8.4. Precision Sodium Tartrate Test
Perform the sodium tartrate test in Section 8.3 multiple times to determine the instruments repeatability. This is a more critical verification of the instrument’s performance.
Mean, Standard Deviation, and Relative Standard Deviation are calculated using the following formulas.
Mean = total of results divided by number of results.
Standard Deviation = | Σ( | x | - x)2 | |
n - 1 | ||||
| ||||
Relative Standard Deviation expressed as percentage = Standard
Deviation divided by Mean, multiplied by 100.
∙Perform the steps in the sodium tartrate test a total of five (5) times.
After all five tests are complete, press [MENU] and select the STORED DATA MENU.
Press [ENT] to select tests.
Arrow up or down to select the five tartrate tests and press [ANALYZE].
The mean of the results should be within ± 0.1 of the value on the bottle label.
∙If the result is out of tolerance, the most common causes of such errors are bent or dirty sample pans, or debris that may have fallen into the balance shaft.
Switch the unit OFF.
Remove the pan support and the balance cover.
Carefully clean the instrument. See page 78.
Clean the oven and check the temperature sensor. See page 80.
If a temperature calibration kit (AZI P/N
∙Repeat the tartrate test again, using a clean sample pan for each of the five samples, and analyze the results.
∙If the mean is still out of tolerance, call AZI customer service at
AZI Customer Service | Page 73 of 92 |
