90002 If you have an emergency with your water heater leaking, your water heater needs to be shut off immediately, here is 90003 how to turn off your water heater step by step 90004. 90009 90002 90018 If you know of any other ways or better methods to safely adjust the water temperature on a water heater, please leave a comment below to assist our other readers. 90021 90009 90126 Please Share Our DIY Repair Help Projects: 90127 90002 ALLEN VETTER — DIY Repair Assistant 90009 Allen is a Home Maintenance / Appliance tech and the author / creator of this website.He has 33 years of experience troubleshooting and repairing all types of machinery. Contact here 90040 90131 More «Do It Yourself» DIY Tips, Tricks, Ideas, Repair: 90132 90040 90040 90002 Tagged as: adjust thermostat water heater, adjust water heater temp, change water heater temp, decrease water heater temp, DIY, electric water heater, gas water heater, how to, increase decrease water temperature, increase water heater temp, replace thermostat, turn off water heater, water heater thermostat 90009.90000 TOP 14 Best Infrared Thermometers 2020 90001 90002 90003 90004 Measure the temperature of your roast meat, electrical equipment, automotive, or other surfaces from a distance with an infrared thermometer. It provides a fast and easy way of measuring the temperature without touching the item you are measuring. And, with the auto shut off feature, you can use the device with minimal supervision. The following discussion elaborates on the uses of this device. We’ll cover 90005 how infrared 90006 90005 thermometers work 90006, different 90005 types 90006 of IR thermometers, their 90005 pros and cons 90006, and 90005 usage tips 90006.We’ll review TOP Best Infrared Thermometers to make choosing one less of a hassle. 90015 90004 Infrared thermometers are used in different industries and work environments to determine the temperature of objects from a distance. The distance can range from an inch to miles. These thermometers are used in areas where other kinds of thermometers can not be used, e.g., electrical circuits, mechanical equipment, building systems, moving objects, and objects in a vacuum for time-sensitive readings. 90015 90002 How it Works 90003 90004 These devices 90005 measure infrared radiation 90006 to determine the temperature of an object.90015 90004 90005 Infrared radiation 90006 is one type that occurs within the electromagnetic spectrum; other types include visible light, x-rays, and microwaves. 90015 90004 It is based on the concept of 90005 blackbody radiation 90006, which means that any object whose temperature is above zero has molecules moving around. Higher temperatures cause the particles to move faster thus, emitting infrared radiation. Increased temperature leads to a higher emission of the infrared radiation, which then begins to emit visible light.It explains the change in the color of metals when they are extremely hot. 90015 90032 90032 90004 Last update on 2020-07-13 / Affiliate links / Images from Amazon Product Advertising API 90015 90004 Other theories state that infrared thermometers 90005 measure the gradient in radiation 90006 90005 between objects 90006.For example, if there is a difference in temperature between an object and the surrounding environment, it is estimated and used as the temperature. As such, if the object has the same temperature as the environment, the net radiation is zero.IR thermometers measure this gradient to determine the temperature of the object and display the results. 90015 90004 The IR light can be absorbed, focused, or reflected. Handheld thermometers use a lens to focus the light from the object to the detector (thermopile).The sensor absorbs radiation and converts it to heat then to electricity. The electricity is then sent to the detector using it to determine the temperature of the object. More electricity is produced as the object becomes hotter. 90015 90002 Uses of IR Thermometers 90003 90046 Professional Applications 90047 90004 HVAC: 90015 90050 90051 Perform 90005 energy audits 90006 to identify infiltration and leaks 90054 90051 Identify 90005 insulation problems 90006 90054 90051 Manufacturing 90054 90051 90005 Monitor manufacturing process 90006 90054 90051 90005 Monitor high- temperature substances 90006 like metals and plastics 90054 90069 90004 Automotive: 90015 90050 90051 Testing the thermostat to 90005 diagnose overheating 90006 90054 90051 Identify 90005 poor performance of A / C systems 90006 90054 90069 90004 Medical: 90015 90050 90051 Measure the body temperature for 90005 fever 90006 (measures the temperature through the ear) 90054 90069 90004 Food: 90015 90050 90051 Avoid 90005 cross-contamination 90006 90054 90051 Check the 90005 quality of food 90006 and safety 90054 90051 Monitor 90005 temperature at critical contro l 90006 points when goods are reheated, cooked, cooled, and served 90054 90069 90046 General Applications: 90047 90050 90051 Check door and window frames for 90005 leakages 90006 90054 90051 Determine the temperature of freezers and refrigerators 90054 90051 Identify 90005 insulation problems 90006 in a home 90054 90069 90002 How to Use an Infrared Thermometer 90003 90004 It’s pretty easy; you only need to fix the batteries in their compartment and activate the desired temperature unit (Celsius or Fahrenheit).90015 90004 Turn on the device by pressing the power button and aim the gun to the surface you want to measure the temperature. 90015 90004 Be sure to stand close to the object or within the DS ratio indicated by the manufacturer for accurate readings. 90015 90004 Pull the trigger to observe the reading on the digital display on the thermometer. 