3. AC Electric Field Testing
Turn on the field meter and set the switch "Field Type" to "E" for
AC electric field. (Picture 14)
Set the switch for the frequency filter to "50 Hz to 400 kHz". Thus
self-inductions due to micromovements (shaking of hand) will be
suppressed. (Picture 14)
Picture 14
During testing always ensure that the grounding lead runs to the
back of the case and that the person performing the survey as
well as anybody else present are located behind the field meter.
Keep the field meter close to your body. The further away you hold the instrument or if it is even
put down, the falsely higher the testing results tend to become. Either point to the suspected field
source or - if no such concrete source is known - check the space systematically. Proceed as fol-
lows:
- First of all, move slowly through the room to be measured.
- Stop frequently and take measurements pointing to the back, to the left, to the right and to the
ceiling. Always keep in mind to have the grounding lead run to the back of the instrument.
- Follow into the direction of the highest reading in order to identify the field source.
- In areas where people spend substantial amounts of time such as in bed or at a workplace,
check all directions as mentioned above and make note of the orientation of the field meter at
maximum readings. In such a position, a reference measurement of the absolute value should
be taken as close to the body as possible.
- After having checked all directions, the maximum measurement value can be used as a first
approximation of the resultant field strength.(See footnote 1))
When the field meter is placed on a tripod or on a table, it is necessary to also place a person 5
cm (2") behind the instrument to obtain accurate measurements. For reproducible measurements,
a metal plate (50 cm x 50 cm) is required to be orthogonal and centered 5 cm behind the instru-
ment.
An EMR survey of sleeping areas should also include measurements under "sleep conditions,"
that is bedside lamp turned off. Under certain circumstances the electric field can even increase
after something was turned off.
Recommended Exposure Limit up to 2 kHz:
Below 10 V/m, better yet below 1 V/m.
(For frequencies above 2 kHz always below 1 V/m)
11
© by
GIGAHERTZ SOLUTIONS
®
GmbH, 90579 Langenzenn, www.gigahertz-solutions.com
Measurement Instructions
GIGAHERTZ
SOLUTIONS
R
