Operating Principle
You require a stable known temperature source.
The certainity of the calibration depends on
1) Stability of the source.
2) Uniformity to which the stable temperature is known.
Designed block diagram of EO-25X is given below.
230VAC
@50
Hz
PID Controller
Control
Output
SSR
heating
element/
Oil/Liquid Reservior
Block diagram of temperature controling systems
