MT-901A Portable LCD Digital Sound Level Meter Noise Detector Tester Data Decibel Measurement 30-130dB Condition: Item Type: Sound Level Meter Material: ABS Color: As shown in the picture Applicable standard IEC61672-1 category 2 Accuracy ±1.4 dB Frequency range 31.5Hz~8KHz Dynamic range 50 dB Measurement level range 30dB〜130dB Frequency weighting dB Microphone 1/2in electret capacitor Display 3 1/2 digits Resolution 0.1 dB Data update 0.5 seconds Maximum hold Maximum value Minimum hold Minimum Screen lock Hold Auto Power Off The meter automatically turns off after about 30 minutes. Inactive for 15 minutes. Power supply 1 x 9V battery, 006P or IEC 6F22 or NEDA 1604 (not included) Battery life At least 30 hours Operating conditions -20℃〜60℃,10％RH〜90％RH Storage conditions -20℃〜60℃,10％RH〜75％RH Size(L x W x H) 144x55x38mm / 5.7x2.2x1.5in Weight 90g/3.2oz