To connect 4 wire (kelvin) probes to an handheld LCR some kind of adapter is usually necessary. The adapter allows to reach the contacts inside the instrument slots used to insert the tested component leads.
Obviously, to be able to connect a kelvin probe, LCR must provide 4 wire measurement method (i.e. the 4 signals are abailable inside the lcr slots). All bench LCR make kelvin measuremnts, but handheld LCR sometimes not. An example is the Keysight U1730C series.
User Voltlog designed a very nice adapter pcb for Hantek LCR meters, it can be bought on tindie.
I derived from his project a version suitable for other LCR models. I have also foreseen the way to mount the capacitors necessary to execute measurements on batteries.
The LCR adapter PCB is designed for theese LCR models:
- MCP BR2832
- B&K Precision 878B / 879B / 880
- Tonghui TH2822A / TH2822C / TH2822D / TH2822E
- Eucol U822,
- Sourcetronic ST2822/ST2822A/ST2822C
I have no information regarding other models. You can check compatibility to your model by comparing your LCR slots (or LCR original probe adaper) with the provided dimesions and pad signal description.
Use examples
The adapter can be used to connect many different types of probes:
- Kelvin clips
- SMD kelvin tweezer probe
- double contacts kelvin pobes
I designed theese DIY probes for battery impedance measurements, are available on my Tindie store.
- single contact "Tester" probes
(note: the 4 wires are connectet on the back of the probe pins)
Use for battery measurements
When using probes to measure battery internal resistance or impedance with the LCR, it is necessary to insulate the instrument from the battery voltage and avoid to damage the LCR. The PCB is provided for mounting of 2 electrolitic capacitors to perform this insulation.
Suggested values:
- C1 470uF
- C2 2.2 uF
When capacitor are not installed the pads shall be short-circuited.
Case
A case to be 3D printed is under development
How to get one
You can order the PCB from my Tindie store.