Laser system tests the water

24 Mar 2006

Water bottling facilities could soon be using a laser-based system that monitors for harmful organisms such as E Coli and Legionella.

JMAR Technologies has signed an agreement with fellow US firm Portaqua which will see its BioSentry water monitoring system enter the bottling market.

The BioSentry uses a laser to provide continuous, online, real-time monitoring of bacteria and protozoa such as Cryptosporidium parvum, E Coli and Salmonella. According to JMAR, the product offers an alternative to current, time-consuming lab batch sample analyses and has applications in food and drink production and testing municipal water supplies.

How the laser system works

The device weighs around 25 kg and is the size of a small suitcase. The beam from a built-in 100 mW, 656 nm laser operating continuous wave is fired perpendicular to the direction of water flow.

"When the incident laser interacts with particles drifting in front of the beam, diffraction patterns are generated and register on a detector," John Ricardi, vice president of business development at JMAR told Optics.org. "These patterns consist of 'fingerprints', unique to the internal and surface features of the particle."

JMAR uses these fingerprints to differentiate the particle into several probable classifications. "During operation, every particle that passes through the laser beam is analyzed by an on-board computer for a possible database match," said Ricardi.

The BioSentry can cope with a water flow rate of up to 3 liters per hour. JMAR hopes to add the ability to detect Bacillus, algae, yeast and mold in the future.

Since launching the product last year, JMAR has installed devices for a range of customers including a unit for a drinking water supply onboard a cruise liner and another two units for monitoring production water at a leading Mexican drinks manufacturer.

BioSentry has also been deployed in a US Homeland Security initiative. Between January and March this year, two units have been testing a major US city's municipal water supply for harmful microbes that could potentially be introduced by terrorists.