BS EN ISO 13350:2015 pdf download – Fans — Performance testing of jet fans.
6.4 Input power Determination of the power input to the electric motor or to the impeller shall be carried out in accordance with ISO 5801:2007, Clause 10. P e and P r are determined by correcting the measured power for a density of 1,2 kg/m 3 . 6.5 Sound level The sound-level measuring system, including microphones, windshields, cables, amplifiers, and frequency analyser, shall be in accordance with the requirements given in ISO 13347. 6.6 Vibration velocity Instruments to measure root mean square (r.m.s.) vibration velocity shall be used to record fan vibration velocities. These shall be in accordance with ISO 14695. 6.7? Volume? flowrate 6.7.1 Instruments for the measurement of pressure Manometers for the measurement of differential pressure and barometers for the measurement of atmospheric pressure in the test enclosure shall comply with the requirements of ISO 5801:2007, Clause 6. 6.7.2 Instruments for the measurement of temperature Thermometers shall comply with the requirements of ISO 5801:2007, Clause 8. 7 Determination of thrust 7.1 General There are two basic configurations acceptable for the determination of fan thrust, T m , by direct measurement, these are — suspended configuration, and — supported configuration.
T m is determined by correcting the measured thrust value for a density of 1,2 kg/m 3 , i.e. T m = Thrust measured · 1,2 [kg/m 3 ]/ρ a [kg/m 3 ]. In addition to the need to measure force accurately, the first method requires that the low friction suspension elements be kept precisely vertical and parallel with a vertical plane(s) passing through the fan axis, while the second method requires accurate construction, low friction, and levelling of the support assembly. In either case, thrust shall be determined by the use of calibrated weights, spring balance, or force transducer. 7.2? Suspended? configuration Figures 2 and 3 show typical arrangements of suspended configurations. The fan is suspended from a framework or gantry with the suspension elements at least one fan-diameter long. The frame should allow free airflow, particularly at the fan inlet. Below or surrounding the fan is a rigid framework which serves a threefold function to a) provide the reference point for the fan test assembly under static conditions, b) provide support for a pulley system to take calibrated weights or a spring balance, and Under operating conditions, the measuring system loads are adjusted to return the fan to the static positions, to within ±2 mm, and thus ensure that the suspension elements are precisely vertical. The thrust can then be measured directly. Note With the thrust/weight ratios typical of a jet fan, it is doubtful whether the desired accuracy of thrust measurement can be attained by other means, such as measuring the angle of the suspension elements from the vertical or the change in height between the fan switched off and operational, and then calculating the thrust.