Firma:                   Unicam

Modell:                Mattson 3000

Kommentar:        Dokumente engl.

Galaxy Series Operating Overview

Each Galaxy series spectrometer, when operated with an attached system plotter, is a complete, stand-alone data-collection and plotting system. In addition, each Galaxy spectrometer can be operated from a computer-based data system running any of Mattson Instruments" FIRST (Fourier Infrared Software Tools) analytical software packages: U-HRST (University 1-IRSI), FIRST Macros, Enhanced FIRST or Advanced FIRST. The computer-based data system and l-;IRST analytical software package can be selected in combination to meet any FTIR need—from the most basic to the most advanced.

This Galaxy Series 3000, 5000 and 7000 FTIR Spectronwer User's Manual describes the stand-alone method of Galaxy operation, as well as the many features inherent in the Galaxy spectrometers regardless of the operating method. Detailed stand-alonc operating instructions are presented in Chapter 4. Instructions for operating the Galaxy spectrometer with an optional data system are detailed in your FIRST software user's manual. For a briet description of available FIRST software packages and related products please refer to Appendix E. For more Information regarding available Galaxy data Systems and aRST analytical and Instrument-control software packages, please contact you Mattson Instruments sales representative.

Versatile, Efficient Stand-Alone Operation

Using the Galaxy's stand-alone operating method, you can collect and plot speetral data with simple Couch-key operation. Data is collected and plotted using the parameters of your choice—or choose to operate with factory preset default data-collection and plotting parameters. An interactive tune procedure is available to help you adjust spectrometer throughput or properly align any sampling accessory. In addition, the Galaxy spectrometer is equipped with a standby mode. Place the spectrometer in standby mode during periods of inactivity to extend the life of the already durable mechanical bearing.

The Galaxy Touch-Key Control Panel

All stand-alone spectrometer operations are directed from the Galaxy's built-in 12-key Couch panel and liquid crystal display (LCD) screen. This interactive user Interface,

illustrated in Figure 1-1, was carefully designed to provide a convenient and, most importantly, an easy-to-use means of speetrometer control. Even if you normally operate your Galaxy from a Computer-based data system using a FIRST analytical Software package, you can operate instead from the Galaxy touch panel at any time.

Figure 1 -1: The Galaxy Spectrometer Touch-Key Control Panel . When you operate the Galaxy spectrometer as a stand-alone data-collection and plotting system, all operations are directed from the spectrometet's built-in, touch-key control panel. Spectral data can be collected and automatically plotted by pressing the Scan key just once if a sample shuttle is installed or twice when a sample shuttle is not in use.

An LCD Screen For Interactive Communications

As you work wich your Galaxy spectrometer, the spectrometer's LCD displays Status messages, for example, "**Ready to collect spectrum**," and menus, or lists of options, that allow you to choose and adjust your preferred data-collection and plotting parameters. Clear and concise Information and prompts also guide you as you perform the spectrometer tune procedure or enter and exit the spectrometer standby mode.

Touch-Key Control

The 12 Galaxy control panel keys are arranged in three groups: 1) a single, large Scan key, 2) four arrow keys (up, down, right, left) surrounding an Enter key, and 3) six function keys, titled Menus, Standby, Tune, Replot, New Reference, and Stop/Reset.

Light Emitting Diodes Show Status At A Glance

Also included on the Galaxy control panel are three Sets of light emitting diodes (LEDs). A Set of four LEDs, titled Mirror Stoppel, Data Acquisition, Ready, and Wait, provide a continuous report of spectrometer Status. Two more LEDs, titled Sample and Reference, are located just to the left of the large Scan key and indicate the type of data—either sample data or reference data—that will be collected when you press the Scan key. Mwee more LEDs, these without titles, are associated with the Menus, Standby and Tune keys. When you press any one of these keys to activate or deactivate the assigned operating mode, the associated LED turns on or off to indicate the spcctromcter's operational state.

