Temperature Independence of an Electro Acoustic Capnograph

End tidal carbon dioxide measurement with an electro acoustic sensor has recently been demonstrated. The sensor consists of an acoustic resonator coupled to a low cost electro acoustic element. The aim of this study was to verify if ambient temperature variation would affect the measurements. By simultaneous measurements with a reference sensor, the electro acoustic capnograph was tested on subjects performing exercise, hypoand hyperventilation. The output from the experimental device correlated well with the reference CO2 readings with a correlation coefficient of 0.91 at varied temperature and relative humidity.