Hach-Lange 9187 sc - Manual (Page 26)

24
Operation
9187sc
To test for Chlorine Dioxide use the DPD Glycine Method, Chlorine Dioxide Reagent Set
(Cat. No. 27709-00) that goes with the DR/4000, DR/2500, and DR/890, and Pocket
Colorimeter II.
Note: Please reference the manufacturer catalog for other methods.
When performing the following steps, calculate the pH first then write down that number
for reference.
4.6.3.1 Process Calibration
When performing these steps, calculate the pH first then write down that number for
reference.
1. From the Main Menu, select SENSOR SETUP and confirm.
2. Highlight the appropriate sensor if more than one sensor is attached and confirm.
3. Select CALIBRATE and confirm.
4. Select PROCESS CONC and confirm.
5. Move Clean Probe to Sample, Press ENTER to continue is displayed. Confirm.
6. Confirm when Stable, VALUE: X.X nA, TEMP: XX.X °C.
7. (9184sc only) Adjust the pH VALUE: +X.XXpH (this is an actual value) with the keypad
and confirm.
8. Adjust the TFC or CONCENTRATION VALUE (depending on instrument purchased):
XXX.X ppb (this is an actual value) with the keypad and confirm.
Note: Refer to section 4.6.3 on page 23 . If adjusting the TFC value, use the Total Free Chlorine
Method.
9. COMPLETE, SLOPE: nA/MG, OFFSET: uA is displayed and confirm to continue.
10. RETURN PROBE TO PROCESS is displayed and confirm.
4.6.4 Zero Calibration
The Zero Calibration can be performed in two different ways: chemically or electrically. To
perform a Zero Calibration, refer to
section 4.6.5 on page 25 .
For most users, the manufacturer recommends using the Electrical Zero Calibration. This
uses a purely electrical means of setting the zero calibration point which is completely
automated. Changing the setting first in CAL CONFIG is the only way to obtain a chemical
zero calibration. The electrical is standard and the chemical is optional. See section 4.6.5
on page 25 .
In low range applications (<50ppb), it is recommended to use the Chemical Zero Method.
The Chemical Zero Method requires a sample that is completely free of any oxidants. An
oxidant free reference sample may be produced by leaving water in an open container for
24 hours. For best results use actual process water. Bubble the water, if possible, to speed
up the oxidant evaporation.
The Upper Level Calibration point is obtained by reference to a laboratory method
(process calibration).