Comparing Thermometers & Thermocouples in Cryogenic Temperatures

This is a sequel to my Fluke 52 II Thermometer Unboxing and Overview video. On this one I take the comparison a little bit further by testing the same 3 thermometers and different type K-type probes in Liquid Nitrogen. Each of these thermometers is rated for measurements down to -200 celsius using K-type thermocouple probe. Only the Tenmars TM-82N can measure beyond this even though official specs say -200c is the lowest value it can measure.
Overall the difference between the actual meters is fairly small, the most difference comes from the actual probe. When it comes to the meters the Tenmars TM-82N is very spot on accuracy wise or sometimes even a bit better than the Fluke 52 II, while Voltcraft K102 being the worst one. K-type thermocouple isn't really meant for measuring cryogenic temperatures, so we have to bin these probes in order to find a good one and the difference in quality is huge. For example, both of the included Fluke branded K-type probes are really bad when measuring temperature while dipped in liquid nitrogen. Both of the probes measure temperature ranging from -206c to -210c, which is way too cold in normal atmospheric ambient pressure, where liquid nitrogen boils at -195.8 degrees celsius. The most reliable probes from the get go are the Kingpin Cooling branded Extreme K-type thermocouples, which you can buy from their website. They have super fast response time and all of them measure near the correct value with any thermometer. You can't really use them in memory heat sinks or small NB pots as they are fairly large and clumsy probes, but very effective on CPU and GPU containers. For smaller targets I would just bin those normal small K-type probes.
The main advantages of the very expensive Fluke 52 II is the super fast response time and real-time update on the display, and support for larger variety of probe standards and larger display with back light. Tenmars TM-82N is very amazing for its price, costing only around 60 euros with shipping included from China it is the cheapest meter from this lot, and can often produce nearly the same end result as the very expensive Fluke 52 II. I would recommend the TM-82N for anyone who is just starting, and doesn't want to spend many hundreds on a thermometer, for the most advanced users the Fluke branded meters are really awesome thanks to the real-time response time.
Kingpin Cooling Extreme K-type probe: kingpincooling...
Fluke 52 II: www.fluke.com/...
Tenmars TM-82N: www.tenmars.com...
Voltcraft K102: www.conrad.com...

[@Scouse29K]

I have just recently bought a Fluke 52 II, looking forward to trying it out. I also have two of those Voltcraft, calibrating it is quite easy, mine needed a little calibrating too when I bought them

[@brunopalacios2006]

Hi! Could you share the link of the thermocouple you used? I need one for -85 °C and don't know what ebay's cheap thermocouple choose. Thank you!!

[@Limeayy]

Wow, surprised that Kingpin has to make or reengineer some K-Type probes and i thought fluke made the best K-Type probes... Thanks Luumi.
Curious Luumi, is there any other difference between Fluke's vs Kingpin's K-Type other than that? Such as the range of temperatures?
EDIT: ^ I went to read up on some literature on the K-Type probe and the Kingpin is only good for liquid nitrogen as it's specifically meant for that purpose if you want accuracy for very cold temps, the Fluke is generically better for majority of temperature ranges...

[@bryantallen703]

I found a really nice Snap-On Ω/Volt/Temp/ect. Meter in a car that i bought along time ago. A friend told me it was $350 new. This thing has about 20 different settings on it.
I didn't even know it was able to read temps until i found a high quality thermocouple in the case.
Its surprisingly accurate. When i get back to the house, i'll post the model number. Though, i need another one. This thing is about 5lbs. and huge.

[@taggxoc]

I use some cheap crappy chinese thermometer with equally crappy probes fullpot is anywhere between -166 and -170 depending on the mood of that thing...
If you really cheap out just hook up the k-type to a multimeter and read the CB in ohms :D