Ocean Optics pH Sensor Patches, Probes and Cuvettes - Manual (Page 34)

B: Troubleshooting
28 PHSENSOR-TRANS-REFLECT-201111
Problem Possible Cause/Suggested Solution
Unsteady and improper
setup If the vessel or probe has play in its ability to move, this will disrupt the
quality of the reading; all components should be entirely static and fixed.
Additionally, the probe should be as close to the patch as possible, flush
against the container. Containers with wall thicknesses greater than 2mm
are not recommended.
Smart pH Cuvettes
Problem Possible Cause/Suggested Solution
Moving cuvette The cuvette should not be removed once usage has begun; use only a
pipette or dropper to add and remove liquids.
Saturation If the spectrometer is still saturating after SpectraSuite auto-adjusts the
integration time, you may be using a spectrometer with too large a slit. An
attenuator will fix the issue.
Colored or turbid analyte If there is sediment or color in the solution being measured, this will disrupt
the quality of reading. Reflective pH Patches should be used in these cases.
All Form Factors
Problem Possible Cause/Suggested Solution
Insufficient Equilibration
Time While Smart pH Cuvettes may only need a few seconds to fully respond, the
reflective patches may require up to 60 seconds for low salinity samples. If
references and calibration points are taken without sufficient equilibration
time, the sensor will not read valid values.
Group 2 Elements If your reference buffers or sample to be measured contain a notable amount
of alkaline earth metal salts (group 2 elements), the sensor will not give valid
readings. Likewise, borate buffers have about a 0.50 pH unit error from their
actual value.
Sterilization
All form factors can be sterilized by ethylene oxide or gamma exposure.