Captrol 511

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Overview

Captrol 511

For process engineers, plant operators, maintenance teams, and OEM system integrators who need a reliable, rugged, and accurate point-level solution for powders, slurries, and liquids, the Captrol 511 offers a solid-state RF capacitance switch with universal power input, adjustable time delay, and a driven-guard probe to eliminate false trips from product buildup.

Unlike competitive point switches, the Captrol 511 provides explosion-proof construction, integral electronics with high dielectric sensitivity, and robust probe options that ensure dependable performance in metallic or non-metallic vessels under harsh industrial conditions.

Omnitrols 610/710

Features

Non-Contact Technology

Driven-Guard RF Capacitance Probe

Eliminates false trips from coating and buildup in viscous or sticky media.

Ultra-Low Power

Universal Power Input (115/230 VAC or 24 VDC)

Supports varied plant standards and simplifies retrofits and stocking.

High Sensitivity

Adjustable Sensitivity & Time Delay

Tunable response to prevent nuisance switching from agitation, splashing, foaming, or turbulence.

Graphite Displacer Reliability

Explosion-Proof Aluminum Housing

NEMA 4/5/7/9/12 rated for hazardous industrial areas.

DPDT Output Relay with Fail-Safe Modes

Field-selectable high- or low-level fail-safe logic for safe pump shutdown and overflow/dry-run protection.

Multiple Host Interfaces

Multiple Probe Options

Stainless steel, Teflon®, ceramic, and abrasion-resistant probes for corrosive liquids, powders, and food-grade applications.

Details

The Captrol 511 uses RF capacitance sensing with driven-guard circuitry, allowing it to ignore conductive coatings and buildup—ensuring reliable switching even in slurries, viscous materials, and powders.
A solid-state design with no moving parts eliminates mechanical failure and reduces maintenance, while the universal power supply makes installation straightforward across multiple plant environments.
With adjustable sensitivity and selectable time delay, technicians can fine-tune switching behavior to match the process media, avoiding false trips from turbulence, vibration, or splashing. Fail-safe relay modes ensure predictable behavior on loss of power, protecting pumps and preventing spills.
Available probes include Teflon®, stainless steel, ceramic, and abrasion-resistant designs, suitable for abrasive solids, aggressive chemicals, sanitary environments, and high-temperature applications. The sensor can also be equipped with remote ground options for use in non-metallic vessels.
Designed for heavy-duty industrial service, the Captrol 511 remains accurate and reliable in chemical processing, food production, water/wastewater operations, grain and powder handling, and industrial process vessels.

Details

Applications

  • Material Buildup: Driven-guard RF design ensures reliable switching even in sticky or viscous products that foul other sensors.
  • Light Solids/Powders: High-sensitivity RF probe reliably actuates even with low-density media.
  • Non-Metallic Tanks: External ground reference capability ensures accurate sensing in plastic or fiberglass vessels where the tank wall cannot provide a natural ground.
  • Pump Protection: Fail-safe relay mode protects pumps and prevents spills by ensuring reliable overflow or dry-run logic.

Technical Specifications

Parameter Description
Technology
RF capacitance point-level switch with driven-guard probe
Power Supply
115 VAC, 230 VAC, or 24 VDC
Output
DPDT relay, 5 A
Sensitivity
0.5 pF to 30 pF adjustable
Fail-Safe Modes
Selectable high-level / low-level
Time Delay
Adjustable 0.3–20 seconds
Temp / Pressure Ratings
Electronics: –40 °C to +71 °C; Probes up to 400 psi
Enclosure
Explosion-proof cast aluminum, NEMA 4/5/7/9/12
Approvals
NEC Class I Div II (C, D); Class II Div II (E, F, G)
Mounting
NPT or flange
Probe Types
Stainless, Teflon®, ceramic, abrasion-resistant; remote ground options
Indicators
Dual LEDs (capacitance state / relay state)

Documents and Downloads

Product Flyer

Have a look at the flyer to get all the tech specs and product features. Brochure

User Manual

Read the manual for detailed information and instructions. Manual

Calibrations

Check out a sample cert from our calibration lab. Certificate

Contact Support

If you have a question that we have not covered then just get in touch and we’ll be happy to help.

Contact Us

FAQs

We have tried to answer the most common questions we are asked here.

Yes — the driven-guard probe prevents false trips caused by buildup, slurry coating, or thick media.

The driven-guard probe design is the key. It creates an electronic shield that prevents conductive buildup or coating on the probe from generating a false signal. The switch only actuates when the bulk material fills the sensing area, ensuring reliable level indication and significantly reducing service calls for cleaning.

Absolutely. The 511 is explosion-proof and approved for Class I & II Div II industrial environments.

Yes. The Captrol 511 features a universal power supply that allows it to operate on 115 VAC, 230 VAC, or 24 VDC input. This simplifies stocking and installation across sites with varied power standards.

The adjustable time delay allows you to set how long the switch must detect the presence or absence of the product before the relay actuates. This is essential for challenging applications with agitation or splashing, as it prevents spurious switching that could unnecessarily trip a pump or alarm.

No. The 511 features adjustable sensitivity and time delay for quick setup and reliable performance.

Yes — it supports external or remote ground references for non-metallic vessels.

Ideal for powder hoppers, slurry tanks, chemical vessels, food processing tanks, and wastewater basins.

Selectable fail-safe logic ensures the relay returns to a safe state on power loss.

Choose from Teflon®, ceramic, stainless-steel, and abrasion-resistant probes for chemical, high-temp, or abrasive media.