Development of Measurement System of Water Vapor Fluctuation using a Far Infrared Absorption Band in Building Canyon

建筑物峡谷远红外吸收波段水汽波动测量系统的研制

基本信息

批准号：
07555473
负责人：
YOSHIDA Atsumasa
金额：
$ 1.22万
依托单位：
Okayama University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A)
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1997
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07555473/
关键词：
Infrared Hygrometer Specific Humidity Fluctuation Eddy Correlation Method Sensible Heat Transfer Field Measurement Building Canyon 化湿

项目摘要

An eddy correlation method is most useful for estimating the latent heat transfer in the complex building canyons. In order to apply this method, it is necessary to measure the fluctuation of specific humidity. In the present study, an infrared hygrometer with optical fiber by using 6.3 mum absorption band of water vapor is newly designed. In the wavelength range, the measurements are insensitive to solar radiation and infrared radiation from the surroundings. The fluctuation of the averaged specific humidity in the measuring path is obtained from the transmittance measurement based on Beer's law. In order to minimize the disturbance of the hygrometer on the measurement, the hygrometer is divided into two parts called a light source block and a measurement block. These blocks are connected by an optical fiber cable.The static characteristics of the hygrometer were examined in a test chamber as a function of the specific humidity (5-20 g/kg), the air temperature (283-303 K) and the path length (150-250 nm). The resolution better than 0.1 g/kg was obtained comparing with an optical dew indicator. The dynamic responses were also checked by the intermittent supply of wet air in the dry test chamber. The dominant frequency obtained from the spectral analysis of the experimental results agreed with the controlled supply frequency less than 10 Hz. The hygrometer was finally changed for the field measurements. They will be performed in several types of building canyons.

涡流相关方法对于估计复杂建筑物峡谷中的潜热传递最有用。为了应用这种方法，有必要测量特定湿度的波动。在本研究中，新设计的是使用6.3 MUM吸收带的光纤的红外湿度计是新设计的。在波长范围内，测量值对周围环境的太阳辐射和红外辐射不敏感。测量路径中平均特定湿度的波动是根据啤酒定律的透射率测量获得的。为了最大程度地减少测量值湿度计的干扰，将湿度计分为两个部分，称为光源块和测量块。这些块通过光纤电缆连接。在测试室中检查了湿度计的静态特性，这是特定湿度（5-20 g/kg），气温（283-303 K）和路径长度（150-250 nm）的函数。与光学露指示剂相比，获得了大于0.1 g/kg的分辨率。还通过干燥测试室中湿空气的间歇供应来检查动态反应。从实验结果的光谱分析获得的主要频率与受控供应频率小于10 Hz一致。最终更改了湿度计以进行现场测量。它们将在几种类型的建筑峡谷中进行。