What should a valid calibration certificate for a new piece of equipment look like? I'm particularly interested in a Temperature/Humidity monitor & logger.

What should a valid calibration certificate for a new piece of equipment look like? I'm particularly interested in a Temperature/Humidity monitor & logger.

The same information that a calibration cert for a used piece of equipment should contain. There is no real difference. It is a calibration of an instrument that determines the gage can make reliable readings.

The same information that a calibration cert for a used piece of equipment should contain. There is no real difference. It is a calibration of an instrument that determines the gage can make reliable readings.

Agreed. Just roughly:

1. Customer information; company information
2. Date/ time, recall information (if applicable).
3. Standards used information
4. Procedure/ guideline listed
5. Instrument under test specific information
6. Data test points, values observed, tolerances
7. Comments, observations
8. Date, signature, review, etc.

As far as the monitor/logger, it depends. A factory calibration may check voltages, board readings, cold junction compensators, etc. Another may check one channel with a simulator; yet another may check all input channels. So the data could be a paragraph, or three pages long.

Al, is any of that helpful?

I won't reiterate what the others have already said. On a certificate for a temp/humidity logger, I would look for three humidity point (low/mid/high), typically somewhere around 20%RH, 50%RH, 80%RH or so. I would look for at least two (preferrably three) temperature data points with ambient being somewhere around the middle.

If there is just a single point cal (particularly on humidity), the accuracy is suspect, as humidity sensors are notorious for non-linearity.

MEASUREMENT UNCERTAINTY!!!!! the 17025 forum and nobody mentions the need for an uncertainty value? :mg:

Really... Nobody

I would also look for whether or not the calibration was accredited or not, meaning performed to ISO-17025. Not that non-accredited may or may not be good, it adds a level of comfort that the calibration was done properly.