BS EN ISO 7096 pdf free download

BS EN ISO 7096 pdf free download.Earth-moving machinery — Laboratory evaluation of operator seat vibration.
4? General 4.1? The laboratory-simulated machine vertical vibration, specified as input spectral class, is based on representative measured data from machines in severe but typical working conditions. The input spectral class is a representative envelope for the machines within the class, as measured under severe conditions. 4.2? Two criteria are used for the evaluation of seat: a)? the Seat Effective Amplitude Transmissibility (SEAT) factor according to ISO 1 0326-1 :1 992, 9.1 , but with frequency weighting according to ISO 2631 -1 ; b)? the maximum transmissibility ratio in the damping test according to ISO 1 0326-1 :1 992, 9.2. 4.3? The measuring equipment shall be in accordance with ISO 8041 (type 1 instrument) and ISO 1 0326-1 :1 992, clauses 4 and 5. The frequency weighting shall include the effects of the band limiting filters, and be in accordance with ISO 2631 -1 . 4.4? Safety precautions shall be in accordance with ISO 1 3090-1 . Any compliant end-stops or devices normally fitted to production versions of the seat to be tested to minimise the effect of suspension overtravel shall be in place for the dynamic tests. 5? Test conditions and test procedure The test conditions and test procedure shall be in accordance with ISO 1 0326-1 :1 992, clauses 7 and 8. 5.1? Simulation of vibration See ISO 1 0326-1 :1 992, clause 5.A platform, the dimensions of which correspond approximately to those of the operator’s platform of an earth- moving machine, shall be mounted on a vibrator which is capable of generating vibration along the vertical axis (see Figure 1 ). NOTE? In the case of classes EM 1 and EM 2 the vibrator should be capable of simulating sinusoidal vibration having a displacement amplitude of at least ? 7,5 cm at a frequency of 2 Hz; see 5.4.1 . 5.2? Test seat The operator seat for the test shall be representative of series-produced models, with regard to construction, static and vibration characteristics and other features which may affect the vibration test result. Before the test, the suspension seats shall be run-in under conditions stipulated by the manufacturer. If the manufacturer does not state such conditions, then the seat shall be run-in for 5 000 cycles, with measurements at 1 000 cycle intervals. For this purpose, the seat shall be loaded with an inert mass of 75 kg and adjusted to the mass in accordance with the manufacturer’s instructions. The seat and suspension shall be mounted on the platform of a vibrator, and a sinusoidal input vibration shall be applied to the platform at approximately the suspension natural frequency. This input vibration shall have a peak to peak displacement sufficient to cause movement of the seat suspension over approximately 75 % of its stroke. A platform peak to peak displacement of approximately 40 % of the seat suspension stroke is likely to achieve this. Care should be taken to ensure against overheating of the suspension damper during the running-in, for which forced cooling is acceptable.The seat shall be considered to have been run-in if the value for the vertical transmissibility remains within a tolerance of ? 5 % when three successive measurements are performed under the condition described above. The time interval between two measurements shall be half an hour, or 1 000 cycles (whichever is less), with the seat being constantly run-in. The seat shall be adjusted to the weight of the test person in accordance with the manufacturer’s instructions. With seats where the suspension stroke available is unaffected by the adjustment for seat height or test person weight, testing shall be performed with the seat adjusted to the centre of the stroke. With seats where the suspension stroke available is affected by the adjustment of the seat height or by test person weight, testing shall be performed in the lowest position which provides the full working suspension stroke as specified by the seat manufacturer. When the inclination of the backrest is adjustable, it shall be set approximately upright, inclined slightly backwards (approximately 1 0° ? 5?). BS EN ISO 7096 pdf download.