Solution for the determination of freezing point of antifreeze glycerol

The freezing point of pure glycerol is 17.9℃. With the increase of water content in glycerol, the freezing point decreases gradually. However, when it drops to -46.5℃, if the content of glycerol continues to decrease, the freezing point increases gradually
The freezing point of glycerol aqueous solution with different concentration (weight %) is
10%, -1.6℃;
30%, to 9.5 ℃;
50%, to 23.0 ℃;
66.7%, to 46.5 ℃;
80%, to 20.3 ℃;
90%, to 1.6 ℃.

Instruments for the experiment
1, SH128 automatic freezing point tester, using embedded system design, the whole process of automatic test detection;Color touch screen;The test results can be stored;You can view historical data;Printing results on the instrument, mechanical automatic mixing, experimental results can be exported through the U disk, stored in the computer can be compared for many times.

2, alcohol,

3, in line with the standard SHT0090-1991 engine coolant freezing point determination method





Experimental steps:
1. After the instrument is unpacked, please count the accessories according to the packing list. If there is any damage, please contact our company.

2. The instrument should be carried vertically, and the tilt Angle along the height of the instrument should not exceed 30 degrees. It should be placed in a dark place and placed smoothly, otherwise there will be vibration after the start of the instrument, which will affect the service life of the instrument.

3. Check the alcohol level in the cold margin tank to ensure that the alcohol level should exceed the refrigeration plate in the cold margin. When the alcohol is insufficient, it is necessary to add enough alcohol first, and then carry out the experiment.

4, the instrument power supply is connected to the capacity of more than 220V/10A socket, pay attention to must have a good grounding wire.

5. Take out the sample of 75 ~ 100ml with the measuring cylinder and put it into the cooling flask.

6. Place the cooling bottle in the coolant and plug the bottle tightly.