AVO, multiminor Mk. IV; circa 1950.
Note the remark in the ad.: only one pair of sockets for all ranges. These days, we would take that for granted (well, in most cases) but in the years just after WW2 there were many multi-range meters on the market that required the user to select appropriate pairs of sockets as well as adjusting the range switch. The problem with that arrangement was that it was easy (on some models) to produce a 'setting' that could give an erroneous measurement - or even seriously damage the meter - for example, inadvertently setting a low current d.c. range but then applying a high voltage to the test prods. Ouch!
Al. / June 20, 2013.
Note the remark in the ad.: only one pair of sockets for all ranges. These days, we would take that for granted (well, in most cases) but in the years just after WW2 there were many multi-range meters on the market that required the user to select appropriate pairs of sockets as well as adjusting the range switch. The problem with that arrangement was that it was easy (on some models) to produce a 'setting' that could give an erroneous measurement - or even seriously damage the meter - for example, inadvertently setting a low current d.c. range but then applying a high voltage to the test prods. Ouch!
Al. / June 20, 2013.