VM92 VUV Spectrometer Software Manual
Contents
1. J 500 Sample Period ms i Ar Plot3 PUN 2 1 Recording Plot 4 AAV 5 I I X O OO Auto Max 0 333 Elapsed Time min I Recent 15 Mins Jog nm DY Stepper Q Photodiode CCD Figure 8 The Time Series tab Sample Rate ms The sample rate controls the acquisition rate and 1s specified in milliseconds ms Note that there is no lower limit to the sample rate and therefore it is possible to use a value the software loop cannot achieve In this case the sample rate will be at the mercy of the application speed somewhat related to the host computer s processor and therefore will be asynchronous and unknown Anything below 30 ms will probably be too quick VM92 Spectrometer Page 14 of 36 Software Manual Record Starts recording the photodiode signal at the specified sample rate and wavelength Stop Stops the recording in progress and denotes the end of a scan Save The save function writes a csv file renamed to a xls file extension so it opens natively in Microsoft Excel A pop up window will appear prompting the user to enter the file name and path A header is written which contains all the pertinent program settings that affect the scan followed by the data A comment box is supplied for the user to enter in any pertinent information about the data to be saved and will appear in the file header The column format is displayed be2. 8 6E 5 103 Figure 22 The Spectrometer Wavelength Calibration settings This section contains the 3 order polynomial coefficients used to convert the step position of the diffraction grating drive motor to wavelength in nanometres Whenever the coefficients are changed a Zero routine must be performed The software locks out all controls until zeroing has been completed The calibration coefficients are calculated from 3 wavelengths and 3 respective step positions During calibration the user would scan until a known peak is found The actual wavelength of the hence known peak would be entered as one of the three calibration wavelengths The step position reported at the peak 1s then entered to pair the two values together This 1s repeated for two more wavelengths and then coefficients can be generated and applied Utilization of the Conversions section of the Settings tab 1s needed for this part found directly after this section Use cursors to obtain the exact x value wavelength of the peak in question Enter it into the VM92 Spectrometer Page 31 of 36 Software Manual Conversions section of the Settings tab and press Convert to obtain a step position and then copy it into the Step A box Alternatively the Grab buttons can be used to facilitate this process These buttons will take the wavelength value of a selected cursor from the Grab Cursor drop down box c
3. Resonance Ltd Optical Solutions and Technologies VM92 VUV Spectrometer Software Manual Prepared by Mike Taras www resonance on ca Table of Contents Installation Y Requirements ssccccssscccccsssssssssscsscccccsssssessees 1 A fr MM 2 Se PPE MOOL DAVE SyS I ea E 2 Gear Lash amp Positionin ACCUTANE EA 2 Photodiode Vs CCD Modern nn a tese tie dtu ad edu e Retos 3 Photodiode Input Cratfiz iovis ahud etui Baht a a MEN alla 3 Senes Elle Setas Mii ia ubi tds disset suot DA 4 Eror IP iu da dean 4 Global Functions o5 enano m OH ist 5 MICA todita 5 DIED DEE A rO lito 6 W dvelene th POsitonin Ss 7 Arrow Key Jogging Arrow SCanNINg ccccccccccnnnoonnnnnnnnnonononannnnnnnnnononnnananenoss 7 EI orsi VM MEI ELM I EE M MM LEM A EU ME 7 Photodiode Mode iia 8 Photodiode Caderas llantas 8 Time entes TAD varias tater ton pede ide 14 Chart Recorder Cabra oca aras 17 AS A 20 Eablack DB 2 gt Pin Diarias 21 e aD 23 i M Eco NRI M MUN TNR TM 23 Data Manip is 28 Scams Tab esuada DD mnn d tii 30 Spectrometer Wavelength Calibration esses 3l CODD CESIOTIS SECON 22 CCDWavelenpth C aliDEJUO eee AA 33 Photodiode Acquisition Setunes oa is 34 Varos o CEILS em 34 Installation amp Requirements TheVM92 software can be installed on any PC running Windows XP Vista or 7 in both 32 bit and 64 bit modes The only driver required is also compatible with all these systems and automatically detects the
4. C Go En Cursor Line Style Create Cursor P Line Width TOA wow Delete Cursor Show Name esee Integration Time ms J300 Averages J1 Figure 16 The CCD tab cursor controls Graphing Controls The software is tailored for repeating scans and therefore allows the user to plot up to 4 scans on the same graph as well as a Result plot which is explained later in the section Data Manipulation VM92 Spectrometer Page 25 of 36 Software Manual Avg spec A Vis Spectrum Parameters Fo Plot 1 AEN J1 M 5 if Date FE qu az Plot2 MEM 2 FoF Time Plot3 v 43 E DN Centre WL I Plot4 MEM a D Int Time Result PAYA E Averages Avgs da Total 4 Figure 17 The CCD tab graphing controls The area 1s structured around 4 static plots each assigned a colour Note that the colour and other parameters such as line width and point style can be changed by directly clicking on the black box with the plot colour icon to produce a menu Each plot displays a scan as denoted in the scan box directly to its right in the Spec column Whenever the user initiates a scan even if it 1s stopped the application holds it in memory and assigns it an index from 1 to infinity Therefore if 100 scans were performed Plot 1 can display a scan fro
