Patent ID: 6924477

Claim:
A method for establishing the cleanliness of a device based on a test that employs an ion mobility spectrometer (IMS), the method comprising: measuring n 1 ≧1 target signal strengths with the IMS, wherein the step of measuring n 1 ≧1 target signal strengths includes providing a target sample having a known concentration of a contaminant and measuring a target signal strength of the target sample with the IMS; measuring n 2 ≧1 test signal strengths of a device sample with the IMS; obtaining a value of a statistical confidence-level parameter that is associated with a particular confidence level; utilizing the value of a the statistical confidence-level parameter and the n 1 target signal strengths to obtain a pass range of signal strengths; calculating an average test signal strength from the n 2 test signal strengths; and determining that the device passes the test, indicating that the device is significantly clean to within the particular confidence level, if the average test signal strength lies in the pass range.