
OleumTech Level Sensors and Switches
THE MOST RELIABLE TANK LEVEL SENSOR
FOR INDUSTRIAL APPLICATIONS
Low-Power, RS485 Modbus/ASCII Liquid Level Gauges
Float-based, Field-Proven Resistive Reed Switch Technology, US Patent 8,763,455 B1

RL3: Modbus | RL4: LevelMaster ASCII
HIGHLIGHTS
- Monitor product, interface, and temperature with a single sensor
- 2x discrete inputs (RL3 Modbus version only)
- Sensor option: flex (PTFE) or rigid (316 SS)
- 1/4” resolution option (±1/8” accuracy)
- 1/2” resolution option (±1/4“ accuracy)
- RS485 interface (Modbus or LevelMaster ASCII)
- Quick and easy to install
- “Set it and forget it” – no on-going calibration required
- Supports a wide temperature range: -40 ˚C to 120 ˚C / -40 ˚F to 248 ˚F
- Multiple fluid compatibility
- Guaranteed against H2S damage, scaling, and paraffin buildup
- 6-30 Vdc power input
- Class I, Division 1 (Zone 0), Intrinsically Safe
- Click here to see level sensor accessories
OleumTech Level Sensors are Ideal for
Production Tanks | Water Tanks | SWD Locations | Separators | Condensate Tanks
Midstream Collection and Blend Tanks | Refinery Holding Tanks | Chemical Tanks | Many Others



Ultimate Level Sensing Solution
Tried and true is the Resistive Tank Level Sensor by OleumTech®, which is part of the H-Series Sensor line of high quality instruments that deliver unrivaled performance, reliability, and accuracy in extreme, hazardous outdoor conditions. With over two decades of innovation and manufacturing expertise, OleumTech’s Resistive Level Sensor is the company’s flagship level monitoring solution that offers industry’s leading 5-in-1 monitoring capabilities: product (oil), interface (water), temperature, and two discrete inputs.
OleumTech’s patented Resistive Sensors are offered in both flexible (PTFE) and rigid (316 SS) materials in various lengths.
Reliable, Scalable, and Safe
The field-proven level sensor can communicate with any Modbus RTU master or LevelMaster device via RS485 Serial connection. The low-power Resistive Level Sensor can be multi-dropped of up to 16 sensors. Additional data such as volume and tank full percentage can be calculated and reported as well, along with the core level variables. The Resistive Level Sensor is certified for use in Class I, Division 1 (Zone 0) hazardous locations.
Contact your OleumTech representative to learn more about its high performance automation solutions.

Do Much More with Less
The OleumTech Resistive Level Sensor give you the ability to continuously measure product (oil), interface (water), and temperature and monitor two discrete inputs from a single instrument, eliminating the need for multiple sensors and multiple tank ports.

No Wiring Hassle
Every Resistive Level Sensor is equipped with a quick connect fitting that joins the sensor to its head without any wires, eliminating wiring error and hassle to help you save valuable time during installation and troubleshooting.

Installs in Minutes
The flexible (PTFE) level sensor is only 20 inches in diameter when coiled making extremely easy to transport. Deployment cost and time can be significantly reduced by enabling just one person to perform the entire installation.

High Scalability
Up to 16 of these low-power level sensing instruments can be multi-dropped using a single power supply. There are multiple 3/4-inch NPT ports available on the sensor head to help you run conduit and wire with ease.

Great Peace of Mind
The OleumTech Resistive Level Sensors are Intrinsically Safe and are certified for use in Class I, Division 1 (Zone 0) hazardous locations, providing the highest level of safety under rigorous, extreme outdoor conditions.

Maximum Flexibility
You can choose either Modbus RTU or LevelMaster ASCII communication protocol option for interfacing virtually any existing SCADA or control system. This digital level sensor is also available with wireless options.

Rigid - 316 Stainless Steel
Resistive Level Sensors are available with the rigid 316SS option, ranging from 2 to 21 ft in lengths with multiple float options. The rigid sensor comes equipped with a 3/4-inch NPT 1-inch NPT height adjustable compression fitting.

