Increasing the sensitivity and detection limit of a photoionisation detector (PID) by low-pressure operation

摘要

According to the prior art, both in the gas chromatography application field and with PID applications in the field of counter detectors, the gas samples are loaded (via a lock) almost unpressurised into the sample cavity, since either the input side or the output side of the detector are open to the atmosphere. In the case of such a configuration, the sensitivity and detection limit depend decisively on the quantity of light emitted by the lamp, the gas matrix and the bias voltage. With low-pressure operation, the efficiency of such a detector can be increased by more than a factor of 2.