new tri-element vacuum tube,which is the core technology behind the solar water heater.
210cm vacuum tube assimilate the advanced 12 layers of spattering deposition
of trivalent element technology to make the tube has high performance of
absorptance and low reflection ratio. It also can stand up to high temperatures
and perform a strong heating ability. And improve the deposition layer's structure
through add rare metal to enhance the effect photosensitive reaction, the
absorbing rate of vacuum tube up to 0.96. Absorbing rate can be raise over
16% than 180cm vacuum tube. So it can be heat if cloudy.