*2.3. Data Acquisition*

To characterize the status of working fluids within the overall process, all relevant parameters are measured and recorded. Table 1 provides an overview of the measurement characteristics for the entire process. Air states are labeled according to Figure 2.


**Table 1.** Data acquisition concept for the entire system separated by subsystems.

In order to take inhomogeneity within the air streams into account, flow averaging is applied according to Slayzak and Ryan [37]. Electricity demand of each component according to Figure 2 is measured separately. Measurement devices in use and related uncertainties are listed in Table 2. All measured data are recorded every minute. A data acquisition system in connection with controlling software is used to control and regulate the entire system.

Due to drifting effects of capacitive humidity sensors (typical 1% rh per year), the resilience of derived quantities, energy and mass balances gets more and more limited as time goes by. Thus, these sensors are recalibrated once a year. The calibration method is relying on 36 set point combinations of temperature and relative humidity in the range of relevant temperatures and humidity ratios.


**Table 2.** Measurement devices and related uncertainties.
