Self Cleaning Sensor for Suspended Solids and Turbidity Monitoring
The TurbiTechw² HR Sensor has been specifically designed for use in wastewater treatment systems where high levels of suspended solids are desirable in the aeration phase. Membrane Bio Reactors (MBR) typically run with MLSS values in the region of 8,000 to 14,000 mg/l. High MLSS concentrations promote numerous process benefits, including stable operation, complete nitrification, and reduced biosolids production reducing biological volume requirements (and associated footprint) to only 20-30 percent of conventional biological processes.
Overview:
The TurbiTechw² HR sensor is suitable for monitoring solids in higher ranges than the standard LA version of the sensor due to it’s shorter path length.
In addition the sensor incorporates a self cleaning mechanism that ensures the optical surfaces are kept clean at all times, the cleaning system is designed to avoid problems with ragging and does not smear the optical system. The cleaning system ensures that manual intervention on a routine basis is not required, the sensor should simply be checked as part of general site housekeeping. The large optical surface and sample volume combine to ensure that the sensor is providing information that is reliable and representative of the solids present in the process. Deposits of fats and grease on the sensing area do not prevent the sensor from measuring unlike sensors with small optical surfaces
The TurbiTechw² HR Sensor uses infrared light at 860 nm and operates using the Light Attenuation Principle. The cleaning mechanism uses a polyurethane wiper seal, sealed by 2 Nitrile ‘H’ Rings that finish the cleaning process. The Nitrile seals can be exchanged for Viton if the process media dictates. The cleaning process is automatically initiated by the 7300w² Monitor at a user determined frequency. The cleaning process takes only 90 seconds, which means that the sensor is available for 99.5% of the time with a 6 hourly cleaning cycle.
General Specification
Physical |
Dimensions (hxwxd) |
Ø80mm, 470 mm long |
Weight |
2.2 kg |
Protection Class |
IP68 |
Enclosure Material |
Black Acetal Co-Polymer, 316 Stainless Steel, Glass |
Seal Material |
Polyurethane, Nitrile, with option of Viton |
Cable Entry |
Integral Cable Gland |
Cable Length |
10 metres standard, 100 metres maximum |
Interface to Monitor |
|
Power Supply |
12 VDC from Monitor |
Sensor Output |
ModTechw², RS485 |
Environmental Data |
|
Operating/Storage Temperature |
0 to 50ºC |
Location |
Indoor/Outdoor |
Pressure Rating |
1Bar or 14.5 psi |
Maintenance |
|
Service |
Seal Service every 3500 cleans (application dependent) |
Calibration |
The sensor is inherently stable, calibration should be carried out to suit the application. Our recommendation is every 6 months. |
Measurement Specification
Measurement Characteristics |
Principal of Operation |
Light Attenuation/Scatter |
Wavelength |
860 nm Infrared |
Accuracy |
Better than +/-5% of reading or 250mg/l whichever is greater |
Resolution |
Dependent on range setting, typically +/-2% of reading |
Display Resolution |
see 7300w² Monitor |
Response Time |
0.5 seconds damping provided by monitor |
Flowrate |
Not affected by flowrate, avoid deadspots and extreme turbulence |
Units |
User Selectable mg/l, g/l, ppm, %SS |
Maximum Range |
0-50,000 mg/l |
Minimum Range |
0-10,000 mg/l |
|
The actual measuring range will depend on the nature of the sample being monitored. The upper range limit will be affected by the nature of the solids being monitored and cannot be guaranteed. |