Pneumatic horns are used wherever extremely loud signalling is required and there is no available power supply. One possible application is in railway track construction to warn personnel of approaching trains. Since the signal has to travel long distances, the maximum volume of the PH1 pneumatic horn of 135 dB(A) is very suitable for such applications. The horn is made with sturdy, corrosion-resistant materials for rugged operation with the use of compressed air or gasses. The pressure needed at standard setting ranges from 2 to 12 bar. The air consumption at such setting is approximately 5 litres/second. Magnetic valves are available as accessories for electric activation of the device.