DW Tomorrow Today August 26, 2019 04:52:00
A handful of these scales worldwide this one is in the united states at the national institute of standards and technology. the high precision scale is based on the principle of electromagnetic force compensation this is how it works the gravitational force of a test mass is balanced with an electromagnetic force the magnetic field is provided by a permanent magnet a coil of wire is immersed in that field. it's like a coil in a loudspeaker and the coil is in a permanent magnetic field an electrical current is run through it to generate a force that force is used to balance the downward force o...
Source: archive.org