## 4 Experiments Results and Discussion
### Experimental Facility  
The calibration experiments were conducted in a shock tube/tunnel that uses detonation driving. The facility is located in the Laboratory of High-Temperature Gas Dynamics (LHD) at the Institute of Mechanics, Chinese Academy of Sciences, Beijing, China. A schematic of the shock tunnel is shown in Figure 10a. The system consists of a dump section, a driver section, a driven section, a hypersonic nozzle, and a test section. The dump, driver, and driven sections are 3, 15, and 11 m in length, respectively, and they have the same inner diameter of 224 mm. The test section is 10 m long and 1.2 m in diameter. The nominal Mach number of the nozzle is 5.5, and the nozzle exit diameter is 300 mm. Both the main and auxiliary diaphragms are flat-scored metal diaphragms. Different depths of the grooves are designed to ensure that they will not fail during initial pressure differences across the diaphragms before igniting the flammable gases. An ignition tube is placed close to the main diaphragm in the driver tube. The mixture in the ignition tube is initially ignited by electrical sparks. A high-temperature jet is formed and propagates into the driving section, thereby igniting the detonable gas directly. This leads to a stable detonation wave traveling upstream in the detonation tube, behind which a Taylor wave follows; the products have high temperature and pressure. Using detonation as the driving method, the facility can provide high-temperature gas conditions for hypersonic flight.  
Figure 9: Corrections of the calorimeter. (**a**) The corrected results (\(r_{0}=2.5\) mm); (**b**) The relative error before and after corrections.  
As a supplement to extend the capabilities of the facility, it can be re-arranged to operate under other types of test conditions. One is called the single detonation shock tunnel, which has a longer test time; the schematic of the facility is shown in Figure 10b. Then the main diaphragm is removed, and the detonation wave propagates to the left side as it is ignited close to the nozzle throat. The high-temperature and high-pressure gas source behind the Taylor wave are used as the experimental gas; namely, the experimental gas composition represents the detonation product. Another test condition is obtained using the detonation-driven shock tube, as shown in Figure 10c. Compared to the detonation shock tunnel (Figure 10a), the nozzle is removed, and the test model is placed at the exit of the driven section.  
In the present study, we use these three types of operations to fully validate our new calorimeters. All the tests in the present study were conducted at room temperature. The measurement system used in this experiment mainly include a conditioner and a data acquisition board, which are integrated into an equipment by Donghua software, INC (Taizhou, Jiangsu, China). Before the experiment, a constant of 10 mA current provided by the conditioner was loaded on each sensor. The voltage at the ends the platinum film resistance were also amplified by the conditioner at a gain factor of 100. All signals from the sensors were acquired by the data acquisition board and were processed on a PC-based data acquisition system at a sampling rate of 1 MHz. The measured voltage signals were converted into temperature signal according to the temperature coefficient of the sensors which had been statically calibrated before the experiment. Besides, the measurement system was also calibrated and the overall measurement deviation was found to be 0.15%. The other details of the facility, the pressure/incident shock speed measurement method or position, and the free-stream parameter calculation method are available in reference [36].