additions of 34.57 g/L thiosulfate ion and 5.444 g/L sodium sulfite were made to that “seasoned” sample.
POTENTIOMETRIC TITRATION STATISTICS
Repeatability Standard Deviation, 1sr & 95 Percent
Confidence Estimate (not including bias)
Repeatability standard deviation is an estimate of the variability one trained analyst should be able to obtain under favorable conditions (analyzing a sample, with one instrument, within one day).
The 95 percent confidence estimate (calculated using the repeatability standard deviation) around a single test will include the mean value 95 percent of the time.
HYPO INDEX (1 mL)
Samples | Mean Level |
| Repeatability | 95 Percent | ||
(N) | Standard Deviation, 1Sr | Confidence Estimate | ||||
(Process | (mL 0.1 N I2) | |||||
| (mL 0.1 N I2) | (mL 0.1 N I2) | ||||
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“Fresh” at “Aim” | 10.02 | 5 | 0.086 | ± | 0.24 | |
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“Seasoned”, As | 15.80 | 5 | 0.073 | ± | 0.20 | |
Received | ||||||
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“Seasoned” with | 19.38 | 5 | 0.14 | ± | 0.39 | |
Standard Addition | ||||||
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| THIOSULFATE |
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Samples | Mean Level |
| Repeatability | 95 Percent | ||
(N) | Standard Deviation, 1Sr | Confidence Estimate | ||||
(Process | = | |||||
(g/L S2O3 ) |
| = |
| = | ||
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| (g/L S2O3 ) | (g/L S2O3 ) | ||
“Fresh” at “Aim” | 81.18 | 5 | 0.67 | ± | 1.9 | |
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“Seasoned”, As | 125.67 | 5 | 0.47 | ± | 1.3 | |
Received | ||||||
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“Seasoned” with | 153.79 | 5 | 0.60 | ± | 1.7 | |
Standard Addition | ||||||
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| SULFITE |
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Samples | Mean Level |
| Repeatability | 95 Percent | ||
(N) | Standard Deviation, 1Sr | Confidence Estimate | ||||
(Process | (g/L Na2SO3) | |||||
| (g/L Na2SO3) | (g/L Na2SO3) | ||||
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“Fresh” at “Aim” | 17.55 | 5 | 0.69 | ± | 1.9 | |
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“Seasoned”, As | 28.92 | 5 | 0.65 | ± | 1.8 | |
Received | ||||||
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“Seasoned” with | 35.69 | 5 | 1.18 | ± | 3.3 | |
Standard Addition | ||||||
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Bias
Bias is a statistically significant deviation of the mean from the known mix level at a 95 percent confidence level. It is determined for “fresh” samples only. Bias is not determined for “seasoned” samples, since the component concentration level was not determined independently of the test method.
A statistically significant bias for thiosulfate of
2 | Processing KODAK Motion Picture Films, Module 3, Analytical Procedures • H24.03 |