Selling breath alcohol monitors has been a sobering experience for two Washington area entrepreneurs, and they hope that using them will be the same kind of experience for area residents, who face a tough new drunk-driving law that went into effect in Washington at midnight last Friday.

D.C.-based SafeChoice is trying to place large coin-operated monitors in area restaurants and is acting as distributor for small monitor kits. But so far only two restaurants have the machines and only two stores have agreed to sell the kit.

Thomas J. Dolan, a Department of Education program analyst, saw the machine, called the Alcohol Guard, in upstate New York last Thanksgiving. He discussed it later with a friend, Glenn Strahs, president of Solar Applications Inc., a four-year-old Washington-based company that builds greenhouses, solar hot water panels and fireplace systems.

"What really got us interested was a really tragic accident in Anne Arundel County last Christmas" in which a number of young people were killed, Dolan recalled. They also saw a television show about the problem of drunk driving in January before deciding to start supplying breath alcohol monitors.

SafeChoice bought the machines from the manufacturer, ACS of Canada, and from other parties who had purchased them from ACS. Dolan and Strah are trying to place them in area restaurants so that patrons can check on whether they are in condition to drive.

The "vast majority of people don't know their blood alcohol level," Dolan said, indicating that so-called rules of thumb about how many drinks are "safe" aren't very reliable because of differences in individual size and metabolism.

"This machine lets you know that how you feel isn't a good indicator of your legal sobriety," Dolan says. "We're supplying a speedometer to the drinking public."

So long as five minutes have passed since your last drink, the Alcohol Guard can analyze accurately the subject's breath alcohol content, which reflects blood alcohol content, according to Dolan and Strahs.

The first step is to plunk 50 cents into the machine, an upright cabinet that is about the size of a standard vending machine. The next step is to take a clean straw, place one end in a hole at the front of the machine and blow hard through it.

A digital display then indicates the alcohol level in terms of milligrams of alcohol per decaliter of blood and one of three lights goes on.

If the red light flashes, it means that alcohol content is 0.10 milligram or above. Information next to this light tells you "don't drive."

If the yellow light goes on, alcohol content is 0.05 to 0.09 milligram, and the machine's assessment is "take it easy."

If the green light goes on, alcohol content is 0.04 milligram or less, and the machine advises: "You're OK, try this test later."

SafeChoice owns 10 machines. One is in Joe Theismann's Restaurant in Camp Springs, and a second was placed in Riddles Restaurant Cafe & Gathering Place in Alexandria in mid-August.

"A lot of people look at it as a toy, but it does work," says Steve Otto, assistant manager at Riddles. "A lot of people have become a lot more aware of the shape they're in."

SafeChoice hopes that each machine it places will be used between 175 and 200 times a week, meaning that it will take about a year to repay the purchase price of $2,575.

The partners -- who deliver and service the machines as well as sell them -- go doggedly on, trying to find homes for the other eight. "It doesn't do me any good to have them in my garage," Strahs comments.

SafeChoice also distributes in a 50-mile radius from Washington the Arrive Alive Balloon Test, which carries a retail price of $1.49. Blowing through a balloon into chemicals indicates breath alcohol content.

The partners are trying to get Virginia and Montgomery County ABC liquor stores to sell the Arrive Alive.

Area drug stores also have been approached, but so far only two party supplies stores, Party Tyme in Sterling, Va., and Party Masters in Arlington, are carrying the portable test kit.

Terry L. Mauney of Falls Church also is tackling distribution problems in the Washington area. He's gearing up to offer stores the Snap'n Hang, patented devices for hanging things from the rails that hold acoustical ceiling tile in place.

The hangers were invented in 1975 by his father, Harold D. Mauney of West Palm Beach, who couldn't find anything suitable to help him hang an "employes only" sign from such a ceiling at his one-man metal-casting foundry and pattern shop.

The elder Mauney worked out one model with a piece of nylon and asked a friend to produce one in his machine shop. The first attempt failed, but he kept trying until he came up with a design that causes the hangers to grasp the rails tighter if they are pulled on.

One type of hanger comes with an eye hook; the other, with a swivel hook. They already are available in stores in New York, California, Florida and Canada. Prices by mail range from $3.00 for a bag of 12 eye-hook hangers to $13.40 for 50 swivel-hook hangers. The company is called Acousti-Clip Mfg., and its address is 2095 Laura Lane, West Palm Beach, Fla. 33406.

"From the beginning, we've had nothing but enthusiastic response," says son Terry, who has kept his job as an ocean engineer with the David Taylor Naval Ship Research and Development Center in Carderock, although his father sold his casting business.

"To begin with, we just kind of had to work with word of mouth," Terry Mauney says, explaining that they picked up several investors over three or four years and have been advertising in merchandising magazines.

So far the Mauneys have spent about $60,000 on the venture, with the biggest problem being where to advertise.

The father-son partnership is no problem, each indicated in separate interviews.

Harold Mauney's innovation has given his son plans for a new career. He said that he "intends to invent things and start a new marketing company."