InterNACHI Certified Radon Tester exam-day guide
InterNACHI Certified Radon Tester · Prepare for the day ahead.
Your checklist
Government-issued photo ID
Bring the original, unexpired ID with a name matching your registration exactly. If your registration name differs from your ID (for example, a nickname or a name change), contact the provider before test day to correct it - confirm with the provider which ID forms they accept.
Login credentials and exam access instructions
Have your username, password, and any exam-access link or access code ready before you sit down. Test the login the day before so a password reset does not eat into your exam time. Confirm with the provider whether the exam is proctored and what platform it uses.
Reliable internet connection and a backup plan
For a remotely proctored or online exam, use a wired or stable connection and know how to tether to a phone hotspot if the primary connection drops. Confirm with the provider how a disconnection is handled and whether the attempt can be resumed.
Computer and browser that meet the provider's requirements
Update your browser and operating system ahead of time, close background apps, and disable notifications. Confirm with the provider which browsers and devices are supported and whether a webcam and microphone are required for proctoring.
Quiet, well-lit, private room
Choose a space with a door you can close, no other people, and a clear desk. Proctoring systems often scan the room and the desk surface at the start; remove notes, phones, and extra screens unless the provider explicitly allows them.
Reference materials only if permitted
Most certification exams are closed-book. Do not bring notes, textbooks, or a second device unless the provider's rules say otherwise. Confirm with the provider whether any reference sheet or calculator is allowed and in what form.
Calculator and scratch materials only if permitted
Radon work involves unit conversions and decay calculations, so a basic calculator or on-screen calculator may be useful. Confirm with the provider whether physical scratch paper, a calculator, or an on-screen equivalent is allowed, and whether scratch paper must be shown and destroyed afterward.
A watch or clock visible without leaving the exam window
Know how much time remains without switching applications or opening a phone. Many platforms show a countdown; if yours does not, a simple watch on the desk is safer than checking a device.
Water and a bathroom visit before starting
Hydrate and use the restroom before you begin. Unless the provider's rules allow scheduled breaks, assume you cannot leave the screen mid-exam without ending or invalidating the attempt.
A calm plan for flagged or skipped questions
Decide in advance how you will handle uncertain items: answer your best choice, flag it if the platform allows, and return after finishing the rest. Never leave a question blank if there is no penalty for guessing - confirm with the provider whether unanswered questions are scored as incorrect.
Provider contact information on hand
Save the provider's support phone number or email so you can report a technical failure immediately. Screenshot any error message and note the time. Confirm with the provider what evidence they require for a technical-issue appeal.
Plan the day
Re-read the exam blueprint or content outline and list the domains you are least confident in: radon physics and health effects, measurement devices and protocols, closed-house conditions and placement, mitigation system basics, and reporting or quality assurance. Spend your remaining study time on those gaps rather than re-reading material you already know. Confirm the exam format, number of questions, time limit, passing score, and whether it is proctored with the provider.
Do a full timed practice run under exam-like conditions: no notes, no phone, one sitting. Review every missed question and write a one-line reason for the correct answer. Focus on the recurring practical themes - minimum and maximum detector placement heights, closed-house duration before and during a test, avoidance of kitchens, bathrooms, laundry rooms, and crawl spaces, and the difference between short-term and long-term test results.
Verify your registration details, name spelling, exam date, time zone, and access method. If the exam is at a physical test center, confirm the address, parking, and arrival time. If it is remote, confirm the proctoring platform and run its system check or equipment test.
Test your login, webcam, microphone, and internet connection end to end. Clear your desk and set up the room. Charge devices and locate chargers. Prepare your ID and any permitted materials in one place. Get a normal night of sleep rather than cramming new topics - late cramming tends to increase careless errors more than it adds knowledge.
Do a light review only: key definitions, unit conversions, and the steps of a standard test protocol. Stop studying early enough to sleep. Set two alarms and, for an in-person exam, plan to arrive with buffer time for traffic and check-in.
Eat a normal meal, hydrate, and use the restroom. Log in or arrive early - aim for well ahead of the start time so technical checks or check-in do not consume exam minutes. Keep the desk clear, silence your phone, and put it out of reach unless the provider requires it for proctoring.
Read each question fully and watch for qualifiers such as 'minimum', 'maximum', 'not', and 'best'. Answer easy questions first, flag uncertain ones, and return to them. For calculation items, write the formula, substitute units carefully, and sanity-check the magnitude of the result. Budget time so you can review flagged items before the clock runs out.
If a technical problem occurs, do not keep clicking or restart blindly. Note the time, screenshot the error, and contact provider support using the channel they specified. If you finish early, use remaining time to confirm you answered every question and that flagged items were resolved.
Note your result and, if the provider reports domain-level performance, record which areas were weakest for any future continuing education. Keep your score report and any confirmation email. If you did not pass, ask the provider about the waiting period before a retake and what feedback is available.
Rules to check
Follow the provider's identity-verification rules exactly. Expect to present a government-issued photo ID with a name matching your registration, and confirm with the provider in advance what to do if your registered name and ID differ.
Assume closed-book conditions unless the provider states otherwise. Do not use notes, textbooks, phones, smart watches, or a second screen, and do not communicate with anyone during the exam. Unauthorized materials or communication can void your attempt.
Do not attempt to copy, screenshot, record, or share exam questions. Exam content is confidential, and sharing it may result in disqualification and loss of certification eligibility.
Breaks are usually restricted during a timed exam. Confirm with the provider whether any scheduled or unscheduled breaks are allowed, whether the clock stops, and whether leaving the camera view during a proctored exam ends the attempt.
Scoring and passing standards are set by the provider. Confirm the passing score, whether unanswered questions count as incorrect, and whether partial credit exists. Do not assume a guessed answer is penalized beyond being wrong.
Report technical failures immediately through the provider's support channel and document them with a screenshot and timestamp. Confirm with the provider what evidence is needed to request a retake or extension; do not simply abandon the attempt.
If you fail, follow the provider's retake policy rather than registering through another route. Confirm the waiting period, fees, and any limit on attempts before scheduling again.
Keep your contact information current with the provider so your results, certificate, and any renewal notices reach you. Certification typically requires renewal and continuing education - confirm the current cycle and requirements with the provider.