Alpha Moisture Systems offer a full range of dewpoint calibration services. All new dewpoint transmitters and hygrometers are supplied with a Calibration Certificate. Calibration Certificates are traceable to NPL (National Physical Laboratory) and, through NPL, the International Humidity standards. All calibration procedures are carried out by highly skilled and experienced technicians operating state-of-the-art equipment. Our climate-controlled laboratory has precision moisture generators and chilled mirror dew point hygrometers. Calibration procedures follow the Alpha Moisture Systems Quality Assurance program, which is accredited to ISO9001.Alpha Moisture Systems recommends annual calibration to maintain reliable dewpoint readings and ensure optimum instrument accuracy. Increasing the calibration frequency to every six months may be appropriate for some critical applications or where a high level of harmful contaminants in the measured gas could be present.