Operating Simplicity: One-Key Data Collection And Plotting

The Galaxy spectrometer gives you operating simplicity. When a sample shuttle accessory is installed, reference and sample data can be collected and plotted with just one press of the Scan Key. Without a sample shuttle, the saure talks can be accomplished by pressing the Scan key twice:

Witte the ** Ready to collect spectrum ** message displayed on the Galaxy LCD, and with the LED titled Reference lit:

1) Make sure the sample holder is empty and then press the Scan key to collect a reference, or background spectrum. After the data collection is completed, the LED titled Sample lights automatically.

2) Next, place a sample in the Galaxy spectrometer sample holder.

3) Press the Scan key a second time to collect, process and automatically plot an infrared spectrum.

Your Choice Of Data-Collection And Plotting Parameters

Collect background and sample spectra with the data-collection and plotting parameters of your choice. Just dehne the method, or set of parameters, you wish to use, or—even easier—select a stored method that you defined earlier. Simpler yet, collect data using the factory-defmed parameters. (Initially, the Galaxy default data-collection and plotting parameters, that is, Chose parameters that are automatically in place each time you turn on or reset the Galaxy spectrometer, are factory-defined parameters. However, your Galaxy spectrometer allows you to redefine the set of default operating parameters. An unalterable set of factory-defined parameters is always available as well.)

Witte the parameters of your choice selected, press the Scan key to begin collecting and automatically processing the interferogram or spectral data you requested. When you operate your Galaxy spectrometer as a stand-alone System, your processed sample data is automatically plotted, unless you specify otherwise.

Defining Data-Collection and Plotting Parameters: The Menus Mode

Data-collection and plotting parameters are defined, and whole sets of parameters are stored or recalled as "methods," by worldng in the menus mode. To enter the menus operating mode, press the Menus key. When you do so, the Galaxy LCD displays a main menu that offers several options to choose from. Depending on the choices you make, various menus, or lists of options, are presented on the Galaxy LCD. You respond to the displayed messages and sets of options by working with the four Galaxy control panel arrow keys and the Enter key. Use these keys to select options or change parameters displayed on the LCD. Complete operating instructions are provided in Chapter 4.

The menus operating mode also gives you access to Galaxy Service operations. Service Operation include several maintenance procedures and a number of diagnostic spectrometer seif test procedures. These procedures are detailed in Chapter 6, Maintenance and Diagnostic Service Guide.

Versatile Data-Collection Parameters

Data-collection parameters you can set from the Galaxy control panel include:

•            Number of Scans . You may enter any number from 1 to 9999.

•            Shuttle Block Averaging . This parameter is only available when a sample shuttle is installed. Witte a sample shuttle installed, this parameter can be set to either of two settings: Yes, to use an installed sample shuttle and No, to not use an installed sample Shuttle. When this parameter is set to Yes, two additional shuttle parameters can be set: Shuttle Position and Shuttle Block Size.

•            Resolution . Galaxy speetrometer allows you to collect data over a wide range of spectral resolutions. On the Galaxy 3000 series benches, available resolutions includr, 512, 256, 128, 64, 32, 16, 8, 4 and 2 wavenumbers. Galaxy 5000 benches provide these saure resolution choices as well as 1 and 0.75 wavenumbers. Galaxy 7000 series benches provide all of the resolution choices available on the 5000 series with the addition of 0.5 and 0.4 wavenumbers. In addition, 0.25 wavenumber resolution is available on the Galaxy 7000 speetrometers as an option.

•            Amount of Zero Fill . Select the amount of zero filling you wish to use: none, 2 x zero fill or 4x zero fill.

•            Apodization . Use this parameter to specify your choice of apodization: Triangle or Boxcar.

•            Type of Spectrum . Available choices are transmittance, absorbance, Kubelka-Munk (diffuse reflectance), reflectance, sample interferogram, background interferogram, sample single beam and background single be n.

