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Message boards :
Science :
Detector locations to avoid, to prevent a biased reading?
(Message 1869)
Posted 3937 days ago by jhelebrant the smoke detectors contain very small amount of Americium-241 so its activity is around 37 000 Bq, according to this source: http://www.world-nuclear.org/info/Non-Power-Nuclear-Applications/Radioisotopes/Smoke-Detectors-and-Americium/#.Udv7cpzYeqs only 0.3 micrograms. They also say: Am-241 emits low energy gamma rays of 60 keV. The Am-241 gamma dose constant of 3.14 mSv/hr at a distance of one metre from a certain amount - 37 GBq - of Am-241. This gives an annual dose at one metre of 27 µSv/yr for an average household smoke detector – around 100 times lower than the dose from natural background radiation. However, we have here a few those elements from smoke detectors in total activity about 75 000 Bq so I did a practical test with our portable detector: https://www.saic.com/products/security/pdf/gr-135_30Jun10.pdf In direct contact I got values about 0.5 microSv/h but in 1 meter distance there was nothing - I measured normal background. So I would say if the smoke detector is on the ceiling then you do not have to worry about it. :-) |
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Message boards :
Science :
Data analysis - What can you really measure?
(Message 1868)
Posted 3938 days ago by jhelebrant Hi Jason, not sure if I fully understand what you mean. However, there is it not averaging - you always have pulse count for certain time interval: sample_ID,host_ID,pulse_count,date_time,Y_coord,x_coord,sample_time,type,experimental,version 45032963,1934,9,2012-06-29 14:16:47,50.037849,14.482327,0.721,n,0,594 45037617,1934,15,2012-06-29 14:17:29,50.037849,14.482327,0.702,n,0,594 45037618,1934,18,2012-06-29 14:18:11,50.037849,14.482327,0.697,n,0,594 45037619,1934,18,2012-06-29 14:18:52,50.037849,14.482327,0.694,n,0,594 Apart from the mentioned data traffic reason there is also another one. As I know, this network was built to provide independent and volunteer radiation monitoring and warning system (although in case of some alarm from such network you should contact institutions responsible for radiation protection or police/fire fighters first). If you use short time interval to calculate the dose rate (usually microGrays or microSieverts per hour) with low sensitivity small geiger tubes (the SBM-20 have lower sensitivity to background values), then your dose rate values varies much - you can see it on older data. If you collect counts for too short period you have too less data to calculate the dose rate "reasonably accurately". And be sure, that most radiation warning sensor networks use 10 minutes and longer intervals not because of the data traffic. Finally, I do not think there is a reason to have recorded each count + time value. Using 4 minutes interval to collect counts and also to calculate the dose rate can reduce false trends in data. |
13)
Message boards :
Science :
Detector behavior in high dose rate levels
(Message 1717)
Posted 4006 days ago by jhelebrant Thanks for suggestion. I moved the source to the other side and the results are much better. Okay, there are some differences in results, but according to my colleague even a small difference in distance has a big influence in this case. However, very positive and important result for us is that the detector does not have problems with measuring such high dose rates. We already tested some other sensors (but with the same GM tube) and they had problems. |
14)
Message boards :
Cafe :
Problem with detector on linux
(Message 1713)
