Did Harry's excellent resource help on the ice? Notice stated in the document a few things. First, the variance that can exist with ice-point standards. Too, the potential errors with thermocouple measurement and the need for a traceable standard are important also.
Have we assisted in your original question? If not, please re-post.
If you are remotely interested, I still have some pointers regarding your general measurement approach. I'm not sure how much of my information is relevant.
First, you might want to view this thread regarding psychrometers:
Hygrometer Calibration - Best way to verify Hygrometer 'reference' accuracy
Are you providing certificates of calibration to your customers? If so, your BMC (best measurement certainty?) for thermocouple of .7C seems fairly optimistic.
Why are you required to perform intermediate verifications of your standard? Is that a customer requirement or your requirement?
What is the critical temperature/ range of your customers use? That, in my opinion, would be the temperature you would want to perform verification. Thermocouples are non-linear which adds to the necessity to verify accuracy at the use range.
Do you verify the customer's temperature/relative humidity in-place on the equipment, or are they pulled out and placed in a standard test environment of some sorts?
Have you considered purchasing a dry block calibrator to perform verifications on your standard?
As stated, if none of this is any assistance, please disregard. Otherwise, I'm just curious about some other aspects of your process. Ice point reference is very common and inexpensive, but many times is does not serve the purpose many feel it does.
Have we assisted in your original question? If not, please re-post.
If you are remotely interested, I still have some pointers regarding your general measurement approach. I'm not sure how much of my information is relevant.
First, you might want to view this thread regarding psychrometers:
Hygrometer Calibration - Best way to verify Hygrometer 'reference' accuracy
Are you providing certificates of calibration to your customers? If so, your BMC (best measurement certainty?) for thermocouple of .7C seems fairly optimistic.
Why are you required to perform intermediate verifications of your standard? Is that a customer requirement or your requirement?
What is the critical temperature/ range of your customers use? That, in my opinion, would be the temperature you would want to perform verification. Thermocouples are non-linear which adds to the necessity to verify accuracy at the use range.
Do you verify the customer's temperature/relative humidity in-place on the equipment, or are they pulled out and placed in a standard test environment of some sorts?
Have you considered purchasing a dry block calibrator to perform verifications on your standard?
As stated, if none of this is any assistance, please disregard. Otherwise, I'm just curious about some other aspects of your process. Ice point reference is very common and inexpensive, but many times is does not serve the purpose many feel it does.