Indexing And Matching Sample Vials; Indexing A Single Sample Vial - VWR TIR 200 Manual De Instrucciones

Standard
800 NTU
Use class A volume pipette and glass flasks.
Use dilution water for the < 0.1 NTU standard.

Indexing and matching sample vials

Matched sample vials are required to minimise the effects of optical variation from glass vial
to glass vial. Alternatively an indexed single sample vial can be used for every measurement.
Once vial orientation in the sample chamber is located, always use this new orientation mark
for all measurements independent of the white pre-printed triangle mark.

Indexing a single sample vial

Note:
Assume the indication "Underrange" is equal to 0.00 NTU.
18
Step 1
Add 50 ml of dilution
water to a clean
100 ml volumetric flask.
1. Fill a clean and dry vial up to the mark with dilution
water (see chapter: Preparing Dilution Water).
2. Cap the vial.
3. Hold the vial by the cap and clean it with the supplied
cleaning tissue to remove water spots and finger prints.
4. Switch the turbidimeter on.
5. Place the vial in the sample chamber.
6. Make sure that the marks are aligned.
7. Place the cover on the instrument.
8. Press [Read] key.
9. Note the displayed result.
10. Rotate the vial in the sample chamber about 45°.
11. Place the cover on the instrument.
12. Press [Read] key.
13. Note the displayed result.
14. Repeat this procedure until the smallest NTU value is
obtained.
15. Mark the vial at this point. Use this orientation mark
for all further measurements.
Step 2
Pipette 20.00 ml well
mixed 4000 NTU
Formazin Stock Solution
to this
100 ml flask.
Step 3
Fill to the mark with
dilution water. Close and
mix the flask.
VWR ver 1 01/2018