ESR meter with extended scale.

[iet]

Basic information here.
https://electronicsdesignfun.blogspot.com/p/esr-meter.html
The meter is adapted to the tester body.
The front panel contains a zero regulator, a power switch, and a graduated scale. The calibration was done using SMD resistors with low inductance.
Scale: 0.005-5 Ohm.
Some changes have been made to the original scheme.
U1-LM833
Resistors:R4-5.6k,R5,R6-0.1,R8-20k,R11-100k
D1,D2-1N5817
The transformer is wound on a ferrite ring
Supply voltage:9v
Frequency:100 kHz
Vpp:100mV

[enut11]

Interesting adaption for an old analog multimeter. How does the scaling work?

[iet]

How does the scaling work?

The values on the ohms scale of the multimeter are indicated in red.
The ESR values in mohms are indicated in blue.

[iet]

As you know, the ESR of a capacitor can react to the heat of your hands. And the result may not correspond to the actual value. In addition, to obtain the most reliable result, very reliable contact between the probes and the legs of the capacitor is necessary.
Therefore, a simple device was made to install and measure the ESR of capacitors.