Providing accurate radiation data to the public is extremely important. A larger database that includes data of substandard quality is not better than a smaller one. The decreased accuracy hinders our ability to properly detect the broader spatial and temporal trends. Therefore, I'm skeptical that it is appropriate to build a Geiger counter directly into a mobile phone, as has been done with the Sharp Pantone 5 (107SH) smartphone just announced by Softbank Mobile.
In the end, I imagine it will be no more than a gimmicky toy (the main contribution of which was increased handset sales). Here's why.
Raw counts must be converted to dose though calibration with a known source, typically Cs-137. Measurements of radiation emitted from any other radionuclide will be inherently less accurate. According to the manufacturer of the primary Geiger counter used by Safecast, the $700 Inspector Alert, this unit's dose conversions exhibit a +/- 15% accuracy, immediately subsequent to proper calibration. Over time, readings produced by any analytical equipment drift, causing reported values to become increasingly inaccurate. Therefore, the device must be periodically calibrated - preferably preemptively, as opposed to after conversions become unreliable.
Calibration frequency of any analytical equipment is dependent on application. For equipment used in public safety, local government regulations will require calibration at a set interval. When collecting data for scientific studies, analytical equipment must be calibrated prior to each usage. For quality control during use, calibration standards must be intermixed with experimental samples to detect and correct any instrumental drift.
Calibration would also be needed after any shock to the device, the kind that would be sustained by, for example, dropping a mobile phone.
Any other way of doing it is just playing around, and toys are for playing.
| 300 cpm ≈ 1.0µSv/hr ≈ 1.1Bq/cm2|
callibrated [sic] for Cs137 ± 15%
On to the phone.
The Softbank 107SH will be available from mid July. In addition to the standard WiFi, Bluetooth, and GPS, here are the major features:
- Android 4.0 Ice Cream Sandwich
- Water resistance (IPX5 and IPX7)
- Geiger counter (0.05 - 9.99 µSv/hr range)
- W-CDMA 900 MHz "Platinum Band", 1500 MHz, 2100 MHz
- One Seg TV
- Keitai Osaifu mobile payments
- Infrared port
- Earthquake warning mail (緊急速報メール) coming with a future update
- 3.7 (854×480 pixel) display
- 4GB ROM
- 1GB RAM
- 8 color choices