Thermometric vapor sensor for measurement of e.g. anesthesia gases or flammable vapor in a gas stream

摘要

The sensor comprises a micropore evaporation end (160) surrounded by a temperature sensor (144) whose temperature falls due to evaporation caused by a vapor stream passing the end of the micropore. The micropore end is connected to a liquid reservoir (156) via a micropore lumen (154). A temperature sensor surrounds the lumen, its temperature sensitive part being in contact with the lumen. Independent claims describe: (1) An apparatus for sensing a vapor in a gas stream comprising: (a) A substrate layer (138) forming a liquid reservoir. (b) A thermal insulating layer (137) on top of the substrate layer. (c) A dry electrical reference temperature sensor (130) with an electrical property that is a function of temperature, for measuring the non-evaporative temperature of the gas stream. (e) A wet electrical temperature sensor as described above. (f) A computer connected to the temperature sensors for determining the temperature difference between the two sensors. (2) A method for making the sensor apparatus as described above. (3) A method for sensing the temperature of the vapor of a volatile liquid in a gas stream by: (a) Sensing the temperature without evaporation. (b) Supplying liquid to the micropore. (c) Sensing the temperature during evaporation. (d) using the two derived temperatures to determine the concentration of vapor in the stream.