90015 90002 Types of Infrared Thermometers 90003 90004 The construction of infrared thermometers comprises an optical system to collect energy, an emissivity adjustment that matches the calibration of the thermometer to characteristics of the object and a detector (thermopile).90015 90004 Modern infrared thermometers mimic the same concept, but numerous advances in technology have introduced sophisticated devices to widen the scope of their applications. As such, detectors are designed to match specific applications to improve performance. 90015 90004 Here are the different types of infrared thermometers. 90015 90050 90051 90005 Spot infrared thermometers 90006: these kinds display the temperature on a particular spot on a surface. 90054 90051 90005 Infrared scanning systems 90006: the devices scan larger areas and are used in manufacturing processes that involve conveyors, e.g., when continuous piles of objects move along a large sheet of metal from an oven. 90054 90051 90005 Infrared thermal imaging cameras 90006: these kinds use cameras to measure the temperature at different points over a larger area to create two-dimensional images called thermograms. The technology applied to the devices is more hardware and software intensive compared to regular infrared thermometers. 90054 90069 90002 What to Look for When Buying Infrared Thermometers 90003 90004 It refers to the efficiency with which an object absorbs or emits infrared energy.The values ​​range from 0.0 to 1.0. 90015 90004 Objects that have an emissive value of 1.0 are called perfect emitters as they radiate 100% energy. 90015 90004 An efficient infrared thermometer should factor in this feature based on the type of object in question because various surfaces emit radiation differently. 90015 90004 Effective IR thermometers deliver temperatures fast and accurately. 90015 90004 Advanced versions factor is 90005 adjustable emissivity 90006 for more accurate readings.Experts allow a + 1% margin of error when using professional IR thermometers and + 2% for less expensive devices. 90015 90004 The primary factor here is whether the thermometer is used for professional or home-based applications. 90015 90004 For regular use, e.g., around the house, a temperature range of -58 to 1022 degrees Fahrenheit is ideal. However, in advanced applications like in manufacturing processes, the temperature range should be more than 1487 degrees Fahrenheit. 90015 90004 The distance to spot ratio affects the accuracy of the readings from the thermometer.The rate is determined by the size of the area being measured in relation to the distance. 90015 90004 For example, if an object has a D / S ratio of 10: 1 and it is 5 inches in size, the maximum distance the thermometer can accurately measure the temperature is within 50 inches. 90015 90004 Distances larger than that range will be inaccurate as the IR thermometer will include the temperature of the surrounding objects and surfaces. Most IR thermometers in the market have a DS ratio of 12: 1. 90015 90004 A warranty is a good indication of a high-quality IR thermometer.The period can range from 90 days to 10 years based on the manufacturer. 90015 90002 10 Best-Selling Infrared Thermometers Comparative Table 90003 90002 Top Infrared Thermometers 90003 90046 1. ANKOVO Thermometer for Fever Digital Medical Infrared 90047 90004 90015 90004 This medical IR thermometer is ideal for all ages. It has a dual mode thus, can function as a forehead and ear thermometer for kids older than three months. 90015 90004 The thermometer delivers temperature readings in just eight seconds, and users can view a maximum of 20 previous readings if monitoring the temperature of a child.90015 90004 The LCD flicker alarm makes this device even more efficient as it alerts the user using seven short, rapid rings when the temperature exceeds 37.5 degrees Celsius. Compared to other thermometers that use mercury, the Ankovo ​​is entirely safe as the glass does not break. 90015 90192 90193 90194 90195 90005 Pros: 90006 90198 90195 90005 Cons: 90006 90198 90203 90194 90195 90050 90051 It is budget-friendly 90054 90051 User-friendly 90054 90051 Has a fever alarm that beeps to alert you to read the results 90054 90069 90198 90195 90050 90051 It takes eight seconds to display the reading 90054 90051 Requires contact with the mouth, ear, or armpit 90054 90051 Requires sterilization using isopropyl or alcohol 90054 90069 90198 90203 90226 90227 90228 90228 90004 Last update on 2020-07-13 / Affiliate links / Images from Amazon Product Advertising API 90015 90004 Ankovo: Check the current price 90015 90046 2.Equinox Digital Thermometer Non Contact Infrared Forehead — 3-Modes 90047 90004 90015 90004 This three-in-one thermometer is designed to measure the body temperature, that of a room, and surfaces. If you are taking the temperature of a child, you do not need to disturb him as you can accurately do it within a distance of 3-5 cm from his forehead. It is fitted with a 3-color changing LCD screen to help the user determine if the subject is normal, has a high temperature, or is just medium. 90015 90004 Equinox thermometer uses infrared technology to deliver instant results, and the built-in alarm system alerts you if a fever is detected.It also has a backlight that turns red and makes a sound if the child has a high fever. Additionally, it displays up to 32 previous readings, so you can monitor the progress of your little one. 90015 90004 Users can also change the settings from Celsius to Fahrenheit (and vice versa) with a simple click of the button. Medical experts say that the Equinox Digital Non-Contact Infrared Forehead Thermometer is the most accurate for taking temperature readings of a child. It measures the body temperature within a range of 32-42.9 degrees Celsius and 0-60 degrees for surface temperature. 