The outdoor microphone are designed for permanent installation in the field, for example airport noise monitoring or industrial plant noise monitoring. It includes anti-bird spikes, a windscreen and a rain cover, all of which are integral parts of the acoustic omnidirectional characteristics offered by the system.

The rain cover contains an electrostatic actuator enabling a precise in-situ calibration at 1000Hz from the internal sine wave generator. Optionally, the complete frequency response may be calibrated using an external generator. A special adaptor allows acoustic calibration.

The microphone diapragm and housing are made of stainless steel to withstand pollution and corrosion. The microphone cartridge is a ½” type with 200V polarisation voltage. The unit comes with a built-in A-curve spectral weighting network in addition to Flat response (no spectral weighting at all) and a 0 or ±20dB amplifier – all set by internal jumpers. An internal heating system is provided to avoid condensation. The output amplifier is a low noise type designed to drive long cables. The microphone is delivered in two versions: Nor1210A, for airport noise monitoring (0° i.e. vertical incidence) and Nor1210C for community or traffic noise monitoring (90° i.e. horizontal incidence)

Both versions are PTB (Physikalisch Technische Bundesanstalt, Germany) approved as part of an IEC 60651 type 1 system. Both versions also comply with ANSI S1.4. The reason for having two versions is that the reference direction (IEC 60651) should be vertical for aircraft monitoring and horizontal for traffic noise monitoring. Norsonic have complete environmental noise measurement solutions for every application, ranging from portable battery powered weather-proof cases up to large airport noise monitoring systems.

Frequency response Nor1210A

Technical Specifications: