We have created an Express VI and some examples for reading Vernier Sensors with NI ELVIS. The Express VI is used to provide the calibration values for a specified sensor.
Of course, you can provide these calibration values directly in your LabVIEW code to convert the raw voltage reading to proper sensor units without the use of the Express VI. The sensors are shipped with a booklet that provides the calibration values, or (in most cases) you can determine these values by performing a simple 2-pt calibration.