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Microwave Leakage Measurement
The cover and cavity of the SMART System
5
are designed for durability and
reliable operation in laboratory conditions. External radiation checks are
performed on the instrument at several points in the manufacturing process to
ensure that microwave leakage is only a fraction of that permitted by U.S. law (5
mW/cm
2
).
The instrument is equipped with a safety interlock system which stops the
generation of microwave energy when the instrument cover is not securely closed.
If the interlock system fails, a monitoring mechanism will blow the fuse through
which power is supplied to the magnetron, rendering the microwave power system
inoperable.
To verify that the cover is sealing and the interlock system is working properly the
SMART System
5
should be tested for microwave leakage. To test for leakage,
operate the instrument at 100% power for 5 minutes. While it is operating, use a
federally approved microwave leakage detector such as the Holaday Model HI-
1500 and measure the microwave leakage around the cavity and at the fan grill.
Leakage should not exceed 5 mW/cm
2
. If the instrument shows excessive
microwave leakage, do not attempt further operation. Contact the CEM Service
Department or the nearest CEM subsidiary or distributor.
Microwave test meters are available from CEM Corporation. CEM does not
recommend use of inexpensive meters available in electronics stores because they
lack the necessary sensitivity to properly test an instrument for microwave
leakage.