Making Accurate Thermocouple Measurements

[@blameblame6146]

Would have been good to talk a little about typical accuracy of the each of the common types of thermocouples and best methods for dealing with the excess thermocouple wire to minimize noise pickup. Also, when does the 34970/2 need an isolation transformer for noise.

[@KeysightHandsOn]

Blame Blame Good point to eliminate the excess wire. The 34970A and 34972A are isolated from earth ground to 300V. Keysight offers an application note "Practical Temperature Measurements" with details on selecting the best thermal couple for a particular application.

[@David_Bruton]

Chapter 2: Thermocouple airs or errors? 😂

[@elmeradams8781]

There wasn't much practical knowledge for the newbie. Like do you use tape to hold the sensor on or your finger, or what.

[@KeysightHandsOn]

Elmer Adams I see a lot of applications that measure temperature over time or need to be repeatable. For applications that require more accuracy we often glue the sensor using a thermal conducting glue. Glue works well as it does not add much thermal mass. Tape could also work if you wanted to avoid the glue residue.

[@elmeradams8781]

Keysight General Purpose Instruments I've been trying the past while to use these. I've been testing temperatures of automotive AC lines. I've been using foil tape (like for hvac ducting) but I was hoping for more information like is wind a problem. The vehicles fan is always blowing and I don't know if air blowing on the probes are a problem or if straight aluminum pipe transfers heat differently then black painted aluminum line. I guess practical info for field testing isn't usually practical for lab testing.

[@KeysightHandsOn]

Elmer Adams Great questions. Heat can be transferred by conduction, convection and it can be radiated. The fan would be changing the temperature by convection. Aluminium is a good conductor which makes it a poor insulator. I don't think the black coating would provide any insulation for the pipe. A black coating would improve the pipes ability to absorb heat but only slightly since the surface area is small. Most of the pipe is rubber as it is a good insulator.

[@blameblame6146]

very "inappropriate" for measuring a small semiconductor device. He did not enunciate very well there and it sounded much like "appropriate". Yes, we know, but newbies don't and they are the target audience.

[@KeysightHandsOn]

Blame Blame You are correct. The video also has close captions as we are not professional speakers.