Flexible - PTFE

Choice is Yours
You can take advantage of the 1/4-inch resolution version of the sensor with ±1/8-inch accuracy or take a more cost-effective approach by using the 1/2-inch resolution version that provides ±1/4-inch accuracy.
HARDWARE FEATURES | |
---|---|
Device Functionality | ∙ Resistive Level Sensor with RS485 Serial Interface |
∙ RL3: Modbus, Provides Product, Interface and Temperature Levels + 2 Discrete Inputs | |
∙ RL4: LevelMaster ASCII, Provides Product, Interface and Temperature Levels | |
Embedded Controller | ∙ Ultra-Low Power RISC Microcontroller with Internal FLASH (Field Upgradeable) |
Configuration | ∙ USB to RS485 Converter (SX1000-CC8) |
Sensor Type | ∙ Resistive Reed Switch |
Resolution | ∙ High Resolution, Depends on Sensor: 1/4" (6.4 mm) or 1/2" (12.7 mm) |
Accuracy | ∙ US: ± 1/8-inch for 1/4-inch Resolution Sensor ; ±1/4-inch for 1/2-inch Resolution Sensor |
∙ Metric: ± 3.2 mm for 6.4 mm Resolution Sensor ; ±6.4 mm for 12.7 mm Resolution Sensor | |
Interface | ∙ RS485 Modbus or LevelMaster ASCII |
Baud Rate | ∙ 1200-115200 bps |
CERTIFICATIONS & COMPLIANCE | |
Safety | ∙ Intrinsically Safe for Use in Hazardous Environments |
∙ Class I, Division 1, Groups C, D T4; Ex ia IIB T4 Ga; Class I, Zone 0, AEx ia IIB T4 Ga, -40 °C ≤ Tamb ≤ 70 °C | |
∙ ATEX: Sira 16ATEX2229X; Ex ia IIB T4 Ga, -40 °C ≤ TA ≤ 70 °C | |
∙ IECEx: SIR 16.0079X; Ex ia IIB T4 Ga, -40 °C ≤ TA ≤ 70 °C | |
MECHANICAL SPECIFICATIONS | |
Dimensions | ∙ 5" (W) x 7.6" (H) x 4.4" (D) / 127 mm (W) x 193 mm (H) x 112 mm (D) |
Package Dimensions | ∙ 10.25" (W) x 14" (H) x 6.5" (D) / 260 mm (W) x 356 mm (H) x 165 mm (D) |
Package Weight | ∙ ~4.5 lbs/ 2.0 kg (Head Only) |
Connection Fitting | ∙ 3/4" NPT Female |
Enclosure Casing Material | ∙ Type 4X Aluminum; IP66 |
ELECTRICAL SPECIFICATIONS | |
DC Power Input | ∙ 6-30 Vdc (30 V Max) |
Power Consumption | ∙ 28.5 mA Maximum / 1.7 mA Idle Current |
Multi-Drop Max Consumption | ∙ 55 mA Maximum based on 16 Sensors Multi-Dropped |
IS Safety Protection | ∙ Barrier Board (See Part Numbers under Ordering Information) |
GENERAL SPECIFICATIONS | |
---|---|
Operating Conditions | ∙ Sensor: Ambient Temperature (Class I, Division 1): -40 °F to 248 °F (-40 °C to 120 °C) |
∙ Transmitter: Ambient Temperature (Class I, Division 1): -40 °F to 158 °F (-40 °C to 70 °C) | |
∙ Transmitter: Ambient Temperature (Non-Hazardous Applications): -40 °F to 176 °F (-40 °C to 80 °C) | |
∙ Humidity: 0 to 99 %, Non-Condensing | |
Warranty | ∙ 2-Year Parts and Labor |
Country of Origin | ∙ USA |
SENSOR | RIGID: 316 Stainless Steel "SS" | FLEX: Polytetrafluoroethylene "PTFE" |
---|---|---|
Type | Extremely Reliable and Accurate Resistive Reed Switch Technology | |
Measurement Capabilities (3-in-1) | Product, Interface, and Temperature | |
Lengths Offered in US Units | 2 to 26 ft Length in 1 ft Increments | 8 to 38 ft Length in 1 ft Increments |
Lengths Offered in Metric | 0.61 to 7.93 m in 0.31 m increments | 2.44 to 11.58 m in 0.31 m increments |
Resolution and Accuracy | Option 1: 1/2-inch (12.7 mm) Resolution with ±1/4-inch ( ±6.4 mm) Accuracy (6-pin Quick Connect) | |
Option 2: 1/4-inch (6.4 mm) Resolution with ±1/8-inch (±3.2 mm) Accuracy (8-pin Quick Connect) | ||
Sensor to Interface Mating Connection (No Wiring Solution) | 316 SS Quick Connect: 6-pin Connection for 1/2" Resolution, 8-pin Connection for 1/4" Resolution | |
Tank Mating Connection (Adjustable Compression Fitting) | 2-15 ft: 3/4" NPT Male / 16-26 ft: 1" NPT Male | 1" NPT Male |
Temperature Accuracy | ±1 °C | |
Sensor Rod/Tubing Diameter | 0.63" (16 mm): 2-15 ft Sensor | 0.85" (22 mm) |
