Process engineers, control technicians, and plant maintenance teams who need continuous and reliable level measurement for liquids, slurries, and bulk solids—with the flexibility of local or remote installation—choose the Cap Analog 420 which delivers unmatched versatility and control.
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 under coating, buildup, or dielectric changes, thanks to coating-rejection circuitry and temperature-stable electronics.
With its remote-mounted electronics enclosure, operators can safely calibrate and service the device at ground level—up to 800 feet from the probe—making 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 reliable, maintenance-free solution that integrates directly with control and alarm systems.
Mount the electronics enclosure in an accessible area for safe, ground-level calibration—ideal for tall or confined tanks.
Provides independent alarm setpoints for overfill, low-level, or control functions alongside the continuous analog signal.
Converts dielectric changes into stable, drift-free output suitable for liquids, slurries, and bulk solids.
Simplifies installation across global facilities and eliminates stocking multiple transmitter versions.
Ensures accurate performance even with sticky or conductive buildup on probes.
Rated NEMA 7/9 for hazardous locations—safe for petroleum, chemical, and industrial applications.
Enables flexible installation between the probe and electronics without signal degradation.
Combines continuous level output with discrete control or alarm functionality in one instrument.
| Parameter | Description |
|---|---|
|
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 relays, 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 LEDs: Red (capacitance > setpoint), Yellow (relay energized) |
|
Temperature Rating (Electronics) |
–40 °F to +160 °F (–40 °C to +71 °C) |
|
Zero / Span Range |
Standard: 10–500 pF zero, 50–1,000 pF span; High-gain: 100–2,000 pF zero, 800–10,000 pF span |
|
Temperature Stability |
±0.5 pF per 30 °F at maximum sensitivity |
|
Build-Up Tolerance |
Up to 1,000 µmho conductivity |
|
Cable Length (Probe–Electronics) |
Up to 800 ft (244 m) |
|
Process Connection |
¾″ NPT standard; Tri-Clamp or flange options available |
|
Housing (Preamp) |
Cast aluminum, explosion-proof, NEMA 4/5/7/9/12 |
|
Housing (Remote Amplifier) |
Glass-reinforced polyester, NEMA 4X |
|
Hazardous Area Approvals |
NEC Class I, Groups C & D; Class II, Groups E, F, & G |
|
Probe Options |
Teflon®, Kynar®, or stainless-steel rigid and flexible probes, up to 250 ft (76 m) |
|
Accessories |
Delevan AFI-150 analog and DFI-150 digital field indicators |
Have a look at the flyer to get all the tech specs and product features.
Brochure
Read the manual for detailed information and instructions.
Manual
Check out a sample cert from our calibration lab.
Certificate
If you have a question that we have not covered then just get in touch and we’ll be happy to help.
We have tried to answer the most common questions we are asked here.
Its remote-mounted electronics can be installed up to 800 feet from the probe, allowing safe and convenient calibration at ground level.
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.
Yes. The built-in coating rejection circuit compensates for buildup and maintains accurate readings even in challenging media.
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.
Absolutely. The preamp housing is explosion-proof (NEMA 7/9) and certified for Class I & II hazardous locations.
It operates on 115 or 230 VAC, or 24 VDC, allowing compatibility with various plant power systems.
It’s commonly used in chemical storage tanks, wastewater sumps, silos, and process vessels where reliable level control and alarm functions are needed.