90015 90192 90193 90194 90195 90005 Pros: 90006 90198 90195 90005 Cons: 90006 90198 90203 90194 90195 90050 90051 Does not need contact 90054 90051 Measures the temperature of other surfaces 90054 90069 90198 90195 90050 90051 Sometimes it delivers inconsistent readings 90054 90069 90198 90203 90226 90227 90274 90274 90004 Last update on 2020-07-13 / Affiliate links / Images from Amazon Product Advertising API 90015 90004 Equinox: Check the current price 90015 90046 3.Etekcity Lasergrip 1080 Non-Contact Digital Laser Infrared Thermometer 90047 90004 90015 90004 The Lasergrip 1080 is designed for indoor and outdoor use. It measures temperature within a range of -58 degree Fahrenheit and 1022 degrees Fahrenheit, which is pretty impressive for household use. The Lasergrip 1080 is fitted with an LCD screen that has a backlight and users can switch between degrees Celsius and Fahrenheit just by a simple click of a button. 90015 90004 Its response time is almost instant, i.e., 15 seconds within a Distance to Spot ratio of 12: 1. For more accurate results, the distance between the object and the thermometer should be 36 cm / 14.17 inches. 90015 90004 The Etekcity Lasergrip 1080 Non-Contact Digital Laser Infrared Thermometer Temperature Gun is designed for various applications such as home repairs, measuring the surface temperatures of objects beyond the freezing and boiling point, barbequing, cooking, and when performing auto maintenance. 90015 90004 A nine-volt battery powers it and the low-battery indicator should alert the user when it needs to be replaced.Note that the lasergrip 1080 does not measure the internal temperature of the object thus, it can not be used to obtain the temperature of animals and humans. 90015 90192 90193 90194 90195 90005 Pros: 90006 90198 90195 90005 Cons: 90006 90198 90203 90194 90195 90050 90051 Offers a wide temperature range 90054 90051 Has an auto shut-off feature helps preserve the life of the battery 90054 90051 Affordable 90054 90051 Has a two -year warranty 90054 90069 90198 90195 90050 90051 Its emissivity is fixed at 0.95 90054 90051 Its plastic construction is delicate 90054 90069 90198 90203 90226 90227 90328 90328 90004 Last update on 2020-07-13 / Affiliate links / Images from Amazon Product Advertising API 90015 90004 Etekcity: Check the current price 90015 90046 4.Thermometer, Infrared Temperature Non-Contact Digital Infrared Temperature Gun 90047 90004 90015 90004 This IR thermometer combines the most recent temperature sensor technology with the advanced Frensel lens to deliver accurate readings with only +/- 1.5% margin of error in just 0.5 seconds. 90015 90004 Its wide temperature range allows application on auto maintenance, cooking, home repair, and barbecuing, among other household tasks. T 90015 90004 he Super IR5D has a built-in laser that delivers instant results displayed in the form of Max / Min / Average / Diff values ​​on the LCD screen.90015 90004 The buzzer alarm beeps immediately it attains the high / low temperature set by the user. The thermometer is powered by a 15mAh battery that lasts 6-12 months. And, with its eight-second auto-off feature, the battery is likely to last longer. 90015 90004 The package comes with a free meat thermometer that has a food-grade stainless steel construction. It measures the inner temperature of food within a range of -50-300 degree Celsius. 90015 90192 90193 90194 90195 90005 Pros: 90006 90198 90195 90005 Cons: 90006 90198 90203 90194 90195 90050 90051 Very accurate 90054 90051 Allows measurement of objects at a long distance 90054 90051 Low-priced 90054 90051 Comes with a free a meat thermometer 90054 90069 90198 90195 90050 90051 Loses accuracy when used within longer distances 90054 90069 90198 90203 90226 90227 90382 90382 90004 Last update on 2020-07-13 / Affiliate links / Images from Amazon Product Advertising API 90015 90004 SURPEER: Check the current price 90015 90046 5.Taylor Precision Products Splash-Proof Dual Temperature Infrared 90047 90004 90015 90004 The thermometer is designed for culinary applications and has a dual function unit that allows users to determine the internal temperature of meat and obtain surface temperatures using the built-in infrared feature. 90015 90004 As such, users can view the temperature of the surfaces before searing the meat or putting the pizza on a stone. 90015 90004 It has a temperature range of -67-482 degrees Fahrenheit.The margin of error is pretty small, i.e., +/- 2 for 14 degrees Fahrenheit and +/- 1% for 149 degrees Fahrenheit. 90015 90004 This thermometer is fitted with three LED lights that signal when the food is cold, hot, or has a medium temperature. 90015 90192 90193 90194 90195 90005 Pros: 90006 90198 90195 90005 Cons: 90006 90198 90203 90194 90195 90050 90051 Measures surface and the internal temperature of food 90054 90051 Has auto-off feature 90054 90051 Its step-down ending creates small punctures 90054 90051 Its construction is splashproof 90054 90069 90198 90195 90050 90051 Is not user-friendly 90054 90051 Does not have a backlit display screen 90054 90051 Takes long to display temperature 90054 90069 90198 90203 90226 90227 90438 90438 90004 Last update on 2020-07-13 / Affiliate links / Images from Amazon Product Advertising API 900 15 90004 Taylor Precision Products: Check the current price 90015 90002 Expert Opinion: Jim Seffrin, Master Thermographer, Infraspection Institute 90003 90004 90447 90447 90015 90004 Jim Seffrin, Master Thermographer, Infraspection Institute 90015 90004 Jim Seffrin is a practicing thermographer with three decades of experience as an infrared thermography consultant.Jim has published many articles on this topic and has been working as an expert witness on projects that involve thermography. 