Thanks for this great video! I've wanting to see inside one of these for years. A much older and more sensitive variant of this is the quadrant electrometer.
Never heard of or seen an *electrostatic* voltmeter before, very interesting. Only knew about the electromagnetic kind. Definately learned something today. :)
thank you for the great video , very informative! I just got one of these rated at 6kv and .5 accuracy (11pf) freq. range 750khz standardized by i assume the same Louis Miller on 8/28/68. I love it!!
I would bet that the old capacitance measurement was at a different frequency and amplitude than your fluke uses, and may have included some leads. I really really distrust the flukes for much more than measuring run/start capacitors for motors. (you also want a 4-wire ohm meter for this sort of work) if you have a function generator you can construct a much more accurate LCR meter on your bench than the fluke provides. (graph that function, the TI89 is a graphing machine!) I used a similar exponent hack on my 89 when I was in school too. Thanks for showing us this. Really neat device.
Very cool, zero idle power. (or at least too tiny to care) I like it the fact that the electric energy(not power)/charge holds the needle up, and will be returned when the voltage does down.
I'm really excited about such a simple replicatable device for reasonable hv readings. Not even any need to switch any dials to go from ac-dc. You could make one with foil, a neddle and a magnet (mag+needle bearing)
How did Alexandra Volta measure the voltage of his voltaic piles, Or Dr Georg Ohm? What devices could measure the voltage of batteries at the period of time?
One of these was dropped in our lab. Considerable disassembly revealed that the connection between the coiled spring and moving vane had snapped. I suppose it's worth a try to re-solder it (silver solder/braze?) but then what :) Likely calibration is totally shot just from disassembly alone. Do you know what the spring material is? Suspect that the moving vane pivot points are probably no good now that I've removed these from their two housings. This one is dated May, 1949!
HI i have a sensitive research instument corp. elecrostatic 300 volt ,voltmeter and i wanted to know is there a newer type of probe wand to test it that will work without damaging the meter? as finding an origional probe is kind of hard. can you make a sugestion on what type to buy? thanks Richard
My 2K Electrostatic Meter has 1X10^15 insulation resistance. Is that what your meter has? I thought you said your meter was 200 Mega Ohm. That seems too low. Did I hear that correctly? By the way, Mine was also certified by Louis Miller.
There is a big difference between Insulation Resistance (DC) and Impedance (AC). The impedance calculations he presented were just the effect of the capacitance at different frequencies.
Wow - they REALLY don't make 'em like this anymore! Such a nice movement - too bad you destroyed it probing around like that XD (I'm just pulling your leg, but I saw it coming!) Thank you for this - it really IS a gorgeous unit, based off a very very old concept. What materials are the rotor and stators made from? (no oxidation seen anywhere within..)
These days you can get "meggers" that put out 2500 or I believe even 5000 volt - should be able to get an idea of how accurate it is. I have no idea how precise they are but I have a 500v one and it seems very accurate (sure 500v is easily measurable by modern multimeters). I even used it to get an idea of how accurate an electrostatic field-meter I stumbled upon was. Seems to work(!) at least for the (very) low charges.
I have the exact meter but the needle rests on 3000 volts with no voltage applied. The zero adjust screw will swing the movement but only = and - a little as it should. I inspected the spring and it does not look distorted. I can not figure out how to get the needle to rest on zero unless maybe I unsolder the spring and let it unwind one turn. But why would that be necessary? The movement is free to swing from zero to full scale. Any suggestions appreciated. I'm about ready to gut it and install a good standard 3000 volt meter movement in the box. Ron W8RJL
+Ron Young Perhaps someone was trying to measure some high voltage RF, in which case, the spring might conduct an appreciable amount of current and overheat. Readjusting the spring would get it back to zero, but then the meter reading may become inaccurate.... or it could become 100% back to normal. It's worth a try.
+Eric Wasatonic After much head scratching I removed the two screws that hold a cross bar on the meter movement. Once I got the cross bar off with spring and needle stops I realized the spring was not connected on the pivot rod. It was apperently snagged thus making it look like it was connected but was broken at the solder point. I will attempt to solder the inner most end of the spring to the shaft. It will be like brain surgery. If I succeed I will have a great HV bench meter. It I fail I will gut the box, cut a new blank plastic panel for the front, cut a circle in the panel and install a standard meter, maybe a 0 - 4,000 volts DC meter. In any case I only paid 25 cents for the meter so I got my moneys worth. Thanks for your video and comments.
Using tweezers, magnification, and a small soldering iron tip I was able to remove the spiral spring, tin the inner end (the one that broke off), solder the inner end to the pivit rod then solder the outer end to the zeroing connection point. During that process the spring was dropped a couple times and first time was as soldered 180 degrees out. The meter is now all back together, needle rests at zero and the zero adjustment works just fine. All I have to do now is get out my HV source and another reference meter to check accuracy. Without your youtube video I would not have been able to bring this vintage beauty back to life. Thank You!
Thanks for this great video! I've wanting to see inside one of these for years. A much older and more sensitive variant of this is the quadrant electrometer.
Eric Wasatonic wow, what a beautiful piece of engineering, thank you for sharing!
Wow, Wonderful Vintage Tech.
