Why do I need to equilibrate my samples for such long time periods before measurement or One Point Adjustment with the PhoxyCube? And how long does it take?

Temperature is an important factor in oxygen and pH measurements, as the raw signals of both sensors are temperature dependent. Furthermore, the oxygen solubility changes with temperature. If you put a sample from ambient temperature into a 37 °C incubator, it might take hours until the temperature of the sample has reached the 37 °C. Whenever possible we therefore recommend to pre-equilibrate the sample medium to the final measurement temperature beforehand.

Another factor that has to be taken into account is the composition of the atmosphere in your measurement set-up. Although your incubator will adjust quickly to the set CO₂ or O₂ content in the gas phase (which is shown by the incubator display), it might take hours until the liquid sample is fully equilibrated.

Absolute equilibration times depend on many factors in your measurement set-up (volume, temperature, incubator atmosphere, shaking, etc.). Therefore, we cannot give a standard time frame for equilibration.

We recommend using the PhoxyCube to watch the kinetics and find the time point of equilibration. You can therefore start generating initial data via time drive measurement. When the wells' signals are stable, you can perform the One point adjustment OPA.