Radiometric Level Measurement

Radiometric Level Measurement

Radiometric level measurement uses gamma radiation attenuation to determine level (and often density or interface) from outside the vessel. A shielded radioactive source is mounted on one side of the process, and a detector on the opposite side measures transmitted radiation. As level changes, absorption through the product changes, producing a stable signal even when the vessel interior is inaccessible or highly disturbed.

This technology is used where other principles become impractical due to extreme process conditions or mechanical constraints. Since the system is non-contact and external, it is unaffected by pressure, temperature, corrosion, build-up, foam, or internal obstructions such as agitators, coils, or heavy deposits. It can address continuous level, point level, interface, and density tasks in liquids, solids, slurries, and suspensions.

Radiometric systems require disciplined engineering and governance. Source handling involves regulatory compliance, radiation safety procedures, and lifecycle planning for licensing, inspections, and decommissioning. Proper shielding design, mounting geometry, and calibration methodology are essential to achieve measurement performance while maintaining safe exposure levels.

Typical applications include high-pressure separators, distillation columns, reactors with severe agitation, abrasive slurries, thick deposits, and high-temperature processes where wetted sensors cannot survive. Interface measurement in complex separators and density tracking in mineral and chemical processes are frequent use cases where radiometric methods provide a practical path to measurement.

Integration is typically straightforward once installed - continuous outputs and diagnostics feed standard control and safety systems. When extreme conditions eliminate conventional sensing options, radiometric measurement provides a proven, externally mounted solution that restores level visibility without process intrusion.

Field Instruments & Controls, Inc. an exclusive authorized representative of sales and service for Endress+Hauser.