“We need to be able to see at a glance that the temperature has been OK so far”
TT260 Chart recorder with optional alarm contacts and Battery back-up has a chart especially for blood refrigeration TTC 20.5-7S, which is accepted by the TGA.
For Blood product freezers, the chart is TTC 0.45-7L with A-line at 25 °C as requested by the TGA.