Permanent Outdoor Microphone with Remote Humidity Sensing Larso A n Indus Davis Exclu try sive! For community, traffic and aircraft noise monitoring Highlights I Use with any electronic sound measurement system Free-field or random incidence response Rugged stainless steel construction Single channel power and signal conditioning 0 and 200 V microphone polarization voltage Electrostatic actuator for calibration check Internal temperature and humidity sensors for desiccant status Bird spikes, rain hat and wind screen Instantaneous overload detection Ability to drive long cables Replaceable desiccant with indicator visible through window Easy access for desiccant change TEDS-IEEE 1451.4 compliant Rugged carrying case Fully supported by the Larson Davis Model 831 sound level meter Typical Model 426A12-FF airport noise monitoring installation. The Larson Davis Model 426A12 Outdoor Microphone has been designed for permanent outdoor use in any weather condition. It is constructed of stainless steel to resist corrosion, and its profile minimizes both wind resistance and acoustic reflections. It includes a rain hat, wind screen and bird spikes and an electrostatic actuator which can be controlled remotely for on-site calibration checks. With the proper choice of microphone, it can provide frequency response characteristics consistent with precision sound level meter requirements for free-field or random incidence measurements. Equipped with A, C and Z-weighting filters and a 20 dB gain, the 426A12 is ideal for use with any electronic sound measurement system. Unattended outdoor installations Environmental noise studies Airport and traffic noise monitoring Industrial and community noise monitoring Complaint investigations IEC 61672 Class 1 compliant outdoor sound measurement A hydrophobic membrane vent and replaceable desiccant cartridges prevent moisture from reaching the microphone through the vent. The saturation status of the desiccant cartridges can be determined remotely using signals from internal temperature and humidity sensors, as well as visually through an observation window. The Larson Davis Model 831 sound level meter is the ideal complement to the Model 426A12 Permanent Outdoor Microphone for Noise Monitoring Systems. Larson Davis

Permanent Outdoor Microphone Electrical Frequency Response Sensitivity Power Supply Frequency Response Z-Weight A-Weight C-Weight A and C-Weight Compared to Z-Weight @ 1 kHz Power Consumption 0 V Microphone Bias 200 V Microphone Bias Operating Temperature Range Operating Humidity Range Acoustical Frequency Response Frequency Range Free-field Response with 377B02 Microphone Random Response with 377B20 Microphone Acoustical Frequency Response Limits with the 250 Hz Level as the Reference Microphone Bias 0 and 200 V (± 2 V), selected using an internal jumper Gain Setting 0 and 20 dB, selected using...