Sunday, April 13, 2014

Lower the volume on your Fluke Multimeter in two minutes (literally).

Industrial multimeters are not designed for your quiet and peaceful electronics lab. They are designed for industrial, loud environments.

That said, testing continuity with a Fluke 87V at an electronics workbench can be quite annoying, reason why I decided to lower its volume a little using a simple, quick and reversible method.

Adding a 4.7k Ohm resistor in series with the buzzer will do the trick, setting your volume at a pleasant level.

Open your DMM and this is what you will find: The piezo buzzer contacts the board with springs to these pads shown here:

What you will see now is the back cover, where the buzzer lives. The two springs at the bottom are (-) and the one at the top is (+).
Just fold the leg of your resistor around the (+) spring and raise the other leg RIGHT ON TOP of the spring like this:

Then isolate both the resistor AND the spring with tape. I used Kapton tape as seen here:

Make your final adjustments so the resistor led lays right on top of the little spring. This leg will make final contact with the pad on the main board of your DMM.

Add another tape to on top of the larger portion of the resistor leg and leave the tip uncovered.

Close the cover gently and test your meter.

Done!  If you are fast with your screwdriver, this literally takes two minutes. But take your time...
Best of all, this is 100% reversible, with no permanent modifications to your DMM.

Note: You may have noticed that some photos show 10K resistor while other photos show 4.7K. That's because I started with 10K but then realized volume was too low. 4.7K seems to be perfect for my needs.