<short-inter-supp-vehicle-test>
For the vehicle test, the vehicle will be positioned in a shielded room (nevertheless, measurements at open air are possible, too). The connection of the measuring receiver is made at the artificial radio at the radio mounting place.
For measurements inside the vehicle, the antennas and mounting places which are used in the production series, should be utilized. Regarding an interference-free radio reception inside the vehicle, the distance between useful signal and interference signal should be sufficiently high at the end of the antenna cable.
During the vehicle test, a maximum interference voltage will be given, which should not be exceeded at the end of the antenna cable which is closed with a resistance.
Voltage characteristics represents possible requirements. The valid values can be gathered from the respective standard, or can be determined in concordance with the EMC department.
 
Measuring methods
The measuring method describes the test equipment with which the DUT is tested regarding its interference emission. There are two typical measuring methods:
1.
 
Absorber lined chamber
2.
 
Open air
Measuring device
Here, the used measuring equipment can be described. Typical measuring equipment are, e.g., measuring receiver and spectrum analyser. The exact description of the setting of the measuring equipment should be documented after the test set-up.
 
Measuring band width
1.
 
Wide-band interference
A wide-band interference is a band width of an interference signal which is equal to or bigger than the chosen measuring band width of the interference measuring receiver.
2.
 
Narrow-band interference
A narrow-band interference is a band width of an interference signal which is smaller than the chosen measuring band width of the interference measuring receiver.
 
Frequency band
The frequency band can be designated here (e.g. long wave, medium wave, short wave, L, M, ...)
 
Frequency range
Specification of the frequency range.
 
Interference suppression level
The interference suppression level defines a value for the maximum interference voltage (see (Interference suppression levels)).
 
Operating state
The operating state defines the state of the system at which the test is performed. If the test is to be performed with various operating states, these can be grouped.
 
Additional specifications
Apart from the a.m. specifications, it is always possible to give additional specifications for a test.
Structure of a vehicle test:
Example for content:

Examples for interference suppression levels for measurings on the artificial vehicle network
Measuring method
Measuring band width
Radio frequency band
Interference suppression level
Operating states
 
Artificial network
Broadband
LW
5
Idle running
Full load
2
Artificial network
Broadband
MW
KW
4
Idle running
Full load
2
Artificial network
Broadband
UKW
3
Idle running
Full load
1
1.
 
Concluding subjective assessment of the interference suppression of ultra-high frequency range in open-air:
The interference should not be heard in the entire frequency range, station finding should not lock.
2.
 
Concluding subjective assessment of the interference suppression of long wave, medium wave and short wave range in open-air:
Radio stations which can be received well should be free of interferences.
Structure of the device description "Open air":