Patent ID: 6549857
Filing Date: 2003-04-15
Classification: G01M

Abstract:
A method for use in detecting a leak in a pipeline system comprising:measuring a difference in a rate of change of pressure due to a leak between one pressure level and at least one other pressure level after compensation has been made for thermally induced changes in the pressure in a pressurized pipeline system, including the steps of (a) pressurizing said pipeline system to a first pressure level and determining a set of first pressure data by measuring a change in pressure in the pipeline system that occurs over a first measurement period; (b) pressurizing said pipeline system to at least a second pressure level and determining a set of second pressure data by measuring a change in pressure in the pipeline system that occurs over at least a second measurement period; and (c) computing a difference in a temperature compensated rate of change of pressure between a first pressure level during said first period and a pressure level during said second period, said computing performed on said first and second pressure data and including a correction for thermally induced non-linear changes of pressure between the measurement periods, wherein the difference in the temperature compensated rate of change of pressure between the pressure levels is computed from the rate of change of pressure calculated from said first and second data and at least one higher order derivative of the pressure data.