Patent ID: 6116082
Filing Date: 2000-09-12
Classification: G01M

Abstract:
A method of determining the rate of leakage of fluid from a leaking fluid containing system, the method comprising pressurising the system, terminating the pressurisation, monitoring from a start time (T.sub.o) and pressure (P.sub.o) a first drop in pressure in the system and the time, determining the time taken (T.sub.1) for the pressure in the system to drop by a predetermined pressure drop (.DELTA.P.sub.1) to pressure P.sub.l, or where .DELTA.P.sub.1 has not been reached in a time less than a predetermined time (T.sub.2), determining pressure drop (.DELTA.P.sub.2) to pressure P.sub.L over the predetermined time T.sub.2, and then, without repressurising the system, monitoring from a new start time which substantially coincides with the end of the time period (T.sub.1) or the predetermined time period (T.sub.2), the time taken (T.sub.3) for a second drop in the pressure in the system (.DELTA.P.sub.3) through the actual leak in the system and a calibrated leak introduced into the system combined, where .DELTA.P.sub.3 =(.DELTA.P.sub.1 or .DELTA.P.sub.2).times.K, whichever of .DELTA.P.sub.1 and .DELTA.P.sub.2 was determined initially being applicable and K being a constant, and calculating the actual leakage rate according to the following formula ##EQU10## where C is a constant.