Multimeter Provides Reliable Test Data Under Rigorous Manufacturing Conditions

Alaska Diesel Electric, Inc., is a Seattle-WA-based manufacturer of marine generator sets and propulsion engines. The company's business is 50% building new electrical generation systems for fishing vessels, and 50% retrofitting or repairing existing systems. The market it serves places a heavy burden on the company because shipboard electrical systems must be reliable.

"Losing power at sea is not an option," says Jim Sanders, production engineer at Alaska Diesel. "Today, mega-dollar vessels are crammed with the latest electronic equipment. One voltage spark can take out thousands of dollars worth of equipment."

Because Alaska Diesel Electric generators operate in locations where one measurement misstep or calibration error could mean lives lost, its test equipment has to be knife-edge precise and reliable as it is rugged. When the company agreed to try the Fluke 179 DMM (digital multimeter) to test its AC-powered Lugger diesel generators, it had three requirements:

1. The test equipment had to operate in the challenging environment of a diesel-engine manufacturer. 2. The test equipment had to be rugged enough to withstand lengthy test procedures (2 1/2 hours for generators; 8 to 9 hours for emissions) and being dropped on the floor.

3. The test equipment had to be accurate and reliable in catching operating problems before the product left the factory.

Alaska Diesel test engineers found that the Fluke 179 could satisfy their requirements for a meter that was both durable and accurate. The unit has been specifically designed for front-line industrial, electrical and electronic technicians in environments that ranged from "clean" bench to harsh conditions, such as those at Alaska Diesel.

According to Gary Flory, Alaska Diesel's test cell lead, his crew's job was to hunt down elusive system glitches. Engineers used the meter to run tests to ensure the generator's electrical systems were working correctly as they were being built. To test the generators, engineers hook the generator to a diesel engine and powered it as if powering a ship. The Fluke multimeter met the company's testing needs for its domestic (50 Hz) and international (60 Hz) generators by supplying an Hz range from 1 Hz to 99.99 kHz (to 0.09% accuracy).

The unit was also able to check for internal temperature rise, an indication of the quality and quantity of copper in the generator. The lower the rise, the more copper and the better the quality. The 179 measures temperature with sensor leads plugged into the front panel sockets.

The unit's safety features also proved useful to Alaska Diesel technicians. Units can withstand an impulse voltage in excess of 8 kV. Also, users can change the unit's batteries with a standard screwdriver without breaking the calibration seal. Calibration adjustments can be made directly from the front panel.

During weeks of on-the-job, non-stop calibrations, Flory and his crew used the 179 in the company's full range of rigorous tests. At the end of the testing period, the 179 took its place on the Alaska Diesel test cell workbench. "The Flukes are shop-floor tough," says Flory, "and we can count on them to give us the razor-sharp measurements we need."

Fluke Corp., PO Box 9090, Everett, WA 98206; 888-492-7550.