Interscan Says That It's Time To Stop Ignoring This 500-Pound Gorilla In The Room

Everyone can agree with this New Year's resolution: Let's make our workplaces safer! One way to achieve this goal is to monitor these environments for the presence of toxic gases. Indeed, OSHA mandates Permissible Exposure Limits (PELs) for more than 600 air contaminants. Unfortunately, many in the industry tend to ignore certain difficulties in this pursuit: Proper calibration and unwanted responses—or interferences—that may be caused by other compounds present in the environment.

Since gas detection analytics is based on some chemical or physical property of the target molecule, complete specificity—if achievable at all—will be rare, and might be more a matter of circumstance. For example, a compound that would interfere with the measurement is simply not normally present in the particular occupancy to be tested. Yet, the whole notion of interferences is often foreign to many instrument "experts," whose entire background has been limited to such parameters as temperature, voltage, or distance.

"Recently, one of our customers told us about a brand new (and expensive) technique for formaldehyde detection that claims sub parts-per-billion sensitivity," says Grant McClure, Interscan's manager of special projects. "We looked into this, and discovered that it would be prone to interference from several common atmospheric chemicals." McClure added that such information did not appear in any of the product documentation.

Responsible gas detection instrument manufacturers will readily reveal interference data, and will help prospective clients deal with such matters. In other words, applications engineering must never be overlooked.