HNL series 842 Air Horns are for use with HNL’s single and multi-point annunciators or any application where a pneumatic audible alarm is required.
- Choice of 5 frequencies
- 118 dB(A) output
- Readily available
HNL series 842 Air Horns uses a vibrating brass diaphragm together with a thermoplastic (or die-cast aluminium) trumpet to provide a sound output of 118dB(A) at 1 metre from the horn.
Sound levels fall by 6dB(A) each time the distance from the horn doubles (e.g. 112dB(A) @ 2m, 106dB(A) @ 4m, etc).
Different frequencies are available enabling different alarms to be identified by its own unique sound. Alternatively a two tone effect can be achieved by alternating between two different horns, using HNL’s horn modulator DS1054.
HNL series 842 Air Horns are operated from a 0.5 to 1.5 bar pressure supply with air consumption of typically 15 to 30 Nl/min. Higher pressures can also be used if the supply is restricted.
For operation with a 1.5 to 4 bar supply a 2mm diameter restriction should be fitted, for operation with a 4 to 10 bar supply a 1mm diameter restriction should be fitted.
Multiple horns may be used from a single supply to give a wider sound spread. Two horns used in this way will increase the sound output to 121dB(A) at 1 metre.
A restrictor should be fitted in the supply of each horn to ensure that in the event of one horn being damaged the supply pressure to the other(s) will not be affected.
Pneumatic connections are available for 6mm or 1/4” metal, nylon or plastic tubing. In addition connections are available for PVC covered copper tube.
HNL series 842 Air Horns are designed for site mounting; the trumpet should be tilted downwards to prevent dust or water ingress. They can be mounted inside an enclosure provided that venting is sufficient to prevent pressure build up within the enclosure. The end of the horn should not be obstructed (minimum clearance of 25mm).
The sound output of the air horns is high so care should be taken to prevent possible aural damage of operators and other personnel.
HNL series 842 Air Horns are available from AMS Instrumentation & Calibration .