PerkinElmer FT-IR User manual

L1050070A
PerkinElmer Ltd, Chalfont Road, Seer Green,
Beaconsfield, BUCKS, HP9 2FX, United Kingdom.
Produced in the UK.
General Purpose Optical Bench with
External LiTaO3Detector Accessory
A Spectrum 100 Series or Spectrum 400 Series FT-IR instrument can be fitted with a General
Purpose Optical Bench. The optical bench is supplied with a parabolic mirror assembly, and an
external LiTaO3detector/pre-amplifier module. The optical bench is bolted to the external
accessory bracket, which is fitted in the handhold on the right of the instrument.
Figure 1 General Purpose Optical Bench with External LiTaO3Detector
This document describes how to:
•Install a window in the right-hand external beam port;
•Fit, and remove, the optical bench;
•Fit the mirror and detector/pre-amplifier modules to the optical bench;
•Configure Spectrum or Spectrum Express software to use an external detector;
•Use Spectrum or Spectrum Express software to select the accessory;
•Optimizing the performance of the detector/pre-amplifier;
•Connect another type of detector/pre-amplifier to the instrument.
Optical bench
Mirror assembly
LiTaO3 detector /
pre-amplifier module
External
beam port
Fixing bolt
Fixing bolt
Fixing block

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Warnings and Safety Information
Electrical safety
Fitting the external beam port window requires you to open the main cover of the
spectrometer.
WARNING
Switch off the mains power supply to the spectrometer, wait 60 seconds,
and disconnect the power cable before you open the cover of the
spectrometer. This makes sure that you are safe from electrical shock and
laser radiation.
The detector/pre-amplifier module is powered by the instrument; no separate power supply is
required. The instrument has no provision for powering any other component. If necessary, you
must provide a separate power supply and ensure that the arrangement meets all the
applicable safety standards.
External electromagnetic interference and electromagnetic compatibility
The General Purpose Optical Bench with External LiTaO3Detector accessory is supplied for use
as an experimental test bed. The user-configurable nature of this product means that
PerkinElmer cannot guarantee the level of immunity to external electromagnetic interference
(EMI) or the possibility that the product may itself cause interference to other nearby
equipment. It is therefore the responsibility of the user to consider Electromagnetic
Compatibility (EMC) issues when selecting a suitable site for the system and to install any
additional EMC protection that may be required for that location.
CAUTION
Some components when mounted on the optical bench may need to be
connected to instrument earth. Connect earth leads to the underside of the
optical bench at a position in the 3 x 3 block of mounting points in the far
right corner, where the anodized surface of the underside of the bench has
been removed. No other position is suitable.
CAUTION
Disconnection of a protective earth terminal could damage the
pre-amplifier/detector module.

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Radiation emitted by the Spectrum 100/400 source
Humidity
Contamination
Safe handling
CAUTION
Caution should be exercised when the beam from an NIR source is directed
onto the external LiTaO3detector. Unless there is a suitable attenuator in
place, the detector could be permanently damaged.
CAUTION
The NIR source is a quartz halogen bulb that emits ultraviolet, visible and
infrared radiation. The majority of this energy is in the infrared region. Do not
stare into the beam produced by this bulb. For further safety and warning
information see the Spectrum 100 Series User’s Guide (L1050021) or
Spectrum 400 Series User’s Guide (L1050056). These are distributed as .pdf
files on the Spectrum Manuals CD (L1050002).
CAUTION
Never remove the window in the external beam and leave this port open to
atmosphere. If the spectrometer is fitted with KBr optics, do not exchange the
window if the humidity is >45% relative humidity.
The humidity sensitive optics will be damaged if subjected to a relative
humidity in excess of the specified level.
CAUTION
Be careful not to touch, or otherwise contaminate, sensitive optical
components such as the parabolic mirror assembly.
These precision optical devices are easily scratched and may not be easy to
clean.
WARNING
The spectrometer is a heavy precision instrument, so two people are required
for safe handling.
CAUTION
Do not attempt to lift the instrument, or to move it to another location, when
the optical bench, or any other external accessory, is attached.
The optical alignment of the external accessory bracket may be disturbed.

