## 5 Regulation Test of Facility
### Adjustment Test of the Temperature and Humidity Control System
#### 5.2.2 Adjustment Test of Humidity Control System  
Under a certain set temperature (assuming that the air temperature has been adjusted to the set value, and is being kept constant), the operators start the humidity control system(humidification or dehumidification).When the humidity reaches the set value, the humidity control system and the stirring fan will be turned off but with the temperature control system still running to keep the temperature at its set value (the humidity is supposed to remain constant after it has reached its set value if the temperature keeps unchanged and no air leak occurs). The main considerations in assessing the performance of the humidity control system are the spatial distribution characteristics of the humidity field and the ability of the system to maintain constant humidity. The parameters that quantitatively depict the performance of the humidity control system are as follows: the average of the measured humidity values at \(n\) locations (\(n=8\)), the root mean square deviation of the \(n\) humidity values from the average, the maximum deviation of the \(n\) measured humidity values from the average, the maximum deviation of the \(n\) humidity values from the set humidity, and the difference between the average and the set humidity values:  
\[H_{\text{avg}}=\frac{\sum\limits_{i=1}^{n}H_{i}}{n}, \tag{15}\]  
\[\sigma_{H}=\sqrt{\frac{\sum\limits_{i=1}^{n}\left(H_{i}-H_{\text{avg}}\right)^ {2}}{n-1}}, \tag{16}\]  
\[\left|H_{i}-H_{\text{avg}}\right|_{\text{max}}=\underset{i}{\max}(\left|H_{i} -H_{\text{avg}}\right|), \tag{17}\]  
\[\left|H_{i}-H_{\text{set}}\right|_{\text{max}}=\underset{i}{\max}(\left|H_{i} -H_{\text{set}}\right|). \tag{18}\]  
In these parameters, \(\left|H_{i}-H_{\text{avg}}\right|_{\text{max}}\) combined with \(\sigma_{H}\) can represent the spatial uniformity of humidity distribution, while \(\left|H_{i}-H_{\text{set}}\right|_{\text{max}}\) and \(\left|H_{\text{avg}}-H_{\text{set}}\right|\) can characterize the accuracy or precision of humidity control. Besides, there are two index parameters to assess the humidity control ability of the system, one is the time (\(t_{\text{z}H}\)) needed to regulate the humidity to the set value, the other is the time (\(t_{\text{m},H}\)) within which the system keeps the chamber humidity constant at the set value after it has been reached. Three temperature values, \(T\) = ambient atmospheric (room) temperature, 30 \({}^{\circ}\)C, and 40 \({}^{\circ}\)C were selected as the set temperatures. Under each set temperature, three humidity values, \(H\) = 20%RH, 60%RH, and 80%RH were chosen as the set (target) humidity values. They constituted nine cases of parameter combination under which the humidity control system was examined. Here the results of only three cases among the nine are presented to illustrate the ability of the humidity control system: 1 \(T\) = ambient atmospheric temperature, \(H\) = 20%RH, 2 \(T\) = 30 \({}^{\circ}\)C, \(H\) = 60%RH, and 3 \(T\) = 40 \({}^{\circ}\)C, \(H\) = 80%RH. For the case \(T\)= ambient atmospheric temperature(\(T\) = 21.5 \({}^{\circ}\)C at the starting moment) and \(H\) = 20%RH, no change in temperature was required, thus the initial (starting) humidity was exactly the ambient atmospheric humidity of 42.7%RH. In view of the situation that the set (target) humidity 20%RH was lower than the initial humidity, the dehumidifier \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \(T_{\text{set}}\) & \(T_{\text{init}}\) (\({}^{\circ}\)C) & \(T_{\text{avg}}\) & \(\sigma_{T}\) & \(1\)\(T_{i}-T_{\text{avg}}\) \(\mid_{\text{max}}\) & \(1\)\(T_{i}-T_{\text{set}}\) \(\mid_{\text{max}}\) & \(1\)\(T_{\text{avg}}-T_{\text{set}}\) \(\mid\) \\ \hline
30 & 23.5 & 29.9 & 0.1432 & 0.5 & 0.6 & 0.1 \\
40 & 29.9 & 39.7 & 0.1364 & 0.4 & 0.7 & 0.3 \\
50 & 38.1 & 50.0 & 0.1985 & 0.7 & 0.7 & 0.0 \\
60 & 49.8 & 60.1 & 0.2668 & 0.8 & 0.9 & 0.1 \\
60 & 26.9 & 60.1 & 0.2793 & 0.8 & 0.9 & 0.1 \\ \hline \hline \end{tabular}
\end{table}