Definition of Thermometer vs Pyrometer

[Conman]

I need assistance defining a digital thermometer (Fluke 51/52 type) vs a Pyrometer. During a recent audit a CAR (corrective action requirement) was generated due the calibration cycle difference between a digital thermometer (12 months) and a pyrometer (6 months). A bean counter can't understand that modern digital thermometers encroach on the pyrometer temperature range. I'm attempting to address this situation and would welcome any clearly worded definitions.

[briansalomon]

For what it's worth, the Metrology Handbook has this in the glossary:

pyrometer
A device for measuring high temperatures, generally above 600 degrees Celsius; also known as
an optical pyrometer.

[Conman]

I appreciate the answer. Unfortunately a Fluke 51/52 has a temperature range that exceeds 600°C (-200°C to 1372°C).

[ck454ss]

Im just curious.

What does the temp ranges have anything to do with the cal interval of the instrument?  Does it have a history of being good or not to justify whatever interval you have.

The CAR seems bogus to me on the surface.

[BamaKid]

I agree with ck454ss, the issue to me is how was the calibration interval determined not what is the definition of the description of the two instruments. If the Fluke Model has better reliability for whatever reason (newer technology, newer instrument, better tolerance design, etc.) than the Pyrometer model instrument than that should be sufficient rationale.

[PurelyNonsense]

Correct me if I'm wrong about the 51/52. Those are digital meters that are taking thermocouple readings. So it's not the meter doing the work, it's the thermocouples. Most Pyrometers that I've seen are in the class of Infrared Thermometry. I don't think it's a mater of temperature range as it the way it's measured. So, Pyrometer's can be optical measurement where thermometers need a physical contact. Don't quote me. It's just how I understand it.

[Conman]

All answers are correct in determining calibration cycle, provided you are not working in the NUKE industry. Bean counters can't understand the difference between a digital thermometer and pyrometer is measurement method. Bean counters assume a thermometer is a low temperature measuring device, below 200°F. Since a Fluke 51/52 measures -200°C to 1372°C the bean counters call this a pyrometer.

[bAdbOb]

What does the bean counter call his meat or oven thermometer?

[ck454ss]

Use the bean counter stupidity against them.

A pyrometer uses radiant IR to measure surface heat.

A thermometer contains mercury or alcohol and is contained in a glass tube.

Since the 51 is digital and uses a thermocouple how the heck do we measure Radiant IR heat?

Root Cause Analysis....Auditor needs to take a class on temperature.  Many are offered through Fluke.  CAR closed.

I have actually put that in Corrective Actions for auditors who try to pull stupid crap like that for whatever measurements.

[griff61]

What does the bean counter call his meat or oven thermometer?

Hot

[NC-Cals]

Does this auditor have a reference that says similar instruments must have similar calibration intervals? Is that stated in your policies anywhere? We have identical Vaisala hygrometers - some are 90-days and others are 12-months depending on how it is used the criticality of the measurements. It really sounds like this auditor had an opinion that he cited as fact. I'd challenge the finding and ask for the reference.