... 2) Atmospheric pressure: 86kPa - 106kPa3) Relative humidity: 10% - 90% 4) Noise: <60dB 5) Temperature: -10°C - 40°C TECHNOLOGY STANDARDS1) ... loss: ≤0.5dBNOTICE1) Meter should work in ventilated and clean surrounding. Be away from rain, sun,high temperature, dust, alkali, acid ... telephone lines to avoid lightning strike 3) The meter is a precision electronic instrument, please don't assign, take apart ...