PLS Level Sensor


Immersion probes are often used in measuring level. These probes are made up of a perfectly fluid-sealed sensitive part and an electrical cable that transmits the signal outside the immersion zone. The pressure exercised by a liquid is proportionate to its height, and in this way it is possible to determine its level by measuring the pressure. The resistance and compatibility with the fluids of the various components, type of material the instrument case, seals and electrical cable are made of are essential
in this application. Titanium probes can be supplied for off-shore and naval applications as they are excellent for resistance to saline corrosion. The PLS sensor takes the measurement of the level of a waterway or water basin by measuring the pressure exercised by the liquid column above and referring it to the atmospheric pressure, so it is an instrument that takes measurements of differential pressure.

The sensor is based on a sensitive piezoresistive element made up of 4 resistors with bridge structure spread on a silicon wafer. The transducer is contained inside a watertight chamber filled with oil and closed by a stainless steel membrane on which the external liquid exercises pressure; the cell refers to the atmospheric pressure from a compensation tube integrated in the cable. The case is in stainless steel, sealed for immersion up to 50 metres.

- Complete customisation :
The sensor in question can be supplied with customised precisions, flow rate, cable length and case material; for example, it can be made in materials particularly resistant to corrosive agents for marine applications.
- Easy maintenance:
Normally housed inside surge pipes, the sensor can be easily maintained and is easy to safely recover out of the water.
-Sturdy and reliable construction:
This makes it an instrument with a long lifetime, which safeguards the customer’s investment. The instrument does not drift due to aging and requires no periodic calibrations.

The sensor is usually housed inside surge pipes made in different materials and lengths depending on the particular installation context.

In certain application cases where it is necessary to monitor a set of water quality parameters, in addition to the simple hydrometric level data the piezometric probe can be placed inside a larger probe that will be customised with specially selected probes to perform the necessary monitoring.

Range of measurement: Various depths, for example 0 .... 6m
Relative humidity: 0..... 100%
Precision: <1 cm (@25° C)
Electrical output: 4-20 mA
Operative temperature: -20° C .... +80° C
Material Pressure sensor: Stainless steel (316L / 1.4435)
Casing: Stainless steel (316L / 1.4435)
Seals: Viton (Standard), EPDM
Cable: PUR, FEP, PE

Monitored Parameters:

  • Water levels
  • Hazards:

  • Coastal flooding
  • Land and river flooding
  • Sea level rise
  • ✓ Relevant to the EWSS


    Minimum Quantity : 1


    Sensor Properties
    Accuracy (error of the measurements) Unit of measurement Data Refresh Time (mins) Wi-Fi Connection 4G Connection External Power Supply Documentation
    <1 cm (@25° C) m None False False True See available docs for PLS Level Sensor
    Reference Partners Project Name Project Year Reference Paper Minimum Purchase Spatial Density
    MBI srl None Not available 1 None
    Purchase operations complexity Assembly/Calibration Operations Complexity Deployment operation Complexity Deployment Cost Data Analysis Operations Complexity
    Very easy Easy Low Easy
    Citizen Science Activities Complexity Assembly Public Involvement Deployment Public Involvement Data analysis Public Involvement Target Users
    Easy Limited Limited Limited Single citizens; local groups; local authorities

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