Introduction
The HOBO U12 4-External Channel Data Logger is a versatile device designed for accurate and reliable measurements. It features a 12-bit resolution and can record up to 43,000 measurements or events. The logger supports various sensors, including temperature and AC current sensors, and uses a USB interface for data transfer.

Specifications

• Measurement Range: 0 to 2.5 DC Volts
• Accuracy: ± 2 mV ± 2.5% of absolute reading
• Resolution: 0.6 mV
• Operating Range: -20 to 70°C (-4° to 158°F)
• Humidity Range: 0 to 95% RH, non-condensing
• Battery Life: 1 year typical use
• Memory: 64K bytes (43,000 12-bit measurements)

Installation and Operation
The logger requires an Onset software starter kit for operation. It can be mounted using various methods provided in the mounting kit. The logger's external channels can power sensors directly with a switched 2.5 V output. It is crucial to ensure proper connections to avoid inaccurate readings or damage.

Data Logging
The logger records samples and events, with a storage capacity of up to 43,000 combined entries. It features an LED indicator for operation status and supports button-initiated logging.

Maintenance and Safety
To maintain the logger, avoid exposure to moisture and extreme temperatures. Replace the battery annually or as needed, especially in extreme conditions. Follow safety guidelines to prevent battery damage.

Warranty and Support
Onset offers a one-year warranty against defects. For support, contact Onset or an authorized dealer. Warranty claims require a Return Merchandise Authorization (RMA) number.

Conclusion
The HOBO U12 4-External Channel Data Logger is a reliable tool for various measurement applications, provided it is used and maintained according to the guidelines.