Product Type 4137 Diameter inch 1/2 Optimised Free-field Standards J, L Nominal Open-circuit Sensitivity mV/Pa 31.6 Polarization Voltage V 0 Optimised Frequency Response Hz 8 to 12500 Dynamic Range with Preamplifier Type dB(A) to dB 15.8 to 146 (2642) Inherent Noise dB (A) 14.2 Capacitance pF 12 Venting Rear Lower Limiting Frequency (-3 dB) Hz 1 to 5 Operating Temperature Range ºC - 30 to 125 Temperature Coefficient dB/ºC + 0.005 Pressure Coefficient dB/kPa - 0.021 Preamplifier Included No