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Fitting and Removing the Optical Bench
In the first instance, the General Purpose Optical Bench is installed by a PerkinElmer Service
Engineer, who will install: a right-hand beam moveable mirror and any other internal parts
required; a KBr window; and an external accessory bracket in the handhold on the right of the
instrument (if not already fitted). This external accessory bracket should not be removed.
Figure 2 Handhold with external accessory bracket fitted
The optical bench should not be removed unless:
•You want to use the external beam port on the right of the instrument with a different
external accessory;
•The spectrometer must be moved to a new location.
For information about moving your spectrometer, refer to the
Spectrum 100 Series User’s
Guide
(L1050021) or Spectrum 400 Series User’s Guide (L1050056). These are distributed
as .pdf files on the
Spectrum Manuals CD (L1050002).
Before you begin, make sure you have read and understood the “Warnings and Safety
Information” beginning on page 2.
Fitting a Window in the Right-hand External Beam Port
1. Switch off the spectrometer, and then remove the power cable.
2. Undo the locks on the front of the spectrometer, and then open the main cover
.
For detailed instructions, refer to the
Advanced Maintenance section of the Spectrum 100
Series User’s Guide
(L1050021) or Spectrum 400 Series User’s Guide (L1050056). These
are distributed as .pdf files on the
Spectrum Manuals CD (L1050002).
3. Using the hexagonal wrench supplied, slacken and remove the M2.5 screws securing the
right-hand external beam port cover to the main cover.
4. Remove the beam port cover and seal. Retain for further use.

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5. Ensure the seal is fitted to the window and is correctly seated (Figure 3).
Figure 3 Seal fitted to window
6. Fit the window to the main cover from the outside in.
Ensure the seal is fully seated and the key on the window lines up with the notch in the
main cover.
Figure 4 Window installed in main cover
7. Secure the window to the main cover by fitting the screws and washers and tightening the
screws using the hexagonal wrench (Figure 4).
8. Close and secure the main cover.
9. Plug in and switch on the instrument.
Seal
Main cover
Screw and washer
Screw and washer
Screw and washer
Screw and washer
Notch and key
Notch and key
Main cover
Window

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Fitting the optical bench
Before you begin, make sure that:
•The instrument’s external beam port is fitted with a suitable window;
•There is at least 500 mm (18 inches) of free bench space to the right of the instrument;
•An external accessory bracket is fitted in the handhold on the right of the instrument;
•The spectrometer is switched off and disconnected from the power supply.
1. If necessary, remove the fixing block from the underside of the left edge of the optical
bench.
Use a suitable hexagonal key to undo the two M6 socket head bolts from the threaded
fixing positions at the near left and far left corners of the optical bench until the fixing
block is free.
2. Place a spring washer and then a plain washer on each bolt, push the M8 bolts supplied
through the plain holes in the fixing block, and then carefully align the bolts with the
threaded holes in the external accessory bracket.
Figure 5 Attaching the fixing block to the external accessory bracket
3. Use a 6 mm hexagonal key to turn each bolt until it engages in the external accessory
bracket, make sure the bolts are perpendicular to the bracket, and then carefully and
evenly tighten the bolts.
NOTE: If these bolts engage incorrectly, the accessory may be misaligned or its fixings
damaged.
Threaded fixing
point for optical
bench
Threaded fixing
point for optical
bench
M8
bolt
M8
bolt

