Specialized functions for carburizing control
T/C block
The thermocouple linearization function block converts the mV input reading and cold junction temperature into a temperature output. It also provides scaling, low pass filtering, offset and manual-override capabilities.
Autotune PID control
Provides a channel output to control a process variable (PV), using a precision PID control algorithm designed by Eurotherm. Autotune is included, as well as a ‘cutback’ feature
to control overshoot behavior. A gain scheduling feature is available for adding extra PID tuning sets, to help maintain tight control at different setpoints.
Thermocouple life*
Derives the working lifespan of thermocouples in days or number or times used, under different ranges of operating temperature. The block monitors usage times and temperatures, and indicates whether the thermocouple is still valid for use according to the AMS2750E standard.
* Available in E+PLC only
Setpoint programmer
Each part of the process is divided into an appropriate
segment (for example, ramp, soak, cool etc.) Within each
segment, appropriate variables can be set (carbon%, time,
ramp rate etc.)
Carbon potential
Provides calculation of the furnace atmosphere’s carbon potential, probe cleaning algorithm and soot notification. Includes probe linearization for several common vendors.
3GASIR (enhanced carbon control) *
Utilizes CO, CO2 and CH4 readings from an infrared gas analyzer, in combination with furnace temperature readings. Calculates appropriate probe adjustment/compensation factors to provide accurate carbon potential value.
Carbon diffusion (online carburizing) *
Mathematically models the diffusion of carbon from a carbon enriched atmosphere into steel within a furnace. Case depth targets are set and the model calculates the carbon profile of the steel (percentage of carbon against depth) in real time. Allows optimization of the heat treat cycle by stopping as soon as complete.
