This document specifies the calibration methods under laboratory conditions for dosemeters used for environmental and area monitoring of X and gamma-rays with respect to the operational quantities of the International Commission on Radiation Units and Measurements (ICRU)[1]. This document extends the dose rate range of ISO 4037-1 below 1,0 µSv·h−1. The specific uncertainty components are described for these calibration methods. This document also specifies the method for routine checking of active area dosemeters. Routine checking is not a calibration, nor does it replace a calibration, but it is a simple and effective method to routinely verify that the performance of the equipment is continuously maintained after calibration and that the calibration is still valid. This document does not deal with the special requirements for the calibration of spectrometer-based environmental dosemeters and passive dosemeters.