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ph_accuracy [27/02/2019 07:32] pieter |
ph_accuracy [13/03/2019 09:59] pieter [The pH meter] |
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* the measurement __linearity__ between and outside the calibration points. | * the measurement __linearity__ between and outside the calibration points. | ||
- | As example, a pH meter with an accuracy given as (0.2%+1 digit) and a resolution of 0.01 pH. It depends on the reproducibility at the calibration points (± 0.01, 1 digit) and the linearity between and outside the calibration points (0.2%). When a calibration is done at pH 7.00 and pH 4.00, the device error at these same points is ±0.01 pH. For a measurement at 5.50 pH , the device error is (1.50 pH * 0.002) | + | As example, a pH meter with an accuracy given as (0.2%+1 digit) and a resolution of 0.01 pH. It depends on the reproducibility at the calibration points (± 0.01, 1 digit) and the linearity between and outside the calibration points (0.2%). When a calibration is done at pH 7.00 and pH 4.00, the device error at these same points is ±0.01 pH. For a measurement at 5.50 pH , the device error is ((1.50 * 0.002) |
==== The pH electrode ==== | ==== The pH electrode ==== | ||
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==== The pH buffers ==== | ==== The pH buffers ==== | ||
- | It is advised to calibrate the meter with electrode using buffers that cover or are near to the measurements to be performed and/or to be acquired. Use at least 2 buffers or more when measuring in a larger pH range. | + | It is advised to calibrate the meter with the electrode using buffers that cover or are near to the measurements to be performed and/or to be acquired. Use at least 2 buffers or more when measuring in a larger pH range. |
Check the accuracy of the pH buffers to know the possible measurement errors. Measuring between 2 buffers, used for the calibration, | Check the accuracy of the pH buffers to know the possible measurement errors. Measuring between 2 buffers, used for the calibration, | ||
- | Also follow | + | ==== The user ==== |
+ | Follow | ||