INFICON Explorer Portable Gas Chromatograph - Manual (Page 334)

Explorer Operator Manual
332
In Explorer the column effluent is split between the PID and the ECD. Make-up gas
is supplied to the ECD in order to maintain a constant flow rate over the detector
and to ensure stability. The low flows normally put though a capillary column may
reduce the baseline. The makeup gas is added to the column effluent before it enters
the detector to maintain the flow through the ECD at a level that will ensure a stable
signal level.