There are different types of cold chain monitoring devices such as freeze alert, Log tag, 30 DTR, and liquid thermometers. Among these devices, which device are more appropriate and convenient to use for monitoring temperature in refrigerators?
"This module of the WHO Vaccine Management Handbook (VMH) focuses on temperature monitoring and provides updated implementation guidance on vaccine vial monitors, and various temperature monitoring tools for cold rooms and fridges, including the new devices which monitor and log temperatures electronically."
The document covers all the cold chain monitoring devices you mention and is available in English and French.
Another resource you might find helpful is the CCE area of TechNet website. It contains detailed information on all WHO PQS-prequalified products, including temperature monitoring devices, and includes installation and maintenance guides, training resources, brochures, videos, photos, etc., as well as feedback from TechNet members. You can also add your own resources if you find some that are missing.