Patent ID: 7821270

Claim:
A demountable pellet for use as an electrode contact assembly in a photoionisation detector, comprising: a base upon which is mounted a plurality of electrodes arranged in respective spaced parallel planes and having respective contacts protruding therefrom, and a closure for the base having a member engaging at least one of the electrode contacts, wherein, in an unassembled condition of the pellet, with the closure separate from the base and the at least one closure member disengaged from its respective electrode contact, the contacts lie in respective spaced parallel planes and wherein, in the assembled condition of the pellet with the least one closure member engaging its respective electrode contact, at least one of the contacts lies in a plane other than that in which it lay in the unassembled condition of the pellet, and wherein, in the assembled condition of the pellet, each electrode contact overlies a corresponding hole through which respective fixed terminal pins are receivable from the exterior of the pellet to provide ohmic contact therebetween, and wherein, in the assembled condition, all the electrode contacts lie in a common plane, and wherein the demountable pellet engages mechanically and electrically with the photoionisation detector.