Posted 4008 days ago by jhelebrant Hi, I am trying to get one of my detector working on linux. First I had problem with the Error 417, which I solved using the cc_config.xml file in /home/jan_helebrant/BOINC: <cc_config> <options> <http_1_0>1</http_1_0> </options> </cc_config> However, I still do not send any data to the server and still see 0% progress, although it looks to be ok: Po 29. duben 2013, 14:43:43 CEST | | Starting BOINC client version 7.0.28 for i686-pc-linux-gnu Po 29. duben 2013, 14:43:43 CEST | | log flags: file_xfer, sched_ops, task Po 29. duben 2013, 14:43:43 CEST | | Libraries: libcurl/7.29.0 OpenSSL/1.0.1c zlib/1.2.7 libidn/1.25 librtmp/2.3 Po 29. duben 2013, 14:43:43 CEST | | Data directory: /home/jan_helebrant/BOINC Po 29. duben 2013, 14:43:43 CEST | | Processor: 4 GenuineIntel Intel(R) Core(TM) i3 CPU M 350 @ 2.27GHz [Family 6 Model 37 Stepping 5] Po 29. duben 2013, 14:43:43 CEST | | Processor: 3.00 MB cache Po 29. duben 2013, 14:43:43 CEST | | Processor features: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe nx rdtscp lm constant_tsc arch_perfmon pebs bts xtopology nonstop_tsc aperfmperf pni dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm pcid sse4_1 sse4_2 popcnt lahf_lm arat dtherm tpr_shadow vnmi flexpriority ept vpid Po 29. duben 2013, 14:43:43 CEST | | OS: Linux: 3.8.0-19-generic Po 29. duben 2013, 14:43:43 CEST | | Memory: 1.84 GB physical, 3.90 GB virtual Po 29. duben 2013, 14:43:43 CEST | | Disk: 82.64 GB total, 63.07 GB free Po 29. duben 2013, 14:43:43 CEST | | Local time is UTC +2 hours Po 29. duben 2013, 14:43:43 CEST | | No usable GPUs found Po 29. duben 2013, 14:43:43 CEST | Radioactive@Home | URL http://radioactiveathome.org/boinc/; Computer ID not assigned yet; resource share 100 Po 29. duben 2013, 14:43:43 CEST | | No general preferences found - using defaults Po 29. duben 2013, 14:43:43 CEST | | Preferences: Po 29. duben 2013, 14:43:43 CEST | | max memory usage when active: 940.02MB Po 29. duben 2013, 14:43:43 CEST | | max memory usage when idle: 1692.04MB Po 29. duben 2013, 14:43:43 CEST | | max disk usage: 10.00GB Po 29. duben 2013, 14:43:43 CEST | | don't use GPU while active Po 29. duben 2013, 14:43:43 CEST | | suspend work if non-BOINC CPU load exceeds 25 % Po 29. duben 2013, 14:43:43 CEST | | (to change preferences, visit the web site of an attached project, or select Preferences in the Manager) Po 29. duben 2013, 14:43:43 CEST | | Not using a proxy Po 29. duben 2013, 14:44:04 CEST | Radioactive@Home | update requested by user Po 29. duben 2013, 14:44:08 CEST | Radioactive@Home | Sending scheduler request: Requested by user. Po 29. duben 2013, 14:44:08 CEST | Radioactive@Home | Requesting new tasks for CPU Po 29. duben 2013, 14:44:09 CEST | Radioactive@Home | Scheduler request completed: got 1 new tasks Po 29. duben 2013, 14:44:09 CEST | Radioactive@Home | New computer location: work Po 29. duben 2013, 14:44:11 CEST | Radioactive@Home | Started download of radac_1.73_i686-pc-linux-gnu__nci Po 29. duben 2013, 14:44:11 CEST | Radioactive@Home | Started download of sensors_linux_1.73.xml Po 29. duben 2013, 14:44:12 CEST | Radioactive@Home | Finished download of radac_1.73_i686-pc-linux-gnu__nci Po 29. duben 2013, 14:44:12 CEST | Radioactive@Home | Finished download of sensors_linux_1.73.xml Po 29. duben 2013, 14:44:12 CEST | Radioactive@Home | Starting task sample_1738013_0 using radac version 173 (nci) in slot 0 I also looked in /home/jan_helebrant/BOINC/slots/0 and found file stderr.txt containing many errors like this: Radac $Rev: 560 $ starting... Warning: cannot query manufacturer for device: error sending control message: Operation not permitted Could not find any of the devices listed in sensors.xml: Device communication error Warning: cannot query manufacturer for device: error sending control message: Operation not permitted Warning: cannot query manufacturer for device: error sending control message: Operation not permitted Warning: cannot query manufacturer for device: error sending control message: Operation not permitted Warning: cannot query manufacturer for device: error sending control message: Operation not permitted[/quote] I googled this thread and via Google Translate followed some advices but I have no idea what is wrong. I can see the device correctly: Bus 002 Device 005: ID 04d8:f6fe Microchip Technology, Inc. and have the same also in sensors.xml: <sensor> <comment>3.01</comment> <hardware_id>04d8:f6fe</hardware_id> <revision>769</revision> <revision_bcd>3.01</revision_bcd> <vendor>microchip</vendor> <product>radioactiveathome.org GRS</product> <usb_protocol>1</usb_protocol> <options> <switch_gmsupply>1</switch_gmsupply> <reset_counters>1</reset_counters> <switch_buzzer>0</switch_buzzer> <switch_backlight>0</switch_backlight> </options> Any idea what could be wrong? Thanks |
15)
Message boards :
Science :
Data analysis - What can you really measure?
