The meter in the photographs was made by Weston Instruments, likely in the late 1950's, in New Jersey. I grew up there, and got my BSEE from Newark College of Engineering (now part of NJIT). Edward Weston was a major benefactor of the college; the main building was Weston Hall (which may actually have been the original home of Weston's company). That is almost certainly a moving-coil movement; I don't think Weston made moving-iron, as their meters were high-end and high quality. I probably have a couple in my basement (bought surplus in the '50s or '60s).
As a former South Floridian who routinely went wading in the Everglades on fishing trips, this advice: Alligators are fine, unless it's a momma guarding the underground nest. Otherwise they don't bother you if you don't bother them. Watch out for the crocodiles, though; THEY are NASTY (as are the water snakes).
@JGrubbs: Max: If you are going to print the faceplates for the meters take a look at "Meter" and "BasicMeter" software from Tonne Software. BasicMeter is free and Meter is $35. You can download the manual from their website.
Hi there -- I just checked into the hotel in Sao Paulo for ESC Brazil -- I'm up to my armpits in alligators at the moment -- but I will look at these apps as soon as I get a free moment.
@traneus ... " it dissipates 4 watts at fullscale deflection"
Sounds about right. We use cheap moving iron meters for battery monitors in our radio sites. The voltmeters are 15V fsd and run around 12-14V all the time. The bare meter sensitivity is around 2-3V I think, so they have a high wattage multiplier resistor built in. After a few years of service the plastic faceplates go brown because of being in proximity to the hot resistor for so long. BUT I've never yet seen one go wrong!
PS - keep your meter under lock and key, Max'll be after it for his projects!!
I have a moving-magnet center-zero DC meter made probably before 1920, likely before 1900. The meter has three terminals connected to two windings (one terminal is common to both windings): a low-resistance, few-turns winding for current measurement, and a high-resistance, many-turns winding for voltage measurement. The meter is so insensitive that it dissipates 4 watts at fullscale deflection! The voltage winding measures 30 ohms, and gives fullscale deflection at 11 volts DC. Perusing an electrical-equipment textbook copyright 1891, showed this was reasonable at that time.
Max: If you are going to print the faceplates for the meters take a look at "Meter" and "BasicMeter" software from Tonne Software. BasicMeter is free and Meter is $35. You can download the manual from their website.
@traneus this is true, but only if the basic meter movement is of the moving-coil type. If it is moving iron, forget it. it will either have a coil of thick wire if it is an ammeter, or of thin wire and probably a multiplier resistor too if it is a voltmeter, but even if you take the multiplier resistor out you will have a fairly insensitive meter, needing a fainr bit of current for FSD. Most AC ammeters are of the moving iron type, they are cheap to produce and rugged.
Max, don't give up on those AC meters. Most AC meters will read DC, though may be nonlinear. near zero. For your custom-scale purposes, that might be OK.
While you have the scale plate off, check the internal wiring of the meter. Many AC meters are actually rectifier-driver DC meters.
High-voltage meters usually have external or internal "multiplier" resistors in series with a low-voltage low-current movement. Many high-current meters have low-resistance current shunts in parallel with low-voltage, low-current movements.