Electronic Basics #15: Temperature Measurement (Part 1) || NTC, PT100, Wheatstone Bridge

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In this episode of electronic basics I will show you how the resistance of different materials is used to measure accurate temperatures. The video will include information about NTC thermistors, PT100, Wheatstone bridge, LM35 and DS18B20. And at the end I will show you how to build a simple thermometer.

[stephenoconnor]

Your videos are such a pleasure to watch. You explore topics any layman would like to learn about but don't gloss over the important theory and troubleshooting that would leave most of us twisting in the wind. I've learned so much from your channel - thank you so much, and please keep up the awesome work!

[hightttech]

Perfect video. I'm preparing to use a PT-100 for the first time, and this is good primer.

[paparoysworkshop]

Great videos... I enjoy them very much. You are clear, precise and to the point.

[pnesap]

Nice handwritten formulas and chart. Doing calculations by hand leads to greater understanding.

[billybbob]

I just took apart a Keurig 2.0 coffee machine. This version was the most over-engineered with full color screen, two hall effect sensors, a color sensor, RGB and a combo water tank/heater with other goodies. My Keurig machine had a broken touchscreen. Because I have no other way to brew coffee right now, I wired a switch to the heater and took an old computer power supply to get 12v to the water and air pump. By monitoring the NTC resistance and the water temp, I found that 3.75k was the resistance for the perfect cup. I plan On controlling the whole thing with an Arduino and will add my own buttons and screen. I'm not sure what the color sensor was used for, but I'll end up using that at some point in another project.

[kevin_delaney]

If you are into 3D Printing. you should make a video about the PT100 RTD in higher precision applications. I use a PT100 with a "daughter board" on my Duet WiFi to get up to about 400 C. Look into the Duet WiFi and dc42 fork or RepRapFirmware. I was confused about how to wire it up initially.

[movaxh]

BTW, for 2/3/4 wire measurements you can use MAX31865 (there are breakout boards on ebay and adafruit) that does almost everything for you basically, including ADC, voltage regulation, precision current source, and precision resistors. One can find them for about 5$ a piece. Not bad. I am still for a quest for water proof but small PT100/PT1000 probes, so they have less thermal mass and quicker response time (I am looking for -25 to 60 deg range, basically common air temperature over entire year). Need to build an array of about 30 such sensors for profiling air temperature.

[sortsvane]

I am addicted to your videos.
keep it up ! aaand I am also left handed :)

[kestergascoyne]

Amazing series Scott, I feel like I'm learning so much so quickly.

[mikelemon]

It's been an year and you still didn't make a video about thermocouples....

[ashokpandys]

Thankyou soo much i was looking temperature meter using thermoresisters

[lensar]

reached minute i did not understand a single thing - hahaha i shouldn`t have stopped taking physicsclasses
You are awesome buddy!

[czarcorey]

Great video! I am building a clapper circuit that uses different numbers of claps to do different things loosely based off if your clapper design now. Thanks for the inspiration!

[Azurren]

Have to admit that you lost me completely with resistor values, wheatstone bridges and complex formulae. May have to go back and re-watch some of your earlier videos!

Btw the past tense of the word "cost" is "cost", not "costed" in most situations. Even though using costed is perfectly understood. :)
"This one only cost me around 5 bucks", "That decision cost me dearly", "I can't believe a simple service cost me over £1000!"
_Your English is excellent, wish I could speak German even half as well_

[jonasduell]

8 year old video, might post something new that I found: TSYS03, digital I²C manually addressable max. 1MHz temperature sensor, tiny package == low thermal mass, +/- 0.5°C at -40 to +125°C with custom precision ranges programmable, eats 2.4-5.5V so virtually any microcontroller or USB power works... And the best part is: Digikey have em in stock :)
Need to order a bunch for testing purposes!

[brenoviniciusrocha]

awesome video as always ! I would like to see you doing a project with the infinite mirror, like a table or something like that . I bet you can do a great job, cause you know, you're such a genius lol

[RokasSondaras]

love your videos! keep uploading them.

[PM-gycc]

Have you made the video about how to eliminate thermal inertia problem?

[hunterwilliams]

This guy is the storyteller of electronics, he says “that’s a subject for another video” almost as much as the storyteller says “that’s a story for another’s day.”

[rayknn]

Is it me or is this just a matter of measuring the resistance of the RTD easily using a multimeter? O I was wondering, the RTD says it's capable of 850 degrees celsius. But can you put the RTD on the surface of for a example a aluminium plate without it burning?