•            Signal Gain . While the usual signal gain factor is unity, Galaxy also allows you to amplify the incoming infrared signal by a factor of four, 10 or 20.

•            Velocity . Fach Galaxy spectrometer offers 17 different mirror velocities. An appropriate electronic filier setting is automatically selected to suit the velocity you choose. However, you can override the automatically selected filier setting by selecting the setting of your choice.

•            Auti-aliasing Filter . Set this parameter to the setting of your choice to override the electronic filier setting automatically set to coincide with your mirror velocity setting.

•            Detector Input. This parameter allows you to indicate which of the thsee
connectors on the spectrometer bench is to be read for detector Input.

•            Detector . Available detector settings include DTGS KBr (Deuterated Triglycine Sulphate with a potassium bromide window, DTGS CsI (with a cesium iodide window), Photoacoustic Cell, Germanium, Silicon, PbSe (lead selenide), InSb (indium antimonide), Narrow Band MCT (Mercury Cadmium Telluride), wide band MCT and DTGS Polyethylen.

•            ADC Sensitivity . Your Galaxy spectrometer may use a 16-bit or an 18-bit analog-to-digital converter (ADC). Use this pammeter to specify the degree of sensitivity you wish your ADC to use. Choices are +0, +1 and +3 to specify 16, 17or 19 biss for a 16-bit ADC or 18, 19 and 21 bit for a 18-bit ADC.

Flexible Data-Plotting Parameters

The Galaxy data-plotting parameters you can set from the Galaxy control panel include:

•            X-Axis Range . Set a starting and ending x-axis range, in wavenumbers or in microns.

•            Y-Axis Range. Set a minimum and a maximum y-axis range, or make both values equal to provide automatic y-axis scaling.

•            Title For Plots. Enter a string of text up to 32 characters long.

•            X-Axis Seale. Available settininclude1 s include 1) expanded wavenumbers, whereby the spectral region below 2000 cm- is expanded by a factor of two as compared with the region above 2000 cm-1, 2) linear wavenumbers, 3) microns and 4) Mattson Pre-Printed Plot Form. This last setting is available for use with Mattson Instruments preprinted plotting paper.

Up To Eight Stored "Methods"

Up to eight methods, that is, eight complete sets of user-defined data-collection and plotting pammeters, can be created and stored in spectrometer memory. By using stored scanning and plotting methods, Galaxy stand-alone Operation is made extremely versatile and convenient. For each of your most common applications, define and Store the most suitable scanning and plotting method. Any stored method can be quickly recalled as the current scanning and plotting parameters as needed.

Factory-Set Parameters and Modifiable Default Parameters

All Galaxy spectrometers gives you the flexibility to coHeet and plot your interferogram or spectral data with the parameters you choose. The Galaxy spectrometer includes an unalterable set of factory-defined data-collection and plotting parameters.

Galaxy speetrometers also provide a default set of data-collection and plotting parameters. The default parameter settings are reinstated each time you Start or reset the Galaxy spectrometer. This means you can begin collecting spectral data, using the Galaxy default parameters, immediately after turning an your Galaxy spectrometer or after bringing the spectrometer out of standby mode. Initi21ly, the Galaxy default

data-collection and plotting pammeters are factory-defined pammeters. However, you can redefine the default operating parameters at any time to suit your current needs.

The Galaxy unalterable factory-defined data-collection and data-plotting pammeters are identified as method 0. The default set of data-collection and plotting pammeters are identified as method 1. Initially, method 1, your default parameters, matches method 0, the factory-defined parameters. Factory-defmed parameter settings are as follows:

•       Scanning Parameters

Number of Scans                         4

Shuttle Block Averaging              On, if shuttle is installed

Shuttle Position                            Reference

Shuttle Block Size                        10 scans

Resolution                                    8 cm ^-1

Data Type                                    transmittance

Signal Gain                                   1

Detector Input                              input 1 (standard)

Detector type                               DTGS CsI (Please see the note below.)

