Plug for capacitance measurements with DMM

thingiverse

Use this adapter to conveniently measure an unknown capacitance with a digital multimeter that supports C-measurements. I own one of these DMMs which can measure capacitance but only provides two contacts in the middle of two tiny slots for that. This is okay for many standard capacitors, but not for unusually small or large pin distances and most variable capacitors. Tired of fiddling around with individual wires, I decided to create a plug which holds some contacts in place and fits into the DMM. Two wires with alligator clips on the other end are soldered to these contacts inside the plug. With these clips any type of capacitor can easily be accessed. First 3D-print the plug. There are two tiny slits in the plug through which you have to insert the contacts. The contacts are 5 mm wide and about 0.5 mm thick. I used a 0.2 mm brass foil that I cut to size (42 mm long) and folded once. The contacts should stick about 10 mm out of the plug. Next remove the contacts again and solder some wire of your choice to them. Insert the contacts again into the plug. They should be a tight fit. Double-check that the soldered part is not higher than the surrounding walls of the plug. Finally, secure the contacts by filling the two holes in the plug with epoxy resin. You can improve the design by coloring the resin to match the color of the 3D-print. As the plug and especially the wires introduce some capacitance to the system, it's very important to perform the zero adjust with the plug attached to the DMM and the wires more or less in the same position as they will have during the following measurement. Print Settings Printer: BQ Hephestos Rafts: Doesn't matter Supports: No Resolution: 0.2 mm Infill: 20%