[en] Portable neutron dose rate meters are calibrated at Los Alamos using a Pu-239/Be (PuBe) neutron source. The source is located in a vertical well and rides on top of an elevator mechanism to vary the dose rate at the top of the well. Instruments are positioned over the well and are exposed at a source-to-detector distance in the range of 25 cm-300 cm to dose rates from several mrem/h to several hundred mrem/h. The dose rate at the top of the well is measured with an Eberline NRD detector that has been calibrated to the source free-in-air. The NRD detector is a 9-in. polyethylene sphere with an internal cadmium foil loading. A BF₃ counter tube is located in the center of the sphere. The complete well calibration procedure is given