Min Max Thermometers
Use in Vaccine Fridges
In Australia a min/max thermometer is required to monitor the temperature inside a vaccine fridge during a power outage. Either an independent battery-powered minimum/maximum thermometer or a method to provide power to the fridge's temperature monitoring system such as a UPS or generator is required. If the vaccine fridge temperature rises to +8°C, the vaccines will need to be transferred to a pre-prepared cooler, cold box or portable purpose-built vaccine refrigerator.
The minimum/maximum thermometer probe should be placed inside an empty vaccine box that is placed on the middle shelf of the vaccine refrigerator. For vaccine fridges with a solid door, the thermometer lead can either be placed through a temperature probe access port that is found in some vaccine fridges or the thermometer lead can be run past the door seal. Running a lead past a door seal is undesirable as it will create an air leak that may cause problems with condensation, ice buildup and increased electricity use. If you have a glass door vaccine fridge, it is easiest to place the min/max thermometer inside the refrigerator.
A min/max thermometer may also be used to identify the location of any cold spots that a refrigerator may have.
Outreach Clinics and During Transport
A min/max thermometer is required to monitor the temperature in coolers, cold boxes and portable fridges. The temperature probe is placed inside the cooler while the thermometer is placed on the outside of the cooler.
During mobile or outreach immunisation clinics it is expected that the cooler will be frequently opened; hence you will need to closely monitor the temperature within the cooler every 15 minutes for the first 2 hours, then at least hourly using a battery-operated minimum/maximum thermometer. The thermometer needs to be reset after each reading.
Battery and Testing
Change the digital min max thermometer battery at least every 6 to 12 months or as indicated by the manufacturer.
A minimum/maximum thermometer must have a minimum accuracy of ±1°C, and the accuracy needs to checked at least every 12 months by performing a slush test as detailed in Australia's Strive for 5 vaccine storage guidelines.