Patent ID: 6096557
Filing Date: 2000-08-01
Classification: G01N,Y10T

Abstract:
A gas detection method using a gas reactive pigment, which comprises,providing a gas detector comprising, as the gas reactive pigment, a tetra phenylporphyrin represented by the following general formula (1), or a metal complex of tetraphenylporphyrin represented by the following general formula (2);bringing at least one gas to be detected which is a hydrogen halide gas, into contact with said gas detector;maintaining the temperature of the detector or the vicinity thereof in the range from 40 to 80.degree. C. while said detector is in contact with the gas to be detected whereby said temperature provides the method with a broader measurable concentration range of the gas to be detected than the measurable concentration range provided by a temperature below 40.degree. C.;irradiating the detector with a light beam while said detector is in contact with the gas to be detected and said temperature is maintained; andmeasuring the spectrum of the light which is reflected or transmitted from said gas detector, whereby the intensity of the spectrum is an indication of the concentration of said gas to be detected: ##STR2## wherein in formula (1) and (2), R represents a substituent selected from the group consisting of a hydrogen atom and a halogen atom,G represents a substituent on the four phenyl groups selected from the group consisting of a halogen atom,a, b, c and d may be the same or different and each represents an integer of 0 to 5, and the substitution position of G on each phenyl group may also be the same or different,M represents a transition metal which is Zn.