A low-cost optical sensing device based on paired emitter-detector light emitting diodes
A low-cost optical sensing device based on paired emitter-detector light emitting diodes
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DOI：
10.1016/j.aca.2005.10.046
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发表时间：
2006-01-31
影响因子：
6.2
通讯作者：
Diamond, D
中科院分区：
文献类型：
--
作者：
Lau, KT;Baldwin, S;Diamond, D
描述了一种低功耗、高灵敏度、低成本的基于发光二极管（LED）的基于强度的光测量装置。在这种方法中，作为光电二极管的反向偏置LED与配置为常规发射模式的第二LED耦合。一个简单的定时器电路测量检测器LED上产生的光电流从逻辑1 （+5 V）放电到逻辑0 （+1.7 V）所需的时间（以微秒为单位）。整个仪器提供了一个固有的数字输出光强度测量几美分。这种光强度相关的放电过程已被应用于测量有色溶液的浓度，并建立了基于比尔-朗伯定律的数学模型。(c) 2005年Elsevier B.V.出版
A low-power, high sensitivity, very low-cost light emitting diode (LED)-based device for intensity-based light measurements is described. In this approach, a reverse-biased LED functioning as a photodiode is coupled with a second LED configured in conventional emission mode. A simple timer circuit measures how long (in microsecond) it takes for the photocurrent generated on the detector LED to discharge its capacitance from logic 1 (+5 V) to logic 0 (+1.7 V). The entire instrument provides an inherently digital output of light intensity measurements for a few cents. This light intensity dependent discharge process has been applied to measuring concentrations of coloured solutions and a mathematical model developed based on the Beer-Lambert Law. (c) 2005 Published by Elsevier B.V.