There are three ways to test, and each suits a different situation.
| Option | Typical cost | Best for | Watch out for |
|---|---|---|---|
| DIY lab kit (charcoal or alpha track, mailed to a lab) | about $20–$30 [PA-1] | First test in your own home; checking after a system is installed | Follow the instructions exactly. Results take days to come back from the lab. |
| Professional test (certified tester, often with a continuous monitor) | about $150–$700 [ANGI]; Colorado’s health department cites about $150 [CO-1] | Home sales, disputes, very high results | Make sure the tester is certified or licensed where your state requires it. |
| Digital monitor (consumer electronic device) | One-time purchase | Ongoing peace of mind, checking that a system keeps working | Consumer monitors aren’t certified by the national programs [NRSB]. Use a lab kit or professional test for decisions. |
Short-term vs long-term
- Short-term tests run for 2 to 90 days. They’re quick but less likely to show your year-round average [EPA-2].
- Long-term tests run for more than 90 days and give a better picture of your average [EPA-2].
- For the follow-up steps after a high short-term result, see what your number means.
Getting an accurate DIY result
The EPA and state programs give the same basic rules [EPA-2][OH-1]:
- Test in the lowest level you use or could use as living space.
- Keep windows and outside doors closed for 12 hours before and during a short-term test, apart from normal coming and going.
- Put the kit about 20 inches or more above the floor, away from exterior walls, windows, drafts, sump pits, kitchens, bathrooms and laundry rooms [OH-1].
- Don’t move or disturb the kit, and mail it back right away.
When to hire a professional
- You’re buying or selling. The other side is more likely to accept a test by a certified or licensed tester, and Ohio’s health department advises buyers not to accept a seller’s own test unless they can show it followed state rules [OH-1].
- Your first result was high and you want a fast, reliable second opinion.
- After mitigation, the EPA suggests an independent test to avoid a conflict of interest [EPA-3].
Digital monitors
Consumer electronic monitors plug in or run on batteries and show a running average. They’re useful for watching trends and checking your system. The NRSB notes these devices haven’t been evaluated or approved by the NRSB, and that there’s no national certification for consumer devices [NRSB].