Velocity                                         8 (10 kHz)

Filter                                             64.0 kHz

•       Plotting Parameters .

       X-Axis Range                               4000-500 cm ^-1

       Y-Axis Range                               0 to 110 % T

       Title For Plots                              Mattson Instruments Galaxy FTIR

       X-Axis Scale                                expanded wavenumbers

Please Note : Factory-set data-collection parameters stored as Method 0 cannot be changed, wich the exception of the Detector Type parameter. Typically you change the setting for the Detector Type parameter only when you also install a different detector. For this reason, it is likely that the last detector type selected will still be the relevant detector type when the spectrometer is next turned an or reset. Therefore, the factory-set default parameters automatically remember-the last detector type selected and put in place that parameter setting each time default parameters are reinstated.

Environmental Temperature Considerations

Table 3-1 shows a range of ambient air temperature specifications (from Optimum to allowable) for operation of the Gahuy 14TIR spectrometer. These ranges and specifications are based an standards established by the International Electrotechnical Commission (IEC) in a docwnent (IEC 1010) entitled "Safety Requirements for Electrical Equipment for Memwement, Control and Laboratory Use."

Note that the optimum and recommended range is 16°-25C (60°-78F).

Table 3-1: Temperature Ranges for the Galaxy FTIR Spectrometer

Humidity and Static Considerations

The Galaxy FTIR Interferometer, including the beamsplitter, is housed in a sealed and desiccated chamber. Therefore, environmental humidity is of less concern than for spectrometers that are not sealed from the outside environment. (Please refer to section 3.8 for important Information about maintaining a sealed and desiccated Interferometer chamber.)

Relative humidity within the laboratory (but not within the Interferometer chamber) may be as high as 50%, noncondensing. Higher measures of relative humidity may be allowable when a continuous dry-air purge is used. (Please refer to section 3.7 for additional Information about purging the spectrometer.)

If the area around your Galaxy FIR spectrometer is carpeted, it is advisable to place a static discharge mat in the area where users stand while working while the instrument.

Purge Gas

Dry air, nitrogen gas, or other dry purge gas with a dew point of less than -50°C can be used. Usually, the primary criteria of a purge gas is that CO2 and H20 not be present. For this reason, liquid nitrogen boil off makes an ideal purge gas.

Factory-Defined Data-Collection Parameters

The factory-defined (and initial default) data-collection parameters for the Galaxy 3000, 5000 and 7000 series FTIR spectrometers are:

Number of scans                              4

Shuttle block averaging                    On, if shuttle is installed. (This parameter does not appear when a shuttle is not installed.)

Resolution                                         8 wavenumbers (cm ^–1 )

Amount of zero fill                             2 X

Apodization                                       triangle

Type of spectrum                             transmittance

Signal gain                                        1

velocity                                              10 kHz (0.633 cm/s)

Anti-aliasing filter                               4.0 kHz (Filter cutoff is 6319 cm ^-1 at default velocity)

Detector input                                   input 1 (standard)

Detector                                            DTGS CsI

ADC Sensitivity                                 16 bits (or 18 bits, depending on ADC type)

Table 4-1: Galaxy Selectable Scanning Velocities

Figure 5-5: Polystyrene Infrared Spectrum. This polystyrene spectrum was collected an the Galaxy FTIR spectrometer. Several assignments of bands from major functional groups are also shown.

Galaxy Spectrometer Major Parts Diagram

This section illustrates and describes Galaxy spectrometer major parts.

The following 13 major components are identified in Figure 6-1 and are each described briefly below:

•            Printed-circuit (PC) control board . (1) The PC board is located at the back of the spectrometer and consists of integrated circuit Chips and connections for a variety of electronic components. The board controls the action of the spectrometer.

•            Spectrometer power supplies. (2) The power supply source provides the correct electrical voltage needed to operate the spectrometer.

