1、 On site calibration method

Standard solution preparation: Select a series of standard solutions that are close to the actual sludge concentration to ensure their stability. For example, a standard suspension of 0-10g/L can be configured to cover the common sludge concentration range.

Environmental condition control: The calibration environment temperature should be stable between 0-50 ℃ to avoid temperature fluctuations affecting sensor sensitivity. At the same time, ensure that there is no strong electromagnetic interference and that the sensor installation location avoids direct sunlight and severe vibrations.

Calibration steps:

Blank calibration: Place the sensor in purified water to eliminate background interference.

Standard solution measurement: Inject the standard solution one by one, record the measurement values at each concentration, and take the average of at least 3 measurements for each solution.

Calibration curve establishment: By fitting the measured values with the standard values through linear regression, a calibration curve is established to ensure that the slope is close to 1 and the intercept is close to 0.

2、 Parameter optimization strategy

Response time adjustment: Set the response time according to process requirements, such as shortening the rapidly changing sludge interface to 10 seconds and extending the stable working condition to 600 seconds.

Threshold and correction factor setting: Adjust the threshold for different sludge characteristics, such as reducing the lower limit of the threshold from 0.3g/L to 0.1g/L in low turbidity source water treatment, to improve the detection accuracy of low concentration sludge.

Optimization of sensor installation: Adjust the installation position according to the type of sedimentation tank. For example, the radial flow sedimentation tank can be installed on the scraper bridge, while the horizontal flow sedimentation tank is installed in the middle part.

3、 Data validation methods

Instant verification: Immediately retest with standard solution after calibration, and the deviation should be within the allowable range.

Actual sample comparison: Collect actual sludge samples, detect concentration using laboratory methods, compare with instrument results, and ensure that the deviation meets process requirements.

Long term stability tracking: Collect sludge samples under stable operating conditions at fixed intervals, record instrument detection values, and ensure that the data remains stable in the normal range for a long time.