A Rapid Timing Sequencer for Toxic Gas Sampling

摘要

As part of a study of toxic hazards it is necessary to obtain samples of gases given off by rapid fire weapons and fast burning rocket motors. A solid state instrument was designed which can program solenoid valves for this purpose. The configuration chosen provides three individually adjustable interval timers. Each can be delayed from 25 to 5,000 milliseconds after firing of weapons, and can remain on for 30 to 4,000 milliseconds. The very short sampling times which are available enable acquisition of gas samples at pressures considerably below ambient, if this is desired to protect analytical instruments or to minimize chemical interactions in the sample. By adjustment of R-C time constants the timer range can be extended or reduced further to provide a versatile tool for future timing applications. Circuit details and performance data are presented. (Author)