Self Cleaning Suspended Solids Sensor
The TurbiTechw² LA Sensor has been designed for use in aeration systems monitoring suspended solids also known as mixed liquor suspended solids or activated sludge where solids are typically in the range of 1,500 to 3,500 mg/l.
The sensor can also measure Returned Activated Sludge (RAS), Surplus Activated Sludge (SAS) and suspended solids or turbidity. The fully automatic self cleaning system ensures that manual intervention on a routine basis is not required.
Overview:
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. 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 TurbiTechw² LA 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 |
+/-5% of reading or 50mg/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, NTU |
| Maximum Range |
0-20,000 mg/l (0-10,000 NTU) |
| |
The actual measuring range will depend on the nature of the sample being monitored, for processes normally operating at 10,000 mg/l or more should consider use of the HR version of this sensor.
Processes that use carbon will provide higher than expected readings and the HR version of the sensor should be used. |
