AVO METER

In July 1923, Donald Macadie, manager of the Post Office Telephone Factory was granted a patent for an instrument that could measure Amps, Volts and Ohms. AVO Ltd was formed to manufacture AVO meters in large quantities. Various models were produced until the final one was assembled in 2008.

I have two instruments of the Model 8. This  was the most popular model for 57 years! Both have a leather case.