Emerson Clarity II Instruction Manual page 44

MODEL CLARITY II
Dark cal in
progress...
Bad Dark cal.
SN Live 0.012NTU
Stablilizing
H2O > 0.5NTU
Continue? Yes
Sensor in Std?
Press ENTER
SN Live
20.18NTU
Stablilizing
Live 20.18NTU
SN Cal
2 2 0.10NTU
SN Live 20.02NTU
Cal Complete
Calibration
Error
Slope too high
Continue? Yes
Slope too low
Continue? Yes
36
10. The screen at left appears showing that the sensor dark current is being
measured. This step takes 30 seconds. If the reading does not stabilize
after about 2 minutes, press ENTER. The analyzer will use the current dark
reading.
If the dark current is too high, the screen at left appears. Be sure the sen-
sor is squarely and securely seated in the calibration cup. Press EXIT and
repeat the calibration. If the dark current measurement is acceptable, the
screen in step 11 appears.
11. The turbidity value in the first line is the turbidity of the water based on the
previous calibration. Stabilizing flashes until the reading is stable.
12. This screen appears if the turbidity of the water is too high (>0.5 NTU). To
continue with the calibration, choose Yes. To start over again, choose No.
No
If you choose to repeat the step, obtain a fresh portion of filtered deionized
water. Rinse the calibration cup and sensor thoroughly with the filtered
water.
13. Once the reading in filtered water is stable, the screen at left appears.
Remove the sensor from the calibration cup and place it in a clean area.
Discard the filtered water. Rinse the calibration cup several times with
small amounts of 20.0 NTU standard. Fill the calibration cup with standard
to the level of the groove cut inside the cup. Place the sensor in the cup.
Swirl the sensor to remove air bubbles. Press ENTER.
14. The screen at left appears. The turbidity value in the first line is the turbidi-
ty of the 20.0 NTU standard based on the previous calibration. Stabilizing
flashes until the reading is stable.
15. Once the reading is stable, the screen at left appears. The turbidity value
in the first line is the apparent turbidity based on the previous calibration.
The turbidity value in the second line is the measured turbidity at the time
the reading became stable. Use the arrow keys to change the turbidity to
match the amount by which you increased the turbidity of the filtered water.
For example, if you added sufficient formazin to increase the turbidity by
20.0 NTU, enter 20.00. See Section 6.2.1. Press ENTER.
16. The screen at left shows the calibration was successful. Press ENTER. The
display returns to one of the screens in step 6. To return to the main dis-
play, press MENU then EXIT.
17. If a calibration error occurred, one of the screens at left appears.
Calibration error means that zero was entered in step 16 — the analyzer
attempted to divide by zero. Slope too high or slope too low implies the
standard was improperly prepared or the wrong value was entered in step
15. For additional troubleshooting information, see Section 8.3.1.
No
If calibration error is showing, the analyzer retains the existing calibration.
To attempt a recalibration, press ENTER. The display returns to step 8. If
No
Slope too high or Slope too low is showing, choose Yes to update the cal-
ibration or choose No to repeat the calibration.
SECTION 6.0
CALIBRATION