Computrac MAX-1000 User's Manual - Arizona Instrument

eliable results, use a high quality or reagent grade (ACS certified) granular sodiumtartrate. Avoid using sodium tartrate that contains lumps or has an unevenconsistency since lumps indicate the absorption of ambient humidity and will yieldvariable results. Sift the sodium tartrate through a #20 sieve to eliminate anylumps or large crystals that pop off the sample pan during the test.The test uses approximately 8 grams of sample and is run at 150°C. Resultsshould be within a range of ±0.100% of the assayed value on the label of thechemical. (typically 15.61% - 15.71%)12.3.1 From the FINAL TEST screen, press the “Memry” key.12.3.2 If the highlight bar is not already on it, use the up and down arrows to select“01 ID: TARTRATE.”12.3.3 Press the “START” key.12.3.4 When the OPEN LID appears on the screen, open the lid and GENTLY place anew, clean sample pan on the pan support.12.3.5 Close the lid and allow the unit to tare.12.3.6 When the OPEN LID appears on the screen again, open the lid and gently andevenly shake sodium tartrate over the surface of the sample pan until the displayshows that 7.9 to 8.1 grams of sample are loaded.12.3.7 Close the lid and the test will begin.12.3.8 Wait for the end of test signal.12.3.9 If this is the first test of the day, discard the results of this test for stability reasons.12.3.10 Results should be within a range of ±0.100% of the assayed value on the bottlelabel.12.4 PRECISION TARTRATE TEST12.4.1 Run five sodium tartrate12.4.2 The mean of the sodium tartrate results should be ±0.10% of the value on thebottle label.12.4.3 If the result is still out of tolerance, The most common causes of such errors arebent or dirty sample pans, or debris falling into the balance shaft, interfering withthe pan support’s ability to freely move up and down. Also, clean the heaterassembly and check the temperature sensor.12.4.4 Repeat the tartrate test again, using a clean sample pan for each of the fivesamples, and analyze the results.57