Designed for use in permanent, semi-permanent or portable noise-monitoring systems.
- Permanent noise-monitoring systems
- Semi-permanent noise-monitoring systems
- Portable noise-monitoring systems
- Noise measurements in most humid and corrosive atmospheres
The impedance matching tube system comprises four tubes of specific lengths. The test sound source consists of two miniature loudspeakers and a transmission tube which feeds the signal to a point below the mouth of the probe tube. Weatherproof Microphone Unit Type 4184 is for use in permanent, semi-permanent or portable noise-monitoring systems.
The unit can be used in most humid and corrosive atmospheres as the casing is made completely of stainless steel and it has a built-in protection system against humidity. Type 4184 complies with standards IEC 651 Type 1 and ANSI S 1.4-1983 Type 1.
The greatest attribute of Type 4184 is its excellent omnidirectional characteristics. It is fully rotational about its vertical axis without any undesirable reflections from its casing affecting the noise measurements being undertaken.
Type 4184 is based on a probe tube system which has allowed the microphone cartridge to be installed within the casing of the unit itself. This ensures that the microphone is afforded rain protection according to Standard IEC 529 IP44.
Each Type 4184 is individually calibrated and is delivered with a calibration chart giving the frequency responses.
- Probe (0.3")
- Dynamic range
- 27 – 140 dB
- Frequency range
- 20 – 20000 Hz
- Inherent noise
- 27 dB A
- Lower limiting frequency -3dB
- 4 Hz
- Ext polarized
- Polarization voltages
- 200 V
- Pressure coefficient
- -0.006 dB/kPa
- 12.5 mV/Pa
- Temperature coefficient
- -0.005 db/ºC
- Temperature range
- -10 – 50 C
- Sound field
- Input type
- Microphone type