Instruction manual

62
MODEL XMT-A-FF/FI SECTION 10.0
CALIBRATION - FREE CHLORINE
9. This screen appears if the zero current is moderately high. To continue,
choose Yes. To repeat the zero step, choose No. See Section 15 for
troubleshooting.
10. If the sensor was just zeroed, place it in the process liquid. If automat-
ic pH correction is being used, calibrate the pH sensor (see Section 14)
and place it in the process liquid. If manual pH correction is being used,
measure the pH of the process liquid and enter the value (See Section
7.3.3). Adjust the sample flow until it is within the range recommended
for the chlorine sensor. Refer to the sensor instruction sheet.
11. Adjust the chlorine concentration until it is near the upper end of the lin-
ear range, point C1 in Figure 10-2. Wait until the transmitter reading is
stable before starting the calibration.
12. Choose pt1.
13. The screen at left appears for two seconds.
14. The screen at left appears. The number in the first line is the concen-
tration of chlorine based on the previous calibration. Wait until the read-
ing is stable, then press ENTER.
15. The screen at left appears. Take a grab sample of the process liquid
and immediately press ENTER. The transmitter will store the present
sensor current and temperature and use those values in the calibration.
16. Immediately determine the free chlorine concentration in the sample.
17. Use the arrow keys to change the value in the second line to match the
results of the laboratory test.
18. This screen appears momentarily if the sensitivity (sensor current divid-
ed by concentration) is much higher or lower than expected. The dis-
play then returns to the screen in step 5. See Section 15 for trou-
bleshooting.
19. Adjust the concentration of chlorine in the sample until it is near the
upper end of the control range (point C2 in Figure 10.2)
20. Choose pt2 and repeat steps 13-17 above.
21. To return to the main display press MENU then EXIT.
Possible ZeroErr
Proceed? Yes
No
Cal?
Zero
pt1
pt2
Cal?
Zero pt1
pt2
Wait for
Stable reading.
Stable? 6.00ppm
Press enter.
Take sample;
Press enter.
Sample 6.00ppm
Cal
6
.00ppm
Calibration
Error