Vintage Electronics Equipment Dynamometer Milliammeter 1951 SRI Corp. Wood Case

Description

We offer for your consideration this vintage 1951 Dynamometer/Milliammeter.
This
Dynamometer/Milliammeter is the Model D made by
Sensitive Research Corporation of
Mt. Vernon, New York.
It is serial no.103128.
It
is a portable Volt-Ampere Watt meter, with a 20- 1000 ma range.
It is for AC use only.
It is, as far as we know, unmodified and in its original state. The wod box has some scratches, and it could use a little varnish refresh.
The leather handle has broken (see pictures)
We found the following in a vintage radio equipment chatt room:
With the internal connections in the VAW and its switching, it is possible to completely characterize an AC load with one meter. Normally a separate voltmeter, ammeter, and wattmeter would be needed. The wattmeter tells you the "real" power taken by the load while the product of the voltage and amperage readings gives you the "apparent" or VA power. Power factor is calculated by dividing real power by apparent power. The VAW was meant to simplify the lives of engineers and technicians who would otherwise have to carry and set up three separate meters everywhere a test had to be made.
If you are a collector of Vintage electronics test equipment, this unit might be something you could add to your collection.