Submersible Pressure Transducer for Level & Pressure



  • High accuracy and reliability
  • Completely submersible pressure transducer and cable
  • Compact, rugged design for easy installation
  • Minimal maintenance and care
  • Water level sensor compatible with most monitoring equipment
  • 4-20mA output
  • Vented cable for automatic barometric compensation
  • Multiple level ranges available from 3′ to 500′
  • Wet-wet water level sensor eliminates vent tube concerns
  • Dynamic temperature compensation system
  • Submersible pressure transducer not affected by foam, wind, or rain
  • Monitors levels in groundwater wells, rivers, streams, tanks, lift stations and open channels
  • CE Certified

Water Level Sensor Product Description

Global Water’s WL400 Water Level Sensor provides highly accurate water level measurement for a wide variety of applications, including those in severe environments. The submersible pressure transducers have a dynamic temperature compensation system, enabling high accuracy measurements over a wide temperature range. The water level sensor is easily adapted to all dataloggers, telemetry, monitoring equipment, and displays.

Each of the water level sensors consist of a solid state submersible pressure transducer encapsulated in a stainless steel 13/16 inch diameter housing. The water level sensor has a molded-on waterproof cable and a two-wire 4-20 mA high level output for connection to a monitoring device. A 25 ft cable is standard, and optional cable lengths are available up to 500 ft.

The Water Level Sensor’s submersible pressure transducer is fully encapsulated with marine-grade epoxy so that moisture can never leak in or work its way down the vent tube to cause drift or level sensor failure (as is the case with other pressure sensors).  The water level sensor uses a unique, highly flexible silicon diaphragm to interface between water and the sensing element.  This silicon diaphragm protects the water level sensor’s electronics from moisture and provides each sensor with exceptional linearity and very low hysteresis.  The design of the submersible pressure transducers eliminates the issues associated with metal foil diaphragms, which tend to crinkle and stretch out over time causing drift, linearity, and hysteresis problems.  The water level sensor is also has automatically barometric compensation due to the attached vent cable and protected by a stainless steel micro-screen cap, which makes fouling with silt, mud, or sludge virtually impossible.  The water level sensor’s design is great for all saltwater applications including tide level monitoring, floating docks, and others.

Pressure transducer level ranges of 0-3, 0-15, 0-30, 0-60, 0-120, 0-250, and 0-500 feet are available. The 0-3 ft low-level range is ideal for measuring shallow flows or small water level changes like those encountered in sewers, storm drains, weirs, and flumes. The 0-3 ft water monitoring sensor accurately measures small changes in water, even when the water’s depth is only a few inches deep. Other metal foil-type water level sensors typically have serious problems at low-level ranges because of sensor crinkling, stretching, and drifting.

Each submersible pressure transducer has a two-wire 4-20 mA output signal that is linear with water depth. From 10 to 36 VDC is required to operate the water level sensor, so the level sensors can be operated from common 12 VDC battery systems. The 4-20 mA signal can run up to 3,000 ft from the submersible pressure transducer to the logging device. Common twisted pair or electrical extension cord wire may be spliced to the vented cable once the cable is out of the water. The 4-20 mA signal may be converted to 0.5 to 2.5 VDC by dropping the current signal across a 125 ohm resistor.

Water Level Sensor Specifications

Sensing Element
Sensor Element: Silicone Diaphragm, Wet/Wet Transducer
Pressure Range: 0-3, 0-15, 0-30, 0-60, 0-120, 0-250, 0-500 ft
Linearity and Hysteresis: ±0.1% FS
Accuracy: ±0.1% of full scale at constant temperature, ±0.2% over 35°F to 70°F (1.37° to 21.1°C) range
Overpressure: Not to exceed 2 x full scale range
Resolution: Infinitesimal (Analog)
Outputs: 4-20 mA or 0.5 to 2.5 VDC across 125 ohms
Supply Voltage: 8 to 36 VDC
Current Draw: Same as sensor output
Warm Up Time: 3 seconds recommended
Operating Temperature: -40° to +185°F (-40° to +85°C)
Compensation: Uses dynamic temperature compensation 30 to 70°F (-1.1 to 21.1°C).  Automatic barometric pressure compensation
Weight: 1/2 lb (227 g)

Material: 304L Stainless Steel, SS microscreen (hundreds of holes to prevent fouling), electronics are fully encapsulated in marine grade epoxy, guaranteed not to leak
Size: up to 13/16 inch diameter x 5 1/2 in long (2 cm dia. x 14 cm long)(small enough for a 1 inch (2.54 cm) well).  Titanium option has 1 inch (2.54 cm) diameter.