Never heard of or seen an *electrostatic* voltmeter before, very interesting. Only knew about the electromagnetic kind. Definately learned something today. :)
thank you for the great video , very informative! I just got one of these rated at 6kv and .5 accuracy (11pf) freq. range 750khz standardized by i assume the same Louis Miller on 8/28/68. I love it!!
I would bet that the old capacitance measurement was at a different frequency and amplitude than your fluke uses, and may have included some leads. I really really distrust the flukes for much more than measuring run/start capacitors for motors. (you also want a 4-wire ohm meter for this sort of work) if you have a function generator you can construct a much more accurate LCR meter on your bench than the fluke provides. (graph that function, the TI89 is a graphing machine!) I used a similar exponent hack on my 89 when I was in school too.
Thanks for showing us this. Really neat device.
Thanx for this one!! Looking forward, to see part two -MeterAction ;)
TubiCal Going up next Friday!
Wow. What an amazing bit of gear. You have me thinking about making one now.
Very cool, zero idle power. (or at least too tiny to care)
I like it the fact that the electric energy(not power)/charge holds the needle up, and will be returned when the voltage does down.
Erlend Ervik Yes, but I wouldn't even be concerned about how many nanojoules that works out to be.
I'm really excited about such a simple replicatable device for reasonable hv readings. Not even any need to switch any dials to go from ac-dc.
You could make one with foil, a neddle and a magnet (mag+needle bearing)
How did Alexandra Volta measure the voltage of his voltaic piles, Or Dr Georg Ohm? What devices could measure the voltage of batteries at the period of time?
One of these was dropped in our lab. Considerable disassembly revealed that the connection between the coiled spring and moving vane had snapped. I suppose it's worth a try to re-solder it (silver solder/braze?) but then what :) Likely calibration is totally shot just from disassembly alone. Do you know what the spring material is? Suspect that the moving vane pivot points are probably no good now that I've removed these from their two housings. This one is dated May, 1949!
HI i have a sensitive research instument corp. elecrostatic 300 volt ,voltmeter and i wanted to know is there a newer type of probe wand to test it that will work without damaging the meter? as finding
an origional probe is kind of hard. can you make a sugestion on what type to buy? thanks Richard
Thank You...this video was really helpfull
That's a very interesting design.
Don't see any of that in products today.
My 2K Electrostatic Meter has 1X10^15 insulation resistance. Is that what your meter has? I thought you said your meter was 200 Mega Ohm. That seems too low. Did I hear that correctly? By the way, Mine was also certified by Louis Miller.
There is a big difference between Insulation Resistance (DC) and Impedance (AC). The impedance calculations he presented were just the effect of the capacitance at different frequencies.
This is quite a coincidence. I have an electrostatic meter just like that and then you showed your Fluke meter and I have one just like it too.
Wow - they REALLY don't make 'em like this anymore! Such a nice movement - too bad you destroyed it probing around like that XD (I'm just pulling your leg, but I saw it coming!) Thank you for this - it really IS a gorgeous unit, based off a very very old concept. What materials are the rotor and stators made from? (no oxidation seen anywhere within..)
Does anyone recognize this meter?
These days you can get "meggers" that put out 2500 or I believe even 5000 volt - should be able to get an idea of how accurate it is. I have no idea how precise they are but I have a 500v one and it seems very accurate (sure 500v is easily measurable by modern multimeters). I even used it to get an idea of how accurate an electrostatic field-meter I stumbled upon was. Seems to work(!) at least for the (very) low charges.
I have the exact meter but the needle rests on 3000 volts with no voltage applied. The zero adjust screw will swing the movement but only = and - a little as it should. I inspected the spring and it does not look distorted. I can not figure out how to get the needle to rest on zero unless maybe I unsolder the spring and let it unwind one turn. But why would that be necessary? The movement is free to swing from zero to full scale. Any suggestions appreciated. I'm about ready to gut it and install a good standard 3000 volt meter movement in the box. Ron W8RJL
+Ron Young Perhaps someone was trying to measure some high voltage RF, in which case, the spring might conduct an appreciable amount of current and overheat. Readjusting the spring would get it back to zero, but then the meter reading may become inaccurate.... or it could become 100% back to normal. It's worth a try.
+Eric Wasatonic After much head scratching I removed the two screws that hold a cross bar on the
meter movement. Once I got the cross bar off with spring and needle stops I
realized the spring was not connected on the pivot rod. It was apperently snagged thus
making it look like it was connected but was broken at the solder point. I will attempt to solder the inner most end of the spring to the shaft. It will be like brain surgery. If I succeed I will have a great HV bench meter.
It I fail I will gut the box, cut a new blank plastic panel for the front, cut a circle in the panel and install a standard meter, maybe a 0 - 4,000 volts DC meter. In any case I only paid 25 cents for the meter so I got my moneys worth. Thanks for your video and comments.
Using tweezers, magnification, and a small soldering iron tip I was able to remove the spiral spring, tin the inner end (the one that broke off), solder the inner end to the pivit rod then solder the outer end to the zeroing connection point. During that process the spring was dropped a couple times and first time was as soldered 180 degrees out. The meter is now all back together, needle rests at zero and the zero adjustment works just fine. All I have to do now is get out my HV source and another reference meter to check accuracy. Without your youtube video I would not have been able to bring this vintage beauty back to life. Thank You!
+Ron Young I'm glad you were able to fix it. It is a remarkable instrument.