Submersible Level Transmitter | Hydrostatic Level Transmitter | Pi993

Fully Submersible, Very Compact Ø25mm and Surge Protected

Pi993 Fixed Range Level and Depth Sensor

At a Glance

  • Ranges: 0-0.5mWG up to 0-100mWG
  • 25mm Diameter
  • Outputs: 4-20mA
  • Environmental Protection: IP68 to 100 metres
  • Accuracy: <±0.25%/FS
  • Optional 0.1% Accuracy Version
  • Compact Only 25mm Diameter
  • Fully Submersible & Long-Term Immersion Protected to 100m 
  • Protected Against Power Surges from Lightning Strikes
  • High Corrosion Resistant Versions for use in Seawater or Leachate Available 
  • Ideal for Landfill Sites


The Pi993 submersible level transmitter / hydrostatic level sensor is designed for use in rivers, reservoirs, tanks, boreholes, vessels and channels.  Thanks to their long term immersion protection to 100 metres, they are also ideal for the measurement of pressure within submerged pipes and vessels.

For applications where aggressive media such as seawater or leachate are present, especially landfill sites, we can provide a high grade duplex stainless steel submersible level transmitter with very high corrosion resistance.

Electrical connection to the hydrostatic level transmitter is made using a triple-sealed back end assembly and custom manufactured vented polyurethane (PUR) cable.  This provides an atmospheric pressure reference and guarantees IP68 integrity to water depths of 100 metres.

The standard submersible level transmitter output is a 2-wire 4-20mA signal which has a surge protection circuit to mitigate the effects of electrical transients caused by nearby lightning strikes and power supply fluctuations.  For applications where data loggers are to be used, a ratiometric version is available which offers a 0.5-4.5Vdc output from a 5Vdc supply.

We are able to customise the Pi993 submersible level transmitter to suit your exact requirements if necessary, whilst ensuring a minimal effect on price and availability.

Product Dimensions

Pi993 Submersible Level Transmitter Outline Drawing

Pi993 Specifications

Pressure Ranges:0.5, 1, 2.5, 5, 10, 20, 25, 50, 75, 100metres Water Gauge (mWG)
Safe Overpressure:150% Pressure Range
Burst Pressure:300% Pressure Range
Supply Voltage:3 min./10 nom./15 max.9 min./32 max.13 min./ 32 max.Volts DC
Load Driving Capacity:N/A1000N/AOhms at Max. Supply Voltage
Rated Output:0.0-2.0mV/V4-20mA0-10Vdc±1%/rated output
Wiring Configuration:4-wire2-wire3-wire
Electrical Connections:Screened polyurethane (PUR) cable with vent tube, strain and drain wire
Accuracy:<0.25 (0.1% optional)±%Pressure Range
Temperature Range Operating:-10 to +80˚C
Temperature Range Compensated:-10 to +80˚C
Temperature Effect on Output:<0.015±%/˚C
Temperature Effect On Zero:<0.02 (0.01 optional)±%/rated output/˚C
Environmental Protection:IP68 to 100mWG (10bar)
Weight:250 approx. (excluding cable)grams
Construction:316L St/Steel (SAF2205 optional), AL2O3 Ceramic (10mWG> only), Viton + PUR
Electrical Protection:EMC Immunity: EN50082-1 & Surge (Lightning) Protection: EN61000-4-5

Pi993 Wiring 4-20mA Output (2-wire)

Red+ve supply
Blue-ve supply & 4-20mA output in series
Whiteto case
Greencable screen

Pi993 0-10Vdc Output (3-wire) Wiring

Red+ve supply
Blue-ve supply
Yellow+ve signal
Whiteto case
Greencable screen

Pi993 mV/V Output (4-wire) Wiring

Red+ve excitation
Blue-ve excitation
White+ve signal
Yellow-ve signal
Greencable screen

Case Studies

Why United Utilities Chose Us To Keep The Water Flowing

Water Level Monitoring Booster Pumps

United Utilities needed a way to monitor the constantly changing water level in their water treatment plant to guarantee a steady flow of water into the reservoir. Learn how they did it using our level transmitters.

Interested in this product? Send us an enquiry...

    Why Applied Measurements?

    • Suppliers of top quality strain gauge sensors and transducers to every corner of industry - UK and worldwide
    • Over 100 years of expert transducer knowledge
    • Our high quality products all come with a 3 year warranty