BS ISO 11171:2016 pdf free
BS ISO 11171:2016 pdf free.Hydraulic fluid power – Calibration of automatic particle counters for liquids
See Figure 1 for a recommended sequence of steps to be followed when performing a full calibration on a new APC. Conduct the procedures of this clause when a new APC is received or following the repair or readjustment of an APC or sensor (see Table 1). Proceed to Clause 6 if neither the APC nor the sensor has been repaired or readjusted, if no detectable change in the operating characteristics has occurred since the last sizing calibration was performed, or if the APC has been subjected to the procedures in Annexes A, B, C, D, and E and the results have been documented. The specific order of Annexes and Clauses specified in Figure 1 and Table 1 are recommendations. The operator may follow a different order, as long as all required parts are performed.
NOTE 1 Annexes A, B, C, and D can be performed by an individual laboratory or by the manufacturer of the APC prior to delivery.
A change in the operating characteristics of the APC can be detected by several different methods,including but not limited to the following:
a) using particle data from control samples collected over time and a statistical process control chart,such as an individuals moving range (IMR) chart, to detect significant changes in calibration;
b) comparing calibration curves over time to detect a significant change in calibration;
c) returning the APC to its manufacturer for evaluation and assessment of the change in calibration;
d) analysing a primary or secondary calibration suspension in accordance with 6.2 and 6.3, then comparing the resulting particle concentration data to the corresponding particle size distribution for the sample. If the results agree within the limits for the maximum allowable Dq given in Table C.2, the ability of the APC to size and count particles has not been significantly affected. If the results do not agree, a significant change has occurred and the operator is instructed to proceed as indicated in Table 1;
e) analysing a primary or secondary calibration suspension and resulting data as described in item
d) then analysing an ISO UFTD sample prepared in accordance with Annex A, then comparing the resulting particle concentration data with the limits given in Table A.1. If the results agree within the limits given in Table A.1, the ability of the APC to size and count particles has not been significantly affected. If the results do not agree with the limits of Table A.1, the APC has experienced a significant change and the operator is instructed to proceed as indicated in Table 1.BS ISO 11171 pdf free.
