Massaflow onder controle

Massaflow onder controle
De meting van een gasstroom is onafhankelijk van de temperatuur en de druk, een procesgas kan dus stabiel en reproduceerbaar zijn.
Massaflowregelaars bevatten een PID-regelaar en kunnen aangestuurd worden via een normsignaal of veldbus. Massaflowmeters hebben geen actuators en dienen enkel om massaflows te meten.
Control valve strokes proportionally
Positioning valves can be combined with pneumatic, motorized, piezoelectric or solenoid actuators. The main differences between the various actuation principles are type of media separation, dynamic and force properties. Solenoid-operated positioning valves are known in practice as proportional valves and cover the nominal diameter range below 25 mm. Open and closed control loops can be developed using proportional valves. Open control loops control the valve without feedback signal, while closed control loops control the difference between the set-point and actual values. Switching solenoid valves, which are normally closed, form the basis for Brkert proportional valves. Direct-acting proportional valves receive their feed below their seat, while servo-assisted models receive their feed above their seat.