Refreshing Technology Maintains 0.8 atm Vacuum*
Hitachi innovation at its finest and most consistent: the sealed pressure-resistant vacuum realises and maintains the vacuumed environment. A vacuum pump extracts air and reduces oxygen to achieve approx. 0.8 atm (atmospheric pressure) throughout usage.
* Vacuum means the space where the pressure is lower than the atmospheric pressure. The pressure in the Vacuum Compartment is about 0.8 atm, which is lower than the atmospheric pressure, hence, Hitachi considers this a vacuum.
