The response time of the analyzer system, including all components in the final installation, is so critical that it should be given careful attention.
One useful method of testing the system time response of the analyzer is to inject test gas directly into the end of the probe inside the process, and to obtain the time that it takes for the alarm to sound. The test gas concentration should be equivalent to at least 10% LFL above the high alarm point.
In some analyzers, the response time during calibration is quite good, while the response time when sampling is much slower and difficult to perceive. Many analyzers inject calibration gases through pressurized ports directly at the analyzer's detection chamber.
This leads to the often false conclusion of a prompt and effective response time, while in reality the sample gases travel through a different flow system, including pumps and/or filters, that can be much slower.
Add new comment