Thermo Scientific 7451 Operating And Maintenance Manual page 42

Menu Entry
Definitions (cont.)
Thermo Scientific
The following is a listing of parameters with their defaults.
• Size: L, M, S (default is M)
• Cycle Time adjusted over a range of 500 to 2000mS (default is
1000mS)
• P: Proportional gain adjusted over a range of 0.0000 to 0.9999
(default 0.25)
• I: Integral gain adjusted over a range of 0.000 to 0.999 (default
0.075)
• D: Differential gain adjusted over a range of 0.00 to 9.99 (default
0.20)
• D/C: Discontinuous or Continuous operation of the controller
when the probe temperature is the same as the set temperature
(default C)
• PR: Cool/Cool+ solenoid precision (minimum on time) adjusted
over a range of 0.01 to 0.99 (default 0.01 or 50mS minimum on
time)
• CP: Cool+ differential temperature adjusted over a range of 1°C to
99°C (default 4°C)
• CM: Cool multiplier determines the cooling proportional and
differential gain constants relative to the constants entered for P
and D, i.e., P (cool) = P*CM, with a range of CM from 0.1 to 9.9
(default 1.0).
H. Use Factory Defaults
This menu item restores the factory-set parameters for the
following items.
• Access Code (0 0 0 0, disabled)
• Probe Calibration (offset and scaler 0)
• Simulation (Off; Cool: 1S, 10S, 90C/m; Heat: 1S, 45S,
9C/m)
• Thermal Controller (Size M, 1000mS, P: 0.25,
I: 0.075, D: 0.2, PR: 0.01, CP: 4, CM: 1.0, C)
• Tracking Alarms (5C, 1m)
Note User Profiles are not affected.
Configuration/Calibration
s
Controlled Rate Freezer
Section 3
3-7