- proportional control
- proportional counter
- proportional counting
- proportional counting tube
- proportional dividers
- proportional division
- proportional expression
- proportional guidance method
- proportional hazard model
- proportional hazard regression model
- proportional hazards model
- proportional-integral-derivative control
- proportional integral derivative controller
- proportional-integral-derivative controller
- proportional integral derivative regulator
- proportional integral derivative regulatory systems
- proportional integral regulator
- proportional-integral regulatory systems
- proportional intensification
- proportional-intergral-dervative control
- proportionality
- proportionality coefficient
- proportionality factor
- proportional limit
- proportional loading