Free RMS Practice Questions

Question 1

A pre-sale radon test is planned for a house with a dry, full-height basement that could become a playroom. The sellers currently use the basement only for storage. Under the ANSI/AARST MAH-2023 time-sensitive protocol, which placement should be used for the primary measurement? Assume all clearances other than those stated are satisfied.

Accepted Answer

In the basement, 30 inches above the floor and 4 feet from the nearest exterior window.

Answer

In the first-floor living room, 30 inches above the floor, because that is the lowest currently occupied level.

Answer

12 inches above the basement floor, closer to suspected soil-gas entry points.

Answer

In the basement, 30 inches above the floor and 2 feet from an exterior window that remains closed.

Question 2

Two continuous radon monitors are colocated for a 48-hour quality-control comparison. Neither has power loss or missing data. Their results are 4.8 and 7.2 pCi/L. Using the ANSI/AARST MS-QA-2023 comparison limits, how should the relative percent difference (RPD) be classified?

Accepted Answer

40% RPD: beyond the 36% control limit; corrective-action review is needed.

Answer

20% RPD: acceptable, below the 28% warning limit.

Answer

33.3% RPD: above the 28% warning limit but below the 36% control limit.

Answer

40% RPD: acceptable because both results support the same mitigation recommendation.

Question 3

During a diagnostic investigation, operating a large exhaust fan makes basement air pressure more negative relative to the soil. Radon subsequently rises. Water use is unchanged, outdoor radon remains far below indoor radon, and the increase recurs when the fan is operated again. Which entry mechanism best explains this pattern?

Accepted Answer

Pressure-driven movement of radon-bearing soil gas through openings in the foundation.

Answer

Release of dissolved radon from household water as it is aerated at fixtures.

Answer

Concentration-driven diffusion of radon through concrete.

Answer

Mixing of outdoor radon into the basement as replacement air enters the house.

Question 4

A homeowner who is not selling obtains an initial short-term result of 6.8 pCi/L, then completes a valid nine-month alpha-track follow-up at the same location. The follow-up result is 3.1 pCi/L. Applying EPA's A Citizen's Guide to Radon, the recommendation should be to:

Accepted Answer

Use the long-term result and discuss considering reduction within EPA's 2-4 pCi/L range.

Answer

Recommend mitigation using the average of the short-term and long-term results as the decision value.

Answer

Use 6.8 pCi/L as the decision result and advise fixing the home.

Answer

Require another short-term test before discussing reduction, because the two completed measurements disagree.

Question 5

An elementary school has separate classrooms on a ground-contact slab, all served by the same air-handling system. The facilities manager proposes one detector in the central hallway to represent the classrooms. Under EPA's Radon Measurement in Schools, what is the principal correction to this plan?

Accepted Answer

Measure every frequently occupied ground-contact room rather than relying on a hallway result.

Answer

Move the detector to the common return-air grille so it samples air mixed from all classrooms.

Answer

Test the classroom nearest the air handler and use its result for rooms on the same system.

Answer

Select classrooms at evenly spaced intervals along the hallway to represent the ground-contact floor.

Question 6

An analyst reviews unexpectedly high electret ion-chamber results from a room with unusually high ambient gamma radiation. The exposure times, initial and final voltages, and chamber configuration have been verified. The electrets remained within their usable voltage range. Which processing error would bias the calculated radon concentration upward?

Accepted Answer

Treating gamma-induced voltage loss as though it were entirely due to radon.

Answer

Subtracting the ambient gamma contribution twice from the measured voltage loss.

Answer

Entering an exposure duration longer than the actual time the chambers were open.

Answer

Entering a final electret voltage higher than the voltage actually measured at retrieval.

Question 7

Simultaneous, valid MAH-2023 measurements produce 8.1 pCi/L in a basement and 1.3 pCi/L in a separately conditioned slab addition. The client requests a single house-wide number. How should the RMS present these findings?

Accepted Answer

Report each location separately and address the elevated basement result in the recommendations.

Answer

Average the measurements to report one overall concentration for the house.

Answer

Weight the concentrations by each area's floor space to produce a representative whole-house value.

Answer

Report only the higher result, since including the lower value could weaken the mitigation recommendation.

Question 8

At deployment for a home sale, the RMS discovers that windows were open until arrival. Required closed-building conditions begin immediately, along with recording by a qualifying hourly CRM. The client has requested 48 hours of valid data. With all other requirements met, which treatment of this deployment complies with ANSI/AARST MAH-2023?

Accepted Answer

Record for 60 hours and report the final 48 hours after the first 12 hours of closure.

Answer

Report all 48 hours, because the windows were closed before the first measurement was recorded.

Answer

Finish at 48 hours and report the last 36 hours after removing the preclosure interval.

Answer

Reject the deployment even if recording is extended, because preclosure cannot be established after placement.

Question 9

Two monitors agree closely during repeated side-by-side field checks. In a traceable chamber exposure, both then read consistently higher than the reference concentration by more than the reference uncertainty. Their readings still agree closely with each other. What does this show about using field agreement as evidence of accuracy?

Accepted Answer

Close agreement does not exclude a positive bias shared by both instruments.

Answer

Averaging the two readings would cancel the common discrepancy from the reference.

Answer

The two agreeing instruments outweigh the single reference value as evidence of accuracy.

Answer

Longer field comparisons can establish accuracy without agreement with a known reference.

Question 10

A current smoker receives a confirmed home radon result of 5.7 pCi/L. He says, 'I plan to quit smoking, so that should take care of the radon risk too.' Which explanation correctly distinguishes the two risk-reduction measures?

Accepted Answer

Address both exposures; quitting smoking does not remove the home's radon hazard.

Answer

Reduce radon first; quitting smoking adds little protection after mitigation.

Answer

Quit smoking first, then repeat the radon test before deciding whether exposure reduction is still warranted.

Answer

Use a higher radon action threshold after quitting, because the combined risk will then be lower.

Free RMS Practice Questions

Domain 1: Problem Evaluation

Question 1

Domain 2: Performance of Tests

Question 2

Question 3

Question 4

Domain 3: Analysis of Measurements

Question 5

Question 6

Question 7

Domain 4: Interpretation of Results

Question 8

Question 9

Domain 5: Report of Findings

Question 10

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