Campbell Scientific CR300 series

The CR300 is a multi-purpose, compact measurement and control data logger. This small, low-cost, high-value data logger offers fast communications, low power requirements, built-in USB, and excellent analog input accuracy and resolution. The CR300 can measure most hydrological, meteorological, environmental, and industrial sensors. It concentrates data, makes it available over varied networks, and delivers it using your preferred protocol. It also performs automated on-site or remote decision making for control and M2M communications. The CR300 is ideal for small applications requiring long-term, remote monitoring and control. The following outlines the primary differences between the CR300, CR310, and CR350 dataloggers:

The CR310 and CR350 offer removable connectors.
The CR310 includes a 10/100 Ethernet connection.
The CR350 has two independent RS-232/RS-485 ports and USB-C.