The outdoor microphones are designed for permanent installation in the field, for example airport noise monitoring or industrial plant noise monitoring. A typical outdoor microphone system 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 diapraghm 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:

• Nor-1210A , for airport noise monitoring
  (0° i.e. vertical incidence)

• Nor-1210C for community or traffic noise monitoring
  (90° i.e. horizontal incidence)

Sensitivity: All units adjusted to 50mV/Pa
Frequency Response: IEC 60651 Type 1 and ANSI S1.4-1983 Type 1. Individually calibrated re. 1000Hz, 0° (vertical) incidence (1210A) or 90° (horizontal) incidence (1210C):
20Hz-80Hz:±1dB
80Hz-4kHz:±0.7dB
4kHz-8kHz:±1dB
8kHz-12kHz:±1.5dB
12Hz-20kHz:+1.5dB, -5dB
Dynamic Range: Upper limit: >156dB SPL
(at -20 dB setting)
Total System Noise Level: (typical values,
including Acoustically screened microphone)
20dBA (Opt. 17dBA)
23dB Lin. 22.5Hz-22.5kHz
Output Impedance: <50 ohms
Output Current : >25mA
Power Supply: 12-18Vdc. 3W
Power Consumption: 120mA at 15V supply voltage (180mA with actuator calibratoractivated)
Operating Temperature Range: -40°C to +50°C
Calibration Level of Electrostatic Actuator: 90dB at 1000Hz ±0.2dB at 23°C
Dimensions:
Casing: 40mm (1.57 in.), outside diameter
Length: 520mm (20.5 in).
Pole Adaptor: 50mm (1.97 in) G 1½" (ISO 228/1)
Weight: 1.3Kg (2.86lbs)
CE classification, EMC
EMC: EN50081-1, EN 50082-1
Safety: EN 61010-1, 1993 portable equipment pollution category 2
Accessories Included:
Complete Windscreen Nor-1471; Spanner kit Nor-1473; Transport Protection Cap; Plug: LEMO FFA.2S.306CLAC62; Instruction manual
Accessories Available:
Acoustical calibrator adaptor Nor-1470; Foam Windscreen Nor-1472; Poles and tripods; Power supply and calibration box Nor-512

• 0º-incidence version, the Nor-1211A which is intended for aircraft fly-over measurements and other applications where the microphone reference direction should be pointing upwards

• 90º-incidence version Nor-1211C which has its reference direction in a horizontal plane and is intended for measurements of community noise, traffic noise, vehicle pass-by noise etc
  
  

  Technical Specifications:

  Sensitivity:
  50mV/Pa nominal (Individually calibrated)
  Polarisation Voltage: 200V (Non polarised version upon request)
  Frequency Response :
  IEC 60651 Type 1 and ANSI S1.4-1983 Type 1.
  Re. 1000Hz, 90° incidence:
  20Hz - 80Hz ±1dB
  80Hz - 4kHz: ±0.7dB
  4kHz - 8kHz: ±1dB
  8kHz - 12kHz: +2dB, -3dB
  12kHz - 20kHz: +3dB, -oodB
  Dynamic Range:
  Upper limit: >156dB SPL
  Noise Level (typical values):
  A-Weighted: 17dB
  Linear (22.5Hz - 22.5kHz):20dB
  The electrical performance is equal to the preamplifier 1201
  Operating Temperature Range:
  -40°C to +55°C
  Dimensions:
  Casing: 29mm (1.14") outside diameter
  Length: 370mm (14.6")
  Weight: 290g (0.638lbs)
  CE classification, EMC
  EMC: EN50081-1, EN 50082-1
  Safety: EN 61010-1, 1993 portable equipment pollution category 2
  Accessories Included:
  Complete Windscreen N-1471
  3 meter standard microphone cable with Lemo connector N-1408/3
  Other length upon request.
  Dessicator box
  Carrying case
  Instruction manual
  Accessories Available:
  Acoustical calibrator adaptor N-1479
  Foam Windscreen N-1472
  Tripod 1.5 to 5 metre adjustable N-1323
  Microphone cable Nor-1408 on the waterproof version Nor-1475