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Measuring EHT, high voltages

N

N_Cook

Jan 1, 1970
0
I usually use a 1000:1 divider with 300M ohm loading but I notice my other,
bigger Tektronix one, is 100 Meg. Is there a standard impedance for
monitoring the output of self-contained generators that may be used in
anything requiring high voltages.

The 40KHz one in front of me is 33V dc supply and label says 5.55KV , 0.3mA
output, but to measure that and state for general purpose use, there must
surely be some standard load for the monitoring.
 
S

Shaun

Jan 1, 1970
0
N_Cook said:
I usually use a 1000:1 divider with 300M ohm loading but I notice my other,
bigger Tektronix one, is 100 Meg. Is there a standard impedance for
monitoring the output of self-contained generators that may be used in
anything requiring high voltages.

The 40KHz one in front of me is 33V dc supply and label says 5.55KV ,
0.3mA
output, but to measure that and state for general purpose use, there must
surely be some standard load for the monitoring.

The frequency of the generator will probably be the determining factor for
what probe you can use, Many probes available are rated for 60Hz and the
accuracy goes way down as the frequency increases, it has to do with self
capacitance and capacitance to ground. This in assuming it's an AC supply,
if it's DC filtered supply then you can disregard my above comments and a
probe made for measureing DC high voltage will be fine. The 100 Mohm or 300
Mohm will not matter in your case, your probe will not LOAD down the
generator. 300 Mohms is only going to load it to 18.5 microamps and 100
Mohms will load 55.5 microamps; you supply is 0.3 mA or 300 microamps.

Shaun
Electronic Technologist
 
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