Low Range Suspended Solids Sensor

suspended solids sensor field tests results

InsiteIG FAQs

Suspended Solids

Frequently Asked Questions:

  1. Why use a near-infrared frequency to measure suspended solids in biological reactors?
  2. What are the advantages of measuring suspended solids with a continuous, online analyzer?
  3. What is the range of suspended solids that can be measured?
  4. Is there a correlation between suspended solids measured in mg/l and turbidity as measured in NTU's?
  5. Is there a method to automatically clean the optics of the sensor?

Answers to FAQs:

1. Why use a near-infrared frequency to measure suspended solids in biological reactors?

Using a near-infrared wave length (880 nanometers) virtually eliminates shifts in calibration caused by color variations in the process being measured. As almost all processes will have slight changes in color, using near-infrared reduces calibration events and provides better accuracy. BACK TO TOP


2. What are the advantages of measuring suspended solids with a continuous, online analyzer?

1. Balance the solids loading in the mixed liquor as flow changes during the day.

2. Reduce the time required to take manual grab samples.

3. Accurately control wasting, thereby maintaining an optimum sludge age. BACK TO TOP


3. What is the range of suspended solids that can be measured?

There are two different sensors that cover a range of 0 to 30,000 mg/l. The model 15L was designed to measure low ranges (0 to 1500 mg/l) typically found in plant and clarifier effluents. The model 15 was designed to measure higher solids concentrations (400 to 30,000 mg/l) typically found in mixed liquor, RAS, and WAS. BACK TO TOP


4. Is there a correlation between suspended solids measured in mg/l and turbidity as measured in NTU's?

No. The mg/l method is a volumetric measure of the actual weight of solids in the sample. The NTU method is a measurement of the clarity of the water. There is no exact correlation between the two methods. BACK TO TOP


5. Is there a method to automatically clean the optics of the sensor?

All sensors are delivered with a ¼ inch quick-disconnect that allows an air or water line to be attached. The analyzer will either open / close a solenoid valve or turn on / off an air compressor at user defined intervals. The solenoid valve is used in applications that already have compressed air or wash water available. The stand-alone compressor can be mounted on the handrail right next to the analyzer. BACK TO TOP