William Francis Houlton Dean,Mark Julian Stockdale
申请号：
GB20170010891
公开号：
GB2561031(A)
申请日:
2017.07.06
申请国别(地区):
英国
年份:
2018
代理人:
摘要：
Detecting a target gas in ambient air using a gas chromatography (GC) column 118, a sensor 126 located downstream of the GC column 118, a pump 110, a gas storage chamber 114 and a pneumatic circuit. In a first state, the pump 110 draws in ambient air and supplies it to the gas storage chamber 114 in order to store ambient air under pressure within the chamber 114, while trapping a sample of ambient air within the pneumatic circuit, specifically in the internal conduit 125 of the four way valve. In the second state the gas storage chamber is connected to the GC column to cause pressurised air drawn from the storage chamber 114 to act as a carrier gas to advance the trapped sample through the GC column and the sensor. A filter 116 is provided to filter out any target gas present in the air entering into (or the air drawn from) the storage chamber 114, so as to avoid the presence of any target gas in the carrier gas. In effect, the ambient air trapped in the valve conduit is the sample and the stored and filtere