90015 90004 «I think the greatest harm and danger comes in missing a person. These [industrial-grade] thermometers are not appropriate for human body measurement because they can be off as much as 7 Fahrenheit degrees, which is way too inaccurate … It is said that drastic times call for desperate measures but one should not be so desperate that we choose something which is ineffective or inaccurate «.90015 90004 90457 90458 90015 90002 14 Best-Selling Infrared Thermometers Comparative Table 90003.90000 How to Use a Multimeter 90001 Favorited Favorite 48 90002 Introduction 90003 90004 So … how do I use a multimeter? This tutorial will show you how to use a digital multimeter (DMM), an indispensable tool that you can use to diagnose circuits, learn about other people’s electronic designs, and even test a battery. Hence the ‘multi’ — ‘meter’ (multiple measurement) name. 90005 90004 The most basic things we measure are voltage and current.A multimeter is also great for some basic sanity checks and troubleshooting. Is your circuit not working? Does the switch work? Put a meter on it! The multimeter is your first defense when troubleshooting a system. In this tutorial we will cover measuring voltage, current, resistance and continuity. 90005 90008 90002 Suggested Reading 90003 These concepts may be helpful with this tutorial: 90004 We will be using the SparkFun VC830L throughout the tutorial, but these methods should apply to most multimeters.90005 90013 Digital Multimeter — Basic 90014 In stock TOL-12966 90004 The digital multimeter (DMM) is an essential tool in every electronic enthusiasts arsenal. The SparkFun Digital Multimeter, h … 90005 21 90002 Video 90003 90004 90020 90021 90005 90002 Looking for the Multimeter that’s right for you? 90003 90004 We’ve got you covered! 90005 90013 Digital Multimeter — Basic 90014 In stock TOL-12966 90004 The digital multimeter (DMM) is an essential tool in every electronic enthusiasts arsenal.The SparkFun Digital Multimeter, h … 90005 21 90013 Smart SMD Tester 90014 In stock TOL-10829 90004 This smart SMD tester is essentially a pair of multimeter tweezers. This allows you to troubleshoot circuits with small SMD p … 90005 1 90008 90002 Parts of a Multimeter 90003 90004 A multimeter is has three parts: 90005 90040 90041 Display 90042 90041 Selection Knob 90042 90041 Ports 90042 90047 90004 The 90049 display 90050 usually has four digits and the ability to display a negative sign.A few multimeters have illuminated displays for better viewing in low light situations. 90005 90004 The 90049 selection knob 90050 allows the user to set the multimeter to read different things such as milliamps (mA) of current, voltage (V) and resistance (& ohm;). 90005 90004 Two probes are plugged into two of the 90049 ports 90050 on the front of the unit. 90049 COM 90050 stands for common and is almost always connected to Ground or ‘-‘ of a circuit. The 90049 COM 90050 probe is conventionally black but there is no difference between the red probe and black probe other than color.90049 10A 90050 is the special port used when measuring large currents (greater than 200mA). 90049 mAVΩ 90050 is the port that the red probe is conventionally plugged in to. This port allows the measurement of current (up to 200mA), voltage (V), and resistance (& ohm;). The probes have a 90067 banana 90068 type connector on the end that plugs into the multimeter. Any probe with a banana plug will work with this meter. This allows for different types of probes to be used. 90005 90004 90067 Using a Multimeter to test the voltage on a LiPo Battery.90068 90005 90008 90002 Probe Types 90003 90004 There are many different types of probes available for multimeters. Here are a few of our favorites: 90005 90040 90041 Banana to Alligator Clips: These are great cables for connecting to large wires or pins on a breadboard. Good for performing longer term tests where you do not have to have to hold the probes in place while you manipulate a circuit. 90042 90041 Banana to IC Hook: IC hooks work well on smaller ICs and legs of ICs.90042 90041 Banana to Tweezers: Tweezers are handy if you are needing to test SMD components. 90042 90041 Banana to Test Probes: If you ever break a probe, they are cheap to replace! 90042 90047 90008 90002 Measuring Voltage 90003 90004 To start, let’s measure voltage on a AA battery: Plug the black probe into 90049 COM 90050 and the red probe into 90049 mAVΩ 90050. Set the multimeter to «2V» in the DC (direct current) range. Almost all portable electronics use direct current), not alternating current.Connect the black probe to the battery’s ground or ‘-‘ and the red probe to power or ‘+’. Squeeze the probes with a little pressure against the positive and negative terminals of the AA battery. If you’ve got a fresh battery, you should see around 1.5V on the display (this battery is brand new, so its voltage is slightly higher than 1.5V). 90005 90004 If you’re measuring DC voltage (such as a battery or a sensor hooked up to an Arduino) you want to set the knob where the V has a straight line.AC voltage (like what comes out of the wall) can be dangerous, so we rarely need to use the AC voltage setting (the V with a wavy line next to it). If you’re messing with AC, we recommend you get a non-contact tester rather than use a digital multimeter. 