| 摘要 |
PURPOSE:To cancel the photosensitivity of an ion sensor (ISFET) having gate insulating type field effect transistor structure by using a light-nontransmittible and gas-permeable film for a gas sensor which uses the ISFET. CONSTITUTION:The ISFET1 has a gate part 3 embedded in a catheter 2 and an electrode part 4 and an enamel wire connected to an electrode are insulated by an insulating material 5 from each other. The gate part 3 and part of a comparison electrode 6 contact a hydrophilic polymer 7 containing a gas absorbing liquid which varies in ion concentration by absorbing gas. The hydrophilic polymer 7 is covered with silicone rubbr 8; this silicone rubber forms the gas-permeable film which possesses both gas permeability and light nontransmittivity and has <=10% light transmittivity, and the quotient D/P of the 0 deg.C gas-permeation coefficient D of gaseous nitrogen by film thickness (d) is >=2.5X10<-8> (cm<3>(STP)/cm<2>.ScmHg). |
