Busy day here at CPS – New Plymouth.

These below photos are from our temperature calibration at our office in New Plymouth.

The setup is 5 hand held temperature meters that are having their external probes being compared to our Fluke Reference probe.

So all 6 probes are inserted to the same depth in our Fluke 7321 and 6331 liquid baths each holding approximately 16 litres of Silicon oil. The oil is stirred to create a uniform temperature gradient across the silicone oil. The silicone oil acts as a temperature conduit, so each probe is pretty much seeing the same temperature. This stirred method creates a very stable and uniform fluid so very accurate comparisons can be made (check out previous blog on these baths).

We then use the Fluke – Compass for pressure software to automate the calibration process, yes the same software which we use for pressure calibration is used for temperature calibration in our lab.

This software allows us to run test profiles for the devices we calibrate in our labs. We have a profile for the actual device and a profile for the pressure or temperature test points we actually want to calibrate too.

The software controls the reference equipment and when the reference equipment is stable be it pressure or temperature it then takes readings from the reference and the device under test.

In this case for temperature calibration work we need to wait about 30 minutes to reach stability and then when we get a reading back from our reference we take 3 sets of readings, each set of readings taken is taken over 10 seconds so we are taking over 60 readings in total per temperature point. When this is all done for the temperature point in question, the software then tells the liquid bath to set a new temperature point as per the test profile and the process starts again and again.