Gas chromatograph and zero adjustment method

摘要

The present invention provides a gas chromatograph that is less likely to cause drift in an output signal from a zero-adjusted thermal conductivity detector, and a zero adjustment method. Multiple stages of zero adjustment are performed on the output signal from the detector. The zero adjustment in multiple stages includes fine adjustment (first adjustment) and intermediate adjustment (second adjustment). In the fine adjustment, the output signal from the detector can be adjusted within the fine adjustment range (first adjustment range). In the intermediate adjustment, the output signal from the detector can be adjusted in an intermediate adjustment range (second adjustment range) wider than the fine adjustment range. If there is a zero point in the fine adjustment range of the output signal of the detector when the sample component does not flow through the cell, the zero adjustment is performed by fine adjustment. If there is no zero point in the fine adjustment range, the fine adjustment is performed after the intermediate adjustment.