Eurotherm

The Eurotherm is usually used to measure and control temperature; however it has also been used to measure pressures. It measures the resistance of an external sensor.

Contents

• Calibration
• Ramping
• PID LookUp

Calibration

The two measurement modes in which the Eurotherm is used are:

1. Measuring a temperature directly: use the None.txt calibration file
2. Measuring a resistance and then using a calibration file to convert to a temperature: In which case use the calibration file which is correct for your sensor. The calibration files are in C:\Instrument\Settings\config\common\temp_sensors

The calibration file is set using the File box in the Sensor Calibration area on the Eurotherm OPI.

Ramping

The Eurotherm can be made to ramp slowly through a temperature gradient. It achieves this by updating the set point every 5s to create the desired ramp rate; It does not check that the Eurotherm can respond quickly enough. To set it into ramping mode:

1. Set the Ramp rate (N.B. The units of this are K/min)
2. Set Ramp to be on

When the Eurotherm is ramping the ramping light will be lit.

PID LookUp

The PID and maximum heater settings can be set dependent on the setpoint temperature. To do this switch the lookup on using the button on the OPI; the light will illuminate.

The values for the settings are stored in a file in C:\Instrument\Settings\config\common\ramps:

1. The ramp file is a space separated file of values for set point temperature, P, I, D and heater (see the example file for the format)
2. The file must be in set point temperature order small to large
3. The set points are the lowest temperature at which the values should be used.
4. Any set point lower than the first entry will use the first entry.

For example if your file was:

SP P I D Heater
100 10 11 12 13
200 20 21 22 23
300 30 31 32 33

Then a setpoint of:

• 220 would use 20 21 22 23
• 300 would use 300 30 31 32 33
• 10 would use 100 10 11 12 13