Why do I need to equilibrate my samples for such long time periods before measurement with the SDR?

Temperature is an important factor in oxygen and pH measurements, as both sensors are temperature dependent. Furthermore, the oxygen solubility changes with temperature. At higher temperatures less oxygen is soluble in the medium and will slowly leave the sample, which will be monitored by our oxygen sensors. So the SDR will only show correct oxygen values, if the measurement temperature entered by the user and the actual temperature of the sample are the same. If you put a sample from ambient temperature into a 37 °C incubator, it will take hours until the temperature of the sample has reached the 37 °C. At low temperatures equilibration takes even longer. 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, it will take hours until the liquid sample is equilibrated.


Select by industry

Presens TV

Watch tutorials, webinars and informative videos about PreSens optical sensor systems.

All videos