Test & Measurement: Portable In-Circuit Tester Measures Capacitor ESR And DCR

A 9-V battery or an optional ac wall adapter can power the Model 881 portable in-circuit equivalent-series resistance (ESR) and dc resistance (DCR) capacitor tester. It measures ESR and DSR from 0.1 to 30 Ω over a capacitance range of 0.47 to 2200 µF. A three-color front-panel chart shows readings of good, fair, and bad. The tester automatically calibrates the internal signal, and its 15-mV 100-kHz p-p output sine-wave test voltage won't turn on any solid-state devices. It has a one-handed tweezer test probe as well. The 881, including a user manual, 9-V dc battery, and tweezer test probe, costs $199.