Cascade TEK’s hi-vac ovens utilize a turbo pump to get into vacuum levels in the 10-7torr range. The interior of a turbo pump is loaded with blades that spin as fast as 20,000 rpm to achieve those hi-vacuum levels. The catch is…. turbo pumps cannot pump at atmospheric pressure. Turbo pumps should only be activated once the 1st stage “rough” vacuum pump has already pumped the system down to a pressure level that is low enough for the turbo to work.