## 5 Regulation Test of Facility
### Adjustment Test of the Temperature and Humidity Control System
#### 5.2.1 Adjustment Test of Temperature Control System  
Heating the air in the enclosed chamber from a certain temperature to a set temperature \(T_{\text{set}}\) and examining the heating performance of the temperature control system, i.e., the temperature spatial distribution characteristics and the capability to maintain a constant set temperature, are a basic procedure to assess the temperature control system. The parameters that quantitatively represent the heating performance are as follows: the average of the measured temperature values at \(n\) locations (\(n=8\)), the root mean square deviation of the \(n\) temperatures from the average, the maximum deviation of the \(n\) measured temperatures from the average, the maximum deviation of the \(n\) temperatures from the set temperature, and the difference between the average and the set temperatures:  
\[T_{\text{avg}}=\frac{\sum\limits_{i=1}^{n}T_{i}}{n}, \tag{11}\]  
\[\sigma_{T}=\sqrt{\frac{\sum\limits_{i=1}^{n}\left(T_{i}-T_{\text{avg}}\right) ^{2}}{n-1}}, \tag{12}\]  
Figure 11: Arrangement of temperature and humidity transducers in an enclosed chamber. \begin{table}
\begin{tabular}{c c c c c} \hline \(V_{\text{set}}\) (m/s) & \(\sigma v/V_{\text{avg}}\) & \(1V_{i}-V_{\text{avg}}\) 1 max/\(V_{\text{avg}}\) & \(1V_{i}-V_{\text{set}}\) 1 max/\(V_{\text{set}}\) & \(1V_{\text{avg}}-V_{\text{set}}\) 1/\(V_{\text{set}}\) \\ \hline
0.1 & 0.1080 & 0.2402 & 0.2410 & 0.000805 \\
0.2 & 0.03314 & 0.1428 & 0.1435 & 0.000686 \\
0.3 & 0.03313 & 0.1782 & 0.1793 & 0.001152 \\
0.4 & 0.02238 & 0.07796 & 0.07650 & 0.001460 \\
0.5 & 0.02101 & 0.05407 & 0.05300 & 0.001073 \\
0.6 & 0.02424 & 0.06531 & 0.06599 & 0.000686 \\
0.7 & 0.02499 & 0.1397 & 0.1413 & 0.001601 \\
0.8 & 0.02073 & 0.05728 & 0.05575 & 0.001527 \\
0.9 & 0.01748 & 0.05004 & 0.04978 & 0.002065 \\
1.0 & 0.01228 & 0.03980 & 0.04140 & 0.001597 \\ \hline \end{tabular}
\end{table} 
Table 5: Relative error in velocity control in constant-speed stage (%). \[|T_{i}-T_{\rm avg}|_{\rm max}=\max_{i}(|T_{i}-T_{\rm avg}|), \tag{13}\]  
\[|T_{i}-T_{\rm set}|_{\rm max}=\max_{i}(|T_{i}-T_{\rm set}|). \tag{14}\]  
Among these parameters, \(|T_{i}-T_{\rm avg}|_{\rm max}\) combined with \(\sigma_{\rm T}\) can represent the spatial uniformity of temperature distribution in the enclosed chamber, while \(|\,T_{i}-T_{\rm set}|_{\rm max}\) and \(|\,T_{\rm avg}-T_{\rm set}|\) can characterize the accuracy or precision of temperature control. In addition, another two parameters are important in appraising temperature control ability of the system, one is the time (\(t_{\rm r,T}\)) required for the control system to adjust the temperature to reach the set value, the other is the time (\(t_{\rm m,T}\)) in which the system can maintain the temperature at a constant set value after the temperature has reached it. The adjustment test of temperature control system involved the following five heating experiments: room temperature to 30 \({}^{\circ}\)C, 30 \({}^{\circ}\)C to 40 \({}^{\circ}\)C, 40 \({}^{\circ}\)C to 50 \({}^{\circ}\)C, 50 \({}^{\circ}\)C to 60 \({}^{\circ}\)C, and room temperature to 60 \({}^{\circ}\)C. Only two typical heating processes are presented here to exhibit the heating control characteristics, namely, 30 \({}^{\circ}\)C to 40 \({}^{\circ}\)C, and 50 \({}^{\circ}\)C to 60 \({}^{\circ}\)C. Figure 12 shows the temperature variation curves of eight transducers during the heating process from real initial temperature 29.9 \({}^{\circ}\)C to the set temperature 40 \({}^{\circ}\)C. The temperature curves show that when the air was heated to time \(t=4500\) s (75 min), eight temperatures and their average met condition \(|\,T-T_{\rm set}|<\) 0.5 \({}^{\circ}\)C. This condition was maintained at least to 5700 s, that is, the chamber at least maintained constant temperature for 5700 s \(-\) 4500 s = 1200 s = 20 min. In the figure, \"Upper\" and \"Lower\" represent the upper and lower limits (i.e., maximum and minimum) of the temperature values permitted by the design criteria, i.e., 40 \({}^{\circ}\)C \(\pm\) 0.5 \({}^{\circ}\)C).