Ocean Optics pH Sensor Patches, Probes and Cuvettes - Manual (Page 21)

2: Desktop Software Installation and Operation
PHSENSOR-TRANS-REFLECT-201111 15
6. Take a low pH reference spectrum at pH 1.0. To do this for your specific system, please refer to
the appropriate subsection below before moving on to 7a:
Transmissive pH Dip-Probe:
Submerge the probe tip in pH 1 buffer and shake back and forth to remove bubbles. Visually
check to ensure no bubbles are present in the optical path.
Reflective pH Patches:
Expose the patch to pH 1 buffer and ensure complete wetting of the mesh. Refer to the previous
section “Proper Sensor Wetting” for instructions on how to properly achieve this. This is critical
for successful calibration and sensor use.
Smart pH Cuvettes:
Use a dropper or pipette to add buffer to the cuvette. Ensure the cuvette is over half way filled so
that the optical path is entirely through the liquid phase. Do not remove the cuvette from the
holder to dump out the liquid. Use a dropper or pipette for both addition and removal of
standards and analytes within the cuvette. It is recommended to perform one rinse of the buffer or
sample before taking a measurement or reference.
a. Wait 30 seconds, then click Acquire. The spectrum shown should have a maximum intensity
around 80% of the saturation level. If saturation is occurring, reduce the integration time
appropriately. If the signal is too low, increase the integration time until the intensity at
620nm is at least over 1000 counts.
b. You can click Acquire repeatedly to update the spectrum after adjusting the integration time;
the last time you press the button will be the last reference that is saved.
c. Once the signal looks strong, make sure you’ve updated the acquisition and then click Next.
7. Take a dark spectrum. To do this, block the light source and click Acquire Dark Spectrum.
Then click Next. Be sure to allow enough time for the system to complete an entire scan while in
the dark before acquiring the spectrum.
8. Unblock the light source.
9. Take a high reference spectrum for pH 11.0.
Transmissive pH Dip-Probe:
Submerge the probe tip in pH 11 buffer and shake back and forth to remove bubbles. It’s a good
idea to rinse the probe with buffer before submersion to ensure residual buffer from before does
not contaminate your sample.
Reflective pH Patches:
Remove the pH 1 buffer without moving the setup, either via pipettor or other device. Replace
with pH 11 buffer, and then remove and add fresh buffer to ensure proper rinsing.