Noise reduction is now an important consideration in the workplace. The Control of Noise at Work Regulations 2005 (the Noise Regulations) came into force for all industry sectors in Great Britain on 6 April 2006. The level at which employers must provide hearing protection and hearing protection zones is now 85 decibels (daily or weekly average exposure) and the level at which employers must assess the risk to workers' health and provide them with information and training is now 80 decibels. There is also an exposure limit value of 87 decibels, taking account of any reduction in exposure provided by hearing protection, above which workers must not be exposed.
It is therefore in the interests of both employer and employee that, wherever possible, quieter plant is chosen without compromising performance or productivity.
A good example is an air motor. Noise tests have recently been conducted by Huco Dynatork on its air motor range and these are soon to be ratified by independent assessment. The initial results, however, have proved very interesting. They highlight the differences in noise output between a standard piston air motor and a vane air motor. But, more importantly, they identify the Huco Dynatork acetal air motor as a potential noise-saving champion.
A single Huco Dynatork 1 piston air motor running with air pressure at 5.5bar produced 83dBA when measured at a distance of 0.5m; all measurements were taken with the motor exhaust piped away so that the results were not affected by the noise of the exhaust air. In contrast, a typical brand new vane-type air motor with input air pressure at 5.5bar emitted 98dBA, which is well above the 85dBA threshold. Because the decibel is a logarithmic scale, actual noise pressure doubles for every increase of 3dB. This means the actual noise pressure of the vane motor is four times that of the equivalent Huco Dynatork piston air motor.
Measured under the same conditions, the Huco Dynatork 1 acetal air motor produced just 76dBA, which means its noise pressure is 16 times lower than the corresponding vane motor. And this motor is not just economical on noise emission; in common with all Huco Dynatork motors, it also consumes up to 80 per cent less air than a vane motor - which can therefore provide significant energy savings even at maximum torque.
Note on noise
More information on the Noise Regulations can be found on the HSE's website.