Are these radon results fubar?

[William Thacker]

Originally Posted by fcarey

Hi Bill,
Sorry that I haven't responded (actually busy the last few days).
I only count the last 48 if I leave it for longer periods. I have only had to do this on two occasions when I first started out. Now I tell the client and realtor to have the house closed or someone is paying double. Haven't had that situation since.
Wayne is something else isn't he?

Hi Frank,

I've been busy too......hope it is a sign of things to come.

With spring hopefully on the way, today's snowstorm not withstanding, I expect to see windows open now and again until A/C season begins. For homes without A/C...it is another story. I simply make it a 3 day test because who is going to pay for an extra invoice? Certainly not the buyer, doubtfully the agent and good luck with the seller.

And yes, Wayne was most courteous and technically astute, as is my own guru, whom I also spoke with today as well. I am sure I would use Wayne's services if I were nearer to Scranton.

Any luck tracking down a spare detector? Try searching ebay for "sun nuclear". There are several detectors up for sale this week. Just be mindful of the calibration fee that will need to factored in.

[Frank J. Carey]

I am bidding on three for the last few days...
hopefully no one else jumps in.. hint hint if you're reading this...
Wayne calibrates as well and he is only 20 minutes away. and respectfully priced lower than most.

[William Thacker]

Frank,

Don't keep bidding up the price, although others will. Set your own upper limit price and try to snipe those machines at the end, if you are around at the end of the auction. There are even sniping services out there to do that too.

Good Luck to you on the auction.

[Chris D. Duphily]

Originally Posted by wthacker

I had a lengthy telephone conversation with Mr. Gemmill today. He was quite helpful and I would recommend him. Mr. Gemmill confirmed that a 60 hour exposure is not a protocol test. As far as if a 46 or 48 hour test is proper, he would rather defer to what the position of the PA DEP is, as there is ambiguity in the EPA protocols that govern radon testing. I called the DEP today and so far have received a less than certain reply to that question.

Sorry Bill, Wayne and the EPA state anything over 48 hours is acceptable (noting why the test was extended). More time = good.

Glad your re-test cleared up the confusion. All the best for a prosperous and safe 09.

[William Thacker]

Originally Posted by cduphily

Sorry Bill, Wayne and the EPA state anything over 48 hours is acceptable (noting why the test was extended). More time = good.

Glad your re-test cleared up the confusion. All the best for a prosperous and safe 09.

Thanks Chris,

I hope you are getting busy as well and stay safe always.

The way I interpret it is the you have 48 hours plus 2 hours grace period. Single test option with a CRM protocol does not say plus or minus two hours. It says a 48 hours minimum. Another protocol allows a 2 hour grace period, it does not say plus or minus two hours.

After that, protocol only allows for increments of 24 hours, making a 60 hour test not valid. I'll only extend a test if closed house conditions are not met or some other calamity produces invalid radon test results. And in that case I simply begin a new 48 hour test. A waste of 48 hours of detector time.

More time = waste of resources. A CRM will integrate so well that the 24 average will be consistent with a 48 hour average. Long ago, radon tests were performed for 24 hours, but the charcoal folks could not produce reliable results in a 24 hour exposure.

There is no need to note why the test was extended by protocol. I've had 3 day exposures purely for convenience.

What is required to be reported by protocol:

• The start times and dates for the measurement.

• Whether the standardized test conditions are met.

• The exact location of the detector, on a diagram of the room or building if possible.

• Other easily obtained information that may be useful, type of building, existance of crawl space or basement, occupants smoking habits, operation of humidifiers, air filters, electrostatic precipatators and clothes dryers.

• Serial number and manufacturer of the detector along with a code number or description which uniquely identifies customer, building, room and sampling position.

• The condition (open or closed) of any crawl space vents.

• Upon retrieval of the the detector the operator should note whether closed building condtions are still in effect.

• Plus what the DEP requires.

I was audited and pinged for the crawl space vent position although I had no crawl space vents.

I did not make up these requirements as they are in the EPA protocols. If you can get someone at the DEP to commit in writing their interpretation of protocol please let me know.

And again, this is only my interpretation and it is what my State approved QAP has as SOP, so I am restricted to what it specifies. I know a 48 hour test is legally defensible. I have my reservations about anything less than 48 hours.

All The Best,

[William Thacker]

Originally Posted by fcarey

I am bidding on three for the last few days...
hopefully no one else jumps in.. hint hint if you're reading this...
Wayne calibrates as well and he is only 20 minutes away. and respectfully priced lower than most.

Any Luck Frank?

[Frank J. Carey]

I grabbed one thankfully. The one that I originally wanted was grabbed while I was on an inspection. Beggars can't be choosers. I will patiently wait for around 5 months and get another, so I can stagger my calibrations better for the side by sides.

[Mark Nahrgang]

Originally Posted by wthacker

The CRMs will record 90 intervals. The average and current values continue to update. On a loss of power, the partial hour value is removed from the average and the current value is lost.

