Guide to EU standard 55025 (CISPR25) As/NZ standard 2557

Laplace Standards

EU standard 55025 (CISPR25)
As/NZ standard 2557

Limits and methods of measurement of radio disturbance characteristics for the protection of receivers used on board vehicles.

This standard contains limits and procedures for the measurement of radio disturbances in the frequency range of 150 KHz to 1 000 MHz. The standard applies to any electronic/electrical component intended for use in vehicles and large devices. The limits are intended to provide protection for receivers installed in a vehicle from disturbances produced by components/modules in the same vehicle. The methods and limits for a complete vehicle are in Section 2 and the methods and limits for components/modules are in Section 3 of the full standard.

The receiver types to be protected are: sound and television receivers, land mobile radio, radio telephone, amateur and citizens’ radio. For the purpose of this standard, a vehicle is a machine which is self-propelled. Vehicles include (but are not limited to) passenger cars, trucks, agricultural tractors and snow mobiles.

The limits in this standard are recommended and subject to modification as agreed between the vehicle manufacturer and the component supplier. This standard is also intended to be applied by manufacturers and suppliers of componenets and equipment which are to be added and connected to the vehicle harness or to an on-board power connector after delivery of the vehicle.

This standard does not include protection of electronic control systems from radio frequency (rf) emissions, or from transient or pulse-type voltage fluctuations. These subjects are expected to be included in ISO publications.

A. Measurement of emissions received by an antenna on the same vehicle...

With the vehicle inside a suitable screened enclosure (to avoid reception of background signals), the signals received by the vehicle’s antenna are measured with an EMC analyser.

B. Measurement of vehicle components and modules....
Conducted:

The RF conducted back down the power lead is measured with a CISPR25 LISN (Line Impedance Stabilisation Network), and from other terminals with a current probe. Frequency range 150KHz to 30MHz.

Radiated:

Specifies the use of monopole (0.15MHz to 30MHz) and biconical or log periodic (30MHz to 1000MHz) in an ALSE (absorber lined shielded enclosure) or a TEM cell (or equivalent) Frequency range 0.15MHz to 1000MHz.

The signals from the antenna, LISN or current probe are all analysed in a CISPR16 EMC analyser.

Section A requires an EMC analyser (SA1000) and suitable antenna matching circuitry with a large screened room. ... The RFG kit fulfils the analyser requirement.
Section B. The complete basic kit to cover both radiated and conducted emissions measurement in accordance with the standard, including a CISPR25 LISN, current probe, monopole antenna, RF200 broadband antenna and ERS (emissions reference source to calibrate the test site. ...RFG-3TMBC

SA1000 EMC analyser
RF200 broadband antenna
ERS
LISN

Help in the selection of the appropriate measurement techniques and automatic display of the relevant limit levels are standard features in the software provided with all Laplace EMC analysers.
Note The above is for guidance only. Refer to the published standard for definitive details, exclusions and exceptions and detailed test technique.


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