Our MBW 973L Model Chilled Mirror Dew Point Hygrometer has a completely new design with an optimal Response Injection System for fast measurement.  It is the first transportable MBW to include mirror pre-cooling, so the measurement range is extended to dew/frost points to -76 °C (1 ppmv). As with our instruments with an integral measuring head, the 973L Model includes a 0.1% accuracy pressure sensor so that dew/frost point measurements can always be referred to the actual pressure.