Posts Tagged aerosol monitoring
Last summer, the U.S. Environmental Protection Agency conducted an air quality survey at Union Station in Chicago. The results showed elevated concentrations of respirable particulate matter (PM2.5) in ambient air on train platforms and nearby streets.
PM2.5 is a mixture of liquid droplets and particles measuring 2.5 micrometers in diameter or smaller. These tiny particles can be inhaled deep into the lungs where they can enter the bloodstream and cause serious health problems. The risk is even more severe for youth, the elderly and those with respiratory conditions like asthma.
Are we running exhaust fans enough to keep the air breathable and safe? Are we over-running fans and wasting energy?
Area exposure monitors are ideal for showing airborne particulate concentration over time in a designated area. Personal exposure monitors can do the same, but they also provide usable details about concentrations within the employee’s breathing zone. Used together, the two device types provide effective real-time data for making decisions regarding employee health and ventilation control.
Recently, we helped a customer with a large welding operation. There was visible smoke on the plant floor during operation, so they needed to address both potential hexavalent chrome and total respirable dust exposure. They decided to use the TSI DustTrak DRX handheld unit for area monitoring, and employees started wearing TSI SidePak AM510s for personal monitoring.
A customer recently asked the question, “Will the EPA accept the TSI DustTrak as evidence of compliance with ambient air standards?”
The answer, simply: Yes.
The USEPA recognizes the TSI DustTrak as an acceptable “other test method” as specified by OTM 34, section 2.3.1.
As we move into summer we all feel the effects of humidity outside. It makes it feel so much hotter. You feel sluggish. The air just feels heavy.
Humidity can have that same effect when you are sampling dust using a photometer. It can overestimate your total mass measurement, making it seem heavier. Why? Photometers measure the light scattered by aerosol particles. When there is more moisture in the air, water hangs on to these particles and makes them appear larger. The instrument, in turn, gives you a higher mass concentration level. This can greatly affect the accuracy of your real-time measurements.
To help combat the effects of humidity, TSI developed a heated inlet conditioner for its DustTrak II and DustTrak DRX aerosol monitors. To test them, they went to Singapore and the coast of Australia. I volunteered tto go and observe. Sadly, I wasn’t invited.
In a training a few weeks ago, that’s how I started my session to a room full of IH and safety professionals: The Star Trek Tricorder just doesn’t exist. There’s no magic instrument that measures everything with 100% accuracy.
And it was sad news to the professionals from power plants, food production, healthcare, and metals industries that had joined us for the day. Their goal was to optimize their IH and safety practices by better use of direct-reading instruments. But before we built them up with knowledge, we had to tear down the idea that there was one tool to rule them all (sorry, mixing SciFi and Fantasy there, but you get it).