What Is Power Frequency Magnetic Field?
Network frequency magnetic field test is an immunity test in which the continuity of function is evaluated by exposing the sample to a magnetic field of defined intensity at a frequency of 50 or 60 Hz. It is defined in IEC 61000-4-8.
Purpose of Power Frequency Magnetic Field
The purpose is to verify that devices operating close to transformers, motors and power lines operate correctly under the influence of a magnetic field.
Which Products Is Power Frequency Magnetic Field Applied To?
- Measuring devices sensitive to magnetic fields
- CRT and precision imaging equipment
- Devices with Hall sensors
- Substation and switchyard equipment
- Medical imaging assistive equipment
In Which Sectors Is Power Frequency Magnetic Field Used?
Standards Related to Power Frequency Magnetic Field
- IEC 61000-4-8
- IEC 61000-6-1
- IEC 61000-6-2
- IEC 60601-1-2electromagnetic compatibility in medical electrical devices test
Power Frequency Magnetic Field Conditions
- Frequency
- 50 Hz or 60 Hz (mains frequency)
- Field strength
- Defined in the standard; typical levels 1, 3, 10, 30, 100 A/m
- Application
- Continuous field; short-term high level can also be defined
- Axes
- Separately in three orthogonal axes
Equipment for Power Frequency Magnetic Field
- Helmholtz or inductive coil
- Current source and field calibration scheme
- Manyetik alan probu
- Function-monitoring system
Sample Requirements for Power Frequency Magnetic Field
- The sample must be placed at a defined position in the coil
- Must be tested separately in three axes
- The function-monitoring method must be defined
- Components sensitive to magnetic fields must be specified
Duration of Power Frequency Magnetic Field
Typically half a working day.
Power Frequency Magnetic Field Procedure
- 1The coil layout is established and the field strength is calibrated.
- 2The sample is placed into the coil.
- 3A continuous field of defined intensity is applied.
- 4It is repeated in three axes.
- 5Function is monitored and observations recorded.
Power Frequency Magnetic Field Acceptance Criteria
The resulting performance criterion is evaluated as A, B or C; The valid criterion is specified in the product standard.
Evaluation of Results
The axis and severity of the distortion is recorded. This information provides input for shielding design.
Power Frequency Magnetic Field Report
- Applied standard and field strength
- Frequency and axis information
- Functional observations
- Performans kriteri sonucu
Accreditation
EUROLAB holds internationally recognised accreditation obtained from accreditation bodies party to the IAF and ILAC multilateral recognition arrangements, under ISO/IEC 17025 for laboratory testing, ISO/IEC 17020 for inspection and surveillance, and ISO/IEC 17021-1 and ISO/IEC 17065 for system and product certification. This chain ensures the reports and certificates issued are accepted worldwide.
Whether this test can be offered within accredited scope depends on your product and the standard applied; since accreditation is method-based, the scope is confirmed in writing at the quotation stage.
Scope and authorisationsRelated Regulations
- EMC 2014/30/EU
- MDR 2017/745 (medical)
EMC / EMI Testleri — What Does This Testing Field Cover?
The section below describes the field that the Power Frequency Magnetic Field test belongs to; the conditions and acceptance criteria of this particular test are given in the sections above. The scope specific to your product is confirmed in writing at the quotation stage.
EMC testing answers a question with two sides: does the device emit an unacceptable level of electromagnetic interference into its surroundings (emission), and does it withstand the interference coming from them (immunity)? The two sides are measured with separate tests and separate set-ups, and both are required.
The field exists because of a simple physical fact: every conductor carrying current behaves like an antenna. A switched-mode power supply, a motor drive or the clock signal of a microcontroller radiates radio frequency energy even though it was never designed to. The same conductor also works in reverse: an external field induces a voltage across it. In an environment crowded with devices, this mutual effect means devices disturbing one another.
On the emission side, conducted and radiated emission are measured separately. Conducted emission is the interference the device imposes on its mains and communication cables and dominates at lower frequencies. Radiated emission is the field the device releases into the air and comes to the fore at higher frequencies. The two are measured in different set-ups, and the limits vary by product group.
On the immunity side, real-world sources of interference are simulated: electrostatic discharge (human touch), radiated radio frequency fields (a nearby transmitter), electrical fast transients (switching), surges (lightning and mains events), conducted radio frequency, power-frequency magnetic fields, voltage dips and short interruptions.
