Temperature/Humidity @ Time of Cal

[briansalomon]

I would like to know what the consensus is on how temperature/humidity is reported on certificates of calibration.

Instead of reporting the actual temp/rh at the time of cal I think it makes more sense to report it as within a defined band, for example 22 deg C +/- 5 deg C.

If I do it that way I have to account for the temperature coefficient on my standards and it makes their tolerance looser but unless the temperature goes outside the band I don't have to account for it's effect.

Many of my primary standards already have tolerances stated this way.

How are you reporting temperature on your certs?

[silv3rstr3]

Our quality manual has a band tolerance for the different sections in the lab.  However we list real time readings on the certificates.  Fluke told us when we switched over to Met/Team last year if we purchased their 1620A the readings would auto fill on the certificate in real time.  This hasn't been the case and they've even sent us a new 1620A to swap and it still doesn't work.  Imagine that....

[RFCAL]

You should always use real time readings. We use a sensor system thru out the lab that displays current temp / hum readings for each section of the lab. Some of our intrinsic standards have a temp tolerance of + / - 1-3 degrees from time of cal.

[N79]

We report the range of temperatures and humidities sampled throughout the measurement time, for example 21.3 - 22.4 ℃, 40.1 % - 41.2 % RH. An environmental sample is taken before every set of readings. In fact, we plot these environmentals in the same chart as our measurements just to see if we can spot any correlation. This is probably overkill but it's no extra effort when it's all automated.

If I were having to report it manually, yes, I would just use the lab or measurement system tolerances.

[silv3rstr3]

We have ours set up logging the data and each month have to upload a graph of the temp/humidity trends to our quality website.  Just disappointed Fluke is full of promises and rarely delivers on them.  It would be great for Met/Team to pull the real time readings automatically when you pull the work order you're completing for a T.I. 

[briansalomon]

As advised, will stick with reporting actual.

Now I don't feel so put about having to keep filing the old charts from our old hygrothermographs every week after reading about some of the new automated systems.