METHOD FOR MEASURING AMMONIA GAS WHICH OCCUR DURING THERMOFORMING OF BRAKE LINING

PROBLEM TO BE SOLVED: To provide a measuring means capable of accurately verifying the state of setting reaction happening during a thermoforming process in real time and performing the verification at a speed with a time margin to enable control over the conditions of the thermoforming process. SOLUTION: In a gas measuring method, a carrier gas 7 is introduced to a mold 1 to thermoform brake-lining material containing thermosetting resin, and gas which occurs due to the reaction between the thermosetting resin and a setting agent during the thermoforming of a break lining is extracted. Then the extracted occurrence gas is measured by an optical measuring means 6 to obtain the amount of ammonia. In the gas measuring method, the amount of the carrier gas to be introduced is controlled and regulated so as to be proportional to the degree of the reaction between the thermosetting resin and the setting agent in the mold 1.