Instruction Manual

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6) If you want to continue to calibrate 100, 400 and 800 NTU, place the 100 NTU
calibration vial in the sample vial holder and press to calibrate. After
calibration is done, press to confirm; repeat the steps to calibrate 400 NTU
and 800 NTU. After calibration is done, press to return to measurement mode.
7) Press to exit calibration mode, the
instrument will return to measurement mode as
shown in Diagram on the right side.
4.3 Notes for Calibration
a) Calibration point verification: The calibration point can be verified after the calibration is
completed. If the calibration point has a large error, enter the calibration mode and repeat the
calibration. For calibration point accuracy, users can refer to the following standards:
b) Calibration point selection: The instrument has been calibrated at full range before leaving
the factory. Users can select 2 or more points as needed to calibrate, as long as the target
measurement range is in between of the two calibration points. In calibration setup mode, press
or to select the calibration point.
c) Low turbidity calibration requirement
⚫ For low turbidity measurements (measurement less than 2 NTU), please test 0.0 NTU
calibration solution. If the accuracy is not meeting your requirements, calibrate the instrument
at 0.0 NTU and 20.0 NTU before test; then use 1
#
or 2
#
vial for measurement.
⚫ Using the same sample vial to calibrate and measure can eliminate the error caused by
different vials, thus achieving higher accuracy. For example, add laboratory distilled water to
1
#
vial for zero-point calibration and then add sample solution to 1
#
vial for measurement.
Note that the test vial should be rinsed thoroughly when changing solutions.
d) High turbidity calibration requirement: For turbidity measurement greater than 2 NTU, it is
recommended to calibrate once a week, or to test a calibration solution close to the sample
Calibration point
Accuracy for reference
0 NTU
≤0.05 NTU
20 NTU
≤±0.2 NTU
100 NTU
≤±2 NTU
400 NTU and 800 NTU
≤±5 NTU