Infrared radiometry for measuring plant leaf temperature during thermal weed control treatment
Infrared radiometry for measuring plant leaf temperature during thermal weed control treatment
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DOI：
10.1016/s1537-5110(03)00138-7
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发表时间：
2003-11-01
影响因子：
5.1
通讯作者：
Jokela, H
中科院分区：
文献类型：
--
作者：
Rahkonen, J;Jokela, H
将植物叶片的一侧暴露于液化石油气火焰中，同时用成像红外辐射计连续测量另一侧的温度。通过对200多片叶片的燃烧实验，研究了叶片温度的变化规律和测量系统的性能。火焰让树叶的温度迅速升高。最高加热速率通常在180摄氏度左右。辐射计的成像速度为50场/s（-1），足以评估温度的历史。燃烧在燃烧的叶片中引起明显的温度差异，脉被加热到比它们之间的薄区域更低的温度。具有良好空间分辨率的热谱图对于描述在1 mm间隔内具有50 ℃梯度的温度分布是必不可少的。使用工厂校准的辐射计，通过使用辐射计确定目标发射率，在20- 90 ℃的温度范围内，绝对温度值的准确度达到+/-2.1 ℃。通过校准辐射计的实际测量条件下的误差可以减少到+/-1.0 ℃。总之，成像红外辐射计是一种上级仪器，用于测量快速，空间分布的温度变化，在植物叶片热杂草控制处理。(C)2003年，Silsoe研究所。版权所有Elsevier Ltd.
One side of a plant leaf was exposed to liquefied petroleum gas flames, while the temperature of the other side was measured continuously with an imaging infrared radiometer. Temperature histories of leaves and the performance of the measuring system were studied by flaming over 200 leaves and recording the measurements for off-line analysis. Flaming raised the temperature of the leaves very rapidly. The peak heating rate was typically around 180degreesCs(-1). The imaging speed of the radiometer, 50 fields s(-1), was sufficient to evaluate the temperature histories.Flaming induced marked temperature differences in the flamed leaves, with veins heated to lower temperatures than the thin areas between them. Thermograms with good spatial resolution were essential to characterise the temperature distribution with gradients as steep as 50degreesC over a 1 mm interval.With a factory calibrated radiometer an accuracy of +/-2.1degreesC in absolute temperature values for a temperature range of 20-90degreesC was achieved by determining the target emissivity with the radiometer. By calibrating the radiometer for the actual conditions under measurements the error could be reduced to +/-1.0degreesC. In conclusion, an imaging infrared radiometer is a superior instrument for measuring fast, spatially distributed temperature changes in plant leaves during thermal weed control treatment. (C) 2003 Silsoe Research Institute. All rights reserved Published by Elsevier Ltd.