5. 105 Scan Parameters a Date S Time E 2 Scan Min M i Autoscale Voltage _ Autoscale Wavelength Scan Max Figure 7 The Photodiode zoom area controls VM92 Spectrometer Page 13 of 36 Software Manual Time Series Tab In this mode the system can be set to record the photodiode signal at a set sample rate and wavelength over time It is similar to a chart recorder but handy for situations where little chunks of data need to be recorded and saved as official records Overall this tab 1s very similar to the Photodiode tab with a few changes to the graphing controls I M200 YUY Spectrometer Photodiode Signal V 0 009 CCD Timer lt 1 second Elapsed gfare Voltage alu lr WL nm 643 486 Chart Recorder CCD I O Settings Cursors x Y Y Plot 1 Plot 1 0 15 0 008 gt Plot 2 Plot 2 0 066666 0 008 BA Plot 3 Plot 3 0 075 0 008 EY plo Plot 4 0 266667 0 008 Cursor Mover 0 002 005 0075 0 1 0 125 0 15 015 02 025 02 027 03 035 035 037 amp Elapsed Time min Record Vis ee Record Parameters a 2011 08 03 Date C 12 33 05 Time C 1643 486448 Wavelength C 1500 Period ms Apply Voltage Scale Apply Time Scale V Min Y Max Time Min Time Max Jo 006 0 1 do J 100 Autoscale Voltage Autoscale Time 0 Total Time l o Save Plot Plot 1 Avgs 3 Total 4 Auto 1 20Y Gain J 81 174 GoWL nm To
6. Plot 2 Ao 0 004 fi L 40 Value J Value ES e Note Edit listbox values by triple clicking them ifsor Mover Listbox Apply D I rd s Scanft Vis Scan Parameters Apply Voltage Scale Apply Wavelength Scale J 100 00833 Scan Minimum Plot 1 nu da 9 s 2011 3 14 Date TE VUE PUE EVA 1109 99359 Scan Maximum Plot 2 AVV Jo VIS 18 04 36 Time j TOR Moo Scan Speed Step Size Plot 3 nu s 100 008330 Scan Min m TOES Plot MN 1109 993593 Scan Max 5 MIA AA aU dS 40 f me Result E 1 918 Speed nm s aut z Step ine saveplot Plot1 1 Save calcule 0 1918 Resolution sE Total 3 Auto 1 20V Gain Start Scan Add Comment Ep Comment Revert zero Status Scan Completed Go Stop 100 008 Go WL nm Arrow Scanning J10 Jog nm J Stepper Photodiode e cep 1 Figure 19 The Data Manipulation pop up window invoked by pressing Calculate Result on the Photodiode or CCD tabs There are two list boxes that hold savable constants in case the user needs to add subtract multiply or divide by the same number from session to session The list boxes can be edited by triple clicking the values and typing a new number Pressing the Save buttons beneath them will write the constants to files in the application root directory called constant1 txt and constant2 txt These are simple text files which can be manually edit
7. 11 10 9 g XXIXXIXXIXII 25 24 23 22 24 20 19 18 17 16 15 14 Figure 13 The LabJack DB25 connector pin diagram Pin Assignment Digital IO DO Digital IO D1 Digital IO D2 3 4 7 Digital IO DS Digital IO D9 Digital 10 D3 Digital IO D4 Digital IO D8 Digital IO D13 Digital IO D14 Digital IO D15 Digital IO D6 Digital IO DIO Digital IO D7 Digital IO D11 9 NoConnection Digital IO D12 Figure 14 The LabJack DB25 connector pin assignments Digital I O The digital I O lines are fully controllable the direction can be changed to either input read or output write In output write mode the pins can be set high 5 V or VM92 Spectrometer Page 21 of 36 Software Manual low 0 V The Direction column sets the pin as an input or output the Write column sets the state and the Read column displays the state only in input mode Analog Inputs There are 8 available single ended analog inputs The signal wire goes directly to the input pin and the ground to the case ground pin The input voltage range 1s 10V with 12 bit resolution These 8 inputs become 4 1f differential mode is used Refer to the LabJack Ul2 user manual for more information about differential measurements Analog Outputs There are two available analog output pins which can supply roughly 0 5V The maximum output voltage is actually the supply voltage which will be slightly mor
8. LTS 20 25 30 35 40 Result 0 39531 E cu VI 0 039531 Resolution Avas 3 3 Total 13 9 1 Step Inc Pine um Auto 1 20V Gain Calculate Result Start Scan Add Comment twn Comment zero Status Scan Completed Jj 100 155 Go WL nm J 10 Jog nm Q Stepper Y Photodiode CCD Figure 4 The Photodiode tab VM92 Spectrometer Page 8 of 36 Software Manual Scan Minimum This parameter sets the minimum wavelength the system will start at when performing a scan Scan Maximum This parameter sets the maximum wavelength the system will end at when performing a scan Note that to produce scans that are an even number of resolution increments the minimum and maximum wavelength values will snap to the nearest step increment Speed nm s The scan speed is controlled essentially by changing the number of steps the grating increments per loop of the control software That is the time between each step is not uniform The time between a groups of steps 1s uniform The Speed control presents the user with the option of how many steps are in a group in the units of nm s The higher the value the more steps are in a group and therefore the faster the instrument will scan Resolution The resolution is closely related to the Speed It displays the minimum increment of travel of the diffraction grating at the selected Speed in the units of nanometre nm Start Scan Initiates a scan using the curr
