The most common industry standard expression for temperature reading stabilization time is the ‘T90’. This is defined as the typical time taken of a given sensor in a given environment (e.g. moving air, still air, liquid etc.) to register 90% of an immediate step change in temperature.

The T90 of TRIX-8 is typically less than 5 minutes in moving air of 1m/s.

As the thermal step response is basically dependent on the latent heat of the two thermal masses involved (the Logger and the surrounding environment) and the rate of thermal transfer between them, the T90 is the same irrespective of the difference of temperatures though at extremes (water freezing and boiling points for example) the environment does not behave homogeneously thereby changing the rates of thermal conduction and therefore changing the resulting T90 value.

For example: in a situation of a 25°C step change say starting at 10°C and moving to 35°C in moving air of 1m/s, the TRIX-8 will typically register 90% of the step after less than 5 minutes – i.e. 0.9×25 = 22.5 -> 10+22.5 = registering 32.5°C within 5mins.

The T90 for a 15°C step in 1 m/s moving air (say 10°C to 25°C) will be the same. 0.9×15 = 13.5°C +10 = registering 23.5°C within 5mins.

T90 is different in slower moving air or still air, though air is never totally ‘still’ when a temperature difference exists as convection will take place.