The mode of operation is available through the Automatic thcoeff measurement option of the Thermostat menu. Selecting this menu item pops up the Thermal Coefficient Measurement control panel (shown in Figure 6-13) as well as the Single Voltage Measurement control panel. The later helps to monitor the measurement channel where the device under test (the device for which the calibration diagram is being measured) is connected to.
The goal of this option is to support device calibration, i.e. the automatic measurement of the thermal coefficient of the device under test.
Figure 6-13: The Thermal Coefficient
Measurement control panel (in its initial state)
The controls in the panel are as follows:
Tmin input field
Enter here the lower limit of the temperature excursion for the automated measurement of the calibration diagram. (5 oC is the lowest possible value according to the hardware specifications.)
Tmax input field
Enter here the upper limit of the temperature excursion for the automated measurement of the calibration diagram. (90 oC is the highest possible value according to the hardware specifications.)
Tstep input field
Enter the size of the temperature step between Tmin and Tmax in oC.
Upwards, Downwards radio buttons
Press one to specify the direction of the temperature excursion during the measurement. Preferred direction is usually Upwards since in this case less cooling is needed.
Start push button
Press this button to start the automatic temperature excursion. While the temparature of device device under test is changed, control its state in the Single Voltage Measurement panel such that now overflow of inderflow takes place in the measurement channel. Note, that the device under test should be "switched off", i.e. no heating power should be applied to the device.
Stop push button
Press this button to stop the automatic temperature excursion.
Save push button
Lets you to save the calibration diagram - such as shown in Figure 6-14 - in a file with an extension .TCO. The T3Ster software automatically calculates the thermal coefficient of the device being measured. This value is to be used as sensitivity data in the corresponding input field of the Channel Attributes window.
Comment input field
The text entered here will be saved as comment text in the .TCO file.
Previosely recorded calibration diagrams can be displayed by selecting the Show results item of the Thermostat menu: any .TCO file loaded through the file browser (Figure 6-15) can be displayed in form of a calibration diagram.
Figure 6-14: Calibration diagram recorded by the T3Ster-thermostat
Figure 6-15: File browser for selecting
.tco (calibration diagram) files
General hints regarding device calibration are described in Appendix II of the T3Ster Hardware Reference Manual.