"The TandD RTR-574-S Wireless Temperature Humidity Light Data Logger The RTR-574-S Wireless Temperature Humidity Light Data Logger includes two sensors that simultaneously measure and record illuminance / UV intensity and temperature/humidity. This high accuracy data logger allows for the measuring and recording of the above items in various places such as facilities where people gather, where important documents and fine arts are being stored or displayed, where food and drink are being stored. Also, cumulative illuminance and the cumulative amount of UV light can be easily viewed even without stopping recording."