Short Locator Meter
In the market there are many company selling a short locator meter. EDS82B Leakseeker from Electronic Design Specialist is one of them. Here’s the excerpt from the website about this meter:
Wouldn’t it be great if leaky or shorted parts just lit up and whistled at you?
Well, guess what … The LeakSeeker 82 from EDS Can guide your right to the culprit with whistles and flashing lights!
Shorted or leaky components in a circuit can be difficult to locate because your ohmmeter will show the same shorted or low reading at every pad along the suspected trace. You’ve probably wished for a better way to find these defective parts in-circuit, rather than cutting up the trace into segments and unsoldering and checking every suspicious part in each segment.Sure, you can use an expensive 6 digit DVM with a milliohm range and compare readings at different pads, looking for the pad with the lowest reading. This is time consuming and only works for dead-shorted components, because the meter’s resolution isn’t high enough for values beyond a few ohms. Also, you would have to keep remembering and comparing all of the readings. Also, no DVM will even register on an active short because their test voltages aren’t high enough. Ever had a shorted vertical chip on the other side of a diode? Notice that the DVM won’t show the short in the 24 volt power supply because it won’t bias the diode forward.
EDS has the better mousetrap.
Simply touch LeakSeeker’s gold-plated probe on any solder pad along the suspicious trace and LeakSeeker automatically calibrates itself to the resistance of the defect, within a 24 milliohm “window”. Because the test voltage is a current-limited eight volts, it will power through good diodes to activate shorted components beyond. Touch a pad in one direction or the other and LeakSeeker beeps higher or lower and lights the LED distance scale to indicate that you’re getting closer or further from the defect. The 24 milliohm window allows about 2 to 3 inches of pcb trace to be checked, then automatically re-calibrates itself to a new window as you get closer to the short.Because LeakSeeker has a range of zero to 150 ohms, it can locate not just shorted, but leaky parts as well. And unlike your DVM, LeakSeeker’s unique “floating reference” circuitry doesn’t give up resolution at these higher leakage values. Once you’re in the general area of the defect, switch from the AUTO to the LOCK position, High Definition mode. This locks the “window” and increases resolution to 0.1 milliohm, so you can pinpoint the location of the defect within a quarter of an inch, even on multi-layer boards with a power plane instead of individual traces. The currently available LeakSeeker 82B HD has indicators for “standard resolution” AUTO and “high definition” LOCK.The solder pad where the beep is highest is the location of the defect!
There is also a special 3-wire test mode that isolates LeakSeeker’s precision power source from the test circuitry to locate thermally defective leaky components, even when a large electrolytic tries to muddy up your readings. Imagine a piece of test equipment that can find a leaky or shorted component only a quarter of an inch from a good one, both soldered to the same trace, on any kind of pc board, and you have a good idea how much time LeakSeeker can save you. LeakSeeker comes with a special set of gold-plated test clips and probes, a complete manual with a hands-on tutorial, a technical assistance phone line, and a 60-day satisfaction or money-back guarantee.