The MBW Calibration 973 is a high-precision portable hygrometer that utilizes the fundamental chilled mirror principle to deliver drift-free and accurate humidity measurements. It is distinguished by its integral measuring head, which allows for direct measurement within the application environment, and its ability to also accurately measure pressure and temperature, enabling the calculation of alternative humidity parameters like relative humidity, ppmv, and absolute humidity.

A standout feature of the 973 is the integrated ice-test function, which allows users to quickly and easily self-check the calibration stability of the instrument in the field, ensuring ongoing confidence in measurement results . The instrument is available with different measuring heads (models 932S, 932E, 932CA, 932L) to suit various pressure ranges and application requirements.

The 973 is supplied in a tough, foam-lined transport case that protects it during site-to-site movement or when shipped for calibration. With its high accuracy (≤±0.1°C dew point), versatility, and robust portable design, the MBW 973 is an ideal instrument for on-site sensor calibration, validation of production conditions, dryer performance tests, and use in standards laboratories .