C.B.S. Scientific TTGEK-2401-220 - Manual (Page 27)

TTGE Instruction Manual, version 8/30/2011
27
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Once the temperature set point has been entered, press the Select/Set Knob to advance to the time (minutes/
seconds) field. Time information is entered the same way as the temperature set point information.
When you press the Select/Set Knob to accept the time displayed time information, the highlighted box will
automatically advance to the set point temperature field associated with the next step of the program.
IMPORTANT: The time field establishes the amount of time the Controller should take to reach the temperature set
point for the next step (i.e., the ramp rate).
View Profile — This allows you to view the programmed time/temperature profile step-by-step. Rotate the Select/Set
Knob to move through the various steps in the program. When the cursor (a vertical line) reaches the beginning of a
step, a message box will appear displaying the step number, set point, and time.
To return to the main operational display, press the ESC Button or allow the display to timeout.
Writing a Temperature Program
Programmable Controllers permit the user to create up to 10 different time/temperature programs, each of which can
have as many as 50 steps and be repeated up to 99 times. The following information is intended to provide you with
some guidelines for creating useful programs.
1. Circulating baths are designed primarily to hold temperatures constant rather than change temperatures rapidly.
Do not underestimate the amount of time the circulator needs to heat or cool a fluid to a given temperature.
Larger baths or circulators being used in closed or open loops will need more time to reach a programmed set
point.
2. Programs may be run using either a Time- or Temperature-based priority. If achieving successive temperature
set points is critical, Temperature should be selected as the priority. If completing a program in a fixed amount of
time is essential, Time should be selected as the priority. See Section 5.12.4 – Preferences for more information.
3. If a program must run within a set period of time (Time priority), have the bath temperature at or very close to
the initial set point before starting the program. The program will not start running until the set point temperature
programmed for the first step is achieved.
4. To incorporate a “soak” period in the program, enter the same set point for two adjacent steps in the program.
The time duration programmed for the first step should equal the desired “soak” period; the time duration for
the second step should be short (e.g., 1 second). The temperature set point for the last step in a program also
functions as an indefinite “soak”. The Controller maintains temperature at the last programmed set point until a
new set point is entered.
5. The step time in a program establishes the ramp rate that will be used to reach the programmed set point for the
next step. If you want to increase/decrease temperature slowly, set a lengthy step time. If you want to increase/
decrease as fast as possible, set a short step time. Keep the heating/cooling capabilities of your instrument
in mind, however. If you are running a program using Time-based priority, fluid temperature may not reach a
desired set point temperature if the time allotted is too short.
3.3 Heater/Stirrer Programming- con’t.