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Wavecontrol produces professional quality instruments for measuring electromagnetic fields for radio safety applications, i.e. evaluation and control of exposure of workers and people in general to electromagnetic fields. Wavecontrol offers advice on the suitable equipment for each application, regulation, law or recommendation concerning exposure to electromagnetic fields. Wavecontrol’s offer of after-sales service includes repairs and ENAC/ILAC certified ISO 17025 calibrations. We are committed to quick response, efficacy, quality and competitive prices. We also offer in-person and webinar training and courses. Electromagnetic Safety or EM Safety refers to the exposure of people to electromagnetic fields, which must be kept below certain limits specified by law, regulations and domestic and international recommendations in that regard. “Radio Frequency Safety” or “RF Safety” refers to the exposure of people to radio frequency electromagnetic fields, which must be kept below certain limits specified by law, regulations and domestic and international recommendations in that regard. This normally concerns fields with frequencies between 3 Hz and 300 GHz. Non-ionising radiation refers to any type of electromagnetic radiation that does not carry enough energy per quantum (photon energy) to ionize atoms or molecules, that is, to completely remove an electron from an atom or molecule. It includes electric and magnetic fields, radio waves, microwaves, infrared, ultraviolet, and visible radiation. Wavecontrol LabCal is Wavecontrol’s calibration laboratory. All equipment manufactured by Wavecontrol is subjected to individual ISO/IEC 17025 certified calibration as part of the quality control process for each instrument. This is a standard operating procedure and does not involve any extra cost for the equipment. Wavecontrol LabCal is equipped with an anechoic chamber, TEM test cell, positioners, antennas, RF and low-frequency amplifiers, signal generators, watt meters, parallel plates, Helmholtz antennas, and many more instruments for calibrating field probes between 1 Hz and 18 GHz. This means that the calibration has been performed by a certified laboratory with certified personnel and procedures. Many countries have an official organization to certify laboratories for testing or calibration. Some examples are A2LA (US), CNAS (China), DAkkS (Germany), UKAS (UK), COFRAC (France), OAA (Argentina), CGCRE (Brazil), TUNAC (Tunisia), ISRAC (Israel), NABL (India), etc. That organization in Spain is ENAC, the Entidad Nacional de Acreditación, which is responsible for certifying laboratories. LabCal Wavecontrol is an ENAC certified calibration laboratory, which guarantees that its personnel are qualified, that it uses optimal criteria and procedures, and that it can produce accurate calibration figures. This link will show you the countries that are parties to the conventions so that you may check whether Wavecontrol calibrations are also official in your country: ILAC Some calibration reports present themselves as ISO 9001, which is misleading. There is no such thing as an “ISO 9001 calibration”. A calibration laboratory can only be ISO 17025 certified, as that is the standard concerning measurement laboratories. ISO 9001 is a general quality standard for enterprises. The fact that an enterprise is ISO 9001 certified does not in any way mean that its laboratory is ISO 17025 certified, i.e. its calibration facilities, personnel and procedures are not certified. Wavecontrol is an ISO 9001 certified enterprise and furthermore its laboratory is ISO 17025 certified, and it can therefore issue calibration certificates recognised by ENAC and internationally valid with the ILAC seal of approval. ICNIRP is the acronym for the International Commission on Non-ionising Radiation Protection. As an independent organization, the International Commission on Non-Ionizing Radiation Protection (ICNIRP) provides scientific advice and guidance on the health and environmental effects of non-ionizing radiation (NIR) to protect people and the environment from detrimental NIR exposure. ICNIRP gives recommendations on limiting exposure for the frequencies in the different NIR subgroups. It develops and publishes Guidelines, Statements, and reviews used by regional, national, and international radiation protection bodies, such as the World Health Organization. CENELEC is the acronym for the European Committee for Electrotechnical Standardisation, the organisation responsible for developing standards for the European Union. Its publications are the standards whose titles begin with the initials EN. IEEE is the acronym for the Institute of Electric and Electronic Engineers. Although it has its headquarters in the United States, it has members around the world. It develops standards that are applied in the US and other countries. IEC is the acronym for the International Electrotechnical Commission, which, like the two preceding organisations, develops technical standards, although at the international level. Those three organisations work wherever possible to harmonise their different standards and so facilitate their application around the world. European Directive 2013/35/EU is the new directive on worker safety and electromagnetic fields. It leads the world in protection in the workplace against a physical phenomenon that is increasingly present in people’s lives and jobs. It addresses all jobs, regardless of industry or activity, and it provides as the salient factors for:
