Voltage Frequency Meter, Yeeco AC 80-300V 45-65.0Hz LCD Display Digital AC Voltage Frequency Meter Frequency Counter Tester Gauge Monitor Panel

Voltage reading accurate. Frequency off by 1-1.5 hz. Expected to much I guess. Using it as a verification for house backup generator. It's monitoring power line 99.9% of the time and generator when power company fails. As long as I know how far it's off when on the power company I can watch for any generator deviation. Shame a simple freq. counter is so hard to build or buy... Don't buy a digital clock from these people or you wouldn't make it to work on time.

two wire connection . Ran two wires to voltage meter and tie in to existing .

I'm using it to monitor voltage and fequency of electricity from a generator after my kill-o-watt was giving questionable frequency readings. So far it has worked great, readings are accurate, display is nice and easy to read, and draws negligble power

Used this for a 1960s military generator hooks up to the 2 wires the old mechanical gauge was attached to Only used it once or twice so far but worked perfect

Not useful to monitor frequency

Voltage readings were accurate. Frequency readings were off (low) by 2 to 2.5 cps and would wander up-down by .5 cps. Not near good enough when you figure that utility Hz varies by about one-tenth cps unless something is really wrong. Maybe just the one I got but worthless as a frequency meter.

its ok

has a bright blue light display and it let us know the hertz our generator is putting out