A Bilateral Comparison on Humidity Standards in the Dew/Frost-point Temperature Range from -30 deg C to 20 deg C

摘要

This is a regional metrology organization (SIM) bilateral comparison of the realizations of the scale of dew/frost point temperature at the participating National Metrology Institutes: NIST (USA) and INMETRO (Brazil). A total of four humidity levels in terms of dew/frost-point temperature are used for the comparison: 20 deg C, 0 deg C, -10 deg C and -30 deg C. At each measured value, the mean and standard deviation of multiple readings of the transfer standard, which is a chilled-mirror type of dew-point hygrometer, were recorded. The results of statistical analysis support the conclusion that the measurement data can be assumed to have the form of normal distribution. Combined standard uncertainty ranged from 0.02 deg C to 0.08 deg C approximately.