Wall Mounted Sound Level Meter 30‑130dB 11in Multifunctional 4 in 1 Digital Display Decibel Meter for Classroom Item Type: Wall Mounted Sound Level Meter Material: ABS Display Method: LED Screen Atmospheric Pressure: 12.5 PSI- 15.4 PSI Sampling Time: 1.5 S Detection Temperature Range: -10℃-50℃ Storage Temperature: -10℃-60℃ Operating Environment, Storage Humidity: 20%-85% Detection Humidity Range: 20%-85% (Accuracy: 5%) Charging: 1000 mA 5V DC Battery : 1 x 18650 2000mAh (shipped with built in battery) Unit: dBA Measurement Range: 30-130dBA Accuracy: ±1.5dBA Frequency Range: 50Hz-8.5kHz Frequency Weighting: A Screen Display: 0.1 dBA Sound Meter Level (Unit dB): Green 1: 55.0 or less Green 2: 65.0-55.0 Orange1: 75.0-65.0 Orange2: 85.0-75.0 Red1: 95.0-85.0 Red 2: 95.0 or more Temperature Rating (unit ℃): Green: 20-30 Orange: Below 20 Red: Above 30