90005 90004 Use the V with a straight line to measure DC Voltage 90005 90004 Use the V with a wavy line to measure AC Voltage 90005 90004 What happens if you switch the red and black probes? The reading on the multimeter is simply negative.Nothing bad happens! The multimeter measures voltage in relation to the common probe. How much voltage is there on the ‘+’ of the battery compared to common or the negative pin? 1.5V. If we switch the probes, we define ‘+’ as the common or zero point. How much voltage is there on the ‘-‘ of the battery compared to our new zero? -1.5V! 90005 90004 Now let’s construct a simple circuit to demonstrate how to measure voltage in a real world scenario. The circuit is simply a 1k & ohm; and a Blue super bright LED powered with a SparkFun Breadboard Power Supply Stick.To begin, let’s make sure the circuit you are working on is powered up correctly. If your project should be at 5V but is less than 4.5V or greater than 5.5V, this would quickly give you an indication that something is wrong and you may need to check your power connections or the wiring of your circuit. 90005 90004 90067 Measuring the voltage coming off of a Power Supply Stick. 90068 90005 90004 Set the knob to «20V» in the DC range (the DC Voltage range has a V with a straight line next to it).Multimeters are generally not autoranging. You have to set the multimeter to a range that it can measure. For example, 90049 2V 90050 measures voltages 90049 up to 2 volts 90050, and 90049 20V 90050 measures voltages 90049 up to 20 volts 90050. So if you’ve measuring a 12V battery, use the 20V setting. 5V system? Use the 20V setting. If you set it incorrectly, you will probably see the meter screen change and then read ‘1’. 90005 90004 With some force (imagine poking a fork into a piece of cooked meat), push the probes onto two exposed pieces of metal.One probe should contact a GND connection. One probe to the VCC or 5V connection. 90005 90004 We can test different parts of the circuit as well. This practice is called nodal analysis, and it is a basic building block in circuit analysis. By measuring the voltage across the circuit we can see how much voltage each component requires. Let’s measure the whole circuit first. Measuring from where the voltage is going in to the resistor and then where ground is on the LED, we should see the full voltage of the circuit, expected to be around 5V.90005 90004 We can then see how much voltage the LED is using. This is what is referred to as the 90049 voltage drop 90050 across the LED. If that does not make sense now, fear not. It will as you explore the world of electronics more. The important thing to take away is that different parts of a circuit can be measured to analyze the circuit as a whole. 90005 90067 This LED is using 2.66V of the available 5V supply to illuminate. This is lower than the forward voltage stated in the datasheet on account of the circuit only having small amount of current running though it, but more on that in a bit.90068 90013 Overload 90014 90004 What happens if you select a voltage setting that is too low for the voltage you’re trying to measure? Nothing bad. The meter will simply display a 1. This is the meter trying to tell you that it is overloaded or out-of-range. Whatever you’re trying to read is too much for that particular setting. Try changing the multimeter knob to a the next highest setting. 90005 90004 90067 Reading the 5V across this circuit is too much for the 2V setting on the multimeter.90068 90005 90013 Selection Knob 90014 90004 Why does the meter knob read 20V and not 10V? If you’re looking to measure a voltage less than 20V, you turn to the 20V setting. This will allow you to read from 90049 2.00 90050 to 90049 19.99 90050. 90005 90004 The first digit on many multimeters is only able to display a ‘1’ so the ranges are limited to 90049 1 90050 9.99 instead of 90049 9 90050 9.99. Hence the 20V max range instead of 99V max range. 90005 90154 Warning! 90155 In general, stick to DC circuits (the settings on the multimeter with straight lines, not curvy lines).Most multimeters can measure AC (alternating current) systems, but AC circuits can be dangerous. A wall outlet with AC or ‘main voltage’ is the stuff that can zap you pretty good. VERY carefully respect AC. If you need to check to see if an outlet is ‘on’ then use a AC tester. Really the only times we’ve needed to measure AC are when we’ve got an outlet that is acting funny (is it really at 110V?), Or if we’re trying to control a heater (such as a hot plate). Go slow and double check everything before you test an AC circuit.90008 90002 Measuring Resistance 90003 90004 Normal resistors have color codes on them. If you do not know what they mean, that’s ok! There are plenty of online calculators that are easy to use. However, if you ever find yourself without internet access, a multimeter is very handy at measuring resistance. 90005 90004 Pick out a random resistor and set the multimeter to the 20kΩ setting. Then hold the probes against the resistor legs with the same amount of pressure you when pressing a key on a keyboard.90005 90004 The meter will read one of three things, 90049 0.00 90050, 90049 1 90050, or the 90049 actual resistor value 90050. 90005 90040 90041 90004 In this case, the meter reads 0.97, meaning this resistor has a value of 970Ω, or about 1kΩ (remember you are in the 20kΩ or 20,000 Ohm mode so you need to move the decimal three places to the right or 970 Ohms) . 90005 90042 90041 90004 If the multimeter 90049 reads 1 90050 or displays 90049 OL 90050, it’s overloaded. You will need to try a higher mode such as 90049 200kΩ 90050 mode or 90049 2MΩ 90050 (megaohm) mode.There is no harm if this happen, it simply means the range knob needs to be adjusted. 90005 90042 90041 90004 If the multimeter reads 90049 0.00 90050 or nearly zero, then you need to lower the mode to 90049 2kΩ 90050 or 90049 200Ω 90050. 