Patent ID: 6889537

Claim:
A method of detecting the presence or absence of a leak sealant additive in refrigerant charges or stores, the method comprising the steps of: connecting a sensing unit between a coupler and a flow indicating device, the sensing unit having a seal-forming surface and a flow-restricting passage calibrated to allow a predetermined rate of refrigerant flow therethrough, the coupler having a depressor for opening a refrigerant access port, and the flow indicator being capable of indicating different refrigerant flow rates through the sensing unit; wetting an internal surface of the sensing unit; engaging the end of the coupler opposite the sensing unit with the refrigerant access port, thereby opening the port and allowing refrigerant to pass through the flow-restricting passage; observing the flow indicator to monitor flow rate of the refrigerant through the flow restricting passage over a preselected time period, the presence of a leak sealant additive being indicated by a reduction in the flow rate and the absence of a leak sealant additive being indicated by a substantially constant flow rate.