Sound Level Meter. SPECIFICATIONS: Sound-Level Range: 44 to 140 dB. Weighting: A, B, and C weighting in accordance with American Standard ASA S1.4-1961 and IEC Publication 123, 1961. Microphone: Omnidirectional, lead-zirconate-titanate ceramic unit. Output: At least 1.5 V behing 20k ohms when meter reads full scale. Meter: Rms response, and fast and slow meter speeds in accordance with ASA S1.4-1961 and IEC Publication 123, 1961. Power Supply: One 1.5 V size C flashlight cell. Battery life approximately 35 hours for 2h/day service. Includes manual and carrying case. Please contact On-Site Instruments using form provided for more details.