BS EN 16974:2016 pdf free.Conveyor belts -Indentationrolling resistance related tobelt width – Requirements,testing.
BS EN 16974 For the measurement of the indentation rolling resistance idlers with varying diameters and shelllengths are used. These are installed in an adjustable frame.The shell length of the idler shall be at least10 % longer than the width of the test belt. The frame shall be in a statically simply fixed position. Itshall be avoided that the position is over-determined and that resulting forces are created.These coulddistort the measurement results. All suspension points shall be equipped with suitable force sensors inorder to determine all suspending forces unambiguously. The perpendicular alignment of themeasuring idler to the belt can be checked with the help of a force sensor which records the forces thatact in axial direction upon the idler, if the alignment is not correct.
ln order to determine the width related indentation rolling resistance the forces are measured whichact upon the left and the right side of the idler – and therefore upon the frame – with suitable forcesensors. To calculate the indentation rolling resistance from these values, the part of the horizontalforce cause by the idler rolling resistance shall be known and shall be subtracted from the measuredhorizontal force FM,h.The idler rolling resistance can either be measured simultaneously with suitablesensors, or it can be measured separately. In this case the test parameters of the measurement ofindentation rolling resistance need to be taken into consideration.
The endless length of the test belts depends on the distance axis-to-axis of the test rig L and the pulleydiameter Dn and deviations from the values stated in clause 5 shall be agreed with the operator of thetest rig. The width of the test belt shall be a minimum of 350 mm. For steel cord belts the width of therubber belt edge shall be chosen as follows:
In fabric belts rubber edges shall be avoided, so that the belt width is equal to the width of the tensioncarrier.
The test belts shall be joined with a splice of minimized length,which can differ from the standardsplice layout. The horizontal force measured in the splice area can differ from the force measured in thebelt.Therefore it is not taken into consideration for the calculation of the indentation rolling resistance.
The cover plate to be measured shall be in contact with the measuring idler.
Prior to each measurement the test rig shall be operated in constant test conditions long enough, so thatthe idler running resistance and the measured horizontal forces reach a steady-state. The complete testrig shall be brought to the desired temperature over a sufficiently long time, so that in the completecross section of the test belt the temperature equals the surrounding temperature in the climatechamber of the test rig.
ln order to cancel the influence of zero drift errors when measuring the horizontal forces acting on themeasuring idler, the belt running direction shall be alternated several times during the measurement.The value of the difference between the measured horizontal force of the belt running to the left Fia.and the belt running to the right FMhris taken into account for the calculation of the indentation rollingresistance.BS EN 16974 pdf download.