| 摘要 |
<p>PURPOSE:To obtain a flow rate-sensitivity characteristic almost flat in the vicinity of an objective flow rate, by preliminarily regulating a synchronous rectifying amplifier so that the max. sensitivity is obtained in a flow rate less than the objective flow rate. CONSTITUTION:The objective flow rate Q0 introduced into gas flow cells 2A, 2B is set within a relatively small flow rate. The flow rate-sensitivity characteristic of the synchronous rectifying amplifier 6 provided to the post-stage of an absorbancy detector 3 is regulated so that the max. sensitivity is obtained in a flow rate Q1 less than the objective flow rate Q0. As a result, the actual flow rate-sensitivity characteristic of this cross-flow type gas analyzer has a region S almost flat in the vicinity of the objective flow rate Q0. Therefore, even when the flow rate of the gas to the cells 2A, 2B changes to a certain extent, measuring sensitivity does not change and, even when flow control apparatuses 10A, 10B are simplified to a large extent, an error due to the effect of a flow rate is hard to generate.</p> |
