The invention relates to equipment, devices and methods for testing a calibrated leak or passage of pressurized gas from a tire. In one example, a test plug including a calibrated cross section orifice and a predetermined gas flow rate is connected to a tire. The test plug applies a pressure opening the tire valve member to release gas from the tire through the test plug. In one example, a TPMS sensor and a TPMS measurement tool are used to measure the decrease of air pressure in the tire through the test plug and determine if the TPMS sensor is operating properly. In one example, a plurality of test plugs with different gas flow rates are provided. A method for testing the calibrated leak using the test plug is further disclosed.