The Thermic Edge Heater Temperature Controller has been designed to be a simple to use, robust, user definable and accurate heater temperature controller that, together with the optional communications facility, makes this unit a very powerful package. The unit is 3U high, half rack width, and is compliant with relevant EU directives. The unit operates by giving a 0-10v output signal controlling either a Thyristor, SSR or PSU.
Temperature controllers are utilised to monitor and control a thermal system such as a substrate heater, stage, or furnace. The controller operates by comparing the temperature measured via a suitable input, usually a thermocouple, and the setpoint on the controller. In this way, the controller can then switch on or off the power supply to the heater to either increase or decrease the temperature of the system.
It is important that a suitable temperature sensor is used alongside the controller. Different sensors have different operating temperatures. Thermocouple types should be specified alongside the controller in order to ensure accurate and stable operation. Most thermocouple types can be accommodated with automatic cold-junction compensation. The controller will usually be configured for type ‘K’; other types are available as an option. The thermocouple type and range is software selected, all that needs to be added is the correct type compensation cable and connectors.
The unit contains a PID controller (Proportional with Integral and Derivative). This provides an auto-tuning function to dynamically tailor the power supply output to the requirements of the heater to reach the desired temperature in an accurate safe, and efficient manner. Thus, overshooting is avoided during temperature ramping. This function is fully compatible with any power supply using a 0-10V input signal.
PID tuning is a method by with the controller increases the accuracy and stability of the system through a trial and error process. This process means that PID controllers are the most stable and accurate system of control compared to On/Off and Proportional Temperature controllers.
In normal operation the temperature controller will display actual and target temperatures (whether or not set point ramp-rate or self-tune is invoked) or indicate if the temperature sensor has failed. In the full configuration mode, all parameters and values can be viewed and edited. Control can be PID, PI, PD, P only or ON/OFF, with values automatically set or manually entered. The output power level is programmable if the sensor fails.
For processes where the maximum temperature must not be exceeded, the ramp-rate facility allows the user to define the temperature rise in programmed units (per second, minute or hour). A self-tuning algorithm automatically sets the PID and the under and overshoot values.
All controllers are supplied with RS-232 input as standard, as well as extensive safety features to ensure low-risk operation. This package also includes software, making external control extremely powerful and simple to use. A 24V interlock is also provided to cut the enable signal should the circuit be broken, example, to maintain the overall system pressure within limits.
The unit is supplied as standard with a mains cable assembly, suitable for local use, requested at the time of ordering the unit. A connector kit is provided for the Output, thermocouple and Interlock trip facility. The unit must also be earthed via the rear panel stud provided; use 2.5mm2 cable or braid connected to your system ‘star-point’ earth.