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OTC Transmitters


Battery-Powered Self-Contained Level Monitoring Solution



  • 1x 1-5 Vdc hydrostatic sensor input
  • Sensor works up to 150 ft / 457 m length
  • Up to a 10-year battery life
  • Advanced local LCD display interface
  • Self-contained, rugged design
  • Installs in minutes
  • Class I, Division 1 (Zone 0)
  • Intrinsically Safe
  • IP66, -40 °C to 70 °C
  • 900 MHz / 2.4 GHz / 868 MHz
  • Secure AES encryption

Works with a Hydrostatic Level Sensor

The OleumTech® “LL4” and “LL5” Hydrostatic Level Transmitters measure level by monitoring pressure at the bottom point of vented top mount tanks, deep wells, water towers, rivers, and lakes. These transmitters are equipped with one 0-5 Vdc analog input and provide high resolution 24-bit analog to digital conversion (ADC). The transmitters can supply up to 9.5 Vdc to the connected sensor. LL4 direct mount version includes a specified length hydrostatic pressure sensor and direct mounting solution while the LL5 allows users to select their own sensor and mounting method. The LL5 also provides one discrete dry contact input for connecting to a high level switch. These ultra-low-powered transmitters are powered by a replaceable battery pack that provides up to a 10-year life. The push button LCD interface allows for device configuration and instant access to process data.

Reliable, Scalable and Safe

The field-proven wireless sensor node communicates with an assigned wireless gateway within the OTC Wireless Sensor and I/O Network creating a highly scalable network, accommodating virtually any I/O requirement. The OleumTech Wireless Transmitter is certified for use in Class I, Division 1 (Zone 0) hazardous locations. It is intrinsically safe, designed not to cause a spark, and can be serviced without being removed from a process.

This product is also available without a local display.

  • 0-5 PSI – 1-5 V, 25 ft Cable Length, Weight Kit Included, Part# A005025K
  • 0-10 PSI – 1-5 V, 50 ft Cable Length, Weight Kit Included, Part# A005050K
  • 0-25 PSI – 1-5 V, 75 ft Cable Length, Weight Kit Included, Part# A005075K


Radio Band∙ ISM Band (License-Free)
900 MHz / 915 MHz∙ FHSS, FSK, AES Encryption 256-bit (900 MHz), 128-bit (915 MHz)
2.4 GHz∙ DSSS, AES Encryption 128-bit
868 MHz∙ LBT-AFA, AES Encryption 128-bit
Bit Rate∙ 900/915 MHz: 9600 bps / 115.2 kbps; 2.4 GHz: 250 kbps; 868 MHz: 80 kpbs
Output Power (Max)∙ 900/915 MHz: 10 mW; 2.4 GHz: 63 mW; 868 MHz: 25mW
Receiving Sensitivity∙ 900/915 MHz: -110 dBm @ 9600 bps, -100 dBm @ 115.2 kbps
∙ 2.4 GHz: -101 dBm @ 250 kbps; 868 MHz: -106 dBm @ 80 kbps
RF Range∙ 900/915 MHz: Up to 7500 Feet / 1.4 Miles (2.3 km) with Clear Line of Sight
∙ 2.4 GHz: Up to 4.3 Miles (7 km) with Clear Line of Sight
∙ 868 MHz: Up to 5.2 Miles (8.4 km) with Clear Line of Sight
Device Functionality∙ Liquid Level Sensing Wireless Transmitter Using Hydrostatic Technology
Embedded Controller∙ Ultra-Low Power RISC Microcontroller with Internal FLASH (Field Upgradeable)
Configuration∙ Standard RS232 Serial / BreeZ® Software for PC
Sensor Type∙ Submersible Hydrostatic Pressure Sensor (Sold Separately), Wide Operating Temperature Range
Power Source∙ Self-Contained, Internal 3.6 Vdc Lithium Battery
Internal Battery Life∙ Up to 10 Years, Based on User Defined Reporting Intervals
Local LCD Display∙ 32-Character Display (16x2 Lines) with 4 Function Keys + Read Button
Instant Displayable Read∙ Level / Battery Voltage / RF Status
Local Configuration∙ Integral LCD with Push Button Interface
Device Diagnostics∙ Health Tags: Battery Voltage, Received Signal Strength Indication (RSSI), RF Refresh, RF Timeout
Dimensions, LL4∙ 5.5" (W) x 19.75" (H) x 4.4" (D) / 140mm (W) x 502mm (H) x 112mm (D)
Dimensions, LL5∙ 5.5" (W) x 12.8" (H) x 4.4" (D) / 140mm (W) x 325mm (H) x 112mm (D)
Package Dimensions, LL4∙ 14" (W) x 30" (H) x 7" (D) / 356mm (W) x 762mm (H) x 177.8mm (D)
Package Dimensions, LL5∙ 10.25" (W) x 14" (H) x 6.5" (D) / 260mm (W) x 356mm (H) x 165mm (D)
Package Weight, LL4∙ ~10 lbs / 4.5 kg
Package Weight, LL5 ∙ ~7 lbs / 3.2 kg
Connection Fitting∙ LL4: 1.5" NPT Male Compression Fitting; LL5: 3/4" NPT Female
Enclosure Casing Material∙ Type 4X Aluminum; IP66
EMC/EMI∙ FCC Part 15 (USA), IC ICES-003 (Canada), ACMA (Australia)
Safety∙ Class I, Division 1, Groups A, B, C, D T3C; Ex ia IIC T3
∙ Class I, Zone 0; AEx ia IIC T3
∙ ATEX: Sira 13ATEX2142X; Ex ia IIC T3 Ga; II 1 G
∙ IECEx: SIR 13.0054X; Ex ia IIC T3 Ga
Operating Conditions∙ Ambient Temperature (Class I, Division 1 / Zone 0): Transmitter -40 °F to 158 °F (-40 °C to 70 °C)
LCD Screen -4 °F to 158 °F (-20 °C to 70 °C)
∙ Ambient Temperature (Non-Hazardous Applications): Transmitter -40 °F to 176 °F (-40 °C to 80 °C)
LCD Screen -4 °F to 158 °F (-20 °C to 70 °C)
∙ Humidity: 0 to 99 %, Non-Condensing
Warranty∙ 2-Year Parts and Labor
Country of Origin∙ USA
Model Numbers∙ 900 MHz: WT-0900-LL4 (Direct Mount) / WT-0900-LL5 (Multi-Vendor)
∙ 2.4 GHz: WT-2400-LL4 (Direct Mount) / WT-2400-LL5 (Multi-Vendor)
Wirelessly Connects To∙ OTC Wireless Gateway
Configuration Cable∙ SX1000-CC2, 20-ft All-in-One Configuration Cable
Replacement Battery∙ Use OleumTech SX1000-BP3 Only