SDI-12 Submersible Depth Sensor | Level & Temperature | Pa993D

SDI-12 Output, Fully Submersible, Very Compact Ø23mm and Surge Protected

Submersible Depth Sensor
Lead Time
4 weeks
Prices From
Quantity, OEM & educational discounts
3D CAD models available

At a Glance

  • Ranges:0-1mWG up to 0-100mWG
  • 23mm Diameter
  • Outputs: SDI-12 v1.4 (RS485 Modbus Optional)
  • Environmental Protection: IP68 to 100 metres
  • Accuracy: <±0.15%/FS (Optional 0.1% and 0.06% Versions)
  • Low Power Consumption: <4mA
  • Compact Only 23mm Diameter
  • Accurate Level & Temperature Readings
  • Fully Submersible & Long-Term Immersion Protected to 100m 
  • Intelligent 16-Bit Electronics for Complex Calibrations
  • High Integrity Waterproof Assembly
  • Robust Stainless Steel Silicon Sensing Element
  • Protected Against Power Surges from Lightning Strikes


The Pa993D SDI-12 submersible depth sensor is an intelligent microprocessor enhanced depth sensor designed for both level and temperature readings as standard.   With its narrow diameter of just 23mm, it is ideal for V-notch weir flow measurement in open channel flow applications and environmental monitoring.

Thanks to its embedded 16-bit microprocessor-based electronics, the Pa993D SDI-12 submersible depth sensor can perform complex linearisation, temperature compensation and calibration to deliver extremely high accuracy of less than ±0.15% full scale, with an option to increase this to 0.1% or 0.06% if required, making them ideal for laboratory & research testing applications, environmental monitoring and flood defence systems.

The Pa993 is perfect for applications using battery or solar panels as it has a very low power consumption and can be powered from as low as 6V supply.  Plus, it is extremely useful in multi-sensor setups as one or more SDI-12 submersible depth sensors can be used to interface with one datalogger.

They have a robust 316 stainless steel silicon sensing element coupled with a choice of Nitrile (NBR), Viton (FKM) or EPDM (Drinking Water Approved) seals, guaranteeing long term immersion protection to 100 metres.  In addition, their moulded cable exit fitted with vented polyurethane (PUR) cable and strain wire provide a high integrity waterproof assembly as standard, making them ideal for the measurement of pressure within rivers, reservoirs and boreholes.

The Pa993D SDI-12 submersible depth sensor has a surge protection circuit to mitigate the effects of electrical transients caused by nearby lightning strikes and power supply fluctuations.

Applied Measurements are proud members of the SDI-12 support group, a non-profit corporation who provide SDI-12 specification and additional information about SDI-12.

Product Dimensions

SDI-12 submersible depth sensor Pa993D outline drawing


CAD Model Files

Our 3D models are provided in STEP format and can be viewed using FreeCAD. Other formats can be provided on request.

The .zip file below contains a separate model for each product variant.

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