Chopin SDmatic - 3. NORMAL USE; Test of the flour damage; Test Preparation

59
User’s manual 
12/2016
GB
SDmatic
3. NORMAL USE IMPORTANT:
■ Test of the flour damage
The starch damage rate of a flour is measured following three
stages:
- weighing of the flour,
- weighing of the chemicals,
- test with SDmatic.
3.1 Test preparation
■ Preparation of the solution
❏ Prepare in a plastic bottle (supplied with the SDmatic):
- 120 ml of distilled water precisely measured (± 0.1 ml),
- 1.5 grams of citric acid (C
6
H
8
O
7
) (± 0.1 g),
- 3 grams of potassium iodide (KI) (± 0.2 g),
- 1 drop of sodium thiosulfate (Na
2
O
3
S
2
) at 0.1 mol/l.
❏ Shake the bottle for a moment and then pour the obtained
solution in a reaction bowl.
Note : - Preparing sodium thiosulfate (Na
2
O
3
S
2
) at 0.1 mol/l starting from
liquid or powdered product (1 mol Na
2
O
3
S
2
weighs 158.17 grams):
pour in a flask 15.82 grams of product, and make up to 1 litre with
distilled water.
- Purity of C6H8O7 and KI: use products pure to more than 99%.
Risk of burn: do not touch the heating resistor because it might
be hot.
Avoid touching measuring devices with fingers (parts in contact
with the reagent): this could cause wrong measurements.