Capacitive Level Transmitter
One probe technology for liquids, powders and granular solids — continuous 4–20 mA level measurement with no moving parts, from −40 to +200 °C.
Technical Data
| Measuring principle | Capacitance between electrode rod and tank wall |
|---|---|
| Measured media | Conductive & low-conductive liquids, granulated solids, adhesive and acid/basic liquids |
| Capacity range | 1 pF – 3 nF · min. dielectric constant ~1.5 |
| Measuring range | ~0.1 m to several metres (rod); longer with cable probe |
| Output signal | 4–20 mA two-wire (9–36 V DC) std.; 0–20 mA / 0–10 V three-wire opt. |
| Linearity | ~0.5% |
| Process connection | Threaded or flanged (EN 1092-1 / ASME B16.5 / customer) |
| Process temperature | -40 to +150 °C std. · 200 °C with cooling apparatus · -196 °C cryogenic option |
| Process pressure | -1 up to 100 bar (model dependent) |
| Probe insulation | PFA std.; PEEK, PTFE, rubber, FKM options |
Selection Guide
Uninsulated rod for non-conductive liquids and dry solids.
Best forOils · powders · granulesPTFE-coated probe for conductive or corrosive liquids.
Best forAcids · aqueous mediaFlexible rope probe reaches down deep vessels and tall silos.
Best forDeep tanks · silosDatasheet & Drawings
GA, hook-up and wiring drawings are prepared per order — supplied with your quotation for approval.
EN 10204 3.1 material certificates are supplied with your shipment.
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Frequently Asked Questions
What can a capacitive level transmitter measure?
Liquids, powders and granular solids, and the interface between two liquids. With the correct probe it handles both conductive and non-conductive products across a wide range of dielectric constants.
What is RF admittance and how does it differ from plain capacitance?
RF admittance is an enhanced capacitance technique that measures the full admittance of the circuit and uses a guard electrode to ignore product build-up on the probe, giving more stable readings on sticky or coating media.
Does the medium have to be conductive?
No. Non-conductive media are measured with a bare probe, while conductive media use an insulated (for example PTFE-coated) probe so the probe does not short to the liquid.
Why does dielectric constant matter?
The bigger the difference between the product's dielectric constant and that of the air above it, the stronger the capacitance change per unit of level, which improves resolution. Low-dielectric products need careful probe selection.
Can it provide both continuous level and a switch point?
Yes. Continuous versions give a 4–20 mA level signal across the probe, and point-level versions provide a switching output for high- or low-level alarms.
Is it suitable for hazardous areas?
Yes. TOTFLEX can supply ATEX/IECEx-certified versions for explosive gas and dust atmospheres.
Engineered to order. Delivered worldwide.
Send your duty conditions — size, pressure, temperature, medium and connections — and our engineers return a drawing, material selection and lead time.
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