We use nitrogen to flush our pouches of trail mix during packaging. We monitor the amount added by checking a package hourly with an Oxygen/Nitrogen gas analyzer. The first annual calibration for this device is due, but some labs only calibrate to NIST.
The SQF standard is not clear on calibration requirements (18.104.22.168). Is NIST (National Institute of Standards & Technology) considered an acceptable "national international reference standard" or should the device be calibrated to ISO 17025?
Any help would be appreciated.