ABSTRACT
This chapter discusses the timing, the frequency, the location(s), and the methods by which an industrial hygienist can conduct LEV system performance assessments, followed by procedures to diagnose the cause for performance deterioration and tools to make improvements. In order to evaluate the initial adequacy of an LEV system's performance or to detect a change in system performance, a baseline of system performance must exist. It describes concurrent information that should be recorded while measuring employee exposure in order to maximize the value of that expensive but vital process. Imagine getting a call that a continuous airflow monitor at the people facility has decreased to an action criterion. Adjustments to an existing LEV system may need to be made for several reasons.
