Hach SOLITAX sc User Manual

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Hach SOLITAX sc User Manual Manual pdf 18 page image

18Operations4.6.3 Calibration for Suspended SolidsSuspended solids calibration requires calibration to the actual sample. This optimizes thecompensation for the particle size and shape typical at a measuring site. It is bestperformed by mounting the sensor as usual for normal measurement, and then grabsamples collected and evaluated by laboratory methods. While a single point calibration isusually sufficient to provide accuracy, the SOLITAX does offer the ability to calibrate withup to 5 calibration points.1. From the Main Menu, select SENSOR SETUP and press confirm.2. Select the appropriate sensor if more than one is attached and confirm.3. Select CALIBRATE and press confirm.4. Select CONFIGURE and confirm.5. Select the number of points desired for calibration (the unit with linearly interpolatevalues between calibration points). Select Factor for a single point calibration.6. Mount the sensor as is during normal operation. Alternatively, place the sensor in thecalibration cylinder (or a container with dark, non-reflective walls) 2 inches ofclearance from the probe face with the probe face submerged by 1 inch or more.7. Select SENSOR MEASURE and record the reading.8. Immediately take a grab sample. Determine the total suspended solids using agravimetric method such as Method 2540 D in Standards Methods for theExamination of Water and WasteWater.9. Calculate the new factor. Refer to section 4.6.3.1 for single point (Factor) calibration.Refer section 4.6.3.2 on page 18 for multiple point calibrations.10. Select FACTOR and press confirm. The corrected measurement should be displayed.4.6.3.1 For Single Point (Factor) CalibrationCalculate the new factor:For example, if a sample measures 2.3 g/L using the SS sensor and the gravimetric valuewas 2.0 g/L, the new factor would be calculated as follows:4.6.3.2 Multi-point Calibration1. Repeat steps 6–8 in section 4.6.3 on page 18 at different times to obtain differentmeasurements.2. From the CONFIGURE menu, select the appropriate calibration point menu.3. Enter the pairs of values for each reading, the target value being the laboratorydetermined value, and the actual value being the reading that the SOLITAX producedin step 5. The pairs should be entered in order from lowest values to highest.New Factor = Determined gravimetric valuemeasured valueNew Factor = 2.0 g/L = 0.872.3 g/L