90005 90042 90047 90004 Remember that many resistors have a 5% tolerance. This means that the color codes may indicate 10,000 Ohms (10kΩ), but because of discrepancies in the manufacturing process a 10kΩ resistor could be as low as 9.5kΩ or as high as 10.5kΩ. Do not worry, it’ll work just fine as a pull-up or general resistor. 90005 90004 Let’s drop the meter down to the next lowest setting, 2K & ohm ;. What happens? 90005 90004 Not a whole lot changed. Because this resistor (a 1K & ohm;) is less than 2K & ohm ;, it still shows up on the display. However, you’ll notice that there is one more digit after the decimal point giving us a slightly higher resolution in our reading. What about the next lowest setting? 90005 90004 Now, since 1k & ohm; is greater than 200 & ohm ;, we’ve maxed out the meter, and it is telling you that it is overloaded and that you need to try a higher value setting.90005 90004 As a rule of thumb, it’s rare to see a resistor less than 1 Ohm. Remember that measuring resistance is not perfect. Temperature can affect the reading a lot. Also, measuring resistance of a device while it is physically installed in a circuit can be very tricky. The surrounding components on a circuit board can greatly affect the reading. 90005 90008 90002 Measuring Current 90003 90004 Reading current is one of the trickiest and most insightful readings in the world of embedded electronics.It’s tricky because you have to measure current in series. Where voltage is measure by poking at VCC and GND (in parallel), to measure current you have to physically interrupt the flow of current and put the meter in-line. To demonstrate this, we’ll use the same circuit we used in the measuring voltage section. 90005 90004 The first thing we’ll need is an extra piece of wire. As mentioned, we’ll need to physically interrupt the circuit to measure the current. Said another way, pull out the VCC wire going to the resistor, add a wire where that wire was connected, and then probe from the power pin on the power supply to the resistor.This effectively «breaks» power to the circuit. We then insert the multimeter in-line so that it can measure the current as it «flows» through to the multimeter into the bread board. 90005 90004 For these pictures, we cheated and used alligator clips. When measuring current, it’s often good to watch what your system does over time, for a few seconds or minutes. While you might want to stand there and hold the probes to the system, sometimes it’s easier to free up your hands. These alligator clip probes can come in handy.Note that almost all multimeters have the same sized jacks (they’re called «banana plugs») so if you’re in a pinch, you can use your friend’s probes. 90005 90004 With the multimeter connected, we can now set the dial to the proper setting and measure some current. Measuring current works the same as voltage and resistance — you have to get the correct range. Set the multimeter to 200mA, and work from there. The current consumption for many breadboard projects is usually under 200mA. Make sure the red probe is plugged into the 200mA fused port.On our favorite multimeter, the 200mA hole is the same port / hole as voltage and resistance reading (the port is labeled 90049 mAVΩ 90050). This means you can keep the red probe in the same port to measure current, voltage, or resistance. However, if you suspect that your circuit will be using close to or more than 200mA, switch your probe to the 10A side, just to be safe. Overloading the current can result in a blown fuse rather than just an overload display. More on that in a bit. 90005 90004 90067 This circuit was only pulling 1.8mA at the time of measurement, not a lot of current. The average reading was closer to 2.1mA. 90068 90005 90004 Realize that the multimeter is acting as a piece of wire — you’ve now completed the circuit, and the circuit will power on. This is important because as time goes on the LED, microcontroller, sensor, or whatever device being measured may change its power consumption (such as turning on an LED can resulting in a 20mA increase for a second, then decrease for a second when it turns off).On the multimeter display you should see the instantaneous current reading. All multimeters take readings over time and then give you the 90049 average 90050, so expect the reading to fluctuate. In general, cheaper meters will average more harshly and respond more slowly, so take each reading with a grain of salt. In your head, take an average range such as 7 to 8mA under normal 5V conditions (not 7.48mA). 90005 90004 Similar to the other measurements, when measuring current, the color of the probes does not matter.What happens if we switch probes? Nothing bad happens! It simply causes the current reading to become negative: 90005 90004 Current is still flowing through the system, you’ve just changed your perspective and now the meter reads negative. 90005 90004 90154 Remember! 90155 When you’re done using the meter, always return the meter to read voltage (return the probes to the voltage port, set the meter to read the DC voltage range if necessary). It’s common to grab a meter and begin to quickly measure the voltage between two pins.If you have left your meter in ‘current’ mode, you will not see the voltage on the display. Instead you’ll see ‘0.000’ indicating that there is no current between VCC and GND. Within that split second you will have connected VCC to GND through your meter and the 200mA fuse will blow = not good. So before you put the meter down for the night, remember to leave your meter in a friendly state. 