Look inside a lab! Today, we’re stepping into a special space for national metrology institutes around the world. The NIST-4 Kibble balance provides the definition of mass for the United States. It’s basing its measurements on the Planck constant that was given a fixed value as part of the redefinition of the kilogram in 2019. But not every country around the world can afford to house that kind of massive instrument. That’s why we have a shrunken version, which our researchers are working to mak

We know there are scales for measuring large objects, but did you know there’s a scale for measuring tiny ones, too? It’s called an electrostatic force balance, or EFB, and is used to measure the mass of small objects that weigh between 50 micrograms and 20 milligrams. Because the device uses electrostatic forces – think the static charge that occurs when you rub a balloon against your hair – it can be traced back to the fundamental constants in the SI (the modern metric system) through electric