Omron EJ1G, User Manual, Page: 67 / 237

46
Adjusting Gradient Temperature Control
Section 3-2
3-2 Adjusting Gradient Temperature Control
Sufficient temperature uniformity is sometimes difficult to achieve if the MV is
saturated when temperatures increase.
Adjust the control balance coefficient if the temperature uniformity is insuffi-
cient and the MV for one of the channels becomes saturated. The control bal-
ance coefficient has the characteristics outlined below and must, therefore, be
adjusted to a value suitable for the system. The SP cannot be reached, how-
ever, if the control balance coefficient is too small. In such cases, return to the
default value of 0.8.
Set the control balance coefficient for the initial channel for each group.
Example: Adjust the control balance coefficient for channel 5 if adjusting
group 2 when the following group settings apply.
MV Hot plate temperature
0
20
40
60
80
100
0 50 100 150
Time [s]
MV
[%]
20
40
60
80
100
120
140
160
0 50 100 150
Time [s]
Temperature
[
°
C]
Saturated MV
Uniformity decreases
as the temperature
increases
Uniformity increases but the
speed of the temperature rise drops Temperature rise speed increases but
uniformity drops
Smaller
Larger
Control balance coefficient
Group Corresponding channels Control type
1 CH1 to CH4 Gradient temperature control
2 CH5 to CH8 Gradient temperature control
3 CH9 to CH12 2-PID control