Digital frequency meter PD7194F-2X1 HZ meter X-Series digital power measurement table: Suitable for power grids, automation ... of current, voltage, frequency, power, power factor and with high accuracy, good stability, anti-vibration can be directlyinstead ... failures: ≥ 50000HWorking conditions: -25 °C ~~ 55 ° C ambient temperature, relative humidity ≤ 93% No corrosive gasAltitude: ≤ 2500M