Advanced Chemical Sensors (ACS) was founded in 1976 by Laurence D. Locker, (Ph.D., MIT) to develop better methods to measure employee exposure to toxic vapors that U.S. occupational safety laws regulate. The goal was improved occupational health so that employees didnt develop health conditions in the short term or long term because of the exposure.
Before, a mechanical pump was used to collect air samples, so the air could be evaluated. Unfortunately, the pump was very taxing to operate, and this left a lot of room for user error.
Fortunately, a passive monitoring technique was developed that ended the need for the pump. This technique involved using a solid adsorbent with a porous membrane between it and the air. The adsorbent acts like a pump without all the moving parts. Not only does this make the process of monitoring the air easier, it is less expensive.
In 1982, Dr. Locker received a U.S. patent for this technique. A Japanese patent followed in 2001.