A aviation & planes forum. AviationBanter

If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

Go Back   Home » AviationBanter forum » rec.aviation newsgroups » General Aviation
Site Map Home Register Authors List Search Today's Posts Mark Forums Read Web Partners

EMI, EMC, tests



 
 
Thread Tools Display Modes
  #1  
Old October 16th 04, 02:54 PM
Fritz
external usenet poster
 
Posts: n/a
Default EMI, EMC, tests

can someone briefly show the difference between EMI, EMC tests?

--
Fritz
  #2  
Old October 17th 04, 09:42 AM
Alan
external usenet poster
 
Posts: n/a
Default

In message , Fritz
writes
can someone briefly show the difference between EMI, EMC tests?

Simple definitions:
ElectroMagnetic Interference (EMI) = How much (quantity) EMI does the
item under test generate.

ElectroMagnetic Compatibility (EMC) = How susceptible to interference is
the item under test.

Example 1:
A radio transmitter may have good EMC properties (i.e. It is not
generally susceptible to interference from other sources) but it
generates a lot of EMI - radio waves; (but that's what it is meant to
do). OK, this is a bit of a special case.

Example 2:
A GPS receiver is listening for very low level radio signals disguised
as noise. It needs to have good EMC properties (i.e. it is not very
susceptible) to allow it to work as intended. It might generate (from
its own internal circuits) some small amount of EMI which could effect
itself or other equipment nearby. Hence most EMC tests have a distance
in the test results, the "safe distance" it can be placed next to
another item.

This "safe distance" can be difficult to understand. However, if you
look at the compass and note the reading, then put your headset next to
the compass it will give a different reading. Now slowly move the
headset away from the compass until the compass reading is back to
normal. Measure the distance from the headset to the compass and you
have the "compass safe" distance for that particular headset/compass
combination. This is the magnetic wave safe distance. In electronics,
we use electromagnetic waves (generated by electricity, not natural
magnetic waves), but the same principle applies.

Hope that helps

--
Alan
  #3  
Old October 20th 04, 11:00 PM
Fritz
external usenet poster
 
Posts: n/a
Default

Alan wrote:

Hope that helps


Clear!

--
Fritz
 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Military looks to next round of tests for Osprey Otis Willie Military Aviation 0 September 18th 04 11:01 PM
Some airmen struggle with new fitness tests, By Charlie Coon, Stars and Stripes Otis Willie Military Aviation 0 April 11th 04 10:59 PM
Key tests for new jet set for April Otis Willie Military Aviation 0 March 25th 04 11:12 PM
Ground tests & pilot logbook. Paul Lee Home Built 13 February 12th 04 03:36 PM
New way to measure up: Air Force's revamped fitness tests start in January Otis Willie Military Aviation 0 October 23rd 03 12:21 AM


All times are GMT +1. The time now is 06:15 PM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 AviationBanter.
The comments are property of their posters.