It was published in 2013 and must be transposed to EU Member States’ domestic law by July 2016. The title of the Directive is as follows: “DIRECTIVE 2013/35/EU of the European Parliament And Of The Council of 26 June 2013on the minimum health and safety requirements regarding the exposure of workers to the risks arising from physical agents (electromagnetic fields) (20th individual Directive within the meaning of Article 16(1) of Directive 89/391/EEC) and repealing Directive 2004/40/EC.” This will depend on the applicable domestic law, but in most cases use of professional broadband measurement equipment is sufficient. The typical configurations include:
A tripod must be used so that the measurements can be taken without the user being present. In some cases, 6-minute sliding window averages and spatial averages must also be taken. This is possible with any SMP2 combination, in keeping with ICNIRP guidelines. The SMP2 complies with the EN 50492 and IEC 62232-1 standards, among others, making it ideal for this application. The measurement data can be downloaded to a PC with USB connection by means of a complete software package that allows you to:
At high frequencies, we normally find ourselves in far-field conditions. Under those conditions, the relationship between the electric field (E) and the magnetic field (H) is direct and constant, and so we only need to measure one of those values. At low frequencies, we often find ourselves in near-field conditions. In this case, we need to measure the electric field and the magnetic field separately. The SMP2+WP400 combination is ideal for such conditions, since the WP400 probe measures both the E and H fields. It also allows both simple and comprehensive measurements by means of:
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It means that the result obtained, e.g. 3 V/m in the case of an E field probe, is the result of including all the energy falling within the probe’s measurement range, i.e. if we use a WPF8 probe (100 kHz – 8 GHz), the result is the total NIR exposure within that range. It means that the device carries out FFT by means of continuous digital processing, so that it can analyse signals and their variation over time with no information loss. FFT spectral analysis produces an output similar to that of a spectrum analyser, although with certain important differences. A spectrum analyser uses analog mixing and filtering to classify the components of the signal into a continuous frequency plot. It is an analog, nonreal-time method, since it sweeps through the band of interest and that process goes on for given time, meaning that it cannot properly track a signal that varies over time. FFT spectral analysis captures the whole signal instantly. If samples are taken at a rate of twice the highest frequency (according to the Nyquist criterion), the signal can be captured with no information loss. This is accomplished with digital processing. With correct overlap processing of successive FFTs, even very short, low-amplitude events can be detected. This ability to detect very brief signals is very useful in industrial processes where signals are not continuous but instead highly variable, with brief peaks. The Weighted Peak Method is a measurement method defined by ICNIRP that allows easy real-time evaluation of compliance with limits. Some standards, such as IEC 62311, refer to this method as Time Domain Assessment. In short you do not need to do anything; the device makes all the calculations for you. ICNIRP and European Directive 2013/35/EU define limits for exposure to low-frequency electromagnetic fields. Those exposure limits are peak values over time. In the case of sinusoidal fields, those peak values are equal to the root mean square (RMS) values multiplied by the square root of 2. In the case of non-sinusoidal fields, both ICNIRP and European Directive 2013/35/EU specify that measurement of exposure must be based on the weighted peak method. The Weighted Peak Method is used for coherent non-sinusoidal signals, which may consist of distorted sinusoidal cycles or a series of non-sinusoidal pulses. In those cases, the resulting spectrum is made up of substantial harmonic components over a broad bandwidth and the waveform can show value peaks that are much higher than the RMS value. In such cases, the method of adding up the different frequency components is not suitable because, if the phase information is not taken into account, the results obtained may be too conservative (excessive overestimates). The SMP2+WP400 combination does this in real time by means of digital processing in the