9. correct driver to install when launched The software has very minimal requirements and can run on netbooks laptops and desktops with processors gt GHz More than 2 GB of RAM is recommended if the software is to log data for a long time on the order of days otherwise any amount of memory will do as long as it is greater than 512 MB In order to successfully install the VM92 software locate the installation package found on the Resonance website http www resonance on ca unzip it if necessary and follow these steps l 2 Make sure all USB cables are unplugged from the USB port of the computer you are installing the software on Install the virtual COM port driver by running the FTDI Setup exe file and following its instructions Install the VM92 software by running the setup exe package that came with the installation package You should notice that shortcuts have been added to the desktop and start menu Do not start the software at this time Plug the USB cables of the CCD stepper drive and LabJack into USB ports on the PC Windows will find the hardware and look for a suitable driver If it asks to look online tell 1t not to Windows will scan 1ts driver directories and automatically find and install the driver which was placed by the executable run in step 2 Restart your computer before attempting to launch the VM92 software VM92 Spectrometer Page 1 of 36 Software Manual Overview The
10. is explained later in the section Data Manipulation Avg Scant Vis m Scan Parameters Plot 1 Ady 3 1 9 s Date E m DE Time Plot3 MM 3 2 I Scan Min J 3 DE Scan Max Result d Step Inc Avgs 7 Total O Auto Gain Figure 6 The Photodiode graphing controls VM92 Spectrometer Page 11 of 36 Software Manual The area 1s structured around 4 static plots each assigned a colour Note that the colour and other parameters such as line width and point style can be changed by directly clicking on the black box with the plot colour icon to produce a menu Each plot displays a scan as denoted in the scan box directly to its right in the Scan column Whenever the user initiates a scan even if it 1s stopped the application holds it in memory and assigns it an index from to infinity Therefore if 100 scans were performed Plot 1 can display a scan from 1 to 100 The Vis column directly to the right selects whether the plot is visible or not By clicking the round green button the user can choose which plots to display and therefore which scans The Scan Parameters to the right of the Vis column displays the parameters associated with a given scan selectable by the vertical radio selection box These parameter fields will show the values for the selected plot If the 3 radio button is selected the parameters for the a plot will be shown and remember the 3 plot is not necessar
11. not need to manually select it The software controls the stepper motor by commanding discrete numbers of steps to occur for the various scanning operations and wavelength positioning There are 3 order polynomial wavelength calibration coefficients which are used to produce a relationship between the step position and wavelength of the system In this way the steps will be transparent to the user who will always be dealing with wavelength but to understand the operating principles of some of the commands explained later in the manual this background information is necessary Gear Lash amp Positioning Accuracy The diffraction grating drive stepper motor is very precise however it is geared and therefore incurs a certain amount of mechanical lash that is present when changing directions In order to prevent this lash from affecting wavelength positioning the drive will always arrive at its intended position from the same direction only Going from a shorter wavelength to a longer wavelength is the preferred direction That 1s if the drive is stepped from 200nm to 300nm it will arrive at its location and there will be no lash If the opposite is performed the drive stepped from 300nm to 200nm the motor will change directions and some lash will be encountered In this case the software automatically steps below the intended wavelength by a certain amount and then steps VM92 Spectrometer Page 2 of 36 Software Manual back up
12. pertinent information about the data to be saved and will appear in the file header VM92 Spectrometer Page 18 of 36 Software Manual The column format is displayed below Elapsed Time min Signal V Signal Avgd Wavelength nm Graphing Controls The graphing controls are exactly the same as those used in the Photodiode and Time Series tabs and therefore either of those sections of the manual should be referenced One important addition also present in the Time Series tab 1s the addition of some controls in the bottom right corner which affect the manually applied graph x axis time limits ry ga Recent SE Mins Time Max 3100 Auto Apply Time Scale Time Min jo Apply Voltage Scale Voltage Min Voltage Max Jo Js The Auto Max button will continually set the time axis limit to the total elapsed time so the graph will always show the most recent information Note that this will only take effect if Apply Time Scale is enabled Recent This toggle in conjunction with the input box Mins will set the time axis lower limit to a value such that only the recent x minutes of data will be displayed where x 1s the time in minutes entered in Mins Note that this will only take effect if Apply Time Scale is enabled VM92 Spectrometer Page 19 of 36 Software Manual I O Tab This tab of the application governs all input and output lines from the La
