Presents an experimental evaluation of different types of commercial chilled- mirror dew-point hygrometer designed to verify their metrological behaviour. Specifically, carries out an analysis of their measurement uncertainties and long-term stability. Applies a computing method to estimate the measurement uncertainty of an indirect determination of the relative humidity using a chilled-mirror dew-point hygrometer and a dry-bulb temperature sensor.

KEYWORDS: year 1995, Accuracy, commercial, dew point, hygrometers, calculating, relative humidity, sensors, instruments, measuring