Is an actual Certificate of Calibration required for BB thermometers?

[Vaatha]

We ordered a Fluke 561 Infrared Thermometer to use for reading temps on returned units. I was told the thermometer was calibrated, but when it arrived, the documentation stated that a Certificate of Calibration to NIST was not available, and if we wanted one, we would have to send it in to be calibrated for $112 on top of the cost already spent for the thermometer.

I called AABB and asked if the thermometer HAD to be calibrated to NIST standards, and their reply was that as long as the thermometer was calibrated by a national standardizing company, that should be sufficient. The statement on the IR says: "Fluke Corporation further certifies that the measurement standards used during the calibration of this product are calibrated, at planned intervals, traceable to SI units through an internationally recognized National Metrology Institute (NMI)"

AABB says that NMI should be an acceptable agency for the calibration. However, the document states that it is not a certificate of calibration or traceability.

Do we actually have to have a certificate, or would it be good enough for the inspectors to keep this document and the shipping receipt (for the date purchased), since this is not our NIST thermometer?

I also have questions about testing out the IR against our other thermometers and checking for variability, emissivity settings, etc-what post would I go to for that, or should I open another?

[Gkloc]

The 16th edition of the AABB manual has suggested quality control performance intervals for equipment and reagents that says Thermometers (vs NIST calibrated or traceable) for electronic thermometers should be done as specified by the manufacturer. Here I get an outside company to come in and calibrate the thermometers and just recently they found one that wasn't accurate and had to be replaced. They also label the thermometers when the next calibration is due and give they give me documentation of the calibrations as well.

[CM2]

What we do for ours is to buy one thermometer that is actually certified (comes with NIST certificate, has expiration date) and use that one annually in comparisons with all the other thermometers in use. As long as you show annually that the thermometers you are using are equivalent to the one standard NIST within a stated allowed number of degrees, you dont need to reinvest in All NIST certified thermometers every year or worry about getting the certificate for the IR therm- just show its been compared in lab and shown equivalent.. Obviously you must compare thermometers intended for use in the same temperature range - if you try to use one single one to cover -80C to +37C you will probably run into problems at the extreme ends of the scale showing greater deviation. You might check with your other lab departments and see if they've already invested in one you can borrow.

[JOANBALONE]

Hi CM2,

How much is the certified thermometer that you purchase?

[khalidm3]

What we do for ours is to buy one thermometer that is actually certified (comes with NIST certificate, has expiration date) and use that one annually in comparisons with all the other thermometers in use. As long as you show annually that the thermometers you are using are equivalent to the one standard NIST within a stated allowed number of degrees, you dont need to reinvest in All NIST certified thermometers every year or worry about getting the certificate for the IR therm- just show its been compared in lab and shown equivalent.. Obviously you must compare thermometers intended for use in the same temperature range - if you try to use one single one to cover -80C to +37C you will probably run into problems at the extreme ends of the scale showing greater deviation. You might check with your other lab departments and see if they've already invested in one you can borrow.

Please! May I have make and name of this NIST calibrated thermometer. I want to buy one. I want to buy one set of NIST traceable weight also, if any one has some information

Thanks

[CM2]

For the waterbath and refrig thermometers I use a mercury standard from chemistry department that they pay to have recertified yearly.

For the -80 I use Item 15-077-961 from fishersci.com $65 - its an electronic thermometer with probe on the end of a long cable and digital display, this lets me put the probe inside the freezer and read it from outside without opening the door. It comes with a 2 year certificate and has a range of -99 to +199 C. I find the +/- 2C accuracy to be too wide for the midrange temps but its ok for this specific application.

[JOANBALONE]

In my search, certified thermometers are much more expensive. Are you sure it certified or just traceable?

[CM2]

Ah, you are correct, it is NIST traceable which has seemed to satisfy the inspectors for our weights and the thermometer checks. Im not sure who needs the higher standard certificate :-?

[Vaatha]

We are using a digital thermometer with a Traceable Certificate of calibration with an accuracy of 0.1C when tested at 22C. We originally bought a NIST mercury thermometer which ran between $1200-2000 but after breaking it twice in a row, and our facility moving to a non-mercury policy, we had to switch. we send it off to the Control Company yearly for calibration. This thermometer works pretty good, but does NOT work for taking temps on units, since the metal probe is too long and we cannot get an accurate temp due to ambient temps interfering. That's why we decided to try an IR so that we would have quick readings of the units. Can IRs take accurate reading on water? If I can put the NIST in water and compare the IR to it, and that's acceptable for validation, I can try that. Otherwise, my only other option to see if we got a new thermometer in the Gen Lab that's small enough I can test the unit temp with it, since most new thermometers come with a certificate of cal good for 2 years.