NIST Low Frost Point Generator (LFPG) Laboratory provides low-humidity calibration and testing services for hygrometers and humidity generators that measure or generate humidity levels between 3 nanomole per mole (nmol/mol, parts per billion, or ppb) of water vapor in nitrogen and 3000 micromole per mole (µmol/mol, parts per million, or ppm).
Hygrometer calibrations are typically performed by subjecting the hygrometer to various H2O/N2 mixtures produced by the NIST LFPG, and comparing the water vapor concentration reported by the device under test (DUT) to that of the LFPG.
n addition to calibration services, NIST provides customized testing services for industries concerned with trace quantities of water vapor in gasses.
The expanded relative uncertainty of water vapor mole fractions produced by the LFPG is 0.8 %, with coverage factor k = 2, plus 0.4 ppb contribution due to outgassing from the sampling system connecting the LFPG to the hygrometer under test.
Devices submitted for calibration or testing must meet the following applicable criteria:
How to Arrange a Calibration
For contact information, shipping address, or cost of calibration, see Humidity Measurements.
100 Bureau Drive, M/S 8363