輻射是一種聞不到也看不到的東西，除非你手上有蓋革計(jì)數(shù)器(Geiger counter)，不然也“聽(tīng)”不到它；但這并不能阻止日本民眾──大概是這些日子以來(lái)全世界最具輻射意識(shí)的一群人──試圖找出一種可“嗅出”輻射的方法。
在上周于日本橫濱舉行的嵌入式技術(shù)研討會(huì)(Embedded Technology conference)上，就有不少平價(jià)的個(gè)人用輻射監(jiān)測(cè)設(shè)備展出。其中一位自己經(jīng)營(yíng)設(shè)計(jì)工作室(Imaoca Engineering Office)的硬件工程師今岡(Michihiro Imaoka)，開(kāi)發(fā)出一種自制的、命名為“Imaocande”的蓋革計(jì)數(shù)器，能與Android智能手機(jī)連結(jié)，讓一般人可將自行量測(cè)到的輻射數(shù)據(jù)上傳到網(wǎng)絡(luò)“云端”，與大眾分享。
為了制作該款手持式蓋革計(jì)數(shù)器，今岡采用了透過(guò)eBay購(gòu)買、俄羅斯軍方流出的二手蓋革米勒管(Geiger-Mueller tube)；其研發(fā)成果的特色在于開(kāi)發(fā)了一個(gè)透過(guò)音訊接口與Android手機(jī)連結(jié)的系統(tǒng)。藉由智能手機(jī)已經(jīng)具備的GPS、CPU與無(wú)線連結(jié)等功能，就能將“Imaocande”所量測(cè)到的輻射信息(所測(cè)得的水準(zhǔn)值、時(shí)間與經(jīng)緯度等) “推”到網(wǎng)絡(luò)上；這些推特資料還能利用其它軟件標(biāo)記成一個(gè)輻射量觀測(cè)地圖。
照片中的今岡將一小包從福島取得的輻射土壤移近自制蓋革計(jì)數(shù)器，并聆聽(tīng)計(jì)數(shù)器所收集到的音訊脈沖v6qesmc
今岡正透過(guò)在日本舉辦一系列講座，分享如何制作“Imaocande”蓋革計(jì)數(shù)器的相關(guān)信息：“我想現(xiàn)在全日本已經(jīng)有接近100套Imaocande?！痹诒粏?wèn)到這種東拼西湊而成的蓋革計(jì)數(shù)器之準(zhǔn)確度是否可信的問(wèn)題時(shí)，他則表示：“這套設(shè)備主要是提供一種平價(jià)的個(gè)人設(shè)備，讓一般民眾可以去感受所在之處是否有輻射?！?
今岡補(bǔ)充指出，以這種個(gè)人蓋革計(jì)數(shù)器所收集的信息，能與日本氣象廳所公布的官方數(shù)計(jì)資料相比對(duì)：“這會(huì)有助于改善所收集資料的可靠度。最重要的是，民眾能藉由這樣的設(shè)備自己收集信息，而不是只能依靠政府機(jī)關(guān)或是大企業(yè)(如東京電力公司)提供信息。”他估計(jì)，“Imaocande”所需的物料清單(BoM)成本不到5,000日?qǐng)A(約65美元)，其中最貴的零件是蓋革米勒管，價(jià)格約50美元。
另外在這場(chǎng)嵌入式技術(shù)大會(huì)上，還有一家來(lái)自福島的嵌入式系統(tǒng)與軟件開(kāi)發(fā)商CA Limited，也展示了數(shù)款個(gè)人用輻射監(jiān)測(cè)裝置；這些裝置能以不同的技術(shù)與PC或是智能手機(jī)連結(jié)，包括藍(lán)牙、以太網(wǎng)絡(luò)、USB等等，發(fā)出音訊脈沖或是顯示在彩色LCD上。
日本福島廠商CA Limited所開(kāi)發(fā)的各種個(gè)人用蓋革計(jì)數(shù)器v6qesmc
CA總裁寺協(xié)(Katsuhiko Terawaki )，也是那些系統(tǒng)的研發(fā)者，親自在該公司攤位上用內(nèi)涵輻射土壤(收集自他的家鄉(xiāng)，距離福島第一核電廠不到65公里處)的小包裹示范操作其系統(tǒng)；他不諱言地指出，他覺(jué)得日本政府與整個(gè)社會(huì)一直堅(jiān)持著“輻射安全性”的謬論，迄今仍是如此。寺協(xié)表示，不久前舉行的東日本女子長(zhǎng)途接力賽(Ekiden)，刻意讓參賽者通過(guò)福島市的輻射熱區(qū)：“這完全是個(gè)愚蠢的行動(dòng)。”
在3月底，寺協(xié)撤離了位于山形(Yamagata，臨近福島)的老家，但他仍通勤到位于福島的公司上班；他坦承：“一開(kāi)始，我不敢告訴別人我棄守了福島的老家；但最近我已經(jīng)能直言不諱。雖然我無(wú)法強(qiáng)迫所有人撤離，但我不再猶豫表達(dá)自己的看法?！?
