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Magnetic Field Cancelling Systems |
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Protecting your Investment in Electron Beam Technology |
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Frequently Asked Questions
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1.
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How much maintenance is required?
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None. In normal usage the cancelling systems should continue working without need for attention. The only exception are DC
systems that need resetting under certain circumstances, such as when the DC sensor has been moved.
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2.
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Do you have to retune the systems if the magnetic field environment changes?
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No. They automatically react to changes in both field frequency and magnitude.
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3.
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How quickly do they react to changes in the field?
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They react in 100 microseconds. But note that the meters on the front panels (which have no effect on cancelling) are not fast enough to show this.
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4.
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How are the cables installed?
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Spicer Consulting generally attaches room size cables to the wall in plastic trunking (38mm x 16mm). Where possible, the cables are routed
under the floor or above the ceiling. In newly built or refurbished sites it may be possible to bury conduit in the walls and
floor.
Where room size installations are not possible cables are mounted using cable ties to the tool's cabinet or on a specially
manufactured aluminium frame.
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5.
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How large are the cables?
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A room size installation can be up to 5 m by 5 m across, by 3 m high.
| Cable Type |
Cable Diameter |
Cable Length |
Size of Connecting Plug
(number of pins on D-type connector) |
| X |
Y |
Z |
| SC20 Room |
8.5 mm |
16 m |
16 m |
20 m |
25 |
| SC22 Room |
6.7 mm |
16 m |
16 m |
20 m |
15 |
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6.
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Do I need a Helmholtz frame?
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Not usually. Helmholtz cables are inconvenient for the user and no better than room size cables for cancelling beam movement. They are typically used for OEM installations and when other cable arrangements are not suitable.
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7.
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Can I install one system to cancel fields in a room with multiple tools?
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A separate system is required for each tool.
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8.
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Can I install two systems side by side?
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Yes, but precautions are needed. Call to discuss.
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9.
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If I install a system on one tool, do I need one on the next door tool?
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Sometimes. It depends on the individual circumstances.
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10.
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Do the trip levels affect cancelling?
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No. They only affect the level at which the Field OK light goes out and the trip indicators come on.
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11.
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Can the systems cancel the effect of lifts (elevators)?
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Yes, using the wideband DC sensor.
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12.
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This isn't true DC cancelling though is it?
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Yes, the system will permanently cancel changes from the DC field level since the last sensor reset.
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13.
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Do I need both an AC and a DC sensor with the SC20/DC?
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The Sensor SC20/DCMR has wide bandwidth (DC-10kHz)
and when used with the System SC20, the system provides DC and
AC field cancelling. You do not need an AC sensor as well.
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14.
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How many systems have been sold?
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Over 900 SC12 systems have been sold from 1996 to 2008 and over 90 of the replacement SC22 system have been sold.
Over 250 of the SC20 family of systems, comprising AC and DC systems and the SC20 fast for cancelling 9kHz magnetic fields, have been sold.
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15.
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What has happened to the SC12?
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The SC12 has been replaced by the SC22. We intend to support those sold
as long as possible.
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