| 摘要 |
A system for monitoring the level of light at a distant location from a central location. A light sensor at the location to be monitored is comprised essentially of a photodiode and an operational amplifier and produces a high-level, analog output signal on an output signal line, the signal being linearly proportional to the level of light at the location. A control unit at a central location is electrically coupled to the sensor and comprises a power supply for providing electrical power to the sensor and a calibration device connected to the output signal line for providing a feedback signal to the sensor. The calibration device may be adjusted so that the output signal at the control unit bears a selected ratio to the light detected. A control unit having a single and power supply may be coupled to a plurality of sensors.
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