I'm using a pH 7 buffer solution to check pH using my colorimeter and the reading is not close to what it should be. What can I do?

Document ID

Document ID TE361

Published Date

Published Date 27/05/2017
Question
I'm using a pH 7 buffer solution to check pH using my colorimeter and the reading is not close to what it should be. What can I do?
Summary
Using pH buffers for colorimetric pH tests
Answer
Make sure the buffer you are using is colorless (Cat. No. 12222-49 or 12222-56) and not yellow. Colorimetric tests depend on the color change of the pH indicator, so colored buffers will not read accurately.

If you don't have any colorless buffer available, you can zero the instrument on the buffer with no phenol red and read the buffer with the phenol red added to it. If the reading is slightly off, you can adjust the calibration using the standard adjust feature.

Was this answer helpful?

Submitting...
Thank you for your feedback!
There was an error with your submission. Please try again.