YSI ADV6600 - Manual (Page 70)

Section 4. Calibration and Diagnostics
ADV6600
Y S I
Environmental
Page 60
contaminate the standards during your calibration protocol and cause either calibration errors
and/or inaccurate field data.
When selecting to calibrate Turbidity, you will be given the choice of a 1-point, 2-point, or 3-point
calibration. For the first usage, a 2- or 3-point calibration should be performed. Once the initial
multi-point calibration has been carried out, the accuracy of the sensor at low NTU may be checked
(or reset) by performing a 1-point calibration before each usage.
A 1-point calibration is normally used to zero the turbidity probe in 0 NTU standard.
A 2-point calibration is performed using two calibration standards. One of the standards must be 0
NTU and the other should be in the range of known turbidity for the water to be monitored. For
example, if the water to be evaluated is known to be low in turbidity, an appropriate choice of
standards might be 0 and 10 NTU. Or, for general purpose measurements an appropriate choice of
standards is usually 0 and 100 NTU.
A 3-point calibration assures maximum accuracy over the entire range of 0 to 1000 NTU. One of
the standards must be 0 NTU. Because of the linearity characteristics of the sensors, it is
recommended that the other two standards have turbidity values of 100 and 1000 NTU. However,
the user can select any values that are deemed appropriate.
Calibration:
1. With the ADV6600 in the upright position, place the correct amount of turbidity standard in a
clean, dry or pre-rinsed calibration cup. Immerse the probe end of the ADV6600 into the
solution, making sure that the temperature sensor is immersed. Allow at least one minute for
temperature equilibration before proceeding.
2. From the Calibrate menu, select Optic Turbidity to access the turbidity calibration choices and
choose either a 1-point, 2-point, or 3-point calibration.
3. Input the value of the first standard at the prompt. No matter how many calibration points you
are using, the first standard should always be 0 NTU.
4. Press Enter and the current values of all enables sensors will appear on the screen and change
with time as they stabilize in the solution.
5. Activate the wiper 1-2 times by pressing 3-Clean Optics as shown on the screen, to remove any
bubbles. Be sure to observe the wiper during these cycles to assure that it is rotating and
parking correctly (180 degrees from optics).
6. Observe the readings. After stabilization is complete, press Enter to confirm the calibration.
The display will indicate if the calibration is accepted.
7. Press Enter again, as instructed on the screen. If a 2- or 3-point calibration was chosen, rinse
the sonde in water and dry the sonde before proceeding with the next turbidity standard,
following the same steps as outlined above.