Environment and Site Survey Measurement
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7 Environment and Site Survey
Measurement
This chapter covers the various site survey topics related to the NMR laboratory. The mea-
surements and associated guidelines include:
• Vibrations
• Magnetic Environment
• Electromagnetic Interference: DC and AC EMF
• RF Interference
Note: The results of measurements carried-out during a site survey only reflect the specific
conditions that were present during the survey. Although these results are useful as a
reference, they would not be conclusive for the after-the-installation system performance if
one or more site conditions change. These changes may be related but not limited to
sources of vibrations and electromagnetic field and RF interference like electro-mechanical
equipment (HVAC, motors, pumps, freezers, etc.), elevators, car/bus/train traffic, power
lines, transformers, radio/TV stations and other possible RF sources.
7.1 Vibrations
External vibrations may cause field modulations in the sample cavity. This could result in vi-
bration sidebands, matched NMR signals that appear on either side of a main signal peak.
The effect of vibrations on NMR performance will depend on the type of work being carried
out, the type of system and the site building materials.
• Ideally the site should be at basement level or on the ground floor to minimize building vi-
brations.
• Possible sources of vibrations are generators, compressors, fans, machinery etc. Vibra-
tions from external sources such as cars, trains, airplanes, and construction sites can
also cause problems.
• Measuring the extent of vibrations at the magnet location is a relatively simple matter; if
you suspect a problem you should contact your local Bruker office.
• For new constructions, Bruker is enforcing a well established method of thick and large
concrete foundations.
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