The detector is said to be able to measure "nuclear radiation"

The Municipal Environmental Protection Bureau announced for the first time that Beijing's radiation environmental information caused the public to pay attention to the radiation index in the living environment. Some citizens also measured electromagnetic radiation by purchasing instruments themselves. Yesterday, the reporter found that the market price of the test instrument technology is not the same and the specifications are confusing. Some people also use “nuclear radiation as a good helper” to promote sales. According to relevant professionals, it is not desirable for citizens to self-test radiation.

Detector said can measure "nuclear radiation"

Hot radiation tester, diamond reputation electromagnetic radiation detection pen, Taiwan's original electromagnetic radiation tester ... ... in Taobao enter the word "radiation", a variety of advertising slogan. After the earthquake in Japan, radiation detectors unattended on weekdays took the “nuclear radiation” ride and opened their markets. Take the electromagnetic radiation tester as an example. The price of this kind of instrument ranged from 89 yuan to over 100 yuan and up to 10,000 yuan. The price of an imported instrument that claims to be imported from Germany is 36,000 yuan. And a 198 yuan home tester actually sold 182 in one month, and there is also an electromagnetic radiation detector from Hong Kong called "a good helper for nuclear radiation." According to experts, electromagnetic radiation is composed of electric energy and magnetic energy that are jointly transferred by space and has nothing to do with nuclear radiation.

After careful observation, the technical specifications of these products are also not the same. Some instruments measure bandwidths from 50 Hz to 3000 MHz. Others have instruments with a frequency range of 50 Hz to 5000 MHz. Some manufacturers specify their own low and high frequencies. The low frequencies range from 5 Hz to 400 000 Hz. The high frequencies are 30 MHz to 2000 MHz. Not only that, instrumental errors are also different, some are 3%, some are 5%.

Professionals pointed out that the bandwidth of the tester should be selected based on the frequency of the radiation source. For the distinction between low frequency and high frequency, the division of the manufacturers is not scientific. In general, ultra-low frequencies have different limits, with more being 50 Hz or 100 Hz. The high frequencies are 100,000 to 30 megahertz, 30 to 300 trillion are ultra-high frequencies, and 300 to 300,000 megabytes are microwave frequencies.

Professional institution starts from 1500 yuan

At present, the Beijing Municipal Environmental Protection Agency does not have an affiliated unit for external testing of electromagnetic radiation. The active market is generally a third-party testing agency.

"The main test is the 'room' test 'station'." A test agency staff told reporters that most of the data they measured were used for lawsuits, there are measured high-voltage electromagnetic field near the cell, there are test equipment room and equipment, Residents living near substations or cell phone base stations also require testing of the radiation environment. They will generally measure the electric field or magnetic field intensity and power density according to the customer's location and requirements and issue a report.

The staff member also told reporters that because the personal test data did not pass the CMA national metrological certification and did not have legal effect, the residents had to ask a professional company to take the test when they went to court.

Due to professional testing, the asking price of these institutions is not low. Beijing Indoor Pollution Detection Technology Center staff revealed that they test the general starting from the three points, a point of 500 yuan, at least 1,500 yuan at a time. Another test center spectrum test center is also the same three points starting 1500 yuan. The staff also "take care" of the reporter: "If you measure personally, we can offer you a discount. If you are a developer or a property commissioner, then you should go for public prices. Naturally, you need to be expensive." It is understood that the agency has done an environmental assessment for the community. The average price is 30,000 yuan to 40,000 yuan.

Electromagnetic radiation environment has national standard

For self-test electromagnetic radiation behavior, professionals pointed out that this practice is not desirable.

An engineer at the Beijing Indoor Environmental Pollution Detection Technology Center told reporters that the testing equipment must first be verified by the China Academy of Metrology before it is used, and that it will be tested at a fixed period during use. Ensure the sensitivity of the instrument. It is impossible for the public to purchase instruments for personal inspection.

So what kind of radiation environment is normal? According to the "Electromagnetic Radiation Protection Regulations" promulgated by the Ministry of Environmental Protection, within the public's most sensitive range of 30 MHz to 3000 MHz, the electromagnetic field power density has a standard limit of 0.4 watts per square meter, which is safer than this value. . Regarding the power frequency electric field and magnetic field strength limits set by ultra-high voltage electrification, we recommend 0.1 milli-Tesla as the evaluation standard of magnetic induction intensity.

The gold engineer also suggested that various types of electromagnetic radiation testing instruments on the market are mixed, and the performance of equipment produced by different manufacturers varies greatly. And electromagnetic radiation is affected by environmental factors, even if the error is difficult to identify, the measured data is not persuasive. If there is such a need, it is recommended that the public invite qualified professional institutions to test. (Reporter Ren Min)