Housed in prepolarized package, ½ in. Model 378A04 enables test engineers to measure extremely low sound pressure levels. Free-field microphone has built-in filter that ensures sensitivity is stable and accurate between 10 Hz and 16 kHz. Sensor is used with data acquisition systems that provide 4–20 mA of constant current. Using common coaxial cables with BNC connectors, Model 378A04 is suited for measuring appliance noise, electric car sound quality, environmental noise, and cabin noise.