Digital Exam Information - National Radon Safety Board


Please check with the state radon representative to see if the state where you will be performing work has regulations.
You can find your states information here:

If you are taking the NRSB exam for a state license, you must check with your state
to make sure you are taking the correct NRSB exam. All exam fees are non-refundable.

Special Instructions:
  • The exams include a virtual live proctor.
  • The exams are multiple choice and the examinee should select the single best answer.
  • You are permitted one piece of scrap paper and a pen or pencil during the exam.
  • There are digital tools available which include a notepad and a calculator.
    To access them click on the “Tools” button on the top right of the menu bar.
  • There is also a check box so you may flag a question for review during or before exiting the exam. 

If you fail the exam you are able to register again after a 14 day wait period.
A score of 70% or above is passing.
All exam fees are non-refundable.


1. Register and pay for the exam
2. Set up your profile on Prolydian
3. Receive an authorization email to schedule your exam
          -  Double check your time zone to ensure it is correct. 
          - You may not cancel or change the day and time within 24 hours of your scheduled exam. All exam fees are non-refundable.
4. Receive confirmation email of date and time of your exam.

5. Review the test-taker handbook if you have questions about the virtual proctor process. Click here for PDF »
6. You will receive a preliminary email after completing the exam with your tentative score.
7. Once your exam has been audited and finalized (within 72 hours of taking the exam), you will receive another email with your final score, detailed score letter and instructions on how to become certified by the NRSB.

Radon Measurement Technician (RMT)

An RMT is only able to place and retrieve a device.

Measurement Technicians are qualified to place and retrieve measurement devices for the purpose of collecting radon data. This must be done in accordance with an active quality assurance program under the supervision of a certified Radon Measurement Specialist (RMS) or Accredited Radon Laboratory (ARL).

75 Questions/ 1.5 Hours / $120


An RMS is able to place, retrieve, read the measurements and sign the reports for a device.

Radon Measurement Specialists are qualified to place, retrieve, analyze the measurements and sign the reports. An RMS is also able to be directly responsible for the operation and oversight of the Quality Assurance program for the radon Laboratory, Tertiary or Secondary chamber.

100 Questions/ 2 Hours / $120


An Radon Mitigation Specialist RRS is qualified to design and install a radon remediation system. To be certified a candidate must have a working knowledge of radon measurement techniques and health risks, and must demonstrate a broad knowledge in all aspects of residential radon mitigation.


125 Questions/ 2.5 Hours / $120

This video is for informational purposes only. It is a sample for live authentication and proctoring.