90005 90004 Measuring current can be tricky the first couple of times. Do not worry if you blow the fuse — we’ve done it dozens of times! We’ll show you how to replace the fuse in a later section.90005 90008 90002 Continuity 90003 90004 Continuity testing is the act of testing the resistance between two points. If there is very low resistance (less than a few & ohm; s), the two points are connected electrically, and a tone is emitted. If there is more than a few & ohm; s of resistance, than the circuit is open, and no tone is emitted. This test helps insure that connections are made correctly between two points. This test also helps us detect if two points are connected that should not be.90005 90004 Continuity is quite possibly the single most important function for embedded hardware gurus. This feature allows us to test for conductivity of materials and to trace where electrical connections have been made or not made. 90005 90004 Set the multimeter to ‘Continuity’ mode. It may vary among DMMs, but look for a diode symbol with propagation waves around it (like sound coming from a speaker). 90005 90004 90067 Multimeter is set to continuity mode. 90068 90005 90004 Now touch the probes together.The multimeter should emit a tone (Note: Not all multimeters have a continuity setting, but most should). This shows that a very small amount of current is allowed to flow without resistance (or at least a very very small resistance) between probes. 90005 90004 90154 Warning! 90155 In general, turn OFF the system before checking for continuity. 90005 90004 On a breadboard that is 90067 not 90068 powered, use the probes to poke at two separate ground pins. You should hear a tone indicating that they are connected.Poke the probes from the VCC pin on a microcontroller to VCC on your power supply. It should emit a tone indicating that power is free to flow from the VCC pin to the micro. If it does not emit a tone, then you can begin to follow the route that copper trace takes and tell if there are breaks in the line, wire, breadboard, or PCB. 90005 90004 Continuity is a great way to test if two SMD pins are touching. If your eyes can not see it, the multimeter is usually a great second testing resource. 90005 90004 When a system is not working, continuity is one more thing to help troubleshoot the system.Here are the steps to take: 90005 90267 90041 If the system is on, carefully check VCC and GND with the voltage setting to make sure the voltage is the correct level. If the 5V system is running at 4.2V check your regulator carefully, it could be very hot indicating the system is pulling too much current. 90042 90041 Power the system down and check continuity between VCC and GND. If there is continuity (if you hear a beep), then you’ve got a short somewhere. 90042 90041 Power the system down.With continuity, check that VCC and GND are correctly wired to the pins on the microcontroller and other devices. The system may be powering up, but the individual ICs may be wired wrong. 90042 90041 Assuming you can get the microcontroller running, set the multimeter aside, and move on to serial debugging or use a logic analyzer to inspect the digital signals. 90042 90276 90004 90049 Continuity and large capacitors: 90050 During normal troubleshooting. you will be probing for continuity between ground and the VCC rail.This is a good sanity check before powering up a prototype to make sure there is not a short on the power system. But do not be surprised if you hear a short ‘beep!’ when probing. This is because there is often significant amounts of capacitance on the power system. The multimeter is looking for very low resistance to see if two points are connected. Capacitors will act like a short for a split second until they fill up with energy, and then act like an open connection. Therefore, you will hear a short beep and then nothing.That’s ok, it’s just the caps charging up. 90005 90008 90002 Changing the Fuse 90003 90004 One of the most common mistakes with a new multimeter is to measure current on a bread board by probing from VCC to GND (bad!). This will immediately short power to ground through the multimeter causing the bread board power supply to brown out. As the current rushes through the multimeter, the internal fuse will heat up and then burn out as 200mA flows through it. It will happen in a split second and without any real audible or physical indication that something is wrong.90005 90004 Wow, that was neat. Now what? Well first, remember that measuring current is done in series (interrupt the VCC line to the breadboard or microcontroller to measure current). If you try to measure the current with a blown fuse, you’ll probably notice that the meter reads ‘0.00’ and that the system does not turn on like it should when you attach the multimeter. This is because the internal fuse is broken and acts as a broken wire or open. Do not worry, this happens all the time, and it costs about $ 1 to fix.90005 90004 To change the fuse, find your handy dandy mini screw driver, and start taking out screws. The SparkFun DMM is pretty easy to pull apart. Start by removing the battery plate and the battery. 90005 90004 Next, remove the two screws hiding behind the battery plate. 90005 90004 Lift the face of the multimeter slightly. 90005 90004 Now notice the hooks on the bottom edge of the face. You will need to slide the face sideways with a little force to disengage these hooks.90005 90004 Once the face is unhooked, it should come out easily. Now you can see inside the multimeter! 90005 90004 Gently lift up on the fuse, and it will pop out. 90005 90004 Make sure to 90049 replace the correct fuse with the correct type 90050. In other words, replace the 200mA fuse with a 200mA fuse. 90005 90004 90154 Warning! 