The HOBO U9 Light On/Off Data Logger records light on and off status, the light threshold is adjustable from 10 to 100 lumens/m2. The large memory records up to 43,000 on/off changes, making the data logger a great tool for monitoring light usage for energy audits.


Choice of four models that record state changes, lights on/off, motor run-times, and/or events
Internal light, motor, and magnetic reed switch sensors
State and event channels with external inputs provide extra reliability
Environment: Indoor
Measurement: Light On/Off


Light threshold: Adjustable from 10 to 100 lumens/m² at 25°C (fluorescent light)
Time accuracy: Approximately ± 1 minute per month at 25°C (77°F); see Plot A
Operating temperature:
Logging: -20° to 70°C (-4° to 158°F)
Launch/readout: 0° to 50°C (32° to 122°F), per USB specification
Humidity range: 0 to 95% RH, non-condensing
Battery life 1 year typical use
Memory 64K bytes (up to 43,000 state changes)
Weight: 25 g (0.8 oz)
Dimensions: 45 x 60 x 20 mm (1.8 x 2.38 x 0.77 inches)
The CE Marking identifies this product as complying with all relevant directives in the European Union (EU).

Producing Area:USA