Campbell Scientific CR21 CR56 Micrologger Data Logger Package w/ Printer

Campbell Scientific CR21 CR56 Micrologger Data Logger Package w/ Printer

This is a Campbell Scientific CR21 Micrologger and CR56 Thermal Printer data logger package, sold as-is for parts or repair. The package includes the CR21 Micrologger datalogger unit, the CR56 Thermal Printer with its CR56 Power Supply panel, two Gates Cyclon sealed rechargeable battery packs, a large weatherproof field enclosure, a smaller enclosure, and associated cabling and connectors. The batteries are present but need replacing and the package is not guaranteed functional.

Specifications & What's Included

• Campbell Scientific CR21 Micrologger — numeric keypad, small display, orange screw-terminal input strips, RS-232 serial interface
• Campbell Scientific CR56 Thermal Printer — clear protective lid, paper roll present, Cassette Monitor jack, Cassette Remote jack, Paper Feed button, DB9 serial connector
• CR56 Power Supply panel — battery test terminals, On/Off switch, Made in USA label
• Two battery carrier packs loaded with Gates Cyclon Sealed Rechargeable batteries (batteries need replacing)
• Large gray weatherproof field enclosure — foam-lined lid, mountable
• Smaller gray enclosure
• Interface/communication cables and connectors included (as shown in photos)
• Interface: RS-232; Cassette Monitor and Remote jacks on CR56 Printer
• Manufacturer: Campbell Scientific Inc., Made in USA
• Sold as-is — not powered or tested at our facility

Applications

The Campbell Scientific CR21 is an early-generation field datalogger designed for remote environmental and scientific monitoring applications. Introduced in the 1980s, the CR21 was widely used in meteorology, hydrology, agriculture, and environmental research for collecting data from sensors such as thermocouples, pyranometers, anemometers, and soil moisture probes. Its battery-powered, weatherproof design made it suitable for deployment at unattended remote sites where AC power is unavailable. The companion CR56 Thermal Printer allowed field technicians to retrieve logged data on-site via printed tape output without requiring a PC or terminal. Campbell Scientific dataloggers from this era remain sought after by researchers maintaining legacy monitoring networks and by educators working with vintage environmental instrumentation.