The KOBOLD NEH is a cable-suspended conductive level switch that monitors up to six switch points in conductive liquids using flexible, weighted electrode cables in place of rigid probes. Designed for tall tanks, deep vessels, and installations with limited overhead access, it detects level electrically in liquids with a minimum conductivity of 20 uS/cm, including media contaminated with dirt or solids.
Neoprene cables with PVC-coated weights extend up to 100 ft, while PTFE cables with PTFE-coated weights reach up to 30 ft, allowing extended range where rigid probes are impractical. The NEH is available as a single measuring probe with a 1/2" NPT fitting or as a multipoint probe with a 1-1/2" NPT fitting supporting up to six measuring points.
How the NEH Detects Liquid Level
The NEH relies on electrical detection for accurate sensing in conductive fluids. Liquid contact at the electrode tip, insulated along the cable except for the exposed end, closes a low-voltage AC circuit (10 VAC, max. 0.5 mA) between the sensing probe and a ground reference, such as the vessel wall for conductive tanks or a ground electrode for insulating tanks.
Adjustable sensitivity from 0-50 kOhm via a potentiometer allows precise adaptation for different liquid conductivity and prevents false signals from foam or residues. Per specifications, the clad design prevents bridging in misty conditions, offering repeatable operation across extended lengths for reliable tank management.
Materials for Corrosive and Dirty Media
Electrodes available in 316Ti stainless steel, Hastelloy, or titanium and fittings in polypropylene or PTFE provide options for a variety of media, including corrosive or harsh chemicals. Housings available in polycarbonate or aluminum provide IP65 protection, and with no moving parts the design suits particulate-heavy or viscous conductive liquids.
The NEH can handle operating pressures up to 90 PSIG and temperatures up to 140°F (60°C) for Neoprene cables or 300°F (150°C) for PTFE cables. Key advantages carried across the range:
- Extended cable lengths up to 100 ft for deep-tank access
- No moving parts, suitable for particulate-heavy or viscous conductive liquids
- Up to six setpoints for full overflow, low-level, or pump control
- Corrosion-resistant materials: stainless steel, Hastelloy C, titanium with Neoprene/PTFE cladding
- Low-voltage operation and adjustable sensitivity for precise detection
- Compact IP65 housing and DIN-rail relays for versatile mounting
Relay Module Requirements - Ordered Separately
The NEH requires a separate relay/power supply module to complete the system. These DIN-rail mountable units process the conductivity signal from the electrodes and provide relay outputs for direct integration with control systems, pumps, or alarms, with modules available for single-point or multipoint configurations to match your monitoring requirements.
The NE-104 provides single-channel control and the NE-304 dual-channel control, with power supply options of 24, 110, or 230 VAC (+/-15%, 50-60 Hz). Each module provides one or two independent SPDT relay outputs rated for 250 VAC at 5 A maximum, enabling fail-safe switching for high or low level alarms. Installation is straightforward: the compact relay module mounts on standard DIN rail in your control panel, connects to the NEH probe via shielded cable, and provides screw-terminal outputs for easy wiring. The IP40-rated enclosure protects internal components in typical industrial electrical environments, across ambient temperatures of -4 to 140°F (-20 to 60°C). When ordering, specify the number of sensing points (1-6), required voltage, and desired relay configuration to ensure seamless system integration.
Automated Pump, Valve, and Alarm Control
In multipoint setups, each independent cable electrode signals its setpoint, activating SPDT relays for automated functions like pumping or alarming. Operation requires one relay channel per function, alarm, or latch control, and two setpoint electrodes and a ground electrode must be connected to the relay unit to provide automatic control, such as latching tank fill and empty.
Documented functionality includes automatic container fill (pump up), automatic pump-down (auto-drain), overflow protection at high level, and minimum level protection at low level, supporting switching outputs in PLC environments.
Build America, Buy America (BABA) Compliance
The KOBOLD NEH cable-suspended conductive level switch is manufactured in the USA and fully BABA compliant, qualifying for federal infrastructure projects under the IIJA with domestically sourced, high-integrity components. BABA-compliant models are available for projects that require documented domestic content.
Common Questions about NEH - Cable-Suspended Conductive Level Switch
An electrode relay applies a low excitation voltage to the probes. When rising liquid touches a setpoint electrode's exposed tip, an electrically conductive path forms between that electrode and the reference. The relay senses the resulting current flow and switches its SPDT contact to perform a control function, such as running a pump or alarm.
Neoprene-clad cables are available in lengths up to 100 ft, and PTFE-clad cables up to 30 ft, according to specifications. Cable diameters are 0.23 in for Neoprene and 0.08 in for PTFE. The weighted cable ends keep each suspended electrode stable at its sensing depth.
Maximum operating pressure is 90 PSIG according to specifications. Temperature limits depend on the cable cladding: 140°F (60°C) with Neoprene and 300°F (150°C) with PTFE. The relay module itself carries an ambient rating spanning -4 to 140°F (-20 to 60°C).
Yes. An NE-104 (single-channel) or NE-304 (dual-channel) electrode relay powers the electrodes and provides the switching output. Modules are offered for 24, 110, or 230 VAC supplies, mount on DIN rail per DIN 46121, and switch SPDT contacts rated up to 250 VAC / 5 A.
Up to six electrodes are available on the NE-Series, making a total of six setpoints possible. One electrode is required per sensing point, and the length of each cable depends on its desired sensing point. Single-point versions use a 1/2" NPT fitting; multipoint versions use a 1-1/2" NPT fitting.
Yes. A conductive vessel can serve as the ground reference, grounded through the stainless steel process fitting or a direct wire from the tank wall to the relay. If the container is not conductive, a second electrode provides the ground reference; a grounding reference electrode is recommended for all applications.
Yes. Wiring two setpoint electrodes plus a ground electrode to a relay channel enables latching control for automatic fill or pump-down. Documented wiring diagrams also cover high level (overflow) and low level protection, and each additional function needs its own relay channel on the NE-104 or NE-304.
Yes. The NEH is produced domestically, and models meeting Build America, Buy America requirements are available for federally funded work under the Infrastructure Investment and Jobs Act. This supports procurement teams that must document domestic content when specifying instrumentation for public infrastructure projects.
No. According to the manual, the NE conductive level switch is not an explosion-proof or intrinsically safe design and should not be used in applications where an explosion-proof design is required. For critical applications, KOBOLD recommends fail-safe system design with redundant backup systems and alarms.
Product Specifications
Contacts
Up To 6 Contacts via External Relays
Fittings
½" NPT, 1½" NPT Male
Material
SS, Hastelloy®, Titanium, PTFE
Max. Temperature
Up To 300°F (150 °C) w/PTFE Cable
Product Features
For Conductive Media Only (>20 uS/cm)
Multiple Switchpoints via Suspended Electrodes
Usable with Dirty / Corrosive Media
BABA (Build America, Buy America) compliant models available
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