Ukraine guests with 12 mm Magnesium Sulfate board to do the test

Test object：12mm Magnesium Sulfate board

Test method：

1. Put the sample in a water for 2 hours.
2. Place it inside freezer camera for 2 hours.
3. Take out the sample from freezer camera and defrost it.
4. Repeat this steps 50-100 times.
5. Break the sample in two with power according to its specification.