General Notes; Guidelines For Photometric Measurements - Tintometer AL250 Mode D'emploi

General notes

GB

Guidelines for photometric measurements

1. Vials, caps and stirring rods should be cleaned thoroughly after each analysis to prevent
interferences. Even minor reagent residues can cause errors in the test result.
2. The outside of the vial must be clean and dry before starting the analysis. Clean the
outside of the vials with a towel. Fingerprints or other marks will be removed.
3. Zero calibration and test must be carried out with the same vial as there may be slight
differences in optical performance between vials.
4. The vials must be positioned in the sample chamber for zeroing and test with the
on the vial aligned with the
5. Always perform zeroing and test with the vial cap tightly closed. Only use the cap with
a sealing ring.
6. Bubbles on the inside wall of the vial lead to incorrect measurements. To prevent this,
remove the bubbles by swirling the vial before performing the test.
7. Avoid spillage of water into the sample chamber because this can lead to incorrect test
results.
8. Contamination of the lens in the sample chamber can result in errors. Check at regular
intervals and – if necessary – clean the light entry surfaces of the sample chamber using
a moist cloth or cotton buds.
9. Large temperature differences between the instrument and the environment can lead to
errors – e.g. due to the formation of condensation in the area of the lens or on the
vial.
10. To avoid errors caused by stray light do not use the instrument in bright sunlight.
11. Always add the reagent tablets to the water sample straight from the foil without touching
them with the fingers.
12. The reagents must be added in the correct sequence.
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AL250_Cl-Br-pH-CyA-TA-CaH_2a 05/2011
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