Characteristics of an aerosol photometer while automatically controlling chamber dilution-air flow rate.
Characteristics of an aerosol photometer while automatically controlling chamber dilution-air flow rate.
复制标题
自动控制室稀释空气流量时气溶胶光度计的特性。
DOI：
10.1080/08958370050138021
复制
发表时间：
2000
影响因子：
2.1
通讯作者：
Hemenway,DR
中科院分区：
文献类型：
--
作者：
O'Shaughnessy,PT;Hemenway,DR
进行了试验，以确定当自动控制曝光室内的气流速度以调节空气中的粉尘浓度时，影响直接跟踪气溶胶光度计准确度的那些因素。光度计的响应受到气溶胶尺寸分布变化的影响，这是由于燃烧室流速的变化引起的。除了稀释效应外，流速还决定了气溶胶在舱内因沉积而损失的相对量。当尝试基于比例-积分-导数(PID)反馈控制算法自动调节流量时，将附加计算添加到计算机控制算法以补偿这些影响。通过与恒定的发电机输出率和稀释空气流量进行的对比试验表明，尽管在使用PID控制时会产生流量的许多变化，但光度计的精度并没有显著降低。同样地，由PID控制的试验产生的室内气溶胶浓度在所需水平的1%以内。
Trials were conducted to determine those factors that affect the accuracy of a directreading aerosol photometer when automatically controlling airflow rate within an exposure chamber to regulate airborne dust concentrations. Photometer response was affected by a shift in the aerosol size distribution caused by changes in chamber flow rate. In addition to a dilution effect, flow rate also determined the relative amount of aerosol lost to sedimentation within the chamber. Additional calculations were added to a computer control algorithm to compensate for these effects when attempting to automatically regulate flow based on a proportional-integral-derivative (PID) feedback control algorithm. A comparison between PID-controlled trials and those performed with a constant generator output rate and dilution-air flow rate demonstrated that there was no significant decrease in photometer accuracy despite the many changes in flow rate produced when using PID control. Likewise, the PID-controlled trials produced chamber aerosol concentrations within 1% of a desired level.