90155 90154 DO NOT put a 10A fuse where a 200mA fuse should go. 90155 The placement of the fuses may not match the placement of the probe ports.Read the metal cap on either end of the fuse to double check which is which. 90005 90004 The components and PCB traces inside the multimeter are designed to take different amounts of current. You will damage and possibly ruin your multimeter if you accidentally push 5A through the 200mA port. 90005 90004 There are times where you need to measure high current devices like a motor or heating element. Do you see the two places to put the red probe on the front of the multimeter? 90049 10A 90050 on the left and 90049 mAVΩ 90050 on the right? If you try to measure more than 200mA on the 90049 mAVΩ 90050 port you run the risk of blowing the fuse.But if you use the 10A port to measure current, you run a much lower risk of blowing the fuse. The trade-off is sensitivity. As we talked about above, by using the 10A port and knob setting, you will only be able to read down to 0.01A or 10mA. Most of my systems use more than 10mA so the 10A setting and port works well enough. If you’re trying to measure very low power (micro or nano amps) the 200mA port with the 2mA, 200uA, or 20uA could be what you need. 90005 90004 90049 Remember: 90050 If your system has the potential to use more than 100mA you should start with the red probe plugged into the 90049 10A 90050 port and 90049 10A 90050 knob setting.90005 90004 With sub $ 50 digital multimeters, the measurements you are likely to take are just trouble shooting readings, not scientific experimental results. If you really need to see how the IC uses current or voltage over time, use an Agilent or other high quality bench unit. These units have higher precision and offer a wide range of fancy functions (some include Tetris!). Bunnie Huang, hardware designer behind Chumby, uses high-precision current readings to trouble shoot boards during the final testing procedures of a Chumby.By looking at the current consumption of different boards that have failed (for example a given failed board uses 210mA over the normal), he could identify what was wrong with the board (when the RAM fails, it generally uses 210mA over normal). By pinpointing what may be potentially wrong, the rework and repair of boards is made much easier. 90005 90008 90002 What Makes a Good Multimeter? 90003 90004 Everyone has his or her preference, but in general multimeters that have continuity are preferred.Every other feature is just icing on the cake. 90005 90004 There are fancy multimeters that are 90049 autoranging 90050, meaning they automatically change their internal range to attempt to find the correct voltage, resistance, or current of the thing you’re poking at. Auto-ranging can be very helpful if you know how to use it. Generally speaking, autoranging multimeters are higher quality and generally have more features. So if someone gives you a multimeter with auto-range, put it to use! Just know how to get it into manual mode.A circuit’s voltage or current can fluctuate quite quickly. With some of the systems, the current or voltage is so sporadic that the auto-range can not keep up sensibly. 90005 90004 A 90049 back-lit LCD 90050 is fancy, but when was the last time you measured your circuit in the dark? We generally steer clear of scary forests and situations that require us to test stuff in the middle of the night, but some people may want or need a dark-friendly multimeter. 90005 90004 A 90049 good click 90050 on the range selector is actually a major plus in our book.A soft knob is usually indicative of a shoddy meter. 90005 90004 90049 Decent probes 90050 are a plus. Over time the leads will tend to break down at the flex point. We’ve seen wires come completely out of probes — and it’s always at the moment you need the probes to work! If you do break a probe, they are reasonably cheap to replace. 90005 90004 90049 Auto-off 90050 is a great feature that is rarely seen on cheaper multimeters. This is a feature that can benefit beginners and advanced users alike, as it’s easy to forget to turn the meter off at 2AM.The SparkFun digital multimeter does not have this feature, but luckily the meter is very low-power. We’ve left the multimeter for two days straight before the 9V battery began to get low. That said, do not forget to turn your meter off! 90005 90004 You’re now ready to use your digital multimeter to start measuring the world around you. Feel free to start using it to answer many questions. I believe my LED is getting 20mA, is it really? How much voltage does a lemon have? Is a glass of water conductive? Can I use aluminum foil to replace these wires? A digital multimeter will answer these and many more questions about electronics.90005 90008 90002 Purchasing a Multimeter 90003 90004 A digital multimeter is an essential tool in every electronic enthusiasts arsenal. Here are a few multimeters and kits with multimeters to suit the needs of beginners and experienced hobbyists alike. 90005 90013 Our Recommendations: 90014 90013 Digital Multimeter — Basic 90014 In stock TOL-12966 90004 The digital multimeter (DMM) is an essential tool in every electronic enthusiasts arsenal.The SparkFun Digital Multimeter, h … 90005 21 90013 Mooshimeter 90014 Retired TOL-13843 90004 The Mooshimeter is a multi-channel circuit testing multimeter that uses your smartphone or tablet, through Bluetooth 4.0, as … 90005 14 90049 Retired 90050 Click to Browse Additional Multimeter Options 90002 Resources and Going Further 90003 90004 Now that you know the basics of how to use a digital multimeter, check out these tutorials to use your new skill: 90005 90004 Or check out some of these related blog posts.90005 .