I purchased the multimeter pictured below for a high voltage power supply I'm working on. It's rated for 100V DC and 10A, but I hope to measure several thousand volts. Is it possible to use a HV voltage probe like I would use with a regular multimeter on this component, or no? Voltmeter/Ampmeter gauge


No. Those cheap meters use a voltage divider adding up to around 280-290K and go directly into an 8-bit MCU (STM8 series).

Typical high voltage probes assume a reasonably accurate 10M\$\Omega\$ input impedance for the multimeter- something like 999M in series with 1.11M (internal divider values), so it would read grossly low on this kind of an input.

  • \$\begingroup\$ It would be highly impractical to manually account for a very uneven correction factor, but OP would be able to feed it higher voltages than before :-) \$\endgroup\$ – winny Jan 8 at 7:35
  • \$\begingroup\$ @winny but only once, I guess. \$\endgroup\$ – Spehro Pefhany Jan 8 at 7:36
  • \$\begingroup\$ How come? The probe division should take the majority of the voltage. \$\endgroup\$ – winny Jan 8 at 8:37
  • \$\begingroup\$ @winny If it's rated for 40kV but only outputs roughly 1/3 the voltage, connecting it to a 120kV source might not be wise. ;-) \$\endgroup\$ – Spehro Pefhany Jan 8 at 12:36
  • \$\begingroup\$ Of course! Hence correction factor! \$\endgroup\$ – winny Jan 8 at 13:27

Only if the input impedances are the same to form a voltage divider.


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