YSI 550A - Troubleshooting Common Issues; Power On and Low Battery Errors; Calibration Failure Troubleshooting; Instrument Lock-up Resolution

Page 12 Y S I Environmental YSI 550A
TROUBLESHOOTING
NOTE: An error displayed briefly during the first few seconds after turning the instrument on
does NOT indicate a problem.
SYMPTOM POSSIBLE SOLUTION
1. Instrument will not turn on,
LCD displays "LO BAT", or
Main display flashes “OFF”
A. Low battery voltage, replace batteries
B. Batteries installed incorrectly, check battery polarity
C. Return system for service
2. Instrument will not calibrate. A. Replace membrane and electrolyte
B. Clean probe electrodes
C. Return system for service
3. Instrument "locks up". A. Remove batteries, wait 15 seconds for reset, replace batteries
B. Replace batteries
C. Return system for service
4. Instrument readings are
inaccurate.
A. Verify calibration altitude and salinity settings are correct and
recalibrate.
B. Probe may not have been in 100% water saturated air during
calibration procedure. Moisten sponge in calibration chamber
and recalibrate.
C. Replace membrane and electrolyte. Recalibrate.
D. Clean probe electrodes.
E. Return system for service.
5. Main display reads “Over” or
“Undr”.
A. Sample O
2
concentration is more than 60 mg/L or 500%, or less
than –0.02 mg/L or -0.3%.
B. Verify calibration altitude and salinity settings are correct and
recalibrate.
C. Replace membrane and electrolyte. Recalibrate.
D. Clean probe electrodes.
E. Return system for service.
6. Main display reads “Over” or
“Undr” during calibration.
A. Replace membrane and electrolyte. Recalibrate.
B. Clean probe electrodes.
C. Return system for service.