Gage Accuracy

[ACoyle]

We all know that gages are important. There are as many opinions as to which are best as grains of sand on the beach. With all of that said, has anyone ever checked the accuracy of their gages? It seems that boost would be easy. Trans temp, not all that hard. Fuel pressure, compare with a mechanical, maybe two and average. The biggie and most important, how could one check the accuracy of an EGT gage?

 

[LSMITH]

The last TDR magazine had a comparison article in it. Basically the smaller the thermocouple the faster the response, all were about the same accuracy. Any of the popular EGT guages is going to be way more than accrate enough. Hope this helps.

 

[DFormstone]

EGT calibration

My understanding is that the EGT gauge is comprised of a thermocouple and a millivolt meter either digital or mechanical.

The thermocouple usually works or it doesn't, there are some problems that can cause inaccuracies but are relatively rare so we will ignore them for now.

The gauge on the other hand can have errors, which depends mostly on the quality of the meter and the quality control at the manufacturing facility. Calibrating the gauge can be done if you have the correct equipment (temp simulator/mV generator) and you know what type of TC it is. The 2 most common are type K (Chromel Allumel) and type J (Iron Constantan).

With the temperature calibrator you simply select the TC type and dial in the temp you want the meter to read. It should be checked at at least 5 points. That's about it.

If you have a friend that is an Instrument Mechanic he should be able to do this for you.

I hope this is of some help.