Advanced Settings
Heat Cool Strategy Configuration (continued)
If no improvement, return to the original value and;
In level 1 halve the value of
CYC.2
If the process hunts between heating and cooling, a
deadband setting may be needed. Enter a small value,
eg. 1 and observe the process. Increase the setting until
hunting stops.
Level 1 adjust value
SET.2
Water cooled applications
Water cooled applications operating at temperatures greater
than 100°C may suffer from the non linear effect caused by
water turning to steam. This can be countered by the non
linear setting for SP2;
In level 2 set
SP2.B
to
nL in
Multi zone applications
When tuning multi zone applications like extruders,
distortions due to thermal interaction between adjacent
zones can be minimised by running autotune on all
controllers at the same time.
CALIBRATION TO ANOTHER INSTRUMENT
If the controller and instrument readings are different, the
ZERO
and/or
SPAN
function in Function
Menu Level 3 will require adjustment.
Adjust
ZERO
to make an equal adjustment across the
full scale of the controller and
SPAN
to make a
correction when the error increases/decreases across the
scale.
1
To adjust using the
ZERO
function
1.1 Substitute measured values in the expression:
Instrument reading – controller reading =
ZERO
Example:
Instrument reading = 396°
Controller reading = 400°
396 – 400 = (-)4°
1.2 Adjust
ZERO
to (-) 4° to correct error.
To make a correction when there are different
errors across the scale.
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