time domain, simultaneously for the three orthogonal field sensors making up the WP400 probe. The SMP2 complies with all standards for measurement of people’s exposure to electromagnetic fields, including: ICNIRP Guidelines, IEC 61786-1, IEC 62577, IEC 62311, IEC 62369, IEC 60601, IEC 62369-1, IEC 62110, IEC 62233, EN 50400, EN 50401, EN 50499, EN 50496, EN 50554, EN 50475, EN 50476, EN 50492, EN 50413, EN 50519, EN 50444, EN 50505, EN 50500, ECC recommendation 02(04), IEEE Std 644™-1994 (R2008), IEEE Std C95.1™-2005, IEEE Std C95.1a™-2010, IEEE Std C95.6™-2002 (R2007), etc. Yes, it can, thanks to its high-speed digital processing that ensures the ability to detect peaks of up to 1 µs. It can also detect isolated very high amplitude peaks thanks to a special self-scaling function that adapts the device’s dynamic margin (amplification) to the necessary levels. ICNIRP, as well as most exposure standards, calls for averaging of measurements over time, normally within any 6-minute window or period. If we want to evaluate all the 6-minute averages, that window needs to be a sliding window, following the rule “new sample – new average”. This technique is mentioned specifically in IEEE C95.3, ITU-T K.83, etc. When a new sample is taken, the oldest sample is eliminated and a new average is calculated, so that the result of each average can be compared with the exposure limit. The diagram below shows that the averages for period 1 and period 2 are lower than an average of 6 intermediate samples, so if we want to measure the worst case, i.e. the highest result, we need to use the sliding window technique. Some exposure standards call for measurements taken from different points and then averaged, which is referred to as the spatial average. For example, measurements may be taken at a given place at three different heights, i.e. 1.1 m, 1.5 m and 1.7 m. A measurement is taken at each of those heights and the final result will be the average of the three. The SMP2 has a function that allows this to be done automatically, not just from three points but from as many as may be necessary. The RMS value is the root mean square value of a signal that varies over time. For an alternating current signal it would be equivalent to the direct current that would produce the same power dissipation in a given load. The effective value gives us an average of the power of a signal, which is the most important factor in most cases. ICNIRP, CENELEC, IEC and IEEE all call for measurements of effective value or RMS. The SMP2 has a dedicated button for a screenshot of the device at any time. The screenshot is saved to memory whether a measurement is being made or not. All saved screenshots are accessible when consulting the data of the device, whether from the SMP2 itself or from the PC software. This is very useful for reports, giving them a very visual and up-to-date appearance. It is also useful for one-click saving of informal measurement data. Yes, the SMP2 is equipped with extraordinary PC software that allows you to:
This tool is highly appreciated by users who have to create high-quality reports quickly. You do not need to connect to any external GPS because the SMP2 is equipped with a high-performance GPS that the user can switch on or off as they wish. This is a function that allows use of the real-time spectral analysis to set the frequency analysis at a given frequency and see its variation over time. This useful if we want to analyse a given frequency and its behaviour. No. The WP400 probe can measure both the electric field and the magnetic field, so you do not need to change the probe to measure both fields. This means lower cost and less time to take both measurements. The SMP2 can be connected by USB or fibre optics for remote control. Fibre optics can be used for laboratory applications or to avoid unwanted feedback; an F.O. to USB adapter is supplied. The USB connection is normally used for downloading data, creating reports, updating firmware, etc. The web or Internet Control Centre is a server running Wavecontrol software in a LAMP (Linux-Apache-MySQL-PHP) environment. It is delivered ready for Internet connection, to receive data from MonitEM or SMP2 devices and to post data on the Internet via a specific web page. Its two main functions are:
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MonitEM devices are equipped with the “Smart Energy” system that allows them to run smoothly on AC, solar power, or both. If both systems are used, the system is smart enough to use AC power only when necessary, optimising energy efficiency and sustainability. The international standard IEC 60529 defines IP (Ingress Protection) codes, a system for classifying degrees of environmental protection provided by the casings of electric or electronic equipment. The code is made up of two numbers: the first refers to protection against ingress of solid particles, and the second refers to ingress of water. In the case of ingress of water, 6 means that the equipment is protected against “very powerful water jets”. Level 7 then refers to “complete immersion in water”. MonitEM devices have a protection level of IP66, the highest for its class and suitable for equipment that has to work permanently outdoors. MonitEM devices communicate with the control centre by IP (Internet Protocol) via a built-in GPRS/3G modem. IP communication means that all those devices can send data simultaneously at any time. The web or Internet Control Centre is a server running Wavecontrol software in a LAMP (Linux-Apache-MySQL-PHP) environment. It is delivered ready for Internet connection, to receive data from MonitEM or SMP2 devices and to post data on the Internet via a specific web page. Its two main functions are:
