Active infrared thermographic testing with distance heating
Active infrared thermographic testing with distance heating
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远距离加热主动红外热成像测试
DOI：
10.1117/12.2176961
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
Hiroyuki Yamada
中科院分区：
文献类型：
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作者：
Nagahisa Ogasawara;Hikaru Ando;Chie Kobayashi;Hiroyuki Yamada
为了有效地检测大面积混凝土结构墙体，研制了一种远距离加热红外热像检测系统。研究内容包括以下三个方面：1.提高辐射采暖效率；2.发展距离采暖方法；3.发展针对采暖和/或墙体吸收率不均匀的数据分析方法。在本文中，我们主要关注第一个问题。为了研究辐射加热器的光谱发射率与混凝土的光谱吸收率之间的关系，采用了近红外型、远红外型和黑体型三种不同类型的辐射加热器对混凝土试件进行加热。结果，黑体型和远红外型(例如陶瓷加热器和黑体涂层加热器)都可以比近红外型(例如卤素灯加热器和氙灯加热器)更有效地加热混凝土墙。这是因为混凝土在远红外区的光谱吸收率高于近红外区。我们发现，选择一个辐射集中在被加热结构表现出最大吸收率的波长附近的加热器可以提高加热过程的效率。混凝土加热过程的效率可以很容易地提高，只需在近红外加热器的表面覆盖一层黑体表面涂层，以模拟黑体的辐射特性。
In order to efficiently inspect very wide area of concrete structure wall, an infrared thermographic testing with a distance heating was developed in this study. The researched subjects were the following three; 1. Improvement of radiant heating efficiency, 2. Development of distance heating method and 3. Development of data analysis method against nonuniformity of a heating and/or a wall absorptivity. In this paper, we focus on the first issue. In order to investigate about combinations between the spectral emissivity of radiant heater and the spectral absorptivity of concrete, three different types of radiant heater, a near infrared type, a far infrared type and blackbody type, were used to heat concrete specimens. As a results, both a blackbody type and a far infrared type, e.g. a ceramics heater and a blackbody coated heater, can heat a concrete wall more efficiently than a near infrared type, e.g. a halogen lamp heater and a xenon lamp heater. This is because the spectral absorptivity of concrete is higher in a far infrared region than in a near infrared region. We find that the efficiency of the heating process may be improved by choosing a heater whose radiation is concentrated near wavelengths at which the structure to be heated exhibits maximal absorptivity. The efficiency of the concrete heating process may be easily improved simply by covering the surface of a near infrared heater with a blackbody surface coating to mimic the radiation characteristics of a blackbody.