Well, well...
The Interscan team took on the challenge that the big boys ran away from: A big CO monitoring system with plenty of oddball special features required by the customer.
Not only did they take up the challenge, they delivered an honest-to-God bravura system, with plenty of fancy control and all touchscreen operator interface. The dual-purpose unit will maintain detailed records of employee exposure, and--in conjunction with a building management system--will also be used to control ventilation in the structure.
As such, the amount of outside air brought in will be sufficient to maintain a healthy environment, without needlessly taxing the heating and air conditioning. Thus, energy is being saved. As one of the guys noted, "Green heavy equipment is being perfected inside a green building that is energy efficient."
All user control of the gas detection system is via touchscreen, and a remote annunciator panel provides additional indication of potentially dangerous carbon monoxide levels in the facility. In all, 32 sampling points are continuously monitoring the air in the testing center.
"There were numerous design challenges in this application," says Scott Richards, Interscan's systems manager. "The size of the equipment being tested in the building, with vehicles as tall as 30 feet (9m), along with the requirement that air sample be drawn from high up, precluded the use of diffusion head sensors."
"Moreover, even with a sample-draw approach (utilizing a diaphragm pump bringing sample back to the analyzer enclosure), conventional end-of-line sample filters could not be employed. Who would want to change them 40 feet (12 m) up in the air?"
"Instead, we chose to use in-line filtration at ground level, along with an automatic sample line backflush feature. Remember, many of these vehicles are diesel-powered, and in test mode they could be putting some particulate into the air," added Richards.
Another factor to be overcome was RFI (Radio Frequency Interference) caused by the omnipresent two-way radios. Special packaging was utilized to combat the effects of RFI on the system electronics.
The monitoring system includes Interscan's popular Arc-Max® data acquisition/archiving package, which will keep track of employee exposure to carbon monoxide, in accordance with OSHA guidelines.
Richards concludes, "As far as we know, this system represents the most extensive use of automation controls ever seen, in a gas detection system."
Kudos to Scott Richards and Omer Gokcen--engineers extraordinaire.
Several photos of the system are available here.