The machine will issue an average based on all hourly results and the EPA average which is with the first four hours removed. The detector must be exposed for 48 hours in order to have the minimum 44 contiguous hours to produce a valid test.

FYI - The co-located test with the machine produced results with a RPD of 1.4%.

And this is how the machine is designed to work. I recently left a machine in a home well in excess of the 90 intervals saved. The reported values was the value that the machine gave me. Not the most recent 48 hours. The 48 hour "standard" is a minimum. Short term tests can be longer. And the longer they are the better the reading is, because there is more data to go off of. Individual spike or other anomalies are (for the most part) averaged out. Sometimes though, when you get an outlier of a reading of 500 pCi/L in an otherwise normal test, you just have to have a do over.

The only times I disregard earlier values is if the home isn't closed when I get there. I close the house up, leave the monitor for 60 hours (12 hours equalization, 48 hours for the test), and do the analysis.

Something everyone should know about the Sun monitors. The hourly reading that is reported, is actually a rounded average. The sun takes 2 to 3 readings an hour, averages those values, rounds it to one decimal place and stores it. The final value it gives you isn't the average of the hourly averages. It is the average of ALL the readings. That average is then rounded to one decimal place.

That is significant, because if you take all the reported values, add them up and take their average, it very likely won't be exactly the same number as it reports as the actual average. So by doing that, you are really giving the client an inaccurate value because there is no way to retrieve the actual readings.

I discovered this when I reported a 4.0 average on a home owned by an engineer. He did his own math and came up with 3.8 as the value. After doing some research and talking to techs at Sun Nuclear, I learned how it worked. This is also why, unless there is evidence of tampering, I no longer deliver the hourly values with my report, just the final values.

[William Thacker]

Originally Posted by mnahrgang

And this is how the machine is designed to work. I recently left a machine in a home well in excess of the 90 intervals saved. The reported values was the value that the machine gave me. Not the most recent 48 hours. The 48 hour "standard" is a minimum. Short term tests can be longer. And the longer they are the better the reading is, because there is more data to go off of. Individual spike or other anomalies are (for the most part) averaged out. Sometimes though, when you get an outlier of a reading of 500 pCi/L in an otherwise normal test, you just have to have a do over.

The only times I disregard earlier values is if the home isn't closed when I get there. I close the house up, leave the monitor for 60 hours (12 hours equalization, 48 hours for the test), and do the analysis.

Something everyone should know about the Sun monitors. The hourly reading that is reported, is actually a rounded average. The sun takes 2 to 3 readings an hour, averages those values, rounds it to one decimal place and stores it. The final value it gives you isn't the average of the hourly averages. It is the average of ALL the readings. That average is then rounded to one decimal place.

That is significant, because if you take all the reported values, add them up and take their average, it very likely won't be exactly the same number as it reports as the actual average. So by doing that, you are really giving the client an inaccurate value because there is no way to retrieve the actual readings.

I discovered this when I reported a 4.0 average on a home owned by an engineer. He did his own math and came up with 3.8 as the value. After doing some research and talking to techs at Sun Nuclear, I learned how it worked. This is also why, unless there is evidence of tampering, I no longer deliver the hourly values with my report, just the final values.

Hi Mark,

The anomalies I experienced I can not explain. Several subsequent co-located tests shows the CRM is tracking with the other. Either the windy conditions affected radon transport into the home or some other mysterious condition manifested itself that weekend.

A 60 hour test is not protocol. Protocol only allows for exposures in 24 hour increments. A longer test is not really any better for the average. If you calculate the first day of data, it will average out to a value very similar to a 48 hour average, especially if radon levels are somewhat elevated. More data is a waste of detector time, unless you have an extended test due to closed house conditions not being met at the start of the test or it is left for more than 48 hours for convenience. Radon tests used to be conducted for 24 hours until the charcoal folks convinced the EPA that 24 hours was insufficient for AC.

And 4.0 pCi/L is not a safe level. It was established in the early 1970's by a newly formed EPA because that was the level that technology at the time could remediate below.

The CRM will integrate each detected alpha decay, (and the yellow LED will blink) into the displayed current reading. The average display is an average of the current 12 hour period. The decimal place is dropped after the levels go triple digit. (Some in my area are that high)

For those in PA, if you have a test result greater than 100 pCi/L, the DEP will provide the homeowner with a free AC canister for confirmation.

Also if you have an active mitigation system installed, the DEP provides a free alpha track detector to the homeowner.

I agree with you Mark. I've never provided the tape to the client personally either. I provide a one page report with the average that I report to the State. (The report is approved by the DEP). Besides that, I use a calibration factor and that will make the reported level different than the machine average.

A 48 hour test is only a 2 day snapshot of levels. If levels are very close to 4.0 pCi/L, it may not be indicative of a true year round average. I really would rather see a level much less than 4.0 or much higher than 4.0.

Have a good day....Spring is on it's way!

[William Thacker]

Originally Posted by fcarey

I grabbed one thankfully. The one that I originally wanted was grabbed while I was on an inspection.

I'm glad you at least got one that you seem satisfied with Frank.