Every two years, almost like clockwork, David N. Ebbert can be seen on an airplane headed for Salt Lake City with a small case sitting on his lap that he carefully guards to prevent undue bumping.

Movie buffs might think Ebbert's case contains a bomb or some contraband, but the 8-pound unit that measures 8 inches by 8 inches by 15 inches actually is a standard cell that has been calibrated by the National Bureau of Standards.The standard cell is used to check DC voltage and is one of the main pieces of equipment at Stabro Laboratories Inc., 25 Kensington Ave., one of 150 independent precision measuring equipment laboratories in the United States. Ebbert is the general manager.

When the standard cell needs calibration, it is shipped to the NBS. But rather than take a chance of the cell's getting tipped over or bumped severely, Ebbert said he chooses to carry it back to Salt Lake City on his lap.

He laughs when recalling that after airport security was beefed up several years ago because of hijackings, his standard cell was X-rayed and he spent quite some time convincing the security guards what was in the little brown box.

Once back at Stabro, the box regains its place in the primary standards laboratory and is used to calibrate the testing equipment, which then is used to determine the accuracy of hundreds of different types of devices that flow into Stabro for calibration and repair.

The other pieces of equipment used as a standard in the calibration and repair process are shipped to the national laboratory and don't require Ebbert's personal airplane ride. But they are just as valuable because they calibrate hundreds of sophisticated pieces of equipment, many of them used in high technology.

Stabro comes from the first three letters of the names of the founders, Jim Stahnke and Jay Brown, both of whom worked in the calibration laboratory at Sperry Univac. They knew there was a market for a calibration laboratory, especially because of the United States' push for high technology in connection with national defense and the space program.

Brown borrowed $1,500, used the money to purchase three pieces of testing equipment and established Stabro in the basement of his home in 1959. In a few months Dave Anderson bought into the company. Their first customer was MonTek, which later became LTV-Memcor.

Their next customer was Litton Industries, which was building microwave ovens and hired Stabro to calibrate the equipment used to check the microwave tubes.

Stahnke left for California in 1960, Brown said, leaving Anderson as the company engineer and Brown as president and technician.

Brown recalls working a night shift at Sperry, picking up equipment for testing and repairing in the day, dropping equipment off to customers and then going back to work. "I didn't get much sleep for two years. Anybody with a quality mind would have quit."

Slowly, Stabro started to grow, and Brown left Sperry in 1962 to devote full time to his fledgling company. Anderson and Betty Gleave, Stahnke's widow, sold out to Clark Reber, the present owner, and Udell Campbell in 1970, and Reber bought out Brown and Campbell 16 months ago.

Brown remains on the Stabro payroll as a consultant and has started his own television production company, Academy Telecine Productions.

Stabro's first big break came in 1966 when it was hired by Litton Data Systems to calibrate and repair 500 pieces of testing equipment. Litton remains the laboratory's biggest customer, and eight of Stabro's employees are stationed there full-time.

From the modest beginning when Stabro had a net income of $2,900 in the first year of operation and Brown was concerned about making the payroll, the laboratory now has 38 employees and service sales of $2.5 million annually.

Reber was raised on a small farm in Mesquite, Nev., attended the University of Nevada at Reno and graduated with a degree in agriculture education. He received a commission in the U.S. Army by finishing the Reserve Officer Training Corps program and served 71/2 years on active duty, including a stint as a helicopter pilot in Vietnam.

He left active duty in 1967 and now is a lieutenant colonel in the Army Reserve. He also has an insurance business and served two terms in the Utah House of Representatives.

A native of Mansfield, Ohio, Ebbert learned the equipment calibration business while serving in the U.S. Air Force for 20 years. He joined in 1952, served as a radio operator, took some equipment calibration courses and then worked in Air Force calibration laboratories in the United States and Guam.

In 1971, Ebbert came to Salt Lake City to attend conference sessions of The Church of Jesus Christ of Latter-day Saints. He visited Stabro and was "hired on the spot" because of his background. He started out as a technician, eventually becoming a supervisor and then general manager.

Ebbert said the desire for accurate weights and measures probably dates back to the Egyptian pharaohs who measured from their nose to the end of an extended arm. But the unit of measure changed when each pharaoh died, an indication of a need for standardization.

"It doesn't matter what the unit of weight or measure is," Ebbert said, "but everyone should be measuring from the same standard."

That's where the NBS comes in because all of the calibration, weights and measures center on the standard in that agency. And that's why Ebbert takes his biennial trip from the NBS clutching his little brown box.

The key word in the equipment calibration industry these days is

"traceability," meaning that NBS equipment is used to calibrate other equipment sent by a laboratory such as Stabro and the calibration process is carried into companies desiring accurate devices.

That means Stabro's customers know their equipment is giving accurate readings.

Each time Stabro's equipment is sent to the NBS for calibration and testing, and each time a Stabro customer has equipment calibrated and repaired, records are kept and the equipment certified as accurate. That is espcially important when companies deal with the federal government and the equipment must be accurate.

Ebbert said NBS officials are continually working for greater accuracy. Each state has its own standards for checking gasoline pumps, scales and other measuring devices.

The evolution of electrical measurement and the measuring instruments has changed rapidly in the past 40 years, Ebbert said.

From the early beginnings of the volt-ohm-meter (VOM), which had an accuracy of between 3 and 10 percent, Ebbert said, evolved the modern instruments such as the digital voltmeter that has an accuracy of 0.00001 percent or 10 parts per million.

"This factor of 10,000 to 1 in accuracy improvement has changed the approach and attitude to calibration throughout the world," he said. The biggest change was caused by the military and the aerospace programs.

Some of the electronic testing devices handled by Stabro are oscilloscopes, frequency counters, digital and analog voltmeters, generators, spectrum analyzers, power supplies, date communication test equipments, logic analyzers, frequency, function and waveform synthesizers, plotters and recorders, televisions test equipment and temperature/humidity measuring instruments.

Some of the mechanical measuring instruments Stabro employees work on are gauge blocks, calipers, micrometers, Geiger counters, pressure recorders, ring and plug gauges, height gauges, dial indicators, thickness gauges, torque measuring instruments and parallels.

They'll even check a simple wooden 12-inch ruler to see if it's long or short.

In addition to the eight full-time employees at Litton, Stabro has one full-time employee at Unisys, another at Iomega in Roy and one who spends three days per week at National Semiconductor. Among the 600 other Stabro customers are Symbion, Rockwell and the Federal Aviation Administration.

For equipment that can't be certified at the site, the company has four mobile vans going to and from the lab with equipment and parts. The employees work in special white coats to reduce static electricity, and in most areas of the lab the temperature is controlled to help maintain the accuracy.

Stabro has $1.5 million worth of testing equipment, $175,000 in parts inventory and 7,000 repair manuals in their library so the technicians can study the problem, make repairs and calibration and get the equipment back in use quickly. Stabro also has satellite labs in Grants Pass, Ore., and Chicago, Ill.

With all of the sophisticated equipment used to test other equipment at Stabro, one of the tests on gloves for Utah Power & Light Co. linemen might be considered slightly crude.

Reber said electrodes are attached to a glove that is immersed in a bucket of water and 40,000 volts of electricity are pumped in. If the electricity burns a hole in the glove it certainly cannot be used by someone working near power lines.

He believes the laboratory has a bright future because companies find it more convenient to take their sophisticated equipment to Stabro rather than build their own calibration and testing laboratory, especially because of the initial cost of equipment.