(Message 1708)
Posted 4013 days ago by jhelebrant Hi TJM, we also wanted to recommend to increase the sampling time. Not only because of the database, but also for improving the measurement quality. In our sensor networks we mostly use 10 minute sampling interval which seems to be the best compromise for stationary measuring stations. I played a little bit with the radioactive@home data from some selected stations and longer sampling interval decreases the value fluctuations very much. |
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Message boards :
Science :
Detector behavior in high dose rate levels
(Message 1704)
Posted 4016 days ago by jhelebrant Hi, we did some testing of the detector using 226Ra source (so called radium needle) with activity approx. 3.5 MBq. However the detector seems to show much smaller values: link to better quality image Are there any display limit for measurements or is the problem of electronics? As I know, the GM tube can measure up to miliSieverts per hour. thanks PS: going to continue in testing[/img] |
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Message boards :
Number crunching :
Is it possible to log data when in experimental mode?
(Message 1691)
Posted 4022 days ago by jhelebrant hi, we would like to test the detector behavior in higher dose rate levels. I have the detector set to experimental mode (of course) but would like to log the data somehow. We need them for further analyses. As I know, those data are not saved in Radioactive@home database, so I need probably to catch them during sending or directly from the device. I was able to identify the device using USB Device Viewer: Device Descriptor: bcdUSB: 0x0110 bDeviceClass: 0x00 bDeviceSubClass: 0x00 bDeviceProtocol: 0x00 bMaxPacketSize0: 0x08 (8) idVendor: 0x04D8 (Microchip Technology Inc.) idProduct: 0xF6FE bcdDevice: 0x0301 iManufacturer: 0x01 0x0409: "microchip" iProduct: 0x02 0x0409: "radioactiveathome.org GRS" iSerialNumber: 0x00 bNumConfigurations: 0x01 ConnectionStatus: DeviceConnected Current Config Value: 0x01 Device Bus Speed: Full Device Address: 0x01 Open Pipes: 1 Endpoint Descriptor: bEndpointAddress: 0x81 IN Transfer Type: Interrupt wMaxPacketSize: 0x0008 (8) bInterval: 0x64 Configuration Descriptor: wTotalLength: 0x0022 bNumInterfaces: 0x01 bConfigurationValue: 0x01 iConfiguration: 0x00 bmAttributes: 0x80 (Bus Powered ) MaxPower: 0x32 (100 Ma) Interface Descriptor: bInterfaceNumber: 0x00 bAlternateSetting: 0x00 bNumEndpoints: 0x01 bInterfaceClass: 0x03 (HID) bInterfaceSubClass: 0x00 bInterfaceProtocol: 0x00 iInterface: 0x00 HID Descriptor: bcdHID: 0x0101 bCountryCode: 0x00 bNumDescriptors: 0x01 bDescriptorType: 0x22 wDescriptorLength: 0x0016 Endpoint Descriptor: bEndpointAddress: 0x81 IN Transfer Type: Interrupt wMaxPacketSize: 0x0008 (8) bInterval: 0x64 and maybe I would be able to log it using something like SnoopyPro, but would be better if there is a more comfortable approach. thanks |
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Message boards :
News :
About our HUGE delay...
(Message 1645)
Posted 4072 days ago by jhelebrant In our case the order was only 2 detectors (ordered and paid in August 2012) - for testing (could be much more in future), but we would also appreciate some news in this case. It is not necessary to have detailed info about particular orders, but would be nice to know at least something like "we already shipped bunch of XYZ detectors and XY % paid during "some month" 2012 will be shipped this month." thanks |
19)
Message boards :
Science :
detector testing with real radioactive sources
(Message 1515)
Posted 4144 days ago by jhelebrant Hi guys, when talking about testing with real sources, I can also help as I work in National radiation protection institute (SURO) in Prague, Czech Republic. We ordered 2 detectors this August/September and we are going to perform a tests using various sources as soon as we will get them. Currently we are testing slightly different Libelium Waspmote platform (almost based on Arduino) and in our case we were not able to measure more than about 120 microSv/h using the SBM-20, while with the Chinese J305 we were able to go to about 170 microSv/h. You can see some of our results here. Our colleague said that the SBM-20 is simply saturated and that we should have to apply some shielding to shift the measuring range to higher dose rate levels. We want to try almost the same with radiactive@home detectors and we are very curious. :-) |
20)
Message boards :
News :
Orders confirmation email
(Message 1513)
Posted 4144 days ago by jhelebrant Hi, I got the email on 19. 8. 2012. Now it is 14.12. and detectors not here yet. I think I successfully confirmed the number of detectors (2) and the shipping address. Now I am a little bit nervous if you have received the confirmation and the delay is caused by your technical problems and terrible workload at the end of the year or whether there is another problems on your or on my side. Would be nice if you could let me know. If this is related with the general delay and I will know it, it is not problem for me. I just do not want to miss something. regards Jan |