MonitEM devices are low power consumption so they can usually work without sunlight for over 13 days straight. MonitEM have a very large built-in storage capacity and they can store all information locally for years. Yes. You can program the device to store all its data internally. When you want to consult the data, you can download them locally to a PC via a USB connection. You can take two basic approaches:
Recommendation ITU-T K.83 “Monitoring of Electromagnetic Fields” is a recommendation issued by the International Telecommunication Union on monitoring electromagnetic fields in connection with personal safety. The summary of the Recommendation ITU-T K.83 states as follows: "Recommendation ITU-T K.83 gives guidance on how to make long-term measurements for the monitoring of electromagnetic fields (EMF) in the selected areas that are under public concern, in order to show that EMFs are under control and under the limits. The purpose of this Recommendation is to provide for the general public clear and easily available data concerning electromagnetic field levels in the form of results of continuous measurement". MonitEM devices comply with Recommendation ITU-T K.83. ICNIRP, as well as most exposure standards, calls for averaging of measurements over time, normally within any 6-minute window or period. If we want to evaluate all the 6-minute averages, that window needs to be a sliding window, following the rule “new sample – new average”. This technique is mentioned specifically in IEEE C95.3, ITU-T K.83, etc. When a new sample is taken, the oldest sample is eliminated and a new average is calculated, so that the result of each average can be compared with the exposure limit. The diagram below shows that the averages for period 1 and period 2 are lower than an average of 6 intermediate samples, so if we want to measure the worst case, i.e. the highest result, we need to use the sliding window technique. No, because the devices transmit their data over the Internet using an IP protocol, so they can send their data, even all at once, and the server will receive the data with no difficulty. |
The compact MonitEM, or cMonitEM, is the MonitEM’s little brother, and they have much in common: they are both electromagnetic field monitoring devices, they can both work uninterruptedly and send their data regularly to a control centre, and they are both sturdy enough for outdoor use with IP 66 protection. The main differences are that the cMonitEM only works with AC power, and not solar power, since it is designed for use indoors or in outdoor locations without direct sunlight, and it only monitors specific services, such as mobile telephone or Wi-Fi signals, without taking broadband measurements. It is powered from a standard AC source. It is designed for indoor use or outdoor use at street level. Those locations usually do not have direct sunlight, so the most suitable power source is AC. The international standard IEC 60529 defines IP (Ingress Protection) codes, a system for classifying degrees of environmental protection provided by the casings of electric or electronic equipment. The code is made up of two numbers: the first refers to protection against ingress of solid particles, and the second refers to ingress of water. In the case of solid particles, 6 is the highest rating (“no ingress of dust under any circumstance”). In the case of ingress of water, 6 means that the equipment is protected against “very powerful water jets”. Level 7 then refers to “complete immersion in water”. MonitEM devices have a protection level of IP66, the highest for its class and suitable for equipment that has to work permanently outdoors. cMonitEM devices communicate with the control centre by IP (Internet Protocol) via a built-in GPRS/3G modem. IP communication means that all those devices can send data simultaneously at any time. The web or Internet Control Centre is a server running Wavecontrol software in a LAMP (Linux-Apache-MySQL-PHP) environment. It is delivered ready for Internet connection, to receive data from MonitEM or SMP2 devices and to post data on the Internet via a specific web page. Its two main functions are:
