Call Menu

ASLD2200 Sludge Blanket Monitor

Continuous Sludge Blanket Level Monitoring – Infrared Sensor

The ASLD2200 is a fully automatic sludge blanket level detector designed for the water and waste water industry. It utilises a servo-driven sensor which continually tracks the settled interface with the sensor at the very top of the interface zone.

Continuous monitoring of the sludge/water interface or sludge blanket is central to the efficient operation of clarifiers, thickeners and settlement tanks. Reliable measurement enables a control system to maintain the optimum depth of sludge in the tank. A sludge interface that is too high can result in pollution incidents caused by carry-over from a final settlement tank. The sludge can also become too thick to extract easily or can turn septic if left too long. If there is insufficient sludge in the tank the settlement process cannot operate correctly and the solids will tend to remain in suspension.

Our infrared sensors are ideally suited to monitoring the sludge/water interface even when the settlement process is not working effectively and the interface has become indistinct.

For specialist advice call:

+44 (0)1726 879800

Online Enquiry
View Related Product Documents
  • Overview
  • General Specification
  • Sensor Specification
  • Ordering Information
  • Commissioning Guide

The ASLD2200 is supplied with a sensor that uses infrared attenuation as the principle of operation which allows Partech to ensure sufficient sensitivity to monitor sludge blankets in a wide variety of applications. It should be noted that sensor selection can be site dependent. Partech are happy to provide full support in the selection of the correct sensor.

The sensor will normally be positioned in the area of the tank just above the sludge and will therefore be kept away from the worst of the fouling that can occur in the treatment of either potable or dirty water. Provision must be made for transmission of the output signal to the control system; this is normally possible via spare slip rings. Where this is not possible a radio telemetry option is available, allowing transmission directly to the control system without the need for installation of cables.

When monitoring the Sludge Blanket Level in settlement tanks it is important to ensure that the sensor is sensitive enough to detect low density solids before ‘carry-over’ to the next process stage occurs, ensuring that potential pollution events are highlighted prior to occurrence. At the same time the sensor should not be ‘blinded’ by solids in the supernatant.

Dimensions (hxwxd)490 x 350 x 300 mm
Weight15 kg
Protection ClassIP55 Outer Enclosure with IP65 electronics housing
Enclosure MaterialGRP Outer Enclosure with Polycarbonate inner
Cable Entry3x M20
Cable Core SizeMax Conductor Size 2.5 mm²
Power Supply85 to 264 VAC 47-65 Hz
Power Rating25W
Environmental Data
Operating/Storage Temperature0 to 50ºC
User Interface
Display3 Digit, 7 Segment LED Display of 0-100%
SetupPotentiometer and Push Buttons on main PCBA
Units of Measurement%age Depth
Output Signals
Analogue Output4-20 mA, max load 500 ohm
Relays1, set at 0 and 100% and is not adjustable
ContactsContact Closure, 0.55 A @ 100VDC
Local Annuication6 LED's on main PCBA

There is a choice of sensors for use with the ASLD2200, all the sensors use infrared attenuation as their operating principle, this makes them sufficiently sensitive for use on thin water treatment sludges as well as the more usual sewage treatment applications.

Measurement Characteristics
Principal of OperationLight Attenuation
Wavelength960 nm Infrared
Accuracy+/- 1 cm of interface
Accuracy will depend on the settling characteristics of the solids and can vary during operation of the plant
Response Time0.5 seconds
FlowrateNot affected by flowrate
Environmental Data
Pressure Rating10 mWC
Physical Data
Weight0.35 kg (inc 10 metres of cable)
Enclosure RatingIP68
Enclosure MaterialMoulded Epoxy Resin
Cable Length10 metres standard, 100 metres maximum
Service RequirementNo routine servicing
The sensor will require manual cleaning, the frequency is application dependent
Sensor Ranges
IR100Range: 0-200 mg/l
Optical Path: 100 mm
Special Application Only
IR40Range: 0-1,500 mg/l
Optical Path: 40 mm
Wastewater Treatment - Final Settlement and Humus Tanks
Drinking Water Treatment - Clarifers
IR15Range: 0-10,000 mg/l
Optical Path: 15 mm
Wastewater Treatment - Primary Settlement Tanks
Drinking Water Treatment - Picket Fence Thickeners
IR8Range: 0-30,000 mg/l
Optical Path: 8 mm
Wastewater Treatment - Picket Fence Thickeners
Part NumberDescription
167430ASLD2200 Monitor for IR and Soli-Tech 20v Sensors
102201IR100 Sensor - ASLD2200 (Cable Length: 10 metres) - Range 0-200 mg/l
101901IR40 Sensor - ASLD2200 (Cable Length: 10 metres) - Range 0-1,500 mg/l
101601IR15 Sensor - ASLD2200 (Cable Length: 10 metres) - Range 0-10,000 mg/l
148121IR8 Sensor - ASLD2200 (Cable Length: 10 metres) - Range 0-30,000 mg/l
Mounting Bracket
101170Mounting Bracket - ASLD2200

Click on the image to view the video

Related Products, Measurements and Applications

ASLD Bracket

FlexTech ASLD2200 Mounting Bracket (PN101170)

This mounting bracket is designed to work with Partech's ASLD2200 Sludge Blanket Monitor

More Details
Sludgewatch 715

SludgeWatch 715 Sludge Blanket Detector

The SludgeWatch 715 provides a simple, low cost method of spot checking the sludge blanket level in a wide variety of settlement tanks

More Details
SludgeWatch Ultra Monitor

SludgeWatch Ultra Sludge Blanket Monitor

Highly sophisticated Sludge Blanket Monitor using an ultrasonic transducer to track the sludge blanket interface

More Details

SludgeWatch 8200w² Monitor

The SludgeWatch 8200w² Monitor provides a reliable method of detecting the sludge blanket level in clarifiers and settlement tanks.

More Details
8100 Monitor with Radio Transmitter

Sludge Blanket Detection

Detecting the presence of the Sludge Blanket at a fixed level is one of the simplest ways of carrying out this control measurement

More Details
ASLD2200 On Site

Sludge Blanket Monitoring

Continuous monitoring of the sludge/water interface or sludge blanket is central to the efficient operation of clarifiers, thickeners and settlement tanks

More Details

Primary Settlement Tank (PST)

The primary settlement or sedimentation tanks are designed to reduce the velocity of the wastewater flow for organic solids (called raw sludge) to settle

More Details

Final Settlement Tanks

Final settlement tanks (FST's) are similar in design to primary settlement tanks and are an integral part of the activated sludge process

More Details