Outdoor Microphones are for permanent outdoor use and are encased in stainless steel units that can withstand all weathers year after year e.g. in airport noise monitoring systems.
Perching birds and their excreta can seriously distort measurements or even overload the measurement equipment. Smaller birds have actually been known to nest on top of the earlier three-pronged anti-bird spikes. Hence, the introduction of the fourth, centre prong.
Two versions are available: one with the measurement direction pointing upwards (0° incidence, for airport noise monitoring) and one with the measurement direction in the horizontal plane (90° incidence, for community noise- or traffic noise measurements).
| Type | 41AM | 41AO | ||
| Sensitivity (unified)[mV/Pa] | 50 | 50 | ||
| Dynamic range [dB] | 20-136 dB re. 20µPa | 20-136dB re. 20µPa | ||
| Frequency response | Type 0 for both: IEC 60651 and ANSI S1.4-1983 | Type 0 for both: IEC 60651 and ANSI S1.4-1983 | ||
| Power supply [VDC] | 12-18 | 12-18 | ||
| Cal. lvl of electro-static actuator | 90dB at 1000Hz | 90dB at 1000Hz | ||
| Outside connector | 6-pin LEMO | 6-pin LEMO | ||
| Pole adapter | 50mm (1.97'') G 1½'' (ISO 228/1) | 50mm (1.97'') G 1½'' (ISO 228/1) | ||
| Reference direction | 0° (vertical for airport noise) | 90° (horizontal for community noise) |