July 3, 2017 at 10:04 am #9993
Random thought, I wonder when the first multimeter was made. and what would have been the method to test continuity before hand?
July 3, 2017 at 10:22 am #9994
Interesting question. Well, I know the Simpson 260 goes back a long ways but let me do a little research and see what we find
July 3, 2017 at 10:26 am #9995
The first moving-pointer current-detecting device was the galvanometer in 1820. These were used to measure resistance and voltage by using a Wheatstone bridge, and comparing the unknown quantity to a reference voltage or resistance. While useful in the lab, the devices were very slow and impractical in the field. These galvanometers were bulky and delicate.
The D’Arsonval/Weston meter movement uses a moving coil which carries a pointer and rotates on pivots or a taut band ligament. The coil rotates in a permanent magnetic field and is restrained by fine spiral springs which also serve to carry current into the moving coil. It gives proportional measurement rather than just detection, and deflection is independent of the orientation of the meter. Instead of balancing a bridge, values could be directly read off the instrument’s scale, which made measurement quick and easy.
July 3, 2017 at 10:50 am #9996
Check this out;
Simpson Electric’s prominence in the panel and test instrument industry dates back to 1927, when our founder, Ray Simpson, built the indicating mechanism for the earth inductor compass that Charles Lindbergh relied upon when he flew “The Spirit of St. Louis” on the first solo flight across the Atlantic Ocean. For thirty-three hours, Lindbergh’s life and success of his historic flight depended largely on this navigational instrument, while the world awaited his arrival in Paris.
Simpson “firsts” indicative of continued leadership and quality in the instrument industry include:
First commercially-practical core meter movement.
First to use split coil frames for controlled damping under special applications.
First to use non-shatter glass in instruments.
First to put a zero adjust on lower-cost high-grade instruments.
First Lucite illuminated meter face providing better scale visibility.
First shielded line of small portable instruments that met requirements for
checking areas where strong magnetic fields exist.
First commercially-practical two-inch wattmeter in America.
First compact “all purpose” volt-ohm-milliammeter, the “260,” that thousands of
military personnel used during World War II.
You must be logged in to reply to this topic.