What is a calibration check for a sampling pump?

• A. Calibrate the pump using a bench test
• B. Check battery status
• C. Inspect the tubing for wear
• D. Verification of the pump's flow rate against a known standard before/after sampling

Answer: (D)

Verifying the actual flow rate of the sampling pump against a known standard before and after sampling is essential to ensure accurate air-volume measurements. By using a calibrated flow reference, you can check that the pump is delivering the intended flow, establishing a baseline before sampling and confirming no drift, leaks, or tubing wear occurred during collection. The volume of air drawn directly affects how the concentration of any contaminant is calculated, so matching the pump’s flow to a traceable standard keeps results reliable. A bench test to set the flow isn’t the same as a real calibration check against a standard in the field, and while battery status and tubing inspection are important maintenance tasks, they don’t quantify the actual flow rate. So the proper calibration check is verifying the flow rate against a known standard before and after sampling.