用于通风率标准棒期间核查的标准装置设计

Design of standard device for routine check of ventilation rate standard bar

为解决通风率标准棒在检定周期内受外界影响而产生量值变化等问题,设计了一种适用于通风率标准棒期间核查的标准装置。采用电子皂膜流量计分别测量总气流量和通风流量,压差计测量标准棒进气端面与出气端面间的压差值,大气压计测量周围环境气压,再通过计算得到通风率。以检定值27.87%、58.83%和71.95%这3种通风率标准棒为对象进行测试,结果表明:标准装置的测量值分别为27.03%、58.32%和71.37%,与检定值的误差均小于1%;扩展不确定度1.42%(k=2),能够满足期间核查需求。该技术可为提高通风率标准棒量值的准确性和可靠性提供支持。

The measurement value of a ventilation rate standard bar is influenced by ambient conditions,therefore a device for the routine check of the standard bar was designed.Electronic soap film flowmeters are used to measure the total airflow and ventilation airflow separately.A differential pressure gauge is adopted to measure the pressure difference between the inlet end and outlet end of the standard bar.A baremeter is used to measure the ambient air pressure.The ventilation rate is obtained by calculation.Three ventilation rate standard bars with certified value of 27.87%,58.83%and 71.95%separately were tested,the results showed that their values measured by the designed device were 27.03%,58.32%and 71.37%respectively,and the errors between the measured values and the certified values were all less than 1%with the expanded uncertainty of 1.42%(k=2),which met the requirements of routine check.This technology provides a support for promoting the accuracy and reliability of the ventilation rate measurement with standard bar.