Process Insights MBW Calibration is recognized internationally as a developer and supplier of high-quality chilled mirror dew point hygrometers used in a variety of humidity calibration, measurement and gas quality applications. Most notably, MBW instruments provide the calibration traceability for many laboratories such as humidity instrument manufacturers and National Metrology Institutes. MBW chilled dew point mirrors continue to be chosen as transfer standards for inter-laboratory comparisons both regionally and internationally.