Model 130D22 from PCB Piezotronics is a combined ICP free field response pre-polarized array microphone and preamplifier used for measuring sound pressure levels and frequencies in the audible range. 130D22 also incorporates an SMB connector, provides easy transitions between data-acquisition systems and software setups, and saves time when connecting multiple units, according to the company. If used with data-acquisition systems that have 2 to 20 mA constant current supply, additional power supplies are not necessary. The unit boasts high sensitivity, uses standard coaxial cables, and has optional TEDS capability for traceability. Applications in the aerospace industry include NVH and general acoustic testing.