follow the numbers
lday38 said:
Does the enviromental rules have to be held on an internal laboratory? We will be going to TS16949:2002. Or can I say ambient the same as whee the equipment is used?
First, I don't know what the environmental rules of TS16949 are with respect to calibration, because I am in a different industry and do not use that standard. That said, however, there is nothing inherently "wrong" about performing calibrations in the same temperature/humidity conditions as the measuring instruments are used in. It's just that the calculations get more complex. Most physical/dimensional calibration (of your own reference standards, for example) is done at about 20 °C, and most electronic calibration is done at about 23 °C. (There are varying ± tolerances for each.) If you perform your calibrations at some other temperature, you
MAY have to make corrections to compensate for thermal expansion or other effects.
On the other hand, you will be removing the decades-old question of "how do I know it's good in the foundry when you calibrate it in the icebox?"
lday38 said:
I can only calibarte to 4 places and if this accuracy is required, outside qualified claibartion labs are used.
In every calibration lab I have worked in or visited, it is routine practice to send work that is beyond their capability out to a more capable vendor. This is often stated in a written policy, but not always with a fixed break-point because conditions change.
For example, right now we can calibrate digital thermometers to ±0.1% of reading; anything tighter than that gets sent out. If E***** ever gets their new model 1*** into production (they've been telling me "six months" for almost 1½ years now ...) then I will be able to calibrate to ±0.05% of reading.
Also, we send out all of our calibration standards that are beyond our capability (naturally)
and any calibration standards that are at the top of our local traceability chain even if we could otherwise calibrate them.
