For AHEAR TEM collection, what is the maximum total liters allowed?

• A. 1200 liters
• B. 1500 liters
• C. 3800 liters
• D. 5000 liters

Answer: (C)

In AHEAR TEM collection, there is a defined cap on the total air volume you can pull through the sampling setup. This limit protects the sorbent media from overload and keeps the collected sample within the method’s calibrated range, ensuring accurate and representative results. The maximum total liters allowed is 3,800 liters.

Think of it this way: the volume you collect depends on the flow rate and the duration of sampling. If you’re operating at a given flow rate, you’d reach the 3,800 L cap after a certain amount of time, which keeps the sample from exceeding the sorbent’s capacity or the instrument’s calibration. For example, at 2.0 L per minute, you’d hit 3,800 L after roughly 1,900 minutes (about 32 hours). Choosing a limit of 3,800 L balances practicality with data quality.

The other options don’t align with the method’s standard: 1,200 or 1,500 L would under-sample relative to the protocol, while 5,000 L would exceed the capacity and risk inaccurate results.