Cognesense - Measure, Monitor, Protect

Captrol 510

The Captrol 510 is designed for process engineers, automation technicians, and plant operators who require reliable dual-point control for liquids, slurries, or bulk solids.

The instrument delivers accurate, maintenance-free level detection with dual relay functionality in a single rugged, explosion-proof device.

Unlike mechanical or optical switches that can clog, wear out, or drift over time, the Captrol 510 uses RF capacitance technology with independent high and low setpoints, non-interacting calibration controls, and solid-state fail-safe electronics. This combination provides stable performance even in demanding industrial environments.

With universal voltage compatibility (115/230 VAC or 24 VDC), dual independent relays, and a rugged NEMA-rated enclosure, the Captrol 510 simplifies control and safety integration in chemical processing, food production, wastewater treatment, and bulk solids handling.

One probe provides two switching points with zero routine maintenance, making it ideal for pump-up/pump-down control, overflow prevention, and bin level management.

Captrol 510 RF Capacitance Dual-Point Level Switch

Details

The Captrol 510 delivers reliable dual-point level control for industrial process environments.

Using RF capacitance sensing at 2 MHz, the instrument detects changes in material dielectric properties to provide precise switching performance that is unaffected by buildup, moisture, or dust.

Two independent relays provide both high and low level detection within a single device. This allows operators to manage pump-up/pump-down, fill/drain, or alarm control without additional instruments.

Each relay features non-interacting setpoint adjustments, allowing one relay to be calibrated without affecting the other. Operators can also configure fail-safe operation, ensuring a predictable output state during power loss or signal failure.

The solid-state electronics and driven-guard probe design allow reliable performance across a wide range of materials, including conductive liquids, slurries, powders, and granular solids.

The transmitter is housed in a die-cast aluminum explosion-proof enclosure, certified for hazardous environments and designed for long-term reliability with minimal maintenance.

Available probe options include rigid or flexible designs in Teflon®, Kynar®, or stainless steel, with optional 3A sanitary fittings for hygienic installations. This flexibility allows the Captrol 510 to be used in chemical processing, food production, wastewater treatment, and general industrial applications.

Technical Specifications

Parameter

Description

Technology

RF capacitance with solid-state electronics and dual adjustable setpoints

Excitation Frequency

2 MHz

Output Relays

Two independent Form C (DPDT) relays; 5 A at 110 VAC, 2.5 A at 220 VAC, 3 A at 24 VDC (non-inductive)

Power Supply

115 VAC (100–130 V), 230 VAC (200–260 V), or 24 VDC (18–28 V)

Power Consumption

≤ 3 VA

Sensitivity

0.5 pF or less

Response Time

100 ms standard; adjustable up to 30 seconds

Fail-Safe Mode

Selectable high or low level (relay de-energized on power loss)

Electronics Temperature Range

–40 °F to +160 °F (–40 °C to +71 °C)

Probe Temperature Limits

Up to +450 °F (+232 °C) with lagging extension

Enclosure

Die-cast aluminum with polyester coating; NEMA 4, 5, 7, 9, 12

Certifications

CSA Class I Groups C & D; Class II Groups E, F, G; Cenelec EEx d IIC T6 (pending)

Mounting Options

¾ in NPT, 3A sanitary, or flanged (carbon steel or stainless steel)

Probe Styles

Rigid probes up to 20 in or flexible cable probes up to 250 ft (76.2 m); Teflon®, Kynar®, or stainless steel

Indicators

Yellow LED: relay energized; Red LED: level above high setpoint

Calibration Controls

Multi-turn potentiometers for setpoint and differential; DIP switches for range and fail-safe selection

Installation Notes

Probe should be grounded to vessel wall; dual or concentric probe required for non-metallic tanks

2026 COST ESTIMATE

Support

If you have a question that is not covered here, please contact the Cognesense support team for assistance.

What makes the Captrol 510 different from other level switches?

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It combines two independent level setpoints in a single device, providing both high and low-level control with non-interacting calibration—perfect for pump-up/pump-down or dual alarm applications.

Can it be used with powders and granular materials?

Yes. The RF capacitance design and driven-guard probe allow accurate detection even in dusty, foamy, or low-dielectric media.

Is it suitable for hazardous locations?

Absolutely. The Captrol 510 is rated NEMA 7/9 explosion-proof and approved for Class I & II Div 1 service.

How is calibration performed?

Each setpoint uses a multi-turn potentiometer for precise adjustment, with separate controls that don’t affect each other.

Why is non-interacting calibration important?

In older dual-point switches, adjusting the high-level setpoint could inadvertently affect the low-level setpoint, leading to unstable operation and repeated service calls. The Captrol 510‘s non-interacting controls ensure that each setpoint and differential can be precisely adjusted independently, guaranteeing stable, simple, and accurate field setup.

What happens during a power loss?

A fail-safe mode can be selected to de-energize relays in either high or low-level conditions, maintaining a predictable, safe state.

Can one probe detect both high and low points?

Yes. The Captrol 510’s dual-point design uses a single probe to measure both levels—reducing penetrations, wiring, and installation cost. It is ideal for efficient pump-up/pump-down control or integrated alarm functions.

How does the Captrol 510 control two levels with one probe?

The Captrol 510 is designed with a single probe that feeds the capacitance signal to two separate, independent electronic circuits within the controller. Each circuit has its own set of potentiometers to define a Set-point (where it switches) and Differential (hysteresis), allowing one circuit to manage the low level and the other to manage the high level, all using the same signal.

What industries commonly use the Captrol 510?

It’s widely used in chemical plants, food and beverage processing, wastewater systems, and bulk solids storage where dependable dual-level control and safety monitoring are critical.

Is the Captrol 510 reliable in media that tends to coat sensors?

Yes. The switch’s high-frequency (2MHz) RF signal and advanced driven guard probe design are highly effective at electronically ignoring conductive buildup or coating on the probe. This allows the switch to maintain accurate detection of the bulk product level, reducing false trips and eliminating the need for frequent cleaning.