One of the key factors to achieve reliable and reproducible QCM measurements is temperature stability. Here we list the top four factors that will help you eliminate temperature induced artifacts in your QCM data.
Key factors to address to achieve temperature stability
Temperature stability is critical in QCM-measurements. Uncontrolled temperature variations will influence the QCM signals in uncontrolled ways and therefore make it difficult to interpret the data. Fortunately, there are ways to prevent temperature-related artifacts. This is done via a combination of instrument-external and instrument-internal factors, i.e. the ambient temperature variations should be reduced to a minimum, and then the instrument can compensate for the temperature variations that are unavoidable. The four key aspects and actions to avoid temperature induced artifacts in the QCM data are:
1) Instrument specification and performance
The number one and most important factor to achieve temperature stability is to make sure that the QCM instrument is equipped with a robust and well-performing temperature controller. This is the factor which in the end will have the biggest impact on measurement robustness and reproducibility.
2) Avoid ambient temperature variations
The more stable the ambient temperature, the less the instrument temperature controller will have to compensate for fluctuations. Also, even the best temperature controller will not be able to fully compensate for large variations in the surrounding temperature. Therefore, the ambient temperature should be kept as constant as possible. Make sure air circulation around the temperature controller is adequate (it often creates a lot of heat when working and needs to be cooled), avoid direct sunshine and air-streams to be pointed directly at the cell where the QCM sensor and sample liquids are placed.
3) Let the instrument temperature stabilize
Having a well performing built-in temperature control and assuring a stable temperature in the lab is a good start. Next up is to let the instrument temperature stabilize before the start of the measurement. If your instrument is equipped with a temperature controller, it should be activated in advance to let the temperature stabilize prior to the sample introduction.
4) Temperature equilibration of sample liquids
Finally, the last step to minimize temperature-induced artifacts is during the measurement itself, where the sample temperature must be considered. Especially if the samples have been stored in the fridge, or in some other location where the temperature significantly differs from the measurement temperature. Let the sample temperature equilibrate to the measurement temperature, and don’t insert samples prior to equilibration.
As uncontrolled temperature variations will introduce artifacts in the measured QCM signal, temperature stability is essential to achieve reliable and reproducible measurement results. Temperature stability can be achieved by minimizing the variations in the ambient and sample temperatures and having a good instrument temperature controller which can compensate for the unavoidable variations.
Download the overview to learn more why temperature stability is critical and how to avoid temperature related problems.
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