OT: Old high school physics lab meters

Some gneeral comments... A good instrument remains a good instrument in many cases. A meter tyhat was good to <1% can be recalibrated and will still be a useful measuring instrument. Soemthing like one of the old potentiometers (I don't mean a 3 terminal variable resisotr, I mean the manual mull-point voltmeter) or measuring bridge is still a very useful thjing to have. In many cases the only advantage that the latest replacemetn gives you is more rapid readings. Which may not matter. I think we all know that just because something is old does not mean it's useless. There si nothing wrong with single-function instruments. I am reminded of a comment in the 'Radio Laboratory Handbook' (M. G. Scroggie). : 'Remember than any instrument, no matter how versatile, can only be in place place in the circuit at any one time'. So while a multimeter is very useful, plain voltmeters, ammeters, etc are also useful. There are also some more specialised meters that turn up occasionally. A moving coil wattmeter is quite a fun thing to have. So is a spot galvanometer (which will measure down to fractions of a microamp in many cases, somethign that nor all DMMs will manage). A ballistic galvanometer, used to measure charge, can be useful. As can electostatic voltmeters. The problem is that these things do not often turn up in school labs. Alas, a lot of school physics equipment (stuff made specifically for schools) was and is cr*p. I bitterly remember some of the stuff we had to sue at school, things like a 'scope with a 2" screen and a continuously variable Y attenuator with approximate calibration markignso n the panel. Fine for seeing a wiggly line, useless for actually measuring anything. Meters that had linearity errors (!) of about 10%. And so on. There are certainly people who collect (and use) old high-quality measuring instruments. I suspect the market for poorer quality ones is a lot less. They might be useful [1] but I doubt anyone will pay a lot for them. I cna;t beleive there's much a of a 'nostalgia market' for them either. [1] For example, if you have a complex analogue device (sauy a radio receiver) that has a naster intermittant fault, you cna connet as many voltmeters as you can find to supply rails, anodes/collectors, etc throughout the device. With it working normally, you note the readings on every meter, or more commonly, just put a mark (chinagraph, write4all, etc) no the meter glass. When it palys up, you cna see what's changeed. You don't need good meters for this, since all you need them to do is show that something has changed. I think I'd want to know a lot more about the instruments in question, brand names, etc. -tony