Gamry Instruments TDC4, Operator'S Manual, Page: 16 / 32

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Chapter 3 -- Use
This chapter covers normal use of the TDC4 Temperature Controller. The TDC4 is intended primarily for
use in the Gamry Instruments CPT110 Critical Pitting Test System. It should also prove useful in other
applications.
The TDC4 is based on the Omega CSi8D temperature controller. Please read the Omega documentation
to familiarize yourself with the operation of this apparatus.
Using Framework Scripts to Setup and Control Your TDC4
For your convenience, the Gamry Instruments Framework includes a number of Explain scripts that
simplify setup and tuning of the TDC4. These scripts include:
• TDC4 Manual Tune.exp Used to simplify manual tuning
•
TDC4 Start Auto Tune.exp Used to start the controller auto tune process
•
TDC4 Initialize Settings.exp Restores the TDC4 to the factory default settings
Tuning the TDC4 so that it works optimally on your experimental setup is very difficult using the front
panel controls of the TDC4. We strongly recommend that you use the scripts listed above to tune your
TDC4.
There is one downside to using these scripts. They will only run on a computer that has a Gamry
potentiostat installed in the system and currently connected. If you do not have a potentiostat in the
system, the script will show an error message and terminate before it outputs anything to the TDC4.
Note
You cannot run the any TDC4 script on a computer that does not include a Gamry
Instruments potentiostat.
Thermal Design of Your Experiment
The TDC4 is used to control the temperature of a electrochemical cell. It does so by turning on and off a
heat source that transfers heat to the cell. Optionally, a cooler can be used to remove heat from the cell.
In either case, the TDC4 switches AC power to the heater or cooler to control the direction of any heat
transfer.
The TDC4 is a closed loop system. It measures the temperature of the cell and uses feedback to control
the heater and/or cooler.
Two major thermal problems are present to some degree in all system designs.
The first problem is temperature gradients in the cell. They are invariably present. However, they can be
minimized by proper cell design. Stirring the electrolyte helps a great deal. The heater should have a
large area of contact with the cell. Water jackets are good in this regard. Cartridge type heaters are poor.
Insulation surrounding the cell may minimize inhomogeneities by slowing the loss of heat through the