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ph_accuracy [13/03/2019 09:59] pieter [The pH meter] |
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 * 0.002) + 0.01) = 0.013 pH. | + | 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) + 0.01) = ±0.013 pH. |
==== The pH electrode ==== | ==== The pH electrode ==== |