7. Operating the calibrator
Function
Meaning
Example for a ramp program
A thermostat with an expected switch range between 120 and 100 °C will be tested.
SP = 100 °C; SP2 = 120 °C; gradient = 2 °C/min.
1. With the [▲] or [▼] button, set SP to 100 °C.
2. Confirm the entry with the [E] button.
3. Press button [F].
4. With the [▲] or [▼] button, set SP2 to 120 °C.
5. Confirm the entry with the [E] button.
6. Press button [F].
7. With the [▲] or [▼] button, set GRD to 2 °C/min.
8. Confirm the entry with the [E] button.
9. Press button [F].
10. With the [▲] or [▼] button, set run to ON.
11. Confirm the entry with the [E] button.
⇒
After pressing the [E] button to confirm the start of the ramp, the oven temperature will ascend with the
heating slope rate. The temperature oscillates between 100 and 120 °C until run OFF is selected. Of
course, there will be some oscillations at the beginning since the ramp slope will not be suitable, but
these only last a short time and then the oven temperature will follow the ramp's set point.
SOn
Switch on
Displays the temperature at which the temperature switch contact closes.
Displays the temperature at which the thermostat would be connected to the terminals.
"SWITCH TEST" has been closed.
SOFF
Switch off
Displays the temperature at which the temperature switch opens.
Displays the temperature at which the thermostat would be connected to the terminals.
"SWITCH TEST" has been opened.
The values of SOn and SOFF will change at each loop or each time you select "run OFF".
7.3.3 Second menu level - Settings for optimising the control
▶
By pressing the [F] and [▲] buttons at the same time, the 2nd level menu is accessed.
▶
With the [F] button, the menu functions can be scrolled through.
▶
By pressing the [F] and [▲] buttons at the same time or waiting for 20 seconds, you return to the main menu.
Function
Meaning
Pb
Value of the Proportional band in percentage of the end value.
1. With the [▲] or [▼] button, set the proportional band.
2. Confirm the entry with the [E] button.
Proportional band means the length of time in the measurement field within which there is the variation of the
regulation probe output alarm and therefore the adjustment of the heating element power.
td
Derivative time in seconds
1. With the [▲] or [▼] button, set the derivative time in seconds.
2. Confirm the entry with the [E] button.
When there is a step variation of temperature, the derivative action induces a greater initial adjustment, so that
the oven will have a greater power than it usually has due to the proportional and integral action only. Since
the error persists, the derivative action reduces the impact giving the integral action the task of reducing the
error.
WIKA operating instructions, model CTD4000
EN
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