时控恒流量采样器的研制

针对目前国产小型采样器 2 4小时采样 ,因连续在博物馆陈列室等处用电存在的不安全性、采样位置受电源位置限制以及流量控制不稳的缺陷 ,根据博物馆实际检测采样的特殊需要 ,自行研制了小型时控恒流量采样器。采样器主要有定时控制、电机控制、电源检测、模式开关和气泵等部分组成。通过电路的特殊设计 ,采取间隙式采样模式以保证连续采样无需外接电源 ,解决电池供电随着使用时间的增加电压下降可能引起采样流量变化的问题。通过电路中稳速系统设计 ,使采样器工作在一确定的电压之上 ,保证电机转速稳定 ,使采样流量不受采样管阻力影响 ,从而保证采样精度。采样器经半年多实际应用最大相对误差为 2 .5 %。能满足博物馆实际检测采样要求。

The development of a minitype sampler with constant sampling rate

There is limitation when the current air sampler used for sampling air in the museum exhibiting room.For example,in many museums the power socket is very limited,it will cause the difficulty in selecting the site of sampling,if the socket is replaced by batteries in order to meet 24h continual and random and security sampling,some problems like the sampling instability will also appear because the voltage of the batteries is gradually lowered during their use.In this work,a kind of minitype sampler with special circuits' design was developed,assured the rate stable during sampling and data validity when using batteries supply,overcame the problem of the voltage fall along with the use time of batteries.Also the sampler being designed can keep the working voltage up in order to avoid the influence of the resistance force in the sampling tube.The comparatively error of 2.5% is found in actual application.