Utility Requirements
H157655_1_008 65
8.5 Lighting
Operation is most convenient when the computer monitor(s) may be viewed under subdued
lighting. However, normal office lighting will be needed in other areas of the laboratory. The
most convenient arrangement is to have separately switchable lights using standard light
bulbs. Make sure that reflections from strong artificial light do not fall upon the monitor
screen. Care should also be taken to minimize reflections from sources such as windows.
• Do not direct spotlights toward the magnet; this could change the surface temperature.
• Consideration should be given to the relative placement of lights to the air conditioning
inputs, which mostly contain the temperature sensors for the air conditioners. Otherwise
the switching of lights might result in a system over-reaction and a considerable
temperature change.
• Neon lights, choke ballast, and electronic ballast are generally not recommended within a
radius of 2 meters from the magnet. LED with DC current are generally not a problem
within this range.
• Lights should not be located directly above the magnets, as it may not be possible to
service the lights.
8.6 HVAC (Heating Ventilation Air Conditioning)
Constant air pressure, temperature and humidity is crucial for high performance operation.
Ideally, an absolute room temperature of between 17-25°C should be kept.
Room should not fluctuate more than +/- 1°C per 24 hours for 300-500 MHz systems, and
+/- 0.5°C per 24 hours for 600 MHz and above, near the magnet or cabinets. Even with small
changes within this narrow range, it is essential that these are random and there is no
periodicity of temperature changes.
Air drafts, particularly those created from air conditioning or heating systems, can have
negative effects on the magnet, thus the location and orientation of air-diffusers must prevent
the air from blowing towards the magnet and spectrometer cabinet. If possible, it is
recommended to have the exhaust (air-return) closer to the NMR spectrometer equipment
(AVANCE console, UPS, CryoCooling unit, BCU-I) that releases most of the heat output into
the space. This would help with removing the heat closer to its sources and ultimately help
with the overall temperature stability in the room.
Gradients
The temperature stability guidelines above are essential for a given point in proximity to the
magnet or console. Absolute temperature values at different elevations in the room can vary
by a much greater tolerance.
Note: When NMR Lock is on and when Autoshim is used, the room should not fluctuate
more than +/- 1.5 °C per 24 hours.
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