Vented Cable
Conductors: 4 each 22 AWG
Material: Marine grade polyether jacket, polyethylene vent tube, full foil shield
Outer Diameter: 0.306 inch (0.78 cm)
Temperature Range: -22° to +185°F (-30° to +85°C)
Weight: 0.7 oz/ft (~65g/m)
Length: Standard 25 ft (7.62 m) (up to 500 ft (152.4 m) from factory)

Water Level Sensor Installation

The submersible pressure sensor may be placed slightly below the lowest expected water level.  Water level sensor level ranges of 0-3, 0-15, 0-30, 0-60, 0-120, 0-250 and 0-500 ft are available.  When ordering, select the level sensor range that will cover the maximum water level change (this is not necessarily the total depth of water).  Selecting the smallest water level range possible will ensure the greatest accuracy.

The 4-20 mA signal can run up to 3,000 ft from the water level sensor to the logging device.  Common twisted pair or electrical extension cord wire may be spliced to the vented cable once the cable is out of the water.  The 4-20 mA signal may be converted to 0.5 to 2.5 VDC by dropping the current signal across a 125 ohm resistor.

Water Level Sensor Applications

The WL400 Water Level Sensor can be used to measure water level, well depth, groundwater level, surface water flow, pipe flow, and water pressure, etc…  NOTE: Polyurethane cable is not recomended for use with hydrocarbons or high concentrations of chlorine.  Please look at the our WL450 Water Level Transmitter to meet the requirements of these types of applications.

Water Level Sensor Options

NOTE: When ordering, specify water level range that will cover the maximum water level change for your application (this is not necessarily the total depth of water). Selecting the smallest water level range possible will ensure the greatest accuracy.

WL400-003-025 Water Level Sensor (PN# AIA025)
Water Level Sensor Range: 0 to 3 ft, Cable length: 25 ft

WL400-015-025 Water Level Sensor (PN# AIB025)
Water Level Sensor Range: 0 to 15 ft, Cable length: 25 ft

WL400-030-050 Water Level Sensor (PN# AIC050)
Water Level Sensor Range: 0 to 30 ft, Cable length: 50 ft

WL400-060-100 Water Level Sensor (PN# AID100)
Water Level Sensor Range: 0 to 60 ft, Cable length: 100 ft

WL400-120-150 Water Level Sensor (PN# AIF150)
Water Level Sensor Range: 0 to 120 ft, Cable length: 150 ft

WL400-250-300 Water Level Sensor (PN# AIG300)
Water Level Sensor Range: 0 to 250 ft, Cable length: 300 ft

WL400-500 Water Level Sensor
Water Level Sensor Range:  0-500 ft.

WLEXC Extra Cable (PN# AE0000)
Cable length is measured from top of logger to bottom of sensor.  Up to 1000 feet of extra cable can be added at the factory.

THO Titanium Option (PN# AJ1000)
Replace the standard stainless steel water level sensor housing with titanium.

PRPP/PRPM Pressure Pipe Option (PN# AL0500/AL0000)
Water level sensor is housed in a 8 inch PVC (PRPP) or stainless steel pipe with 3/4 inch NPT male thread (PRPM) for logging pressure in municipal water systems.  10 ft cable standard.  Calibrated in psi with ranges of 0 to 30 psi, 60 psi, 100 psi available.

WL-SWO Sewer Flow Option (PN# AG0000)
Mouse-shaped cover protects sensor from fouling and velocity effects in sewer, stormwater and irrigation pipe flows.  Mouse is attached to 4 inch X 24 inch stainless steel strap for mounting sensor on pipe bottom.


WL-T Temperature Output Option (PN# AN0000)
Range: 0-50° C, Accuracy: 1% of reading, Output: 0-10mA


WL430 Sewage Lift Station Wastewater Level Sensor
Includes 40 ft of cable

WL450 High Accuracy Submersible Water Level Transmitters

WL705 Ultrasonic Water Level Sensor
Specify Water Level Range: 3, 12, or 48 ft.  Includes 6 ft cable.

EZ100 EZ Sensor Display
LCD readout display for both portable use and permanent installations.


WL16 Water Level Logger
Submersible pressure transducer and datalogger for recording water level data.

DCX-22 Self Contained Water Level Datalogger

WQMS Water Quality Monitoring System
The standard unit includes a datalogger, temperature sensor, pH sensor, conductivity sensor (with a 0-5000µS range unless otherwise specified), and DO sensor.

SIT65 Satellite Water Level Telemetry
Retrieve water level data from virtually anywhere, without the typical radio or cellular setup issues.


SIT70 Premium Satellite Internet Telemetry