Industrial 1,1,1,2-Tetrafluoroethane (HFC-134a) (3)

4.

Carry out according to the regulations in 2.

Take the arithmetic mean of the two parallel determination results as the determination result, and the relative deviation of the two parallel determination results shall not exceed 40%

4.

4.

The water in the sample reacts quantitatively with the iodine in the electrolyte, and the reaction is:

I ₂ +SO ₂ +H ₂ O→2HI+SO ₃

2I ^-— 2e→I ₂

The number of iodine molecules participating in the reaction is equal to the number of water molecules, and the electrolysis produced is proportional to the amount of electricity consumed.

4.

4.

4.

4.

4.

4.

The electrolyte (commercially available reagent) matched with the coulometric moisture meter

4.

4.

Add electrolyte to adjust the Coulomb Moisture Analyzer to make the titration cell reach an anhydrous state

4.
4.
4.
2 Determination

Weigh the mass of the sampling cylinder containing the sample to the nearest 0.
1g
.
Connect the small and small joints of the stainless steel (or suitable material) tube for the injection needle to the outlet valve of the sampling cylinder, insert the injection needle into the bottom of the electrolytic cell of the coulometric moisture analyzer, and control the injection speed to (1～2) g/min , The injection volume is about 10g or adjust the injection volume appropriately according to the water content.
After the injection, the mass of the sampling cylinder is weighed again to the nearest 0.
1g
.
After the sample is injected, electrolysis is performed immediately, and the water quality is directly read on the digital display of the coulometric moisture analyzer
.

4.
4.
5 Expression of analysis results

The moisture content expressed by mass fraction is w ₂ (%) and calculated according to formula (2):

In the formula: m—the mass of water g;

m ₁ —The mass of the steel cylinder and sample sampled before sampling, g;

m ₂ —The mass of the sampled cylinder and sample after sample injection, g
.

Take the arithmetic mean of the two parallel determination results as the determination result, and the relative deviation of the two parallel determination results shall not exceed 20%
.