For the last 30 years, the official U.S. standard for measuring pressure has been a 3-meter-tall (about 10-foot) device called a manometer. American industry relies on the U.S. pressure standard for everything from silicon chip manufacturing to sensors that tell pilots how high their planes are flying.
Last month, NIST workers decommissioned the U.S. standard manometer’s nearly identical twin, kept on hand as a backup for the main device. The twin device was dismantled as part of a global effort to phase out instruments that rely on mercury, a toxin.
“This is an exciting first step in decommissioning our mercury manometer program at NIST to make way for our new standard,” said NIST physicist Jay Hendricks. The new standard – called the Fixed Length Optical Cavity (FLOC) – will be a smaller, portable machine that makes its measurements using light.
Source: No Longer Under Pressure: NIST Dismantles Giant Mercury Manometer | NIST
