Ocean Optics Transmissive pH Probe - Manual (Page 7)

pH Probe Instructions
PH-BCG-TRANS-01-0210 7
6. Take a low pH reference spectrum at pH 1.0. To do this,
a. Submerge the probe tip in pH 1 buffer and shake back and forth to remove bubbles.
b. Wait 30 seconds, then click Acquire. The spectrum shown should have a maximum
intensity around 80% of the saturation level. Most Ocean Optics spectrometers have a
saturation limit of 4000 counts. 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.
c. 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.
d. 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. To do this, 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. Allow 30 seconds, and then click Acquire. When complete, click Next.
10. Follow the wizard and repeat Step 9 for pH buffers 5, 6, 7, and 8 (follow on-screen prompts).
Again, it is a good idea to rinse the probe tip with buffer before submersion to prevent sample
contamination. Then, click Finish.
11. You are now ready to take pH measurements.
Taking pH Measurements
Now that you have finished calibrating your pH sensor system, you can take pH measurements in the
biological range.
► Procedure
1. Submerge the probe tip into analyte solution for pH measurement in the biological range. The
pH value appears on the screen in the Current pH field (upper right corner).