Technical
“ Factory Based Testing
So how do manufacturers test their machines for noise? Well, the rules are laid out under EN352 and have to be applied uniformly for each and every test. Testing has to be carried out on a flat, open area of high quality turf cut to 30mm, which is visibly free of grass clippings, debris, moisture, frost or snow.
The weather plays its part too; wind speed must not exceed 8 m/sec, the temperature has to be a minimum of 5O
temperature and air pressure all have to be recorded.
The test microphones are preferably connected by a cable and background noise recordings are taken prior to the machine noise test. The mower is stabilised, by running at operating speed for at least thirty minutes and the test is carried out immediately after stabilisation.
The machine must be stationary, have less than half a tank of fuel, the cutting units must be at their maximum speed and the engine must be running at full speed. If grass boxes are fitted, they must be empty. There should be no operator present.
Six microphones are used and evenly spaced around the machine, measuring the noise levels for fifteen seconds at each of the six recordings that are taken to achieve a standard deviation of repeatability, thus ensuring that each test falls within agreed parameters. Readings are also taken at the ear level of the operator.
The measuring equipment has to be tested and calibrated every two years to ensure conformity, and best practice includes taking a current model off the production line and testing it against the original noise data on an annual basis.
Obviously, new machinery with well-balanced blades and good bearings will make less noise than an older machine which may have worn components or spurious spare parts fitted to it.
C and wind speed, direction, air
However, a well maintained machine shouldn’t make any more noise than a new one, so there is an added incentive to keep up on servicing and maintenance of machinery.
Conclusion
Employers should issue personal hearing protection to employees where extra protection is needed above what has been achieved using noise control; and, as a short-term measure, while other methods of controlling noise are being developed. Hearing protection should not be used as an alternative to controlling noise by technical and organisational means.
Also, employees should be issued with hearing protectors and it is the employer’s responsibility to make sure they use them fully and properly when their noise exposure exceeds the upper exposure action values.
You should only use CE-marked hearing protectors and maintain them so that they work effectively. Factors that affect the level of protection, such as the headband tension and the condition of seals, should be checked as part of general maintenance procedures.
Employees have a duty to report any defects in hearing protection and should be provided with training so that they understand the risks they may be exposed to, and their duties and responsibilities.
Consulting with trade union-appointed safety representatives or other employee representatives is a legal requirement and employers must provide health surveillance for all employees who are likely to be frequently exposed above the upper exposure action values, or are at risk for any reason.
Employees have a duty to report any defects in hearing protection and should be provided with training so that they understand the risks they may be exposed to
” PC OCTOBER/NOVEMBER 2015 I 129
The machine must be stationary, have less than half a tank of fuel, the cutting units must be at their maximum speed and the engine must be running at full speed. If grass boxes are fitted, they must be empty. There should be no operator present
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