MOOR INSTRUMENTS moorLDI2 RESEARCH USER MANUAL
119
20. MAINTENANCE
The following schedule of maintenance should be carried out on an annual basis by a suitably
qualified person. Note that only a Moor Instrument trained engineer should undertake
servicing of the imager.
Circuit diagrams and parts lists will be made available to approved service personnel upon
request.
20.1 LASER OUTPUT POWER
The laser output power of the moorLDI2-VR, HR, IR and HIR should be checked using an optical
power monitor capable of measuring 0-5mW at the specified wavelength of the imager. Both the
measurement beam (unattenuated) and the target aiming beam in an imager (the attenuated
measurement beam) if applicable, should be checked against the acceptable values stated within the
specifications section for the type of model being measured.
(Care must be taken to take account of the effect of ambient light on the power measurements). If the
power of either beam falls outside its acceptable values the equipment should not be used and should
be returned to Moor Instruments for service.
20.2 LASER BEAM PROPERTIES
Examination of the beam profile.
The laser beam follows the path through the scanner head as indicated in Figure 1 Section 1.3. It
reflects off a small mirror positioned in front of the photodetectors, and between the two convex light
collecting lenses, before being reflected from the centre of the scanning mirror, through the aperture
optical window, to the tissue surface being measured.
The beam profile can most easily be assessed if the attenuated (~200
µ
W) beam is examined when it
is incident on a white card at about 30-50cm from the aperture. The beam should have a circular
cross section and to the eye appear to have an approximate uniform intensity distribution across most
of the beam front.
The beam should maintain this appearance wherever it is positioned in the scan area. If it does not (or
there is evidence of scattering of the laser light within the scanner head) it is probable that one or
more optical components has become misaligned. This should be reported to your distributor or
directly to Moor Instruments who will arrange servicing.
20.3 MECHANICAL CHECKS
a. Check all external screws and bolts if the scan head is attached to a yoke. Tighten if
necessary. Also check the screws and bolts of the stand being used.
b. During operation of the scanner check for any unusual sounds or vibrations or jitter (sudden
acceleration or deceleration) of the laser beam which could indicate that a component is loose
or is exhibiting undue wear.
Report any perceived problems to your distributor or Moor Instruments who will arrange
servicing.
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