It is not necessary to perform a new calibration when using the Light Sensor, order code LS-BTA, $59 in the classroom. You can simply connect the sensor to a Vernier data-collection interface and start your Vernier data-collection program. When the sensor is automatically identified by the program, the appropriate calibration is loaded. If you change the range switch on the sensor box, the calibration will be updated to the new setting.
If you connect a Light Sensor to a non-Vernier interface, it is possible to read the voltage output of the sensor. For this sensor, voltage is always proportional to light intensity.
If you do want to calibrate the Light Sensor, you can do so using a calibrated light meter. The process is similar to calibrating any other Vernier probe; you will preform a two-point calibration.
1) From the Sensor Setup screen, choose "Calibrate".
2) Hold the Light Sensor and your calibrated light meter side by side. Shine a light on them. Note that our Light Sensor is very directional, so it makes a big difference exactly how it is pointed. That may or may not be true of the other light meter.
3) In the software, choose "Calibrate Now", enter the lux read by the calibrated light meter in the first reading, then click on "Keep".
4) Change the light level and keep the lux reading, as you did before. One easy light level to use for the second calibration point is "zero". Completely block all light from the Light Sensor and call that 0 lux.
5) The new calibration is now listed among the sensor calibration.
If you want to calibrate more than one range, you will need to repeat the procedure; the software treats each range as a separate probe.