Sewer network level measurement with millimetric accuracy

LIDoTT Sewer Level Monitoring Sensor

Not an ordinary sewer level monitoring sensor

  • Ultrasonic level measurement (above water)
  • Narrow beam angle
  • No deadband effect
  • Pressure sensor depth measurement (under water)
  • Integral temperature sensor
  • Modbus communications
  • ATEX and IECEx Zone 0 certified

LIDoTT® is a next generation ATEX sewer network level measurement sensor. It integrates ultrasonic level, pressure depth and temperature sensors into one compact device. LIDoTT® delivers high-quality data throughout normal dry-weather operating and either wet-weather or blockage induced surcharge conditions.

LIDoTT® is a unique, UK patented design. On rising and falling water levels, LIDoTT® seamlessly transitions from ultrasonic level measurement to pressure depth measurement and back again – delivering continuous data.

widespread deployment

As a sewer network level measurement solution, LIDoTT® is cost efficient and therefore ideal for widespread deployment. It is ideal in sewer networks, in domestic sewer manholes and throughout other water courses.

millimetric accuracy

When used for sewer network level measurement, the measured data is of such high quality and accuracy that it is revolutionising the ability of AI Machine-Learning systems to detect minor changes in network characteristics and predict operational issues BEFORE they become real problems.

Detectronic have created something very special with the LIDoTT. The fact that it can deliver level monitoring to within + or – 2mm accuracy is something I have hitherto never seen.

Tom Wooley, Royal HaskoningDHV

designed for convenience

LIDoTT® is simple to install and ultra-low maintenance by design. It requires no external atmospheric breather for its pressure-sensor.

The enclosure is moulded from a carefully selected, resilient, naturally self-cleaning plastic polymer and is submersible. LIDoTT® is safe to use in all environments being
ATEX and IECEx certified Zone 0.

continuous measurement

When the sewer network is stressed during storm weather events or by blockages, the LIDoTT® automatically switches sensor mode from ultrasonic (level) to pressure (depth) as the liquid level rises, seamlessly delivering high-quality network management data. This transition is transparent to the external datalogging device which needs only a single recording channel.


Three sensors in one

Ultrasonic level sensor

The LIDoTT® sensor reliably detects subtle changes in “normal” operating conditions – accurately delivering, for example, small silt-induced variations in Depth of flow.

“In Air” Temperature sensor

Primarily used to calibrate distance measurement for changes in air density, temperature can optionally be delivered to the datalogger as a measured parameter.

Pressure sensor

With its 10m H2O operating range, the pressure sensor deals with exceptional Depth measurement. LIDoTT® delivers seamless transition from Level measurement – using its Ultrasonic sensor, to Depth measurement – using its Pressure sensor. The pressure-sensor is activated and measures rising depth before the Ultrasonic sensor blanking distance (dead-band) is reached.

how it works

As the liquid level rises, the ultrasonic sensor is in charge. Once the level reaches the bottom of the pressure sensor, pressure reading starts and a calibration sequence begins.

By the time the level enters the ultrasonic dead-band, the calibration sequence is complete and the calibrated pressure sensor takes over, delivering continuous, accurate depth data.


data communications

The LIDoTT® Sensor communicates using a number of serial protocols including Modbus and will connect to many compatible data loggers.

  • Real time monitoring helps you better understand your sewer network
  • Automatic sensor switching enables continuous delivery of high quality network management data.
  • Data logging device needs only a single depth recording channel.
  • Designed to be compatible with many manufacturers’ data loggers.


product specification

Type: Piezo-ceramic, temperature-compensated
Range: 0.000 – 1.500m
Accuracy: +/- 2mm

Type: High Precision CMOS Temperature device

Type: Isolated Silicon Diaphragm
Range: 0-10.00m
Accuracy: ±0.2% FS

Operating temperature: -20°C to +60°C.
Protection: IP68/NEMA6P.
Connectors: IP68 Mil – Spec.
Dimensions: 200mm(h) x 125mm(d) x 115mm(w)


ATEX Zone 0 certified CML 20ATEX2039X
IECEx Zone 0 certified IECEx CML 20.0019X
II 1 G, Ex ia IIB T4 Ga. Ta= -20°C to +60°C

Patent No. GB2591274



MMS D049 – LIDoTT Sensor iss4

UK Patent certificate


project applications

Contact Us


+44 (0)1282 449124

Regent St
Whitewalls Industrial Estate


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