The standard to be applied depends on WHERE the product is used, and that choice determines the entire outcome. Residential and industrial environments carry different sets of limits; in vehicles the UNECE R10 regime applies rather than CE; for medical devices IEC 60601-1-2 brings additional requirements; and for products containing a radio, radio legislation comes into play and harmonised ETSI standards are used.
In immunity testing the acceptance criterion is a PERFORMANCE CRITERION class, not a binary pass/fail. A device continuing to function without interruption during the test, being temporarily affected and recovering by itself, or recovering only through user intervention are different classes. Which class is acceptable is defined in the product standard; the tolerance for a device carrying a safety function differs from that of a consumer device.
The most common shortcoming of an EMC file is that it covers only one side. A file carrying an emission report alone is not complete in terms of the EMC directive. The second common gap is a test set-up that does not represent actual use: if the device is measured on a bare bench with cables different from its real ones, the result does not carry over to the field.
Method groups in this field
Conducted emission
Interference imposed on the cable through mains and communication ports, measured via an artificial mains network (LISN).
Radiated emission
The field released into the air by the device, measured at a defined distance in an anechoic or semi-anechoic chamber.
Harmonics and flicker
The harmonic content of the current drawn from the mains and voltage fluctuation; the side that affects mains quality.
Electrostatic discharge
Contact and air discharge together with indirect discharge; the most frequently applied immunity test.
Radiated and conducted RF immunity
The device is exposed to a defined field strength and to an RF signal injected into the cable.
Mains-borne events
Electrical fast transients, surges, voltage dips and short interruptions.
Commonly confused in this field
- An emission report alone does not complete an EMC file; immunity must be demonstrated as well.
- An FCC report is not accepted in a CE file; the limits, measurement distances and set-ups are different.
- The EMC Directive does not apply to vehicles; the UNECE R10 regime does. Specifications requiring both together should be reviewed.
- The warning that a Class A device may cause interference in a residential environment is mandatory in the manual; market surveillance checks that this warning is present.
- The test set-up is part of the report. If cable type, length or routing changes, the result changes; measurement must be made in the series-production configuration.
- CISPR 22 and CISPR 13 have been withdrawn; their current counterparts are CISPR 32 and CISPR 35.
Which decisions these results support
- CE declaration under the EMC Directive
- The EMC part of radio equipment conformity
- A UNECE R10 file for a vehicle component
- Resolving field interference complaints and correcting the design
- Assessing the EMC impact of a board or wiring-harness change
Related Tests
Frequently Asked Questions About Power Frequency Magnetic Field
According to which standard is Power Frequency Magnetic Field made?
Power Frequency Magnetic Field is executed in scope IEC 61000-4-8, IEC 61000-6-1, IEC 61000-6-2 and IEC 60601-1-2. The limit values and acceptance criteria to be applied are defined in the product standard; The version valid for your product is confirmed in writing at the offer stage.
Which products does Power Frequency Magnetic Field apply to?
Mainly applied to Measuring devices sensitive to magnetic fields, CRT and precision imaging equipment, Devices with Hall sensors, Substation and switchyard equipment and Medical imaging assistive equipment. Whether your product is included in the scope is determined by examining its technical specifications and intended use.
Under what conditions is Power Frequency Magnetic Field done?
The determining parameters are: Frequency — 50 Hz or 60 Hz (mains frequency), Field strength — Defined in the standard; typical levels 1, 3, 10, 30, 100 A/m and Application — Continuous field; short-term high level can also be defined. The full terms are in the "Test Conditions" section on the page and vary depending on the product standard.
What kind of sample is needed for Power Frequency Magnetic Field?
The sample must be placed at a defined position in the coil, Must be tested separately in three axes and The function-monitoring method must be defined. The number of samples is determined according to the product standard and the scope to be reported.
How long does Power Frequency Magnetic Field take?
Typically half a working day. This duration belongs to the experiment itself; sample preparation, queuing and reporting are also evaluated. A realistic schedule for your product is given in the offer.
What is the Power Frequency Magnetic Field result called "appropriate"?
The resulting performance criterion is evaluated as A, B or C; The valid criterion is specified in the product standard.