Statistical Calibration of instruments Using Water Activity Determination As An Example

An example is given of a method for establishing the confidence limits for the calibration of an electronic instrument utilized in measuring water activity. The method consists of the inverse use of a regression line with associated Working‐Hotelling‐Scheffe bounds for the true line and the construction of limits suitable for repeated use of the derived calibration. Interval estimates are given for the Kaymont‐Rotronics Hydroskop DT, calibrated with vapor pressure manometer measurements of equilibrated salt solutions as standards. The statistical approach has general applicability and should be applied routinely for all calibration problems.