jdeoliveira2
(John Paul de Oliveira, GB-2 #86934 / AB #44580)
1
The Corentium Pro sells for $1500, has 4 sensors, no sensitivity rating(probably good) and supposedly is accurate to within 7% 24 hours and 5% after a week.
Sun nuclear 1028 sells for $1000, has 2 sensors, sensitivity rating in hours instead of minutes, and is accurate to within 25%.
Sun nuclear 1027 sells for $900, has 1 sensor, and is accurate to within** ??
**25% doesn’t seem that accurate when a clients health is on the line. Does anybody have any recommendations on a quality CRM? Radstar? I would like to upgrade from canisters, which I think are accurate to within 5% (Airchek), for quicker turn around time?
This is like debating Chevy vs Ford. Everyone will have an opinion. Take a look at Radalink and compare their equipment to those you mentioned (Sun, Radstar, etc). In Illinois, a licensed state for radon, I do believe the Corentium is in the works for approval but has not as of yet made the list?
The Corentium Plus isn’t, so I don’t get how it gets labelled for professional use. Maybe it’s in that 25 % range. The 1028/7 lit says it’s based on a 1987 patent. Reading the fine print it’s the greater of 25% or +/- 1 pCi/l. Read another way that would be a Minimum of +/-1 pCi/. That reading would be better than nothing.
I called Corentium 3 times, emailed about documentation, nothing. E mailed NRPP directly, and they had nothing to say about any of the devices on their approved list.
The Radstar RS 300 sells for $900, if I read the documentation right 10%, sensitivity .27 cpm/pci/l.
Radalink Telemonitor no listed price on lease, 10%, sensitivity .33 cpm/pci/l
Radalink Aircat no listed price on lease, no information %, sensitivity .42 cpm/pci/l
Yes, everyone has an opinion, but it would be good to base it on facts.
Correct, I’ve been using them for awhile now, I also tested them against my sun 1027’s, found only negligible differences and sold off the 1027s.
Just curious what kind of radon levels do you get in NM?
jdeoliveira2
(John Paul de Oliveira, GB-2 #86934 / AB #44580)
12
Albuquerque is situated in the Rio Grande rift, a geologic subduction zone. To the East are mountains, lifted up Granite, along with newer construction and the radon levels get progressively higher close to the mountains. West of the river the houses sit on sand and the levels are usually much lower. The EPA map generally shows high levels for counties in the mountain areas of NM.
Another factor is the extensive use of evaporative coolers which act as whole house fans. It is pointless to test for radon when they are in use.
I doubt the radon detectors are much different from model to model.
Probably just the software that goes with them that generates the reports.
Highest I’ve gotten in Baltimore metro is 26.
Up near the Pa. border can get over 100.
jdeoliveira2
(John Paul de Oliveira, GB-2 #86934 / AB #44580)
14
Corentium feedback:
**Tom** (Airthings)
Nov 1, 09:41 CET
[FONT="]Hello John Paul,
first of all thank you very much for writing to us and for your input.
The CRMs that you have mentioned are all AARST/NRPP-approved, so they are suitable for professional work: their performance is good enough that an independent body certified that Home Inspectors in the US can use them.
On top of this, we are actually planning a comparison study run by a reference lab where all these monitors will be side-by-side: that would help a lot, and as soon as we have the result, I will make sure that you receive the feedback from the lab. In the meantime, please find attached a table with the information on what these machines can offer. As you can see, most of them can only offer the AARST-approval, which is ok but not enough for home Inspectors.
Let me know if there is something else you would like to know. And thanks again fro writing to us.
Best regards,
Airthings
Sales & Support, Global www.airthings.com
[/FONT]
Attachment(s) comparison.pdf
One other thought about +/- accuracy of short term radon testing.
Short term radon testing is somewhat limited in accuracy simply because it’s short term and radon fluctuates over time.
I always inform my clients of this and that if they want they can do their own long term test after they move in.
I send them to RTCA.com to purchase a 3 month test.
Thomas, you hit the nail on the head. Short term testing is only practical for real estate transactions. And it does come with a short fall, which is accuracy. Long term testing is by far the better choice for testing a home. Longer exposure + more data = better accuracy. However as we all know, the buyer wants a quick answer to determine who writes the check for the mitigation system. Thus short term testing is not going away any time soon.
When a home tests below 4.0 pCi/l I too always recommend that a customer have a long term test performed after they move in. Or at least re-test in 3 years at a different time of year. Short term testing is a snap shot in time, much like a home inspection.
I know of some colleagues that have done the side by side testing with the Correntium, RadStar, Sun, Air Cat, and E-Perms. The differences with the results are hardly negligible. IMO all the manufacturers make models which are more than suitable for home inspector use. Just be sure you are using models which incorporate tamper protection and environmental data.
You mentioned tamper resistance, which with the 1027’s I used to use that could be an issue. Though I think it’s pretty rare.
They are plug in and sizable so they are an easy target for an unscrupulous person.
Just put a bowl over it and you’ve screwed the results.
One of the things I like about the Corentium’s is they are battery powered and very small.
I usually put them up in the basement ceiling framing.
No one would ever know where it is.
I’d get my license revoked if I put a monitor up in the ceiling!
You really want it in the breathing zone. Illinois requires placement to be minimum of 20 inches from the floor, and no more than 6 feet from the floor. IMO if you put it in the ceiling you might as well just test the floor above, you aren’t getting a representative sample of the basement that way. My .02
Md goes by EPA guidelines, no state license or protocols.
More than 20" inches above the floor, yes.
In the situation I just described its in the open framing of a low basement ceiling.
Are you saying that you usually place the devices there, or only when you encounter basements with low ceilings?
Though I see your logic in placement location to protect from tampering with the device, you will find that most states with protocols, and most device manufacturers will stipulate that the device should be placed in the breathing zone. Interesting what flies in regulated vs non regulated states.
In Illinois, only the Correntium Pro has been approved for use.