0.85" (22 mm): 16-26 ft Sensor | ||
Anchor Weight Diameter | N/A | 2.88" / 73 mm |
Height of Anchor Weight | N/A | Up to 26 ft sensor: 4.75" / 121 mm |
26 - 38 ft sensor: 8" / 203 mm | ||
Coiled Diameter | N/A | 20" (50.8 cm) Coiled Diameter |
Minimum Measurement from Bottom (Deadband) | 2" (50.8 mm) from Bottom | From Top of Anchor Weight |
Sensor Pressure Rating | Float Dependent | Float Dependent |
316 Stainless Steel - Standard (Included w/Rigid <=15 ft | 440 PSI / 30 Bar | N/A |
316 Stainless Steel - Large | 363 PSI / 25 Bar | 142 PSI / 9.8 Bar |
Polypropylene (PP) (Inc. w/Flex and w/Rigid >=16ft | 72 PSI / 5 Bar | 72 PSI / 5 Bar |
Float Options: | ||
316 Stainless Steel - Standard, 440 PSI/30 Bar | Compatible Only with Rigid Sensor Length up to 15 ft Prod: 0.64 SG, Intf: 0.96 SG, ID 0.72" (18.3 mm) | |
OD 2.05" (52.1 mm), Inner Clearance: 0.1" (2.6 mm) | ||
316 Stainless Steel - Large, 363 PSI/25 Bar | Product: 0.62 SG, Interface: 0.95 SG, ID 1.1" (27.9 mm), OD 2.76" (70.1 mm), Inner Clearance: 0.5" (12.7 mm) | |
Polypropylene (PP), 72 PSI/5 Bar | Product: 0.64 SG, Interface: 0.96 SG, ID 1.1" (27.9 mm), OD 2.91" (73.9 mm), Inner Clearance: 0.5" (12.7 mm) | |
Operating Temp. Sensing Area | -40 °F to 248 °F (-40 °C to 120 °C) | |
Certifications | Class I, Division 1, Groups C, D T4; Ex ia IIB T4 Ga; Class I, Zone 0, AEx ia IIB T4 Ga, -40 °C ≤ Tamb ≤ 70 °C | |
ATEX: Sira 16ATEX2229X; Ex ia IIB T4 Ga, -40 °C ≤ Tamb ≤ 70 °C | ||
IECEx: SIR 16.0079X; Ex ia IIB T4 Ga, -40 °C ≤ Tamb ≤ 70 °C | ||
Power (Wireless) | 3.6 V Lithium Replaceable Battery Pack, 10-Year Life @ 1 min Read Interval | |
Power (Hardwired) | External 6-30 Vdc (30 V max) | |
Wireless Compatibility | OTC - WT / SM Series Resistive Transmitters and Sigfox-enabled Resistive Nodes | |
Hardwire Serial Interface (H-Series Only) | RS485, 2-Wire, 16 or 32-bit Modbus RTU, LevelMaster ASCII, Termination for Daisy-chain | |
Minimum Sensor Read Interval | Down to 5 Seconds | |
Model #: 1/2" Resolution with ±1/4-inch Accuracy | 60-4001-xxx | 60-4101-xxx |
Model #:1/4" Resolution with ±1/8-inch Accuracy | 60-4101-xxx | 60-4102-xxx |
Kit #: 1/2" Resolution with Float(s) | ZG-xxx-Fxx | TG-xxx-Fxx |
Kit #: 1/4" Resolution with Float(s) | ZH-xxx-Fxx | TH-xxx-Fxx |
ORDERING INFORMATION | |
---|---|
Model Numbers | ∙ 1/2" Resolution (6-pin): HW5000-RL3 (Modbus), HW5000-RL4 (LevelMaster ASCII) |
∙ 1/4" Resolution (8-pin): HW5800-RL3 (Modbus), HW5800-RL4 (LevelMaster ASCII) | |
IS Barrier Boards | ∙ 12 V Kit: SX1000-B12, 1x RS485 Module (61-6002-001) + 1x 12 V Module (61-6003-001) |
∙ 24 V Kit: SX1000-B24, 1x RS485 Module (61-6002-001) + 1x 24 V Module (61-6004-001) | |
Configuration Kit | ∙ H-Series Configuration Kit (SX1000-CC8) |
CERTIFICATIONS & COMPLIANCE | |
---|---|
Safety | ∙ Intrinsically Safe for Use in Hazardous Environments |
∙ Class I, Division 1, Groups C, D T4; Ex ia IIB T4 Ga; Class I, Zone 0, AEx ia IIB T4 Ga, -40 °C ≤ Tamb ≤ 70 °C | |
∙ ATEX: Sira 16ATEX2229X; Ex ia IIB T4 Ga, -40 °C ≤ Tamb ≤ 70 °C | |
∙ IECEx: SIR 16.0079X; Ex ia IIB T4 Ga, -40 °C ≤ Tamb ≤ 70 °C |
LEARN MORE ABOUT OTHER LEVEL SENSING INSTRUMENTS BY OLEUMTECH
Wireless Level Sensors
Best-in-class tank level gauge and wireless interface combination for self-contained, battery-powered standalone operation.
Hydrostatic Level Sensors
Cost-effective wireless level monitoring solution using a low-power 1-5 V analog submersible hydrostatic pressure transducer.
High Level Switches
Instantly detect high level conditions for providing overfill protection and spills prevention. Detect high and high-high levels.
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