Light sensor with three ranges
The Light sensor BT50i measures light intensities in three ranges: 0 .. 1500 lux. 0 .. 15000 lux, and 0 .. 150000 lux.
The desired range can be selected by pressing a switch located on the top of the sensor box. A green diode indicates the actual selected range. A photodiode, which is located at the end of the plastic tube, converts light intensity in an output voltage adjusted to a range of 0 to 5V, which can be measured by an interface. The photodiode is equipped with a flat glass window with built in color correction filter, giving an approximation to the spectral response of the human eye.
The 0 - 1500 lux range is the most sensitive range, it is suitable for low levels of illumination. The 0 - 15000 lux is a good general-purpose range for indoor light levels. The 0 - 150000 lux range is suitable for measurements in daylight. Full sun illumination is within the range of the sensor. The sensor can also be used as a light gate.
The Light sensor can be used in a variety of experiments in biology, chemistry, physics or environmental science, such as:
• verifying inverse square law.
• bserving darkening of a solution caused by a chemical reaction,
• investigating reflection and absorption light,
• studying weather - monitoring sunrise and sunset times,
• studying solar energy,
and digital applications (as a light gate) such as:
• measuring the acceleration due to gravity,
• measuring the speed of a moving cart.
The Light sensor BT50i can be directly connected to the analog BT inputs of the CMA interfaces. Attention:
The sensor cable BT - IEEE1394 needed to connect the sensor to an interface is not
supplied with the sensor and has to be purchased separately (CMA Art. Nr BTsc_1).
Technical specifications of the sensor are described in its User's guide