寺協(xié)指出，現(xiàn)有的大型獨(dú)立式輻射監(jiān)測(cè)系統(tǒng)──例如其它兩家福島企業(yè)Kaine與NB所開(kāi)發(fā)的系統(tǒng)──是配備了太陽(yáng)能發(fā)電板以及大型的LED顯示器，以每小時(shí)微希(micro-Sieverts per hour)為單位顯示輻射量；該類設(shè)備可安裝在特定公共場(chǎng)所，成本約100萬(wàn)日?qǐng)A(1萬(wàn)3,000美元)，但就只能監(jiān)測(cè)那個(gè)特定區(qū)域的輻射量。但包括今岡與寺協(xié)都認(rèn)為，有一些微小的輻射熱區(qū)，會(huì)是這種公用輻射監(jiān)測(cè)設(shè)備在過(guò)去忽略、未來(lái)也不會(huì)發(fā)現(xiàn)的。
因此寺協(xié)表示：“人們需要自己的輻射監(jiān)測(cè)系統(tǒng)?！彼⒃V說(shuō)自己的經(jīng)驗(yàn)：就在今年3月15日(也就是311大地震后4天)，他曾在家里聽(tīng)到自己一年前買的一臺(tái)蓋革計(jì)數(shù)器，以一分鐘60次的頻率嗶嗶叫個(gè)不停。
編譯：Judith Cheng
參考英文原文： Personal Geiger counter, anyone?，by Junko Yoshida
本文授權(quán)編譯自EE Times，版權(quán)所有，謝絕轉(zhuǎn)載
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Personal Geiger counter, anyone?
Junko Yoshida
Editor's note: To add context to the following story, please read "Forget ‘Occupy Wall Street,’ time to ‘Abandon Fukushima.’"
YOKOHAMA – Radiation is something you cannot smell or see. Unless you have your own Geiger counter, you can’t hear it, either. But that isn’t stopping the Japanese — probably the most radiation-conscious people in the world these days — from figuring out a way to “sniff it out.”
So, inevitably, Japan’s Embedded Technology conference here this week offered a variety of affordable personal radiation monitoring devices.
Michihiro Imaoka, a hardware designer running his own design house called Imaoca Engineering Office, has devised a home-made personal Geiger counter, called “Imaocande,” connected with an Android-based smartphone. It’s designed to crowd-source and tweet the collected Geiger-data to the cloud.
For its handheld personal Geiger counter, Imaoka’s company is using a second-hand Geiger-Mueller tube, bought on eBay from Red Army surplus in Russia. The real meat of his development lies in creating a system to connect it to an Android smartphone via the audio interface. By using GPS, CPU and connectivity functions already available in the smartphone, it’s possible to “tweet” the radiation data (detected level, time and longitude/latitude) collected by the Imaocande. The tweeted data can then be shared with masses, once it is mapped into a radiation map using another piece of software.
Michihiro Imaoka listens to audio pulse generated by his personal Geiger counter as he brings closer to the device a small packet of radiated soil he brought back from Fukushima
Imaoka has been sharing the information on how to build the Imaocande by offering classes throughout Japan. “I think that there are close to 100 units of Imaocande out there.”
Asked if the accuracy of a patchwork Geiger counter might be a concern, Imaoka said, “This is meant to be an affordable personal device, allowing people to sense whether where they stand now is radioactive.”
Imaoka, however, added that one can correlate data gathered by such personal Geiger counters with information released by the Japan Space Weather Information Center, using Cloud services.
“It can help improve the reliability of the collected data.” Imaoka stressed, “What’s important here is that this can offer consumers a means of gathering information without being solely dependent upon the government or big businesses [like Tokyo Electric Power Co.]”
Imaoka estimated the bill of materials for Imaocande is less than 5,000 yen ($65). “The most expensive part is a Geiger-Mueller tube – which is about $50.”
In a more conventional (corporate) vein, CA Limited, a Fukushima-based embedded system and software development company, showed off several models of personal radiation monitoring systems featuring different connectivity technologies at the Embedded Technology show. Connectivity used between the company’s personal Geiger counter and a PC and/or a smartphone ranges from Bluetooth, Ethernet, USB to pulse audio and color LCD.
A variety of personal Geiger counters developed by CA Limited, a Fukushima-based company
Katsuhiko Terawaki, CA’s president, developed the system. In his company’s booth, he demonstrated his systems by using a packet of radiated soil (which he collected from his home, located within 65 kilometers of the now-infamous Fukushima Daiichi Nuclear Power Plant).
Terawaki did not mince words about how he feels Japanese government and Japanese society has maintained a fallacy of “radiation safety” – even to this date.
Terasaki cited last weekend’s East Japan Women’s “Ekiden,” a long-distance relay running race that required female athletes to run through the radiation hot zone in Fukushima city. Terasaki called the event “nothing but an act of lunacy.”
At the end of March, Terasaki himself evacuated from his home to Yamagata, a nearby prefecture. But he commutes to his company, still based in Fukushima. He acknowledged, “At first, I was afraid to tell other people that I abandoned my home in Fukushima. But lately, I’ve been straight with them. While I can’t force people to evacuate, I no longer hesitate to express my own opinion.”
Terasaki pointed out that there are large, standalone radiation monitoring systems – such as one developed by two other Fukushima-based companies, Kaine and NR. Equipped with a solar panel to generate power and a large LED display to show the radiation level in micro-Sieverts per hour, these systems can be installed in public designated locations and cost about a million yen ($13,000). But such systems monitor certain public spaces only. Both Imaoka and Terasaki believe that there are a number of micro hotspots, previously gone unnoticed or not likely to be discovered in the future by such public radiation monitoring equipment.
Terasaki said, “People want their own personal radiation monitoring system.” He was speaking from experience, recalling March 15th (four days after the tsunami) when he heard, inside his house, a Geiger counter he had bought years ago, pulsing and beeping at a rate of 60 beeps a minute.
