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ARGN
14-04-2017, 09:06 AM
Just wondering what people use to measure temperature, thermistors or K-type thermocouples and is one better than the other or are they pretty much all the same?

Greek_engineer
14-04-2017, 09:20 AM
classical multimeter.

Grizzly
14-04-2017, 11:19 AM
Welcome to the forum ARGN.
My layman's take on this is it depends upon what temperature range you are wishing to monitor.
Thermistors have a high resistance at low temperatures, so are more commonly used in say Fire alarm systems.
Whereas.Thermocouples are usually used at low temps as it is easier to calibrate the resistance values.
Be they Positive rise or Negative rise.

That's my understanding of it, if that Helps?

Grizzly

HVACRsaurus
14-04-2017, 11:25 AM
Are you talking hand - held or fixed controller?

HVACRsaurus
14-04-2017, 11:27 AM
Hand held is whatever the manufacturer could be bothered with. I am yet to use a hand held unit worth a pinch of sh1t

HVACRsaurus
14-04-2017, 11:43 AM
Fixed controller is different story,

Thermocouple is great - it is cheap, and is good for measuring temperature within a steel smelter (aka bloo dy hot) Aaaand there is about a dozen different types of thermocouple combinations.. Bong Bong, not very good for us fridge mechanics..

Thermistor - also great, also cheap - but instead of a dozen different combinations there are only about thirty. 30 strewth! And because no one supplier wants you to swap with another, they each chose a different one to lock you in. Then the poor fridge mechanic needs look up tables & Thermistor charts for each, high resolution multimeter and a packet of Prozac for smoko.

The golden benchmark is Pt (platinum) element. Only two main elements (Pt100 & Pt1000) resistance charts are just a google away, near linear characteristics, available with numerous probe styles, suitable for the "small" temperature window that we deal with (-50 C through 150 C) And come on, who doesn't like platinum!

Cold reality is, in a service situation, identify what is, get a new one, stick it in & on to the next..

ARGN
15-04-2017, 05:59 AM
I'm looking at buying a new hand held temperature thermometer, I used to have a fieldpiece ST4. While I have been looking around I have come across Cooper Atkins pipe straps which look really easy to use and wouldn't mind a couple straps myself but they are thermistors which made me wonder if one is better, more accurate or doesn't need to be calibrated as much as the other or are they really all the same in that regard?

ARGN
15-04-2017, 06:02 AM
Speaking of pipe straps to measure temperature, what are the ones people like to use the most?