Smart-Level® Thickener

Thickener mud level measurement

The Smart-Level® thickener measures the mud level in the thickener.

A key component of the Smart-Level® thickener system is the SonarTXM® probe, which has been designed for continuous operational measurement of the mud level in thickeners. The instrument periodically lowers the sensing probe into the thickener taking measurements all the way down.

After measuring into the mud as far as possible, the sensing probe is automatically retracted into the dock where is it washed automatically with sprayers.

The time between measurements is designed to ensure that the measurement is done to avoid the rake movement. The Smart-Level® thickener system consists of the following main components.

sonarTXM® Sensor

This is a specialized, purposed designed, sensing device which can be submerged to 50 m which has its own internal circuitry to conduct several types of measurements.

The measurements are primarily ultrasound attenuation at one or more wavelengths to suit the mud characteristics. The connecting cable provides power communications to and from the sensor. The sensor has some intelligence built-in to ensure optimum, reliable, repeatable and accurate measurements.

Cable and Drum

The sensor cable (14.5 mm diameter) is a heavy duty polyurethane type, selected for outstanding abrasion, oil and chemical resistance.

The drum is designed to wind the cable evenly each revolution and some safety is provided by the expanded stainless steel mesh around the drum.

A warning sounder and orange lamp will be activated a few seconds before the sonarTXM® is lowered and will remain activated while the measurement is taking place, i.e. the drum is in motion.

Internal Motor Drum Drive

A stepper motor and chain drive is used to operate the drum. Special slip rings are used to provide reliable communications and power from the control circuitry to the sonarTXM® sensor. All these components are well “over-specified” to ensure a long life with several self-preservation features.


Primary construction using stainless steel 316. The dock enclosure has an IP67 rating. Clean water is required for spray cleaning of sonarTXM® sensor.

The dock provides a digital output when the sonarTXM® sensor is at the home position.

The stainless steel frame structure suitable for various mounting options.

The dock includes a water pressure transmitter, ball valve, water filter and a solenoid valve with four sprayers with double dock switches for safety.

System Overview

Components Gallery

Large coloured indicators suitable for daylight use will indicate the system status.

Essentially the basic philosophy being:

  • Green only – all is good, no attention required.
  • Orange – on or flashing, measurement in progress, caution advised.
  • Yellow – on, no attention required, just a system status indication, perhaps sensor is docked,
  • Flashing – for washing in progress.
  • Red – on, some fault detected, flashing with audio sounder, serious fault requiring urgent attention.

Local display of mud depth using a clearly daylight visible display.

  • Auto/manual operation key-switch selectable.
    • Auto – measurements and controls all taken care of by the system.
    • Manual – all operations can be done manually.
  • Raise or lower sonarTXM® sensor.
  • Activate spray system.
  • Rake emergency stop testing.

Stainless steel 316.
IP65 rating.
Sun/weather shield on top (optional) .
Stainless steel frame structure suitable for various mounting options.
Approximate dimensions: 1,100 x 500 x 500 mm (width x height x depth).
Expanded mesh surround for the cable drum.
Metal frame design for mounting onto existing gantry or railing structures.

The various system cables are fitted through high quality cable glands for standard plant instrumentation cables and armoured power cables. All external connections are provided using internal and clearly labelled, DIN rail terminals for stranded or feruled wires of diameter at least 4mm2. A connection diagram will be located inside the unit stuck to one of the sides for convenient installation and maintenance.

Analogue Inputs:

Rake motor torque: 0–20 mA, 4-20 mA, 0-10 V, 1-5 V.
Underflow Density: 0–20 mA, 4-20 mA, 0-10 V, 1-5 V.

Digital Inputs:

Rake position switch: potential free contact, NPN or PNP proximity sensor.
sonarTXM® home dock switch: potential free contact, NPN or PNP proximity sensor.
Emergency stop.

Analogue Outputs:

Mud level: 0–20 mA, 4-20 mA, 0-10 V, 1-5 V

Digital Outputs:

Spray solenoid output (+24 VDC).
Mud-Level High Alarm (relay).
Mud-Level Low Alarm (relay).
Cable drum fault (relay).
Measurement in process (relay).
Rake disable (relay).

Plant Control System Interface:

The system will run in autonomous control mode and will interface with the plant control system via process signals (4-20 mA) and relays (standard).

A selection of other optional communication interfaces is on offer at additional cost:

  • Modbus RTU (RS485).
  • Profibus.
  • Industrial Ethernet.
  • Other interfaces on request.

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Regular checks of each component of the device is highly recommended. Follow the instructions on the Maintenance page for more information.

A detailed user manual will be provided for the specific system delivered. It will include maintenance information and enough information to be able to do basic repairs, testing and module replacement.