We know that with this external probes and the sleeve method with this external probe that are reused and opened to possible contamination from reused, that they need to be verified for calibration.
Currently, the ASTM F2170 Standard calls-out for verification of calibration of these external probe methods within 30 days of its use, that's probably go to 90 days. But regardless, we've also seen that just trying to verify the calibration of these external probes is not easy.
We saw an example of a manufacturer's calibration set-up to allow verification of the calibration of these probes. It's a tedious process and if it comes down to actually calibration, a user in the field cannot calibrate the probes and in fact again a review if a probes falls-out of calibration, often it's just cheaper to buy another probe. Verifying calibration is not a trivial matter but verifying calibration can be a very tedious procedure.
The Rapid RH comes NIST traceable. It is traceable. Its calibration is traceable to the National Institute of Standards and Testing. It is not reused and because of that it does not get contaminated because what happens when a probe becomes contaminated it begins to re-down scale. That's a major problem.
And a lot of field applications, I've had the opportunity to talk with people using the Rapid RH where other testing firms have come in behind them using alternate methods for testing relative humidity. The problem is with these methods they have not shown that they have been verified for calibration and they're often reading very, very low. There are other reasons for that; they could have nothing to do with calibration. But, not having that calibration verification shown on the documentation makes them dead on the water from the get-go.
The Rapid RH does not have that problem again because they come from the factory traceable to the National Institute of Standards and Technology. And that calibration certification is good for two-year period of time. So these Rapid RH probes do not have to be verified for calibration, they go in a hole, they're not prone to contamination from reuse, so you know you get accurate relative humidity readings traceable to a national standard. That could be very critical, if something goes array in a floor installation situation and you have to go on in a stand in the court and testify that you did things properly with a certificate of calibration from the Rapid RH you can show that you done due diligence.