A NEW METHOD FOR MEASURING N2O CONCENTRATION

For the purpose to establish a simple method for measuring N2O gas the discharge light has been investigated under various conditions. Different from other gases it showed an intense after-glow, which appeared in a flowing sample at the distal portion of the discharge electrodes. The intensity of the after-glow has been measured by varying the vacuum pressure, the flow-rate, the concentration and the applied voltage. The intensity showed the maxi-mum at 3 mmHg when 1 Mc AC of 2, 000 volt was applied. For the flow-rate and the concentration the intensity increased hyperbolically not linearly respectively. However, at a concentration range lower than 30% it was fairly linear. The after-glow was not influenced from other respiratory gases. Furthermore, the intensity was reproduced within 1% errors for the same concentration, and the response time was about 1 sec at the flow-rate of 30 ml/min. From the data obtained the after-glow seemed to be used for the continuous determination of N2O concentration.