For more information, contact:

Jim Donaldson Advanced Energy Industries, Inc. 970.407.6374

Marna Shillman Advanced Energy Industries, Inc. 970.407.6280 marna.shillman@aei.com

Longmont, Colo., May 8, 2001—EMCO Flow Systems, an Advanced Energy (AE) Company (Nasdaq: AEIS), today announced the introduction of its Sono-Trak™ ultrasonic flowmeter for the semiconductor industry. The Sono-Trak flowmeter accurately measures the velocity of liquids in pipes using transit-time ultrasonic technology. Unlike similar ultrasonic flowmeters, the Sono-Trak flowmeter comes standard with an easy-to-read backlit display, a four-button keypad and a universal power supply for AC or DC power inputs. Semiconductor applications that are well suited for the Sono-Trak flowmeter include deionized water delivery systems, ultrapure water systems, slurries, as well as in the wastewater treatment side of the process.

"The Sono-Trak flowmeter features technology that provides our customers with best-of-breed performance—one of EMCO’s and AE’s core objectives," said Kaveh Zarkar, vice president of semiconductor products for EMCO. "Feedback from our install base at a major end-user site has been very positive. The Sono-Trak flowmeter has proven to be an effective and versatile instrument, ideally suited for the most stringent requirements of DI water flow measurement."

The Sono-Trak's advanced signal processing technology dramatically increases the accuracy of flow rate measurement, with accuracy ratings of +1.0 percent to 2.0 percent, and repeatability of +0.1 percent of reading. The Sono-Trak flowmeter uses a noninvasive flow technology that installs quickly and easily to pipe sizes ranging from 2 to 100 inches. The clamp-on design enables the unit to be installed without shutting down flow, and eliminates the need for pipe penetration that can cause fluid contamination. In addition, the Sono- Trak flowmeter does not have any moving parts, making it virtually maintenance- free.

The Sono-Trak flowmeter offers:

• A simple, noninvasive design
• High reliability and accuracy
• Fast, easy installation
• Increased flexibility
• Rugged, maintenance-free operation

Copies of the brochure describing the Sono-Trak flowmeter are available on AE's website at is www.advanced-energy.com or by sending a request via e-mail to sales.support@ aei.com.

About Advanced Energy
Advanced Energy is a global leader in the development, marketing and support of technology solutions that are central in the manufacture of semiconductors, data storage products and flat panel displays. Original equipment manufacturers (OEMs) and end-users around the world depend on AE products when plasma-based technology plays a vital role in their manufacturing process. AE offers a comprehensive suite of products for vacuum process systems, including power management, temperature sensing, dynamic temperature control, gas delivery management, process monitoring and machine control tools, ion-beam sources, and plasma abatement technologies. AE technology solutions are sold and supported globally by direct offices, representatives and distributors. Founded in 1981, AE is a publicly held company traded on Nasdaq under the symbol AEIS. AE's URL is www.advanced-energy.com.