Sensor Systems Group, Electronic & Electrical Engineering Department, University of Sheffield, Portobello Centre, Pitt Street, Sheffield S1 4ET, UK.
Department of Civil & Structural Engineering, University of Sheffield, Sir Frederick Mappin Building, Mappin Street, Sheffield S1 3JD, UK.
Sensors (Basel). 2022 Aug 17;22(16):6143. doi: 10.3390/s22166143.
The understanding of blast loads is critical for the development of infrastructure that protects against explosions. However, the lack of high-quality experimental work on the characterisation of such loads prevents a better understanding of many scenarios. Blast loads are typically characterised by use of some form of pressure gauge, from which the temperature can be inferred from a pressure measurement. However, such an approach to temperature measurement is limited; it assumes ideal gas laws apply throughout, which may not be the case for high temperature and pressure scenarios. In contrast, infrared radiation thermometers (IRTs) perform a measurement of temperature based upon the emitted radiance from the target object. The IRTs can measure fast changes in transient temperature, making them seemingly ideal for the measurement of a fireball's temperature. In this work, we present the use of a high-speed IRT for the measurement of early-stage explosive development and fireball expansion within a confined blast, with the temperature of the explosive fireball measured from its emitted radiance. The temperature measured by the IRT was corroborated against the temperature inferred from a pressure gauge measurement; both instruments measured the same temperature from the quasi-static pressure (QSP) point onwards. Before the QSP point, it is deduced that the IRT measures the average temperature of the fireball over a wide field-of-view (FOV), as opposed to that inferred from the singular shocks detected by the pressure gauge. Therefore, use of an IRT, in tandem with a pressure gauge, provides a potential invaluable measurement technique for the characterisation the early stages of a fireball as it develops and expands.
爆炸荷载的理解对于开发能够抵御爆炸的基础设施至关重要。然而，由于缺乏对这种荷载特性的高质量实验工作，许多场景的爆炸荷载仍未得到充分理解。爆炸荷载通常采用某种形式的压力计进行特性描述，从而可以从压力测量中推断出温度。然而，这种温度测量方法存在局限性；它假设理想气体定律在整个过程中都适用，但在高温和高压情况下可能并非如此。相比之下，红外辐射温度计 (IRT) 通过测量目标物体发出的辐射亮度来进行温度测量。IRT 可以快速测量瞬态温度的变化，因此似乎非常适合测量火球的温度。在这项工作中，我们展示了使用高速 IRT 测量封闭爆炸中早期爆炸发展和火球膨胀的情况，并通过测量爆炸火球的发射辐射来测量其温度。IRT 测量的温度与通过压力计测量推断的温度进行了比较；两个仪器都从准静态压力 (QSP) 点开始测量相同的温度。在 QSP 点之前，推断出 IRT 测量火球在宽视场 (FOV) 内的平均温度，而不是压力计检测到的单个冲击波推断出的温度。因此，IRT 与压力计结合使用，为火球发展和膨胀的早期阶段的特性描述提供了一种潜在的非常有价值的测量技术。
