Overview of Electromagnetic Field (EMF) Testing
Every time an electrical appliance and equipment is used, it becomes a source of electromagnetic field emissions. There is an increase in their exposure, and so the concern about their effects is also growing rapidly. An electromagnetic field test measures an amount of electric, magnetic and electromagnetic exposure that a product emits to its users, including the static, extremely low frequency and radio frequency fields. Thus, Electromagnetic Field (EMF) Testing is required to assess the levels of exposure and compare them against reference levels. Electromagnetic Field (EMF) Testing is crucial to establish the problem's location and magnitude when the EMF problem is visible or suspected.
The most basic sources for high electromagnetic fields include the proximity to the power lines, transformers or appliances, flaws in internal buildings' wiring systems and stray currents on utility pipes. Electromagnetic field testing is generally conducted for the following reasons:
If the proper Electromagnetic Field (EMF) testing is not done, then it can have various adverse effects on the human body. Symptoms and levels of severity from different electromagnetic field (EMF) intensities and frequencies. Any overexposure or sensitivity to Electromagnetic Field is expressed via the following symptoms:
Common Sources of Electromagnetic Fields
Followings are the common source of the Electromagnetic Field (EMF) where Electromagnetic field (EMF) testing is required:
Types of Electromagnetic Field
Following are four types of Electromagnetic Fields (EMF):
- Magnetic Field
It is caused by net current flowing and the current flowing in places it should not be, such as:
- Electric Field
The electric field is caused by building wiring being energised, and such an electric field includes voltage on the body.
Electromagnetic field from the equipment and other devices that send and receive information wirelessly. The followings create higher frequency radiation:
- Dirty Electricity
A higher frequency of transients and harmonies is found in the wiring of a building. Power supplies that convert the electricity from Alternating Current, AC to Direct Current, DC create dirty electricity.
Procedure for Electromagnetic Field (EMF) Testing
The following are the most relevant steps to be followed while conducting Electromagnetic Field (EMF) Testing:
- Development Test
This test ensures that the best possible Electromagnetic Field (EMF) performance is obtained. It is much easier to make changes at this stage, and any circuit layout, screening and other aspects of design are easily changed or modified at this stage.
- Pre-Compliance Test
It is done once a representative working model of the final equipment or device is available. Testing is generally performed at the development lab as part of the product testing programme. The main purpose of such a test is to check the performance of the complete product, equipment or device.
- Electromagnetic Field (EMF) Compliance Test
When the product, equipment or device development is complete, it is necessary to undertake a full run of the EMF compliance testing. It ensures that the product meets all the requirements with respect to the standards it is required to meet. The basic nature of the test depends on the product, equipment or device; however, it needs to be sufficient to ensure that the product conforms to all the Electromagnetic Field (EMF) standards.
- Production Test
The main Electromagnetic Field (EMF) testing enables the product, equipment or device to be sold in the market effectively without any sign of danger or harm to public health. However, there is an obligation on the manufacturer or any related person to ensure that such product, equipment or device is meeting the stated.
Checklist for Electromagnetic Field (EMF) Testing
The followings are required checklist for conducting successful Electromagnetic Field Testing:
- Stray current
It is entered into the building via water, gas and coaxial internet service lines or HVAC system. It is also measured in amperes and flux density.
- Complete Grounding system
An assessment check & measuring in mV, amperes & fundamental frequencies on each are often not in 60 Hz. This is required to check two testing, one the EGC Equipment Ground Conductor Systems and another the Overload Lightening Protection System.
- AC Magnetic Field to 30 MHz
Both indoors and outdoors are measured in the process of Electromagnetic Field (EMF) testing. The most overlooked bandwidth spectrum range is between 1-30 MHz because the equipment to measure it correctly is expensive. AC Magnetic emission from any appliances and other sources points such as power lines, risers, electrical conduits and heating panels require to be measured.
- AC Electric Field to 60 MHz
It is measured in volts per meter, i.e., V/m, and it includes all the e-fields emitted by the undergrounded lamps and appliances along with the unshielded home electrical wiring & poorly grounded electrical distribution lines.
- DC Magnetic Field
It is measured in nanotesla (nT) with a state-of-the-art DC magnetometer used for the scientific research. Geomagnetic stress is a serious issue at a certain location, and it should not be overlooked.
- DC Electrostatic Field
It is measured for the source point identification, and it is measured in V/m for commercial inferences applications and surface voltage for those with pacemakers or heart conditions. A DC shock causes serious harm.
- Epidermal Voltage
It is measured at the workstations and sleeping areas to determine and remediate source points. Much of this work is generally done during an assessment. We measure our own epidermal voltage as a reference.
- Electromagnetic Interference
Electromagnetic Interferences, EMI are generally by mistake termed as Dirty Electricity (DE) that is measured on the phase, neutral & ground using an oscilloscope amplitude & FFT.
- Radio Frequencies
Radio Frequency is analysed in 3D with a 100% Percentage of Intercept (POI) spectrum analyser using units dBm, watts, voltage & amperage from frequencies as low as 9kHz to determine & isolate source points' directionality.
- Baseline testing
A full and final conclusive Electromagnetic Field (EMF) assessment of all emissions entering the home from the outdoors or the surrounding apartments versus which is actually produced within the home.
Frequently Asked Questions
- People with pacemakers
- Pregnant woman
- Elderly persons
- Power plants
- Production lines
- Evaluation of Electromagnetic Field (EMF) levels and exposures with comparison to action levels and Exposure limits.
- Electromagnetic Field (EMF) action plans and equipment zoning
- Information, instruction and training on Electromagnetic fields in the workplace.