What is the flow rate range for sampling on 0.8 micron MCE filters?

• A. 0.1-2 LPM
• B. 1-20 LPM
• C. 5-25 LPM
• D. 0.5-16 LPM

Answer: (D)

The flow rate for sampling with a 0.8 μm MCE filter is chosen to keep the collection accurate and the sampling practical. The best range to use is 0.5 to 16 LPM.

This range balances getting enough particulate mass on the filter for reliable analysis with avoiding problems from too high a flow. At the lower end (around 0.5 LPM), you can run longer samples or collect in low-concentration environments without overloading the filter, which helps maintain accuracy and filter integrity. At the higher end (up to about 16 LPM), you can obtain a measurable mass more quickly when concentrations are higher or when you need shorter sampling times, while still staying within what the filter and typical pumps can handle without causing excessive pressure drop or particle bounce.

Flows well below this window may yield too little collected material for accurate analysis, increasing uncertainty. Flows above this window can increase face velocity, accelerate filter loading, and risk distorting the collection or damaging the filter.