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Old 17th Sep 2018, 7:28 pm   #1
Join Date: Sep 2018
Location: Twickenham, London, UK.
Posts: 183
Default GEC Selectest Super 50 Mk2 fifty year MOT

I've known this instrument almost since it was new. I joined a company as an R&D engineer in its newly formed electronics division in 1969. As it turned out I was the only R&D engineer and a few pieces of test equipment had been purchased and this Selectest Super 50 was one of them. I worked on a couple of projects with them but they closed the division down after about 3 years and I acquired the meter when much of the lab equipment was disposed of. It then became my main test meter at home but steadily fell into disuse with the advent of decent digital multi meters at affordable prices. That said, every now and again it would get put into use when an analogue meter was the better choice. The only maintenance it has ever had was when I had to refit the loose glass, it has never been calibrated. With the meter around 50 years old I decided to see how its accuracy had stood up to the test of time. I have (hopefully) attached the results of my checks, the main reference was an AD584L (0.05%). It is not a complete check but covers all the ranges I am likely to use. As you will see, other than a few readings at low deflections, the accuracy is still better than 1%. This surely says a lot for the design and quality of this meter which was always in the shadow of the much more popular AVO 8.
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