Sencore LC 101 Z meter problem.

[Ray Decoteau]

I have a Sencore LC 101 Z meter and have the same question that was
asked here a couple of years ago. I searched the groups and didn't
find the answer.

While testing a capacitor in leakage mode, I'm wonering why the
voltage applied to the cap, when read with a DVM is less then half the
value shown on the meter. The low voltage ranges are fine.. but after
you get to about 15 volts the voltage is way to low. For example it
reads about 348 volts when set on the 1000 volt range.

Also, I have a newer LC77 Z meter and it works fine in all ranges. I'm
wonder if sencore changed the way the meter works.

I'm asking because this question was asked before.. and wondering if
the voltage on the older meters is not pure dc but perhaps an ac
waveform

Thanks in advance for any information.

Ray

 

[Jim Adney]

While testing a capacitor in leakage mode, I'm wonering why the
voltage applied to the cap, when read with a DVM is less then half the
value shown on the meter. The low voltage ranges are fine.. but after
you get to about 15 volts the voltage is way to low. For example it
reads about 348 volts when set on the 1000 volt range.

Is it possible that your voltmeter's input impedance is rather low,
and is pulling down the Sencore voltage? I wouldn't be surprised if
the Sencore's voltage source output impedance is rather high. It's
also possible that its output impedance goes up as its output voltage
goes up.

This would explain what you're seeing. Try measuring the voltage with
a high impedance meter.

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