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I. Safety Considerations and Accurate Temperature Control
For usage with heaters other than heating mantles or for safety-critical and unusual organic reactions
(particularly polymeric reactions), the user must do either of the following:
1. Carefully watch the response to ensure the tuning parameters are adequate for the current application, or
2. Autotune the controller for the application. Before starting any high-value or safety-critical reaction, call
Ecodyst to discuss your application with an engineer.
If the controller is adjusted to the application being heated, your ECODYST controller can regulate practically any
application to ± 0.1°C. Because the tuning settings for your application may not be properly adjusted, the user must
watch a fresh reaction to ensure the controller’s functionality. A brief tutorial on tuning is provided here, with a more
extensive description provided in Section 2.1.
Tuning is the process of matching the controller’s control properties to the heating characteristics of the process being
regulated. To regulate heating, the controller employs a PID (Proportional, Integral, Derivative) algorithm. Each term in
the PID equation has a constant that scales the equation to the heating process. These constants (together with two
other related words) are known as the “tuning constants,” and they are generally written in units of time since they
reflect delay periods, rate of heat transfer durations, and rate of error accumulation. Each constant’s relative value
is determined by the physical properties of the process being heated. Even with the self-adaptive algorithms of the
controller, the tuning constants must be somewhat near to a correct set otherwise the controller will not give steady
temperature control (section 2.1).
When a controller is shipped, the default set of tuning constants loaded into the controller are those appropriate for
heating typical organic reactions (i.e., small molecule chemistry in low boiling (< 160°C) organic solvents) using heating
mantles, since this is the most common application for Ecodyst controllers. Because Ecodyst
cannot forecast the
application
for which the controller will be used, the researcher must be aware that the tuning constants entered into
the controller may not be a set that results in stable temperature management.
It is the obligation of the researcher
to monitor the temperature regulation of a reaction.
If your Ecodyst controller fails to heat consistently during a
process, you have two options.
In any event that you need technical assistance with operating our machine, or have questions about an application,
please contact us; we are always eager to assist our customers.
6. Appendix
High Powered Heating Mantle Controllers