Weighing filtration membrane is often used to get the dust concentration of environment.However,this method is discommodious and can not get the instantaneous transformation of dust concentration.

环境浓度的测定一般使用滤膜称重方法测得,该方法力,且不得到瞬浓度的变化。

But all of that are usually discommodious and insecure to some extent, for example toting, forgetting, losing and peculating and so on.

但各种措施都或多或少地伴随着要携带、易遗忘、易丢失、被盗用等不方便和不安全的因素。