Understanding the CAL "Derivative Sensitivity" Parameter (dEr.S)

-         The CAL "Derivative Sensitivity" Parameter (dEr.S) in Level 4 changes the rate at which the rate of PV change (PV delta) is calculated when working out the value of the derivative power.

-         If the derivative time is long, it can take relatively long time for the controller to begin reacting to a change in the PV delta. Derivative Sensitivity is used to reduce the delay.           

-         At the default dEr.S value of 0.5, derivative is calculated twice for every derivative time. E.g if dEr.t =180, the PV delta is calculated every 90s, and a new value for derivative power applied.

-         Reducing the value of dEr.S will recalculate the derivative more often, reducing the delay in control response (if dEr.S = 0.1, and dEr.t =180, the PV delta is calculated every 18s).

-         *see also Solution  "Understanding the CAL Derivative and DAC.          

-         Applies to CAL3200, 3300, 9300, 9400 and 9500