They are usually installed indoors (offices, schools, hospitals, etc.) or outdoors at street level in areas where people are normally present. On the other hand, the MonitEM model is designed for high level installation on buildings, near mobile telephone antennas. Recommendation ITU-T K.83 “Monitoring of Electromagnetic Fields” is a recommendation issued by the International Telecommunication Union on monitoring electromagnetic fields in connection with personal safety. The summary of the Recommendation ITU-T K.83 states as follows: "Recommendation ITU-T K.83 gives guidance on how to make long-term measurements for the monitoring of electromagnetic fields (EMF) in the selected areas that are under public concern, in order to show that EMFs are under control and under the limits. The purpose of this Recommendation is to provide for the general public clear and easily available data concerning electromagnetic field levels in the form of results of continuous measurement". cMonitEM devices comply with Recommendation ITU-T K.83. ICNIRP, as well as most exposure standards, calls for averaging of measurements over time, normally within any 6-minute window or period. If we want to evaluate all the 6-minute averages, that window needs to be a sliding window, following the rule “new sample – new average”. This technique is mentioned specifically in IEEE C95.3, ITU-T K.83, etc. When a new sample is taken, the oldest sample is eliminated and a new average is calculated, so that the result of each average can be compared with the exposure limit. The diagram below shows that the averages for period 1 and period 2 are lower than an average of 6 intermediate samples, so if we want to measure the worst case, i.e. the highest result, we need to use the sliding window technique. No, because the devices transmit their data over the Internet using an IP protocol, so they can send their data, even all at once, and the server will receive the data with no difficulty. |
An isotropic probe is one that measures electromagnetic radiation arriving from anywhere in space. The result does not depend on the direction of the electromagnetic field or its position. The isotropicity is not perfect, however, since response is not identical for all spatial directions. This is known as isotropy error, normally defined as ± x dB, which should be stated on the technical data sheet. The lower the figure, the smaller the measurement error. The RMS value is the root mean square value of a signal that varies over time. For an alternating current signal it would be equivalent to the direct current that would produce the same power dissipation in a given load. The effective value gives us an average of the power of a signal, which is the most important factor in most cases. ICNIRP, CENELEC, IEC and IEEE all call for measurements of effective value or RMS. A broadband probe is one that measures across its full working frequency band at once. It is useful because:
This is a built-in function of the SMP2 and MonitEM that detects and recognises a probe automatically when it is connected. The type, model and serial number of the probe is shown on the screen and in the output. You do not have to switch the device off to change the probe: you can disconnect the current probe and connect a new one, and the device will recognise and continue working with the new probe. Field probes with flat frequency response show the same response across their full frequency range. This means that they measure fields of any frequency in the same way. The flatness is not perfect, however, since response is not identical for all frequencies, and this should be stated on the technical data sheet. It is normally stated as “frequency response” or “flatness” and defined as ± x dB deviation. The lower the figure, the smaller the measurement error. Linearity is a characteristic that defines the response of the probe to different field levels. A probe should be equally responsive to all levels within its measurement range, i.e. we want the probe to respond the same to 0.5 V/m as to 100 V/m. If the response of the probe is not linear, it will measure some levels well but it will be substantially off at other levels. Linearity is not a perfect characteristic, and this should be stated on the technical data sheet for each probe, defined as ± x dB deviation. The lower the figure, the smaller the measurement error. Probe sensitivity is defined as the lowest value that it can measure. This should be stated on the technical data sheet. The temperature response of a field probe is one of the factors that we find on its technical data sheet. It refers to the different response of the probe at different temperatures. The response to a given field will not be exactly the same when measured at -10°C as at 40°C, and that difference needs to be shown correctly. It is normally defined as variation in dB per degree of temperature (x dB/°C) related to a reference temperature. Wavecontrol broadband high frequency probes have a very high attenuation, of 80 dB, at 50/60 Hz. This is very important because they are often used in situations where 50/60 Hz electric and magnetic fields are present, since that is frequency of power grids. If you do not use a probe with that degree of attenuation, your results will be masked or affected by those fields, producing incorrect values. |