Sample Cal-Calibration By Comparison To A Winkler Titration; Sample Cal-Calibration By Comparison To A Hand-Held Do Analyzer - Hach LDO User Manual

5.6.2 Sample Cal—Calibration by Comparison to a Winkler Titration
5.6.3 Sample Cal—Calibration by Comparison to a Hand-held DO Analyzer
three minutes for the reading to stabilize is typical, however, if it has not stabilized after
45 minutes, the display will ready "Unable to Calibrate". After calibration, one of the
responses in Table 5 on page 26
11. Follow the prompts to return the sensor to the process.
1. From the Main Menu, select SENSOR SETUP and confirm.
2. Select the appropriate sensor if more than one is attached and confirm.
3. Select CALIBRATE and confirm.
4. Select SAMPLE CAL. Select the available Output Mode (Active, Hold, or Transfer)
from the list box and confirm.
Note: An output that has been placed in Hold or Transfer status will be automatically released when
the calibration is complete.
5. Remove the sensor from the process stream and gently wipe with a wet cloth to
remove all debris and biological growth. Remaining debris will affect the Winkler
Method of analysis.
6. Measure 1000 mL of deionized water. Allow the water to come to the thermal and
dissolved oxygen equilibrium (approximately 20 minutes).
7. Fill a standard BOD bottle and then place the sensor in a beaker containing the
remainder of the deionized water.
8. Perform the Winkler Tritration using Cat. No. 146900 Winkler Test Kit on the deionized
water in the BOD bottle while waiting for the process sensor to stabilize.
9. Move the sensor to the sample.
10. The display will show "Press
temperature readings. When the reading is confirmed or when the reading has been
accepted as stable, the display will change to an entry screen. If
pressed, the sensor will determine when the reading is stable. Two to three minutes
for the reading to stabilize is typical, however, if it has not stabilized after 45 minutes,
the display will show "Unable to Calibrate".
11. When a stable reading has been accepted, the display will show "Sample Cal" and an
area for entry of the value obtained from the comparison method. When the entry
screen is displayed, enter the value from the hand-held or winkler titration and confirm.
12. After calibration, one of the responses in
1. Place the dissolved oxygen sensor as close to the LDO sensor as possible.
2. Wait for the hand-held DO analyzer to stabilize.
3. From the Main Menu, select SENSOR SETUP and confirm.
4. Select the appropriate sensor if more than one is attached and confirm.
will be displayed.
when Stabilized" and the current DO and
ENTER
Table 5 on page 26
Operation
is not
ENTER
will be displayed.
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