Should you use a Thermal Buffer?
A thermal buffer is a substance that a sensor probe tip is placed in, to slow down (buffer) the temperature fluctuations of the air in a fridge/freezer/warmer unit due to events such as doors being opened, or defrost/cleaning cycles etc. Typically, the tip of the sensor is placed into the thermal buffer, which is then secured in an appropriate place inside the unit.
Temperature readings taken from a probe immersed in a thermal buffer will more closely approximate the temperature of the food in the unit, than the temperature of the air in the unit. As buffered temperatures are less susceptible to doors being opened, defrost cycles etc, they are much less likely to cause temperature range alarms to go off, hence these alarms can be set to narrower ranges than if no buffer is used.
So, if it is important to you to record temperatures approximating the temperature of the food rather than the air; or if you wish to set your min/max temp alarms to allow for doors being opened and defrost cycles, etc, then you should use thermal buffers.