ENDRESS+HAUSER  FTG20-AA14A1AA

Application

• Non-invasive point level measurement for liquids, solids, suspensions and sludges etc.
• Used under extreme measuring conditions, e.g. high pressure, high temperature, corrosiveness, toxicity, abrasion.
• All kinds of process vessels, e.g. reactors, autoclaves, separators, acid tanks, mixers, cyclones, cupola furnaces.

Your Benefits

• Sensor and transmitter: One instrument for all measuring tasks
• Highest availability, reliability and safety, even for extreme process and ambient conditions
• Optimum adjustment to the respective application and measuring range via a variety of sensitivity versions:
• Relay, 8/16 mA (passive) or 4 to 20 mA output for easy system integration
• Aluminium or stainless steel housing for heavy-duty applications
• Easy commissioning and fast, on-site operation
• Can be used universally due to numerous certificates and approvals
• Short response time
• No recalibration required following replacement of electronics
• Electronics self-monitoring

Measuring principle

Radiometric point level detection is based on the fact that gamma radiation is attenuated when it penetrates a material. As a general rule, the attenuation is a function of the following parameters: Density r and thickness d of the material as well as a substance-specific, linear attenuation coefficient μ which depends on the type of radiation source.

The attenuation is defined by the following formula: Fs = e -μrd

A gamma radiation source and a Gammapilot FTG20 are mounted on opposite sides of the vessel at the height of the desired level limit.

"μ" and "d" remain constant for point level detection and the radiation intensity only depends on the medium being present:

• The count rate at the FTG20 reaches a maximum if the radiation path in the vessel is free (no medium in the radiation path).
• The count rate at the FTG20 reaches a minimum if the radiation path in the vessel is covered with medium and the radiation is attenuated as a result.

The min. and max. count rates, N min , N max , are determined when the transmitter is commissioned and are calibrated, whereby the following formula defines the relationship between them: N min = N max e -μrd

The switching points are defined automatically following calibration.