Big things are happening for an Orono company whose work is measured in minuscule amounts. The amount of money Sensor Research and Development Corp. has been awarded recently in government contracts can be measured in the millions – more than $5 million to be more precise. The money comes in the form of research and development funds from the federal Defense and Homeland Security departments.

If the word “billion” is mentioned at the firm’s Godfrey Drive offices, however, it likely is in reference to the microscopic research the company is doing. SRD is developing hand-held sensors that can detect harmful substances such as poisonous chemicals or biological agents measured in parts per billion or even parts per trillion.

According to SRD President Carl Freeman, there is a lot of room to grow in the field of detecting things so small.

“There’s a chance for a lot of reward here, but it’s extremely intense,” Freeman said recently of SRD’s working environment. “We have solved some interesting problems along the way.”

SRD traces its roots to the early 1990s when Freeman, a former Marine pilot, was teaching electrical engineering at University of Maine.

At that time, the university was studying ways to use sensors that detect how certain metals react with chemical gases in the air. Freeman, who had worked previously in the Washington area for Litton Industries and Rockwell International, was able to use his government contacts to help the university land a $1.8 million grant to study how a more specific category of chemicals could be detected more effectively.

The U.S. military’s experience in the 1991 Gulf War, during which Iraqi forces possessed and possibly used chemical weapons, prompted the government’s interest in the subject, he said.

“The hot button at that time was chemical warfare agents,” Freeman said. “Department of Defense was starting to become really interested in chemical warfare.”

Besides UMaine, no one else was using solid state technology to detect chemical agents, he said, and SRD was quickly established to help fill the research and development void. SRD was formed in 1993 and in early 1997 was spun off from UMaine to become a completely separate entity.

“The company took off, basically,” he said.

Since Sept. 11, 2001, the federal government’s interest in detecting chemical and biological agents in military and emergency response situations has only increased further. The departments of Defense, Energy and Homeland Security each have a slightly different list of chemical or biological agents that they want to be able to detect, according to Freeman. SRD’s prototypes, which are about the size of a brick but not as heavy, have to meet the criteria for each agency if the firm eventually is going to win a contract to produce large quantities of its sensors for the government.

The federal agencies require the detection devices to be much more sensitive and much more exact than, say, a home radon gas detector, Freeman said. They want sensors that are easily portable, that each can detect a variety of harmful agents well before they reach lethal concentrations, and that do not trigger false alarms. The computer compatible devices, each of which consists of an array of 16 microsensors, would be used in military situations or at possible hazardous substance exposures.

“It’s very subtle differences sometimes,” Freeman said of the microscopic reactions the sensors have to detect. “It’s supersensitive. It’s really an analyzer.”

During a tour of SRD’s laboratory across the hall, Brent Marquis, the firm’s director of technology development, said the prototypes have to be able to sort through “interference” – secondhand smoke, for example, or household cleaner vapors – in order to avoid a false alarm. Sensors should not be triggered by diesel fumes but should detect even the smallest particle of anthrax or mustard gas.

“Most technologies can’t go down to those levels [of sensitivity],” Marquis said.

Marquis said SRD uses simulated substances when it tests its sensors on site. At periodic deadlines, the military tests the equipment with the real agents at authorized testing sites outside of Maine, he said.

Besides such sensitive detection devices, SRD also is developing “robust” equipment that can survive in harsh environments, according to Marquis. One such type of sensor would be mounted at the top of smokestacks where it would test manufacturing emissions for certain gases or compounds. Marquis said SRD also tests protective clothing such as body suits or gloves by seeing how long it takes a certain type of substance to penetrate through and then comparing that time to the protection offered by bluejeans or T- shirts.

Because of its exacting research, SRD has had to develop ways to deliver gases in ways that previously were unavailable, according to Freeman. As a result, SRD now makes custom gas delivery systems for other research entities.

“It’s not a gas-sensor system,” Freeman said. “It’s a derivative of that [research] and it’s very lucrative.”

Like many scientific or technical firms in Maine, SRD occasionally has trouble attracting experienced American scientists to live in northern Maine, Freeman said. As a result many of the firm’s 32 technical staff positions, 13 of which hold doctorate degrees, come from foreign countries such as Belarus or China. Six members of the technical staff are UMaine graduates, he said.

The firm has added about 10 positions in the past year for a total of 40 and hopes to add four or five more within the next 12 months, according to Freeman. Because SRD can afford to pay its scientists well – their average salary is “well over” $80,000 a year, he said – the company has assembled a staff that should be able to take it to the next level.

Later this year, federal officials are expected to whittle down the number of research firms hoping to win sensor manufacturing contracts from seven to three.

“We have the most highly qualified staff we’ve ever had,” Freeman said. “We’re in great shape.”

A microsensor array chip rests in the palm of a technician’s hand at Sensor Research and Development Corp. in Orono.

Carl Freeman owns Orono’s Sensor Research Development Corp.