## 4 Energy Measurement Results
### Transferred Energy Results
#### 4.2.3 Energy Measurement Results of the Piston Type of Device  
The piston type of device is used to measure the transferred energy, and the \"off-on target\" method is deployed to measure the speed of the piston out of the cylinder. The principle of the off-on target method is: installing a wire on the piston to connect to the signal source, there are three parallel target \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Sample Size** & **Sample Mean ()** & **Sample Standard Deviation ()** & **Sample Coefficient of Variation** \\ \hline
11 & 125.183 & 13.626 & 0.109 \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Sample statistical data of transferred energy measured by the aluminum honeycomb device. Figure 17: Distance marking in the test of the aluminum honeycomb type of measuring device. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Sample Size** & **Sample Mean (mm)** & **Sample Standard Deviation (mm)** & **Sample Coefficient of Variation** \\ \hline
11 & 36.370 & 3.959 & 0.109 \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Sample statistical data of the compression length of the aluminum honeycomb. wires (fragile fuses) on the \(\pi\)-like structure, and each fuse is connected to a signal terminal. When the piston hits the fuse, the circuit is connected to generate a signal, and three sets of signals are generated after sequential hits. Then, dividing the distance between two adjacent fuses by the time difference of the signal, the average speed can be calculated. The mass of the piston is weighed before each fire. A total of 16 firings were tested and the recorded data are shown in Table 7, in which, \(\Delta\)t\({}_{1}\) represents the time difference between the piston hitting the first and second fuse, while \(\Delta\)t\({}_{2}\) represents the time difference between the piston hitting the second and third fuse. According to the data above, the sample statistical data of the transferred energy measured by the piston device can be calculated by the equation \(E=mv^{2}/2\), as shown in Table 8.  
The pin-rod type device is also used to measure the transferred energy, and a photoelectric target is used to measure the output speed of the pin-rod. The principle of the photoelectric target is similar to that of the target line method, except that the electrical signal is changed to an optical signal, which is easier to use than the target line, and there is no need to re-lay the fuse after each test. After every firing, a new shell body and pin-rod need to be replaced, and the mass of the pin-rod with additional mass is 167.7 g.  
As mentioned before, the second set of the target line system is away from the export, so the obtained speed may not be the off-cylinder speed; however, due to the short distance and the average processing, this will have little influence on the energy. The velocity data are as shown in Table 9. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**No.** & **Mass (g)** & \(\Delta\)**t\({}_{1}\) (us)** & \(\Delta\)**t\({}_{2}\) (us)** & **Velocity (m\(\cdot\)s\({}^{-1}\))** \\ \hline
1 & 643.3 & 490.12 & 510.33 & 29.987 \\
2 & 647.2 & 492.79 & 508.19 & 29.971 \\
3 & 643.4 & 516.87 & 516.87 & 29.021 \\
4 & 644.5 & 508.52 & 461.58 & 30.925 \\
5 & 643.9 & 503.24 & 555.93 & 28.324 \\
6 & 645.7 & 502.23 & 542.16 & 28.725 \\
7 & 642.4 & 516.53 & 540.83 & 28.373 \\
8 & 636.2 & 515.84 & 533.63 & 28.586 \\
9 & 641.0 & 515.73 & 473.46 & 30.328 \\
10 & 640.9 & 478.67 & 504.90 & 30.501 \\
11 & 641.7 & 490.95 & 511.12 & 29.938 \\
12 & 642.8 & 501.67 & 523.67 & 29.259 \\
13 & 646.3 & 539.34 & 535.31 & 27.916 \\
14 & 646.9 & 520.43 & 520.43 & 28.822 \\
15 & 648.2 & 520.61 & 525.72 & 28.672 \\
16 & 646.8 & 517.08 & 513.77 & 29.102 \\ \hline \hline \end{tabular}
\end{table} 
Table 7: Compression lengths of the aluminum honeycomb. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Sample Size** & **Sample Mean (J)** & **Sample Standard Deviation (J)** & **Sample Coefficient of Variation** \\ \hline
16 & 276.167 & 16.592 & 0.060 \\ \hline \hline \end{tabular}
\end{table}