NIS two-pressure humidity generator

Abstract

Abstract. There are several techniques available to generate humidity references by using stream of saturated gas with well-known water vapor content. Two-pressure humidity generator (2-P) is the most commonly used for the realization of temperature and relative humidity scales at National Institute for standards (NIS) and for disseminating traceability. This generator has been shown to be highly reproducible when properly used. In order to obtain traceable measurements and best performance, the temperature sensors and pressure gauges of this generator should be calibrated. This paper explained the calibration of 2-P temperature sensors and pressure gauges and the analysis of their performance for the first time at NIS.

Extending dew-point temperature scale up to +50 °C

“…The uncertainty budget of the generator at dew-point temperature range (À10 to +50°C) involves the uncertainties of each source and the method of estimation for Table 3 shows explicitly an example of the calculated uncertainty budget at +10°C dew-point temperature with an expanded uncertainty of 0.0659°C [7][8][9][10]. Thus, in the concerned dew-point temperature range, it was found that the measurement uncertainties ranged from 0.0654 to 0.0669°C at dew-point temperatures of 0 to +50°C, respectively, and the measurement uncertainty at À10°C was found to be 0.0697°C.…”