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8100 and 8200 Sludge Blanket Detectors


This product is no longer in production – please see SludgeWatch 8200w² Monitor for new requirements

The 8100 and 8200 monitors provide an exceptionally simple and reliable method of detecting the sludge blanket level in clarifiers and settlement tanks in wastewater, drinking water and industrial effluent treatment.

Control of the sludge blanket level is essential to ensure discharge consent compliance and efficient control of the treatment process. If the sludge blanket in a settlement tank is allowed to rise close to the surface there is a danger that solids will leave the tank and contaminate the next process stage or be discharged into the water course. Alternatively, if the sludge blanket is not allowed to stabilise, form a blanket or is pumped out too frequently, the settlement process does not take place at all and solids will remain in suspension.

Our infrared sensors are ideally suited to monitoring the top of the sludge/water interface ensuring early detection of any rising sludge that represents a threat to the treatment process and effluent quality.

For specialist advice call:

+44 (0)1726 879800

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  • Overview
  • General Specification
  • Sensor Selection
  • Ordering Information

The 8100 Monitor is suitable for mounting outdoors on the bridge of settlement tanks, as the enclosure is IP65 rated and no outer enclosure is required, although outer protection is often preferable to avoid degradation of the enclosure due to environmental conditions. 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.

The 8200 Monitor is a two channel version of the monitor providing the option of alarming at two positions in a tank or on two tanks that are located close together.

Partech offer a selection of sensors that are for use in conjunction with our range of Sludge Blanket monitoring instruments. 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. 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. Advice on sensor selection is included in the brochure and our engineers are available to provide further advice if required.

Dimensions (hxwxd)160 x 195 x 105 mm
Weight1 kg
Protection ClassIP65
Enclosure MaterialABS
Cable Entry4 x M20 (cable 5 to 10 mm)
Cable Core SizeMax Conductor Size 2.5 mm²
Power Supply100 to 240VAC 50/60 Hz
9 to 36VDC option vailable
Power Rating8 W
Environmental Data
Monitor: -20 to 60ºC
Sensor: 0-40°C
User Interface
Local AnnunciationGreen LED for Normal
Red LED for Blanket Alarm
Orange LED for Fault
Adjustment5 - 95% of Sensor Range
Response Time1 to 90 Seconds
Number2, 1 Blanket High, 1 System Fault
Rating5 A @ 230VAC, [email protected]

The 8100 and 8200 Monitors are offered with a choice of sensors, the details below give information about the specifications of the sensors.

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
1636008100 Monitor - Single Channel Sludge Level Detector (85 to 264VAC, 1 x Alarm Relay & 1 Fault Relay)
2236448100 Monitor - Single Channel Sludge Level Detector (9 to 36VDC, 2 x Alarm Relay & 1 Fault Relay)
1636108200 Monitor - Dual Channel Sludge Level Detector (85 to 264VAC, 2 x Alarm Relay & 1 Fault Relay)
2236468200 Monitor - Dual Channel Sludge Level Detector (9 to 36VDC, 2 x Alarm Relay & 1 Fault Relay)
Monitor Bracket
226370FlexTech Monitor Bracket Assembly (7200/8100/8200 Monitor, Handrail
102200IR100 Sensor - 8100/8200/7200 (Cable Length: 10 metres) Range 0-200 mg/l
101900IR40 Sensor - 8100/8200/7200 (Cable Length: 10 metres) Range 0-1,500 mg/l
101600IR15 Sensor - 8100/8200/7200 (Cable Length: 10 metres) Range 0-10,000 mg/l
148120IR8 Sensor - 8100/8200/7200 (Cable Length: 10 metres) Range 0-30,000 mg/l
Sensor Bracket
171290Mounting Bracket - IR, Soli-Tech 20v2 (Handrail)

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