Patent ID: 6819253
Filing Date: 2004-11-16
Classification: G08B

Abstract:
A method for confirming the presence or absence of a particular chemical compound upon the report thereof generated by an analytical system that is arranged to detect the presence of that chemical compound in the gas being monitored, said method comprising:providing a monitoring system that cyclically samples a gaseous atmosphere to obtain a sample for analysis and immediately thereafter analyzes said sample to determine the presence or absence of said chemical compound; providing a confirmation sampler, said confirmation sampler having at least two sorbent-containing sampling tubes that are arranged such that one sampling tube is sampling the same gaseous atmosphere as is said monitoring system while the other sampling tube is purging to desorb contaminants captured on said sorbent; providing control means that synchronize the operation of said confirmation sampler with that of said monitoring system, so that when the monitoring system is sampling so also is one of the tubes of the confirmation sampler; and causing said monitoring system to generate an alarm signal upon detection of said chemical agent, said signal also causing the confirmation sampler to retain and not desorb the sampling tube collected during that cycle of the monitoring system which triggered said alarm to thereby leave the sample collected by said sampling tube available for retrieval and analysis for confirmation of the presence or absence of said chemical agent.