Omega Engineering CN9400 - Manual (Page 28)

Advanced Settings
Heat Cool Strategy Configuration (continued)
If no improvement, return to the original value and;
In level 1 halve the value of
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
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 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
and/or function in Function Menu Level 3
will require adjustment.
Adjust
to make an equal adjustment across the full scale
of the controller and
to make a correction when the error increases/
decreases across the scale.
1 To adjust using the function
1.1 Substitute measured values in the expression:
Instrument reading – controller reading =
Example:
Instrument reading = 396°
Controller reading = 400°
396 – 400 = (-)4°
1.2 Adjust to (-) 4° to correct error.
24
CYC.2
ZERO SPAN
ZERO
ZERO
ZERO
ZERO
SPAN
SET.2
SP2.B