3 tips about Dracal user-Calibration mechanism

Tips featured in this article

Tip #1. You can access the raw values of the actual calibrated channels

Even when calibration points are implemented and active, it is still possible to access the raw values of the actual channels via the Math Channels. Simply append the suffix _nc (not calibrated) to the invocation of the channel in question, as shown below.

These channels are accessible both in the graphical tab of the visualization software and in the logging tab. This functionality allows you to

    • compare the effect of your calibration points on the raw data of your device and to validate the choice;
    • obtain temporal samples of non-calibrated data to eventually update your calibration points.

Note: This trick does not apply to virtual channels, i.e. invoking a virtual channel followed by the suffix _nc has no impact on the returned value. The latter is always calculated from the active value of the real channels.


1. Implementation of the math channel

In the image below, the MATH:00 math channel is set to display uncalibrated temperature data. No calibration point has been recorded yet, so the value returned by both channels is identical.

DracalView Sources tab, channel ID not_calibrated


2. Implementation of calibration points

Here, a single calibration point is implemented whose effect is to deviate the temperature channel by +2 °C.

DracalView Sources tab and Calibration channel box

3. Comparison of the two channels once the calibration points have been implemented

Now that at least one calibration point has been activated, the real channel displays the calibrated value while the math channel still displays, as desired, the uncalibrated value.

DracalView Sources tab with the calibrated and non-calibrated temperature channel

4. Displaying both channels in the Graph View tab

The calibrated real channel and the uncalibrated math channel can be observed simultaneously on the graph.

DracalView Sources tab, Graph box ticked


DracalView Graph View tab to show the effect of a calibration

5. Recording of both channels via the Logging tab

The calibrated real channel and the uncalibrated math channel can also be logged simultaneously via the logging tab.

DracalView Logging tab with two channel boxes ticked
DracalView Logging tab, with the Log file over it, to show the effect of the calibration

Tip #2. You can hide the calibration buttons

When you do not need to modify or consult calibration points, it is possible to hide the calibration buttons without losing their function. This feature allows you to lighten the visual of your "Sources" tab, but also to limit the risks of bad manipulations.

The control of the display is done in the "Configuration" tab, as shown below.


1. The buttons are visible by default

DracalView Sources tab, Calibrate buttons showing

2. You can hide the buttons via the Configuration tab

DracalView Configuration tab with Show calibration setting buttons

3. The buttons are no longer visible

DracalView Sources tab, Active calibration shows by green arrows

Tip #3. You can disable calibration points without deleting them

Sometimes it is necessary, for analysis or comparison purposes, to disable calibration points without deleting them. The "Disable calibration for this channel" option in the dialog box for each calibratable channel allows you to do just that, as shown below. Note that the arrows next to the channel turn from green to red when the calibration feature is not activated, to let you know that there are calibration points saved but they are currently inactive.

Warning: This "deactivation" takes place at the level of the graphic software only. If you access your data via our dracal-usb-get command line tool, the calibration points, stored in the device, are still considered activated.


1. Calibration points are active by default

The presence of green arrows indicates the presence of registered and active calibration points.

DracalView Sources tab, Calibrate buttons showing

2. Deactivation of calibration points without deleting them

DracalView Sources tab, Calibrate channel box, Disable calibration option ticked on

3. Calibration disabled

The calibration points are now disabled, but still stored in the device.

DracalView Sources tab, Calibration disabled effect