Negative Pressuer Board

When the user sets the value of the negative pressure, vacuum pump, negative pressure sensor provides a signal to the control panel, the negative pressure reaches the set value, the control panel to signal to the vacuum pump stops working, when below the set value, the pump will start automatically, Hold that negative value set by the user. when the pressure is too large, negative pressure meter and will give a signal to the control board, then the two-way valve start deflation and ensure the negative pressure value set by the user.