Larson Davis, a division of PCB Piezotronics products

The Model 831-INT provides the 426A12 outdoor microphone with both electrical power and control commands for its electrostatic actuator, temperature and humidity readout. The Vaisala WXT520 (SEN031) weather sensor is connected to the Model 831-INT for wind speed and direction, temperature and humidity, barometic pressure, rain and hail.