Owner's manual

Tools 9-9
9.3.1.1.4 Heat Control Tab
The Heat Control tab (Figure 9-6) shows control parameters that are used to define the heating process for
your specific system. Heaters that are only controlled by ON/OFF can fluctuate around a desired setpoint
by as much as 20 to 30° F. Each element in the control tab helps to regulate the heat more accurately.
 NOTE All values are set at the Nordson ASYMTEK factory prior to shipping and should not be
changed by the user. For more information, consult the Heater User Guide included with
your dispensing system documentation.
Command Description
Proportional Band
(PB)
Eliminates extreme deviations from the desired setpoint by
regulating the output in proportion to the process variable’s
distance from the setpoint.
Integral (TI)
Integral (TI) works in conjunction with PB to correct for offset
errors. For example, if the heater seems to settle at 5° below the
setpoint, use TI to bring it up to the desired setpoint.
Derivative (TD)
Corrects for overshoot of setpoint when heaters are warming up.
PB and TI, working in conjunction, can often overshoot the
setpoint upon startup. TD anticipates the overshoot and adjusts
the output appropriately.
Output Filter The Output Filter dampens the analog output response.
Heat/Cool Spread
Heat/Cool Spread is used only when regulating heaters in
On/Off mode. Spread is a value above or below the setpoint.
Temperatures above the spread turn the heater off.
Temperatures below, turn the heater on.
Figure 9-6 Loop Parameters – Heater Control Tab