NIST logo

Publication Citation: A Reference Standard for Measuring Humidity of Air Using a Re-entrant Radio Frequency Resonator

NIST Authors in Bold

Author(s): Peter H. Huang; Dean C. Ripple; Michael R. Moldover; Gregory E. Scace;
Title: A Reference Standard for Measuring Humidity of Air Using a Re-entrant Radio Frequency Resonator
Published: May 02, 2006
Abstract: We developed a stable reference hygrometer suitable for operation at temperatures above ambient that has a robust design, inherent stability, and a well-understood theory of measurement. This hygrometer uses a reentrant, radio-frequency, cavity resonator operating near 370 MHz to convert the known humidity-dependence of the dielectric constant of H2O/air mixture into easily-measured frequency changes. In this paper, we discuss the achievable repeatability of this device. We expect this hygrometer will be especially valuable for validation of humidity standard generators at mixing ratios in moist gases higher than 20000 parts per million by mass.
Proceedings: 5th International Symposium on Humidity and Moisture; ISHM 2006 Brazil
Location: Rio de Janeiro, -1
Dates: May 2-5, 2006
Keywords: fuel cell, high humidity, high temperature, humidity standards, hygrometer, radio-frequency, resonat
Research Areas: Measurement Standards, SI (Thermodynamics Units), Standards, Chemical Engineering & Processing, Manufacturing, Chemistry, Metrology, Humidity, Humidity
PDF version: PDF Document Click here to retrieve PDF version of paper (158KB)