Moving belt shaft

Exhibit no. 642

The moving belt is a transport type LC/MS interface developed in the seventies and eighties of the last century. The eluent from the chromatograph was deposited on the moving belt near the rear idler wheel by a spray depositor positioned in the inlet housing. The belt then passed through three tunnel seals in a two stage vacuum lock where the pressure was reduced to that of the source housing, and finally through another seal into the ion chamber, where the sample was evaporated by the sample heater situated immediately behind the belt. As it returned to the inlet housing, the belt passed over the clean-up heater, which removed any trace of material not evaporated in the ion chamber. The belt was driven by a stepping motor mounted on the inlet housing, and the vacuum locks were evacuated by rotary pumps.