RFQ: Supply of -100 °C Frost-point Hygrometer

The National Physical Laboratory's requirement is for a trace moisture condensation principle hygrometer with the ability to measure down to an extreme low range of humidity of -100°C frost-point temperature with an accuracy of ≤ ±0.2 °C. This level of accuracy is needed to give confidence to the humidity generated by NPL's primary standard generator and to act as a reference standard hygrometer for comparison calibrations at this level. NPL requires an instrument with this level of accuracy to be able to perf...