•            HeNe laser and laser power supply. (3) The HeNe laser provides the monochromatic light source that serves as the reference signal for timing data acquisition and measuring movement of the Scanning mirror. The laser power supply is located under the HeNe laser in the interferometer chamber. This is a high voltage D/C supply source needed to operate the HeNe laser.

CAUTION : The power supply and power supply. wires for the HeNe laser carry EXTREMELY HIGH VOLTAGE. Never touch the power supply or the wires until after the spectrometer has been disconnected all power sources.

•            Fixed-position cube-corner mirror. (4) The fixed-position mirror is also located in the interferometer chamber. Two septum’s on top of the interferometer chamber housing are used to provide access to two micrometers that control the position of the fixed-position mirror. When performing the tune procedure, adjust the micrometers as needed to provide maximum signal throughput (See section 6.6 for more Information.)

•            Infrared source. (5) The infrared source is enclosed in a protective housing within the interferometer chamber. A window located on the interferometer housing allows you to view the infrared source to ensure that the element is lit whenever the Instrument is turned on. This air-cooled element bums very hot (>1000*C) and can cause severe burns. Please make every effort to avoid touching the housing that surrounds the infrared source element.

•            Source mirror. (6) The source, mirror, also known as a collimating mirror, directs light emitted from the infrared source to the beamsplitter.

•            Beamsplitter. (7) The beamsplitter is the interferometer component that splits the infrared light into two halves. One half of the Split light beam travels to a moving interferometer mirror while the other part travels to the interferometer's stationary mirror. Both beams are reflected back to the beamsplitter where they recombine. Half of the recombined light is transmitted to the detector and half is reflected back to the infrared source.

•            Moving cube-corner mirror. (8) The moving cube-Comer mirror, also called the Scanning mirror, is located under the interferometer housing. The moving mirror should be scanning at all times when the spectrometer power is on. The only time the scanning mirror should not be moving is when the spectrometer is in the standby mode. (You can put the spectrometer in standby by pressing the Standby key.)

•            Optional beam-translation mirror. (9) This optional mirror accessory allows you to direct the infrared beam to an external sampling compartment.

•            Sample mirror. (10) The sample mirror is a focusing mirror, which takes the transmitted infrared beam and focuses it at the sample holder.

•            Sample holder . (11) The Standard Galaxy sample holder is located in the spectrometer sample compartment and contains the sample during data collection.

Spectral analyses sampling accessories are largely based on four primary techniques: 1)   transmission analysis, the most common sampling method; 2) specular reflectance, a method of spectroscopy used for surface analysis on highly reflectant Samples; 3) diffuse reflectance, a method of spectral acquisition used for solids and powders that highly scatter the infrared beam; and 4) ATR (attenuated total reflectance), a method used for obtaining spectra from smooth surface solids and liquids including polymers, gels, pastes, and fine-powdered Samples. Over 100 varieties of sampling accessories, too numerous to mention here, can work with the Galaxy spectrometer.

For more Information on a specific sampling accessory contact the Mattson Instruments application department or refer to your sample accessories operator's manual.

WARNING : Never touch or clean any of the spectrometer mirrors with your Fingers or any other type of material. If a spectrometer mirror gets dusty, spray with a light stream of dry air over the mirror surface. (See section 6.5 for more information.)

•            Detector mirror. (12) The detector mirror is another focusing mirror used to focus the infrared beam an die detector.

•            Detector . (13) The detector is the component of the Galaxy spectrometer that converts radiant energy into electrical signals. As the radiant energy striking the detector changes, the electrical signals produced by the detector changes also.

Figure 6-1: Galaxy Spectrometer Major Parts. The following parts are used to perform FTIR data acquisition: 1) printed-circuit (PC) control board, 2) spectrometer power supplies, 3) laser and laser power supplies, 4) fixed-position cube-comer mirror, 5) infrared source, 6) source mirror, 7) beamsplitter, 8) moving cube-comer mirror, 9) optional beam-translation mirror, 10) sample mirror, 11) sample holder, 12) detector mirror, and 13) detector,