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4. Screw the two M6 socket head bolts into the threaded fixing positions at the near-left and
far-left corners of the optical bench, align the optical bench with the fixing block, and then
carefully and evenly tighten the bolts.
Figure 6 Bench fitted to fixing block
NOTE: If these bolts engage incorrectly, the accessory may be misaligned or its fixings
damaged.
Removing the optical bench
Before you begin, make sure that:
•The spectrometer is switched off and disconnected from the power supply;
•All the components associated with the optical bench are disconnected from the
spectrometer, and that no component is powered.
1. Use a hexagonal key to carefully and evenly undo the two M6 socket head bolts from the
threaded fixing positions at the near-left and far-left corners of the optical bench until the
bench is free of the fixing block.
2. Lift the optical bench off the fixing block and carefully place it to one side.
3. Using a 6 mm hexagonal key, undo the two M8 socket head bolts that attach the fixing
block to the external accessory bracket.
The fixing block is attached to the external accessory bracket using two M8 socket head
bolts, two plain washers and two spring washers.
Do not attempt remove the accessory bracket itself.
It may be convenient to refit the fixing block to the optical bench for safe storage.
M6 bolt
M6 bolt
Detector/preamplifier
default fixing positions
Mirror module default
fixing positions

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Fitting the Detector/Pre-amplifier and Mirror Modules
Both modules are fixed to the optical bench using M6 bolts. The default fixing positions for the
pillars are marked on the optical bench; see Figure 6.
Detector/pre-amplifier module
1. Connect the earth lead from the optical bench to the detector/pre-amplifier module.
Figure 7 Detector/pre-amplifier earthing points
The earth should be connected to the underside bench at a position in the 3 x 3 block of
mounting points in the far right corner where the anodized surface has been removed. No
other position is suitable.
It should be connected to the detector/pre-amplifier module via the underside of the
circuit board on the base of the module.
See Figure 7.
2. Bolt the detector module sub-base to the optical bench using two M6 bolts.
NOTE: One of the bolt holes is easily accessible on the left side of the detector/preamplifier
module. The other is accessed through a hole drilled in the upper plate, behind the
circuit board. You should fit the bolt into the lower plate and then secure with an Allen
key, through the top plate, as shown in Figure 8.
CAUTION
Take care not to touch the detector window or any of the circuit-board
components of the detector/preamplifier module, as they may be damaged by
static electricity.
Detector/preamplifier
earthing points
Base of detector/
preamplifier module

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Figure 8 Fixing the detector/preamplifier module to the bench
3. Ensure that the detector/preamplifier module is fixed to the bench so that the detector is
facing the position on the bench where you will fit the mirror module.
Figure 9 Detector/preamplifier fitted to the bench
4. The gain adjustment potentiometer (Figure 9) allows adjustment to give an acceptable
signal level.
To ensure that some signal is present but the pre-amplifier is not overloaded when the
power is applied, turn the gain potentiometer screw fully counter-clockwise until it “clicks”
(its minimum setting) and then give it two turns clockwise.
5. Connect the detector/pre-amplifier module to the instrument EXT.R connector.
For more information about aligning the detector and adjusting the gain potentiometer setting,
see “Optimizing Performance” on page 16.
Detector
Gain adjustment
potentiometer

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Mirror module
Bolt the two pillars and cross-bar that support the parabolic mirror to the optical bench,
oriented to that the mirror faces the detector. See Figure 6 for details of fixing position.
Figure 10 Mirror assembly fitted to bench
Later, you can adjust the vertical alignment of the parabolic mirror to the detector using the
adjustment screw in the cross bar. See “Optimizing Performance” on page 16.
Configuring Spectrum or Spectrum Express Software to Use
an External Detector
The General Purpose Optical Bench with External LiTaO3Detector accessory is supported by
Spectrum version 6.3.5 (or later) for the Spectrum 400 Series Spectrometers, or Spectrum
version 6.3.3 (or later), or Spectrum Express version 1.2 (or later), for the Spectrum 100 Series
Spectrometers.
This section describes how to create a modified instrument configuration file for use with an
external detector.
NOTE: It is not necessary to power the instrument to complete this procedure.
1. Browse to C:\pel_apps\bin\
The instrument configuration file is named C*****.cfg, where ***** is the five-digit serial
number of the instrument.
The spectrometer serial number is located on its base casting, in the sample compartment,
under the sample accessory baseplate.
2. Copy the appropriate C*****.cfg file and save it as, for example, C*****.intdet
NOTE: Make sure you save this backup of the original instrument configuration file. If you
remove the optical bench, you will re-instate this file.
M6 fixing bolt
M6 fixing bolt
Vertical alignment
adjustment screw