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I got my hands on a BK880 LCR meter and now it's the second time that I destroyed the device.

It can't hold the measurement voltage - So it always tries to measure with around 0V.

What I am doing is: connect the LCR meter to a pcb which as an analog and digital area. The digital area is powered with 12V and the analog area is measured with an ADC from the digital area. I connect the device to the input of the analog area, but except for the LCR meter I don't put any voltage in the analog area.

The analog area looks like this, where I connect the LCR Meter to FPB-PULSE and GND.

Analog area

I connected the LCR meter to the PC and used at a while, the next day it was damaged.

What could I have done? I switched between the voltages the LCR meter is able to generate while being connected to the circuit, could this destroy the device?

It's the BK 880 device.

After a night loading and fiddling around with the device, I made the following observations:

The testvoltage of the device is not always working - but just not always. When I connect the device after powering it up and change some settings, the test voltage is ok.

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LCR meters can't be used on live circuits. The LCR meter injects its own test voltage or current into the circuit and takes measurements using a sensitive circuit to determine the behaviour of the circuit using that stimulus. From the observed behaviour it estimates the LRC values. By using it on a live circuit you probably damaged the meter's own circuitry.

I switched between the voltages while being connected to the circuit, could this destroy the device?

That would not have been a problem if the circuit had been powered down.

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  • \$\begingroup\$ What I meant with switching voltages is, I changed the testvoltage the LCR meter is able to, while being connected with the cap. I don't see why the circuit should damage the device. It's an ADC input which is the connection to a live circuit, but nothing else is powered in the area the LCR meter is making it's measurements. \$\endgroup\$
    – Eggi
    Commented Feb 5, 2020 at 11:33
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    \$\begingroup\$ Your question says, "The digital area is powered with 12V ..." You might want to edit that and clarify exactly how you performed the test, how you "destroyed" the device, how it was repaired (which suggests that it wasn't destroyed, but damaged). You might also include a link to the user manual of the meter. \$\endgroup\$
    – Transistor
    Commented Feb 5, 2020 at 12:13

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