The calibration of the Doppler Flow analysis must be done before starting a new examination because it is necessary to provide information about the size of the Doppler waveform generated by ultrasound system. The calibration factor changes depending on the settings of your ultrasound machine. You should check the calibration at each new examination.
CAUTION: the lack of calibration can generate a software malfunction.

Calibrate the Doppler Flow analysis
- Locate, on the x axis of the Doppler flow profile, a known time length (1 sec in the example in figure).
- In the Doppler Panel, select from the "x-line length" drop-down menu, the time length specified above.
- In the Doppler Panel, click on the Set Doppler X-Calibration
button (button remains active).
- Draw a line on the image corresponding to the known distance: click on one end and drag the mouse to the other extreme (press the Shift key on your keyboard if you want the line to be not horizontal).
- Locate, on the y axis of the Doppler flow profile, a known flow velocity value (200 cm/sec in the example in figure).
- In the Doppler Panel, select from the "y-line length" drop-down menu, the flow velocity value specified above.
- In the Doppler Panel, click on the Set Doppler Y-Calibration
button (button remains active).
- Draw a line on the image corresponding to the known distance: click on one end and drag the mouse to the other extreme (press the Shift key on your keyboard if you want the line to be not vertical).
NOTE: you can directly type the calibration values in the "x-calib" and "y-calib" fields of the Doppler Panel (if you already known the values).