By Mark DeSorbo
MILPITAS, Calif.—In a rather surprising entrepreneurial shift that has the potential to significantly impact environmental monitoring in a gamut of industries, Lighthouse Worldwide Solutions, a longtime systems developer, has unveiled a handheld, 0.2-µm particle counter—an ultra-sensitive device that displays both cumulative and differential particle count data through an illuminated touch screen.
“This is a technological breakthrough,” says Demi DeSoto, marketing manager. “You could not get 0.2-µm sensitivity in a handheld device before. Up until now, it took a toaster-sized unit to take those measurements, which involved wheeling it on a cart, and when you're wheeling a cart around, you could be possibly introducing contamination into the cleanroom.”
Lighthouse's lithium ion-battery-powered Handheld 2016 is a departure from developing cleanroom monitoring systems, which it has done predominantly since opening its doors in 1982.
“We were mostly a system provider for cleanroom monitoring systems, but we found that the quality of the products we were using was going down,” says Scott Salton, Lighthouse's vice chair. “We got a lot of perspective from our customers. We felt that we were pushed into a corner, and that we had to develop a product. We couldn't buy them, so we made them ourselves.”
The 2016 also displays temperature and relative humidity data on its 3.8-inch screen, and can be integrated into a larger facility monitoring/management system using AC power.
The 0.2-µm sensitivity operates at a flow rate of 0.1 cubic feet per minute (cfm), which allows the device to simultaneously view six particle sizes up to 2 µm. The unit also includes an audible alarm and a temperature-relative humidity sensor outfitted with a probe.
The lightweight, ergonomically designed 2016 is also equipped with a large memory cache that can store 3,000 records, which can be downloaded onto a PC using the company's LMS Express software. Data can be reported in ISO-14644-1, British Standard-5295 and in Federal-Standard 209E cleanroom environmental monitoring classifications.
Lighthouse already had a 0.3-µm particle counter on the market, and while a tenth of a micron may not seem that big of a leap, attaining that level of sensitivity proved to be a task, warranting a complete evaluation of its latest technology generation.
“One of the greatest challenges was to come up with this level of sensitivity in a handheld device,” says Rocco Pochy, vice president of engineering. “We couldn't just put in a high-power laser, huge lenses or huge electronics the way it was done in the past.”
“The electronics were looked at closely, the optics were evaluated; it was a team effort,” Pochy says. “Everybody brought something to the table. It wasn't any one subsystem.”
Pochy, along with Bill Shade, optical engineering manager, say it was all a matter of evaluating existing technology, namely honing signal-to-noise ratios that define detection sensitivity.
“We had all the systems experience, and we were able to put a lot of the manufacturing infrastructure in place ourselves because we had already been doing that for years,” says Shade.
And present geometries of optical and microelectronic components needed for such devices are perhaps the smallest and fastest ever, allowing the company to stuff increased sensitivity and greater capabilities into a tight package.