Cognesense - Measure, Monitor, Protect

Cap Analog 410

The Cap Analog 420 is designed for process engineers, control technicians, and plant maintenance teams who need continuous and reliable level measurement for liquids, slurries, and bulk solids, with the added flexibility of local or remote installation.

This remote RF capacitance transmitter combines continuous analog output, dual relay alarms, and universal power compatibility in a rugged, explosion-proof package.

Designed for harsh or hazardous environments, the Cap Analog 420 maintains accuracy even when coating, buildup, or dielectric changes occur. This performance is achieved through coating-rejection circuitry and temperature-stable electronics.

With its remote-mounted electronics enclosure, operators can calibrate and service the transmitter safely at ground level, up to 800 feet from the probe. This makes it ideal for tall silos, buried tanks, and confined installations.

Whether used in chemical processing, wastewater plants, or bulk material handling, the Cap Analog 420 provides a dependable, maintenance-free solution that integrates directly with plant control and alarm systems.

Cap Analog 420 RF Remote Transmitter with Relay Outputs

Cap Analog 420

Features

Calibration and setup occur at the remote amplifier, enabling safe adjustments without climbing tanks or accessing hazardous or confined locations.

Drift-free sensing remains accurate across liquids, slurries, and solids due to shielding, temperature-stable circuitry, and selectable dielectric measurement ranges.

Compensates for conductive or sticky buildup on the probe, maintaining reliable level readings without cleaning interruptions or recalibration.

Accepts 115/230 VAC or 24 VDC, simplifying site standardization and reducing spare-parts variability across different facilities.

Provides continuous analog measurement plus two independently adjustable alarm points, allowing integrated level control and safety interlocks.

Supports up to 800 ft of probe-to-electronics separation, enabling remote mounting for improved access and reduced environmental exposure.

Applications

Coating or Fouling Liquids: RF sensing maintains accuracy in viscous or conductive products where traditional probes drift, foul, or require frequent cleaning.
Remote Access Tanks: Remote electronics allow safe calibration from accessible locations when tanks are tall, buried, or difficult to reach.
Slurries and Solids: Solid-state capacitance detection provides dependable level response where mechanical switches jam, wear, or stick in abrasive materials.
Chemical Storage Vessels: Wide dielectric range and corrosion-resistant probes support stable measurement in aggressive chemical environments.
Process Alarm Control: Dual relays enable high/low pump control, overfill protection, or interlocks directly from the transmitter.
Hazardous-Area Installations: Explosion-proof preamp and certified housings ensure compliant operation where flammable vapors or dusts are present.

Specifications

Measurement Technology

RF Capacitance, remote transmitter with integral preamplifier

Output Signal

4–20 mA DC or 0–10 V DC (selectable)

Relay Outputs

2 × SPDT, independently adjustable; 5 A @115 VAC (non-inductive)

Power Supply

115 VAC (90–135 V), 230 VAC (180–279 V), or 24 VDC (15–28 V)

Power Consumption

< 6 VA

Frequency

50–80 Hz

Fail-Safe Mode

Switch-selectable (energized or de-energized on high level)

Status Indicators

Dual LED (red for capacitance > setpoint; yellow for relay energized)

Temperature Rating (Electronics)

–40 °F to +160 °F (–40 °C to +71 °C)

Temperature Stability

±0.5 pF per 30 °F at maximum sensitivity

Build-Up Tolerance

Up to 1,000 µmho conductivity

Cable Length (Probe to Electronics)

Up to 800 ft (244 m)

Process Connection

¾″ NPT (standard); Tri-Clamp or flange options available

Hazardous Area Approvals

NEC Class I, Groups C & D; Class II, Groups E, F, & G

Accessories

AFI-150 analog and DFI-150 digital field indicators

Probe Options

Teflon®, Kynar®, or stainless-steel rigid and flexible probes up to 250 ft (76 m)

2026 COST ESTIMATE

Contact Support

If you have questions not covered here, please contact the Cognesense support team for assistance.

What makes the Cap Analog 420 ideal for remote or hard-to-access tanks?

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Its remote-mounted electronics can be installed up to 800 feet from the probe, allowing safe and convenient calibration at ground level.

What is the benefit of the remote-mounted electronics design?

The main benefit is safety and serviceability. In applications where the tank top is high, difficult to access, or in a highly hazardous area, the primary electronics enclosure can be mounted safely at grade level or on an accessible platform. This allows all calibration and troubleshooting to be performed easily without climbing the tank.

Can it handle sticky or viscous materials?

Yes. The built-in coating rejection circuit compensates for buildup and maintains accurate readings even in challenging media.

Does the Cap Analog 420 provide both continuous measurement and alarm outputs?

It does. The transmitter delivers a 4–20 mA or 0–10 V analog output plus two independent SPDT relay outputs for alarms or control.

Is the transmitter suitable for hazardous environments?

Absolutely. The preamp housing is explosion-proof (NEMA 7/9) and certified for Class I & II hazardous locations.

How is the transmitter powered?

It operates on 115 or 230 VAC, or 24 VDC, allowing compatibility with various plant power systems.

How does it maintain signal stability over an 800 ft cable run?

The device uses a two-piece design. A small, rugged preamplifier is installed right on the probe and tank, which conditions the low-level capacitance signal. This signal is then transmitted over the long, shielded cable to the remote, powerful amplifier unit, ensuring reliable, noise-free data over the 800 ft distance.

What are the typical applications for this transmitter?

It’s commonly used in chemical storage tanks, wastewater sumps, silos, and process vessels where reliable level control and alarm functions are needed.

Summary

Building on decades of RF capacitance innovation, the Cap Analog 420 offers a robust, flexible, and field-proven level transmitter for liquids, slurries, and solids. 

With remote electronics, dual relay alarms, and universal power compatibility, it simplifies control and monitoring in tanks where accessibility, buildup, or harsh conditions challenge other sensors. 

Combining capacitance precision, hazardous-area safety, and reliability, the Cap Analog 420 offers an ideal balance of performance, flexibility, and long-term value across chemical, wastewater, food, and bulk storage applications.