## 5 System Test  
The test environment of the system mainly includes gas equipment laboratory and user's home environment. The test system mainly consists of a gas pipeline, diaphragm gas meter, indirect gas consumption metering terminal, indoor gas safety valve and domestic gas stove. The users' homes are located in different floors between the 1 st and 22 th floors. Diaphragm gas meters of different brands and specifications are tested and used. In the laboratory test environment of gas equipment, the inlet of the gas pipeline is equipped with a high precision gas flowmeter, which can control the system parameters precisely under the condition of large flow. In addition, two or four household gas cookers can be extended to the end of the gas pipeline through the two-way pipe, so as to realize the system experimental test of the diaphragm gas meter under the limit flow velocity (2.5 m\({}^{3}\)/h). The gas consumption indirect metering device test system is shown in Figure 10. \begin{table}
\begin{tabular}{c c c} \hline
**Velocity Output Value \(S\)** & **Confidence Intervals for Periodic** & **Approximate Value of Period** \\  & **Extraction Results \(L(s)\)** & **N(s)** \\ \hline \(0<S\leq\frac{V_{\mathrm{H}}}{2}\) & \(15<L<90\) & 65 \\ \(\frac{V_{\mathrm{H}}}{2}<S\leq V_{\mathrm{B1}}\) & \(10<L<75\) & 27.5 \\ \(V_{\mathrm{B1}}<S\leq\frac{3V_{\mathrm{B2}}}{4}\) & \(5<L<40\) & 12.5 \\ \(\frac{3V_{\mathrm{H}}}{4}<S\leq V_{\mathrm{B2}}\) & \(L<15\) & 7.5 \\ \hline \end{tabular}
\end{table} 
Table 1: Signal periodic rationality test and approximate value of period. Figure 9: The output value of gas flow velocity sensor and its corresponding signal period interval. The user cooking process involves one or more gas use states, including single stove and double stoves in the use of various fire states, a long-term use process (the gas dosage is greater than 6 dm\({}^{3}\)), and a short-term use process (the gas dosage is less than 6 dm\({}^{3}\)). The process also includes a variety of unconventional operating conditions, such as multiple igniting operations due to fire failure, frequent fire adjustments and minimal fire adjustments. Each group of experiments is a complete family cooking process. The test site is distributed over different floors and test times, including peak gas use and non-peak gas use periods. According to the experimental results, the maximum error rate of the test group is 7.88%. The gas consumption is 4357.56 dm\({}^{3}\) in all the experiments, and the calculated measurement value is 4420.64 dm\({}^{3}\). The cumulative error rate is 1.45%. The gas metering test results of household cooking process are shown in Table 2. The single group of experimental errors are mainly caused by the approximate gas metering signal section and the user's igniting operation. However, due to the positive and negative error rate, the statistical average can further reduce the system error rate. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Number** & **Gas Temperature** & **Pipe static** & **Correction** & **Code Disk** & **Result of** & **Error Rate** \\  & (°C) & **Pressure (Pa)** & **Factor** & **Value (L)** & **Calculation (L)** & & \\ \hline
1 & 3.79 & 104,608 & 1.09 & 72 & 70.54 & \(-\)2.03\% \\
2 & 12.76 & 105,176 & 1.06 & 50.4 & 49.58 & \(-\)1.63\% \\
3 &  
Because the test time is winter, the gas temperature is low and the static pressure of the gas pipeline is 2000-3000 Pa higher than the standard atmospheric pressure, it is necessary to multiply the measured value by the corresponding temperature-pressure correction coefficient to get the gas measurement value under the standard condition. Figure 11 shows the numerical comparison of gas volume before and after correcting by the temperature and pressure. As shown in the Figure 11, the gas metering value of the diaphragm gas meter in winter is lower than the gas volume of the standard condition, and the pipe pressure is higher than the standard atmospheric pressure.