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Viewing 15 posts - 721 through 735 (of 769 total)
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  • in reply to: [Solved] Unit won’t connect from 4G network #931
    uRADMonitor
    Keymaster

    Thanks, let me know if that helps.

    in reply to: cpm -> mSv #928
    uRADMonitor
    Keymaster

    Well the dose depends on several factors, that include energy and type of radiation.
    The geiger tubes are unable to provide such information, so calculating the dose using a Geiger tube is only possible for known radiation.
    This is why their datasheets often indicate a CPM to R/h factor, but always for a specific isotope, with a discrete number of emissions (like Ra226, Cs137, Co60, etc).
    For convenience, uRADMonitor webpage shows a value in uSv/h, which is only an approximation, and should be considered so. On the other hand, the exact readings in CPM are provided, and the tube type for all measurements.

    It is know that a geiger tube also expresses a non-linear response to energy, due to the absorption coefficient of any material that increases with decreasing energy. Practically everything below 150keV will trigger a relatively higher response in a Geiger tube.

    The context for what we do here is extremely important: remember that uRADMonitor measures background radiation. This background is composed of cosmic radiation, of very high energy, and three main terrestrial components of background gammas that are K-40 1462 keV, Bi-214 1760 keV from the U decay series, and Tl-206 from the Th decay series. Smaller contributions to total background come from Pb-212 239 keV, Bi-209 609 keV, Tl-208 908 keV and Bi-214 1120 keV. The most serious non-linearity of energy response in uncompensated GM tubes occurs below 150 keV – and most of that below 100 keV – so none of the background emissions listed above will be seriously affected, nor will the majority of cosmic rays.
    The most seriously affected – and, in many ways, the most interesting – part of the background gamma spectrum that will fall within the GM tube’s most non-linear energy response region is skyshine – the radiation scattered by the air above both natural and man-made sources like particle accelerators, reactors, and high-level waste dumps. Most skyshine falls below 500 keV, and most of that below 100 keV.
    So this means that CPM to Gray/hr conversions, using manufacturers data based on either Cs-137 or Co-60 will not be too inaccurate to be of use across the natural background gamma spectrum.

    Regarding the conversion made in uRADMonitor, the following aspects have been used:
    – the uRADMonitor units send radiation measurements as CPM
    – the server calculates the approximation in Sv/h, to serve as a reference, using the CPM value and the specific tube type information.
    – any changes in this calculation will be done on the server, and doesn’t impact in any way the units already deployed

    To derive the best conversion value, the following approach has been performed, separately for all tubes used:
    – measure the background radiation in CPM, over a long time interval (>4h) and scale it against measurements in uSV/h done with calibrated dosimeters (Three have been used: Gamma Scout, Terra-P, Radex 1706)
    – measure the radiation in CPM when exposed to different radioactive samples (Th232, Cs137, Ra226), scale it against measurements done with calibrated dosimeters. Repeat for different geometries (increasing distance).
    – average the results, and compute a linear factor to use with the CPM readings.

    • This reply was modified 10 years, 9 months ago by uRADMonitor.
    in reply to: Force accept invalid header HTTP Gets #927
    uRADMonitor
    Keymaster

    Hi Ben,

    You are right. I tried mod_headers and it does a good job, but only on valid headers.

    For the 400 ones, the log is the last place where I get to see them, every attempt to handle them fails.

    @Sigitas had the idea of using a proxy between the Apache and the Internet, to filter traffic and intercept the invalid requests in an attempt to fix them.
    I find this very time consuming and I see it as a workaround for the real problem. Yet, I don’t see any other solution.

    in reply to: Nuclear places in your country(map)? #926
    uRADMonitor
    Keymaster
    in reply to: What the heck are we counting? #925
    uRADMonitor
    Keymaster

    I seem to be unable to connect to radviews.com .

    in reply to: [Solved] Unit won’t connect from 4G network #924
    uRADMonitor
    Keymaster

    @Erik, is it possible.

    The problem is the packages from both units reach the uradmonitor.com server, but they come with malformed headers (something is modifying them, maybe a proxy / antivirus / firewall, like you said). Because of the incorrect headers, the server drops these HTTP requests with HTTP 400 (bad request).

    in reply to: morning sports #918
    uRADMonitor
    Keymaster

    Nice.. there should be a prize for this 🙂

    The checksum will be changed to a more secure implementation.

    in reply to: detect and act on an incident #917
    uRADMonitor
    Keymaster

    Yes!

    We should start this discussion and decide how to handle such events / alarms.

    in reply to: Unit received and plugged in for testing #916
    uRADMonitor
    Keymaster

    I will do my best to implement everything that helps this project, so it becomes useful.

    in reply to: Temperature reading #907
    uRADMonitor
    Keymaster

    The temperature is the internal temperature of the unit, as the DS18B20 sensor is mounted inside.
    It is equal to the ambient temperature plus a few degrees added by internal electronic component heating (especially the Ethernet module).

    in reply to: Unit received and plugged in for testing #906
    uRADMonitor
    Keymaster

    The “real” address pool is in plan.

    in reply to: Firmware upgrade #903
    uRADMonitor
    Keymaster

    Yup, that’s the one. Just remember to set it to 3.3V when using it with the uRADMonitor PCB.

    By default it comes configured for 5V, and there is a switch (or a resistor that needs to be cracked/unsoldered) to change it to 3.3V. There is silk print indicating this on one of the sides.

    in reply to: New servers #902
    uRADMonitor
    Keymaster

    Sounds great! I’ll just need a few more days to have an automated clone / deployment in place, and all the GIT repos.

    in reply to: [Solved] Unit won’t connect from 4G network #895
    uRADMonitor
    Keymaster

    It does look normal, but the header is missing. This results in the 400 Error code. The image shows a dash on each row. For other units there’s the user agent there.

    What’s strange is that a few days ago, 11000016 was working fine . Did anything change in the network setup?

    For Rick’s unit, 11000009 the problem was from the beginning.

    But both units worked perfectly here, while running the tests.

    in reply to: [Solved] Unit won’t connect from 4G network #891
    uRADMonitor
    Keymaster

    @Rick, the problem for 11000009:
    [Fri Dec 12 21:46:27 2014] [debug] protocol.c(792): [client 72.47.*.*] Request header field is missing ‘:’ separator: \x01\xff\xff\xff
    [Fri Dec 12 21:46:27 2014] [error] [client 72.47.*.*] request failed: error reading the headers


    @Lars
    , the problem for 11000016:
    [Fri Dec 12 21:44:42 2014] [debug] protocol.c(792): [client 178.255.*.*] Request header field is missing ‘:’ separator: /\xf3\x01\xff\xff\xff
    [Fri Dec 12 21:44:42 2014] [error] [client 178.255.*.*] request failed: error reading the headers

    • This reply was modified 10 years, 9 months ago by uRADMonitor.
Viewing 15 posts - 721 through 735 (of 769 total)