Navigator 600 Phosphate
Multi-stream
Appendix C – Troubleshooting
73
IM/NAV6P/MS–EN Rev. F
C.3.2 Optical System Errors
Symptom
Action
Unstable mV values
The optical system receives mV signals from the cuvette and cuvette reference sensors. For accurate
readings both these values must be stable.
Note.
When viewing these readings, be aware that if the phosphate level in the analyzer changes
gradually, the cuvette voltage also changes gradually.
To check mV values:
1. Press and select 'Diagnostic Information', 'Measurement Status'. The 'Measurement Status'
window is displayed and a mV signal value is displayed for the cuvette and the cuvette reference
sensors.
2. If the mV values are unstable and fluctuate by more than ± 20 mV over a short period of time, there
could be bubbles developing within the cuvette.
3. If bubbles are confirmed in the cuvette, check the tube connections – see Section C.3.1 above. If
the problem persists, perform a manual system clean – see Section 7.4, page 45.
Calibration failure or
no response from
optical system
If there is no response or calibrations fail, check the output of the optical sensors as follows:
1. Empty the cuvette of reacted chemicals:
a. Press the
key.
b. Select 'Calibration & Maintenance'.
c. Select 'Manual Test Settings'.
d. Select 'Test Pumps'.
e. Switch the reagent pump off and increase the speed of the sample pump to 5 rpm.
f.
Run the sample pump at the increased speed for 5 minutes.
g. Set the sample pump speed back to its normal (previous) speed.
2. View the mV values in the 'Measurement Status' window.
3. If the optical unit is functioning correctly, the mV values are within the following ranges:
–
Cuvette: 1000 to 2300 mV
–
Cuvette Ref: 1000 to 2300 mV
4. If the Cuvette Ref signal is low, replace the optical unit
(see Appendix
– part number
AW601110)
.
5. If the Cuvette signal is low, perform a manual system clean – see Section 7.4, page 45. If the
problem persists, replace the optical unit
(see Appendix
, page
– part number AW601110)
