Accurate pH test

by Roger
(Cincinnati)

In order to maintain a reasonable degree of accuracy when making a pH measurement, proper handling, storage, and use of buffers is important. If the buffers are contaminated or used improperly, the calibration will be in error and all subsequent measurements will be wrong.


Remember:

• Do not use buffers after their expiration date. Store buffers at controlled room temperature.

• Protect buffers from excessive exposure to air. Always cap the buffer container when storing.

• Before starting calibration, be sure the sensor and the buffer are at the same temperature. If possible, calibrate with buffers having the same temperature as the process.

• Do not return used buffer to the stock bottle. Discard it.

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Nov 28, 2015
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Temperature of buffer?
by: Sarah

Very useful info. A query though: the buffer solutions provided with my ATC PH meter state use @ 25 degrees. However, elsewhere it is stated that the buffer and the medium to be tested should be near the same temperature. As I am testing pondwater which is never anywhere near 25 degrees, would I still have accuracy having used a buffer at 25 degrees to calibrate? Any advice gratefully received.

May 29, 2010
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Temperature dependent
by: David

Buffer values are dependent upon temperature. Make sure you use the right number. Check the supplied table that gives the pH value of your buffer at various temperatures.



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Download the new release ISO 14001:2015