Multimeter 3rd Hand Probe with Sense

A stable, self-supporting multimeter probe with low thermal mass. An almost negligible voltage drop, low impedance, a separate wire for sense and force, with the sense wire ahead of the force all contributing to very sensitive and responsive measurements of small values.

Print instructions

What you will need per probe:

Printed:
1x Base
1x Upper Arm
1x Forearm

Purchased:
1x multimeter probe tip (3mm in diameter, such as the one in the 3rd photo)
2x M4x18 button head cap screws
2x M4 flat washers
2x M4 hex nuts
2X lengths of 18AWG stranded copper wire
2x female DuPont connectors
1x zip tie
Superglue (CA)
Heat Shrink
Slip resistant material (to adhere to the bottom of the base)

Tools:
Allen wrench
Spanner
Soldering iron & solder
DuPont crimper
Wire stripper
Flush cutters

Building considerations:

The build should be very straightforward and quick. Attention should be payed to the quality and placement of the solder joints of the force and sense wires onto the tip, and done as shown in the photos. The sense wire is placed closer to the tip than the force wire, and marked on the base for easy and consistent use. The two bolted joints should also only be tight enough to not wobble. They are intended to not have any resistance so that the probe can fall under its own weight to make good contact. I placed a drop of superglue into the nuts after tightening appropriately. A drop of glue should also be used to hold the DuPont connectors into the base.