Radiometric Level Measurement

Radiometric Level Measurement

Endress+Hauser’s radiometric (gamma) level portfolio is built for the places where other principles run out of headroom, extreme temperature/pressure, corrosive or abrasive media, heavy foam, internals and refractory linings, or difficult geometries. A sealed radioactive source emits a defined gamma beam through the vessel wall; a detector on the opposite side measures attenuation and converts it to level, point level, interface position, or density. Because nothing intrudes into the process, there are effectively no process‐side limits, and measurement remains stable across liquids, slurries, and bulk solids. The portfolio combines compact detectors (Gammapilot), matched source containers, gamma sources, and accessories that harden the signal path and simplify lifecycle compliance.

At the core is Gammapilot FMG50, a multifunction compact detector for continuous level, point level, interface, and density. It’s the first true 2‑wire, loop‑powered radiometric transmitter, cutting installation effort, while providing 4–20 mA/HART, Bluetooth® setup, Heartbeat Technology for in‑process diagnostics/verification, and functional safety up to SIL 2/3 for all measuring tasks. FMG50 is specified for ambient temperatures to +80 °C without external cooling and is applied across reactors, autoclaves, separators, acid tanks, and cyclones. These capabilities, together with automatic self‑monitoring and proof‑test support, make FMG50 the default detector for modern gamma measurement points.

For point level, Gammapilot FTG20 employs one to three Geiger–Müller counters in a rugged housing with separate transmitter options. It combines very high sensitivity with fast switching (typ. ≤ 0.4 s) for reliable high/low alarms in the harshest duties. Because the measuring path is entirely external, process temperature and pressure are effectively “any” (non‑invasive), and outputs include relay, two‑wire 8/16 mA, or 4–20 mA for straightforward interlocks and PLC inputs. Typical vessels include reactors, autoclaves, cyclones, cupola furnaces, and corrosive storage where conventional probes cannot survive. HistoROM data handling and automatic decay compensation minimize recalibration after electronics replacement.

Safe, well‑engineered source containers shape and protect the beam. FQG61/FQG62 mount outside the vessel and provide a heavily collimated beam with a manual or pneumatic shutter, maximizing personnel safety and minimizing stray radiation; activity ranges cover Cs‑137 and Co‑60 within defined limits. Where full‑beam illumination is needed for density and interface profiling, FQG63 uses a flexible dip‑tube to lower the source into a protection pipe inside the tank; when shuttered “off,” the capsule is fully shielded in the container. FQG63 supports Cs‑137 up to 185 GBq and Co‑60 up to 3.7 GBq, with –52…+400 °C process temperature and typical ISO 2919 class C66646 source classification for robustness. Endress+Hauser supplies the matched FSG60 (Cs‑137) and FSG61 (Co‑60) gamma sources; Cs‑137’s long half‑life underpins cost‑effective operation and stable calibration over many years.

Plants with non‑destructive testing (NDT) or other external radiation benefit from the Gamma Modulator FHG65 and Synchronizer FHG66. FHG65 chops the beam at a fixed frequency so Gammapilot can separate the “useful” modulated signal from background/extraneous radiation, maintaining measurement during radiography and other interference events. FHG66 lets you synchronize multiple modulators and monitor status for diagnostics. All FMG50 versions evaluate the modulated beam directly, extending availability and avoiding unnecessary shutdowns; the approach is equally effective where the medium itself carries radioactive particles (e.g., certain mining slurries).

Where does radiometry shine? In oil & gas, gamma interface measurement tracks sand/water/emulsion/oil/foam layers in separators and desalters, enabling tighter residence‑time control and cleaner crude; multi‑detector profiles visualize up to five distinct layers. In delayed coker drums, radiometric level/foam measurement resists vapor, temperature, and build‑up, driving antifoam spray logic and protecting overheads. In mining, chemicals, and pulp & paper, non‑intrusive density measurement on abrasive or hot pipelines delivers stable mass‑balance data without tapping the line. Across industries, gamma devices solve level and point level in thick‑walled or refractory‑lined vessels, tanks with internals, and hazardous or toxic media where zero intrusion is non‑negotiable.

Why this portfolio? Radiometric instruments deliver process‑agnostic measurement: no moving parts, no impulse lines to plug, no dependence on dielectric or conductivity, and no process‑side limits on pressure or temperature because hardware remains outside the vessel. The Gammapilot platform adds modern diagnostics (Heartbeat) and Bluetooth commissioning; source containers provide engineered shielding and positive shuttering to minimize dose; and accessories like FHG65 harden measurement in active plants. Taken together, Endress+Hauser’s radiometric package offers a complete, safety‑documented path from engineering through operation for the truly difficult applications that demand non‑contact certainty.

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