Calibration gas preparation for non-disposable portable MOx, PID, and IER VOC detectors

A novel calibration gas mixture was developed for portable volatile organic compound (VOC) detectors used to screening of indoor air. We selected three types of typical non-disposable portable VOC detectors using different detection principles-a photo-ionization detector (PID), metal oxide semiconductor (MOx) detector, and interference enhanced reflection method (IER) detector. A mixture of 31 kinds of VOC mixed gas, simulated VOC mixed gas, used for the calibration of portable VOC detectors. The simulated VOC mixed gas was designed on the basis of three different reports published by the Joint Research Centre, Ministry of Health, Labour and Welfare Japan, and the International Organization for Standardization. However, the simulated VOC mixed gas is too expensive for practical use as a calibration gas. Therefore, a study was done to investigate different calibration gas mixtures using one, two, four, and six kinds of VOC mixed gases as candidates of calibration gas mixtures. Responses of the portable detectors were evaluated using these VOC mixed gases, and the results were verified by the test using the simulated VOC mixed gas, for identification of the reasonable simplified calibration gas mixture.