Sensor Description

The sensor structure consists of an integrated heater located on a thin electrical and thermal insulating membrane. Two thin film resistors are used for heating and measuring the temperature of the membrane. Two resistors are integrated on the silicon beside the membrane for the compensation of the ambient temperature changes. Gases that have lower density than air (CH4) decrease on the surface membrane temperature. Gases with densities higher than ​air (CO2) increase the temperature of the measuring resistor.

Design

The 2750 is a rugged, portable, easy-to-use gas analyzer that monitors purge gases and the cooling gas in hydrogen-cooled turbine generators. Three selectable ranges monitor purge gas composition during maintenance purging and spot-checks hydrogen purity during normal generator operation. The portability of the unit eliminates installation costs and makes it easy to move between generators. There are no moving parts to wear out, no filters to change and no traps to clean; so, the 2750 is virtually maintenance free. A simple periodic calibration is all that is needed to assure years of trouble-free service.

Maintenance

To minimize downtime, it is important for the 2-step purge process to proceed quickly and effectively. The 2750 helps achieve those objectives. During the first stage of maintenance purging, the unit monitors the changing H2/CO2 mixture. This allows operators to know the earliest moment to begin the second stage (air purge). This also saves money by minimizing CO2 usage. During the second stage, the 2750 monitors air-in-CO2, which helps you decide when workers can begin maintenance.

Other Benefits

• Minimizes costly maintenance downtime
• Saves money by avoiding needless waste of CO2 purge gas
• Assures optimum efficiency by detecting air contamination
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