Safecast workshop (bGeigie-nano) in Aizu

Written by: Norio Watanabe
Safecast Volunteer from Koriyama


On a cloudy day in early summer, Safecast members and volunteers gathered in Aizu-Wakamatsu to hold a bGeigie Nano-assembling workshop. The workshop took place at the IT company Eyes, JAPAN Co., Ltd. courtesy of the company president Mr. Yamadera.
At Eyes, JAPAN in Aizu-Wakamatsu City

Through the first round of measurements by car, Safecast mostly completed the radiation map of Fukushima Prefecture in 2011. The map is available on the website. Data has been collected at 10 million points so far and is being updated every day. The radiation map is becoming more detailed as volunteers take measurements while either cycling or walking in order to measure radiation in places that cannot be accessed by car.
The bGeigie Nano is small, light and much easier to use than the original b-Geigie. It has a measuring mode and a recording mode. In measuring mode, you can take the bGeigie Nano out of the case and measure surface contamination. The measurements can be converted from CPM to Bq/m2. In recording mode, CPM measurements are recorded on the microSD card along with the GPS coordinates, the time and the name of the person taking the measurements (the owner’s name is registered in each bGeigie Nano). The data can be shared and shown on the map by uploading it onto the Safecast website.
If you have soldering experience, assembling the bGeigie Nano should be relatively easy (although, with my old eyes, some parts are difficult without a magnifier). It does not require detailed soldering of ICs for example because most of the circuit parts are provided in the form of commercially available add-on boards, called “breakouts.” All you need to do is solder resistors, capacitors, transistors, switches, connectors, and some wires. (If your kit contains any incorrect parts, I recommend that you use the opportunity to visit nearby parts shops or to communicate with a Safecast member or volunteer who has experience in making the bGeigie Nano. Both are fun experiences.)
Assembling the bGeigie Nano takes about an hour if you’re experienced. It may take half a day if you are a beginner and need guidance. The bGeigie Nano is not yet sold as a finished product, and it gives you the opportunity to enjoy learning how it works while assembling it. You will also appreciate that despite its high performance, the price of the kit is low.

文:norio watanabe
セーフキャスト 郡山ボランティア


初夏の曇り空の会津若松にSafecastのメンバーとボランティアが集結して、bGeigie Nanoの組立ワークショップが開催されました。会場はIT企業のEyes JAPAN、山寺社長の会社を会場に提供していただきました。ありがとうございます。

会津若松市内 Eyes JAPANにて

今回のbGeigie Nanoは、小型軽量で操作も初期のb-Geigieに比べて段違いに簡単になりました。測定モードと、記録モードがあり、測定モードではケースからbGeigie Nanoを取り出し、表面汚染をベクレル/平方mでも換算表示できるようになりました。記録モードではCPM単位をベースにGPSの位置情報と時刻、測定者(bGeigie Nanoには個体ごとに所持者の名前が記録されています)が、microSDカードに記録され、Safecastのサイトにアップロードするとデータの共有とデータのマップ表示が可能になります。
製作は慣れれば1時間ほどです。初心者は指導を受けながらだと半日でしょうか。完成品として市販はしていませんからbGeigie Nanoは組立ながら構造を理解する楽しみがあります。その分、性能のわりに安価で提供されています。

Assembling bGeigie Nanos

Geiger counters visualize invisible radiation. The visualization of radioactivity by mapping it not only provides the information for protecting yourself, but also helps remove anxiety about invisible radiation by learning about it.
iPhone APP「Safecast」

The visualization of measurements on the Google Earth relief map

One Geiger counter enables us to know whether radiation measurements on a specific spot are high or low as well as the distribution of different air radiation levels in the areas where we live. I think that knowing the facts removes fear and helps us to take the next steps.
The bGeigie Nano and various other radiation measuring devices

It takes some learning to get the hang of assembling the kit

Parts included in the bGeigie Nano kit

Many people in Fukushima Prefecture have been living under considerable stress due to radiation being invisible. It sometimes feels easier to “see no evil, hear no evil, speak no evil” in order to restore our pre-earthquake lives by acting as if there is no radioactivity. However, I believe that we can find ways to tackle the problem if we have the courage to find out about it.
Assembly is completed by installing the GPS board, the memory board, the OLED board, and the CPU board onto the main circuit board

The case is water-resistant. A large pancake GM tube is installed underneath the circuit boards

Completed b-Geigie Nanos

To conclude my workshop report, I want to talk a bit about why I am involved in Safecast. The reason is because those gathered at Safecast have pure spirits, innocent minds and warm hearts. The majority of active members are from overseas, they come from various different countries and have different technical backgrounds. I was touched to know that they really love Japan and try to use their skills for Japan. Safecast is a group of adults who have the curiosity of children. This is why I have been able to work with them for a long period of time, while managing to communicate with them using my Fukushima dialect instead of their languages! I really want to thank them all.
Get-together with people of various nationalities

Powerful discussions continued deep into the night

(Translation: Megumi Minami & Kevin Stride)
*** Updates from Fukushima Prefecture ***
Measurement using the original b-Geigie

Some areas in Nihonmatsu City and Motomiya City still have high levels of radiation

Flexible container bags filled with contaminated soil, etc. are placed in many places along the roads

bGeigie Nanoの製作中


iPhone APP「Safecast」

Google Earthに測定データを立体地図で見える化


いろいろな線量計とbGeigie Nano


bGeigie Nano キットの中身









*** 福島県の今 ***