NIST researchers have developed a new photonic pressure sensor called the Fixed Length Optical Cavity (FLOC) that outperforms the traditional mercury-based pressure standard at low pressure ranges. The FLOC is mercury-free, smaller, and faster, taking less than a second per measurement compared to the mercury manometer’s one minute per measurement. The device works by detecting changes in the frequency of light passing through a nitrogen gas-filled cavity, measuring pressure through changes in optical path length. While the FLOC is currently less accurate than the mercury standard at higher pressures, NIST plans to develop a variable-length optical cavity (VLOC) using helium gas to improve accuracy. The next step is to use FLOCs alongside the mercury standard to calibrate customers’ pressure gauges this summer.
Keywords: photonic pressure sensor, mercury-based, FLOC
