The final objective is to lay down minimum requirements for the protection of workers against risks to their health and safety arising or likely to arise from exposure to electromagnetic fields during their work. Royal Decree 299/2016 has recently been published in accordance with the 2013/35/UE directive regulating the control of electromagnetic exposures.
Risks may be due to both the direct effects of electromagnetic fields on the body (thermal or non-thermal in nature) and indirect effects resulting from the presence of objects. Also, certain people may be exposed to particular risks associated with electromagnetic fields, such as those with active and/or passive implanted medical devices, medical devices and pregnant women.
Today we will focus specifically on those electromagnetic fields that cause both thermal and non-thermal effects.
According to BOE (Official State Gazette) such effects count:
This standard therefore applies to static electric fields, static magnetic fields and time-varying electric, magnetic and electromagnetic fields with frequencies ranging from 0 Hz to 300 GHz. Some of the effects are.
1. Direct biophysical effects: the effects on the human body caused directly by its presence in electromagnetic fields, among them:
- Thermal effects: such as the heating of tissues by absorbing energy from electromagnetic fields. Exposure levels depend on the field (E and H) and must be lower than the following graph:
- Non-thermal effects: such as stimulation of muscles, nerves or sensory organs; these effects may be detrimental to the physical and mental health of exposed workers; furthermore, stimulation of sensory organs may result in transient symptoms, such as vertigo or retinal phosphenes. These effects could cause temporary discomfort, alter knowledge or other brain or muscle functions and could therefore affect the worker’s ability to work safely; in short, they could pose safety risks. In this case for the low frequency ranges we have:
- Limb currents: These can be generated when the worker is exposed to electromagnetic fields of a certain level. These levels are regulated by tables 7 and 12 of Annex II and III respectively.
2. Indirect effects: effects caused by the presence of an object in an electromagnetic field which may present a risk to health or safety, such as:.
- Interference with electronic medical equipment and devices (including cardiac pacemakers and other medical devices implanted or worn in the body).
- Risk of projection of ferromagnetic objects in static magnetic fields.
- Activation of electro-explosive devices (detonators).
- Fires and explosions resulting from ignition of flammable materials by sparks caused by induced fields, contact currents or spark discharges.
- Contact currents.
The VLE (Values Exposure Limits) are defined within the directive. These units are difficult to quantify in the vast majority of cases, and that is why they define NA (Action Levels) to ensure compliance with ELVs.
There are different areas of application of this directive. Some of them are:
Activities in which workers are or may be exposed to risks arising from electromagnetic fields as a result of their work. This may pose a risk to the health and safety of workers due to known direct biophysical effects and indirect effects caused by electromagnetic fields. In addition, we must consider that there are scientifically proven links between short-term direct biophysical effects and exposure to electromagnetic fields.
These effects may be related to telecommunications, industrial processes such as welding, induction or microwave heating, chemical industry processes such as electrolysis, railways, aeronautics, defence, medicine, power generation and distribution, etc.
In Ayscom dataTec we have the necessary equipment to make this type of measurements.
Narda electromagnetic equipment in Ayscom dataTec:
- NBM are compact handheld devices.
- Measurement of electric and magnetic fields.
- The NBM-550 is capable of storing up to 5000 measurement results.
- The frequency range of the NBM-550 is from 1Hz to 90GHz.
- The frequency range of the NBM-520 is from 100KHz to 90GHz
- Frequency selective equipment for measuring field strength.
- Measurement system for fast, reliable safety.
- It allows measuring or even demodulating mobile technologies such as 3G and 4G.
- Frequency range SRM-3006 is from 9KHz to 6GHz.
- Personal monitors with LED lighting or screens to indicate exposure.
- RadMan XT and Nardalert allow you to save the data.
- The frequency range of the RadMan is from 27MHz to 40GHz.
- The frequency range of the Nardalert is from 100KHz to 100GHz.
EHP – 50F
- Selective frequency measurement system with high dynamic range. Measurement of magnetic and electric fields for both near and far field regions.
- Sensors for the three axes that provide an isotropic result.
- The frequency range of the EHP-50F is from 1Hz to 400KHz
- The frequency range of the EHP-200A is from 9KHz to 30MHz.
ELT – 400
- A device for measuring electric and magnetic fields ranging from 1Hz to 400KHz.
THM – 1176
- Measuring device for static and low frequency magnetic fields.
- Allows non-directional measurement with its Hall isotropic probe (3 axes).
- The frequency range of the THM-1176 0Hz to 1KHz.
- Isotropic probe.
- Fast measurement.
- Reliable results.
- Standard compatible.
- Very easy to use.
- Economical, lightweight and compact.
- Real-time evaluation of frequency response.
- Audible and visible alarms.
- Remote monitoring.
- User configurable alarm thresholds.