# Optimization I-Gain

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While optimizing I-Gain, the gas flow determined above has to be constant at all time.

Start with P-Gain set to half of the value found when optimizing P-Gain and set I-Gain to 1.0.

Keep the P-Gain constant.

Set chamber pressure to SP2, wait until the pressure is stable. Set pressure to SP1. If the transition from SP2 to SP1 results in a significant pressure over shoot or if the valve position does not stabilize, I-Gain is too high. If the transition results in a slow asymptotical pressure rise and there is still a constant deviation to SP2, the I-Gain is too low.

The optimal value for I-Gain is found if the transition from SP2 to SP1 result in just a slight pressure over shoot, a stable valve position and the actual pressure matches SP2 exactly.

Example:

Check control performance over the whole control range with parameters above.

Required information for support:

•Go to ‘Tools / Create Diagnostic File’ in ‘Control Performance Analyzer’ and save file

•Pressure / flow / gas conditions to be controlled

•Chamber volume

•Pumping speed (l/s) and pump type (e.g. turbo pump)

•System description

•Problem description

Send diagnostic file with and all required information to Mechatronic.Support@vatgroup.com .