13. software written for the VM200 VUV Spectrometer is a complete control application combining wavelength scanning time series recording chart recording functions digital VO control data manipulation and file saving There are two choices for the detector a photodiode or a CCD which allows for two main modes of operation The software 1s designed to offer the user a complex set of functions without the complex eraphical user interface The various functions are organized into their own respective tabs grouped with their supporting options and controls In this way the various functions can be cycled through simply by selecting the desired tab The software is interlocked to prevent the user from erroneously changing parameters or causing conflicts with the control motors while certain functions are active For example the system cannot be moved to a certain wavelength until it has been zeroed to ensure the stepper motor will not drive the diffraction grating into a hard stop Stepper Motor Drive System The system uses a very precise stepper motor to control the angle of the diffraction grating of the spectrometer The motor is driven by a microprocessor in the electronics case which communicates via serial commands with the software The software therefore needs to have the correct COM port selected to interface with the stepper driver COM ports are automatically searched on startup and unless the instrument wasn t found the user does
14. Independent of the currently selected GUI tab the following indicators and controls are available to the user at all times Indicators WL nm Displays the current wavelength the grating drive 1s currently positioned for signal V Displays the current signal from the photodiode This control will be grayed if the CCD is in use VM92 Spectrometer Page 5 of 36 Software Manual CCD Timer Displays the amount of time remaining before the next CCD acquisition and screen refresh 1s due based upon the selected integration time and number of averages This control will be grayed if the photodiode is in use Status Displays useful information while the software performs various operations For example it will indicate if the system is zeroing if the CCD is running if an exit command has been given etc LEDs The software interfaces with 3 main hardware systems the stepper microprocessor the data acquisition board LabJack and the CCD camera Each of these systems has their own indicator LEDs on the front panel which gives the user a convenient and quick way of determining if they are functioning properly Note that systems not in use will appear as grayed Y Stepper 9 Photodiode CCD Figure 3 The 3 hardware indicator LEDs The Stepper LED is lit when a valid serial handshake has been made to the microprocessor driving the stepper motors The Photodiode LED is lit when communication has been establis
15. M200dataV If for any reason the existing or missing settings file needs to be corrected replaced or if the user needs to revert to older settings one of the files found in the Mata folder can be opened in notepad and its values copied to the active Settings ini file Alternatively one of the backup files can simply be renamed to Settings ini and copied to the program s root directory overwriting the existing file Error Log The program s error log can be found in the Settings tab When errors occur during the operation of the software they are reported and appear with a timestamp in the error log The log 1s also written to a text file stored in the program s data directory the same folder the executable resides as explained above in a folder called data When errors occur they are automatically appended to the error log text file There can only be l error log file per day and each file is given a file name with a time stamp This is to prevent the log from reaching an unmanageable length if they fill with too many errors over time Typical errors have to do with serial handshaking and transmission Do not be alarmed if errors appear in this section The software is designed to respond to errors and keep any operations active Unless the program becomes unresponsive or behaves erratically the error log can usually be ignored otherwise 1t becomes an invaluable debugging tool VM92 Spectrometer Page 4 of 36 Software Man
16. ata in a given session in one graph It acquires a signal reading at a rate specified by the Update Interval It is recommended that this interval kept above 500 ms since all data is stored in memory and after an hour of usage the program may slow down if the graph is not cleared Annotations are used to show events and whenever a scan or record 1s made in the Photodiode or Time Series tabs the start and end of the scan is annotated directly onto the graphed chart recorder data The user can also add annotations at any time using the Add Comment button fi M200 YUY Spectrometer Photodiode Time Series Chart Recorder CCD 1 0 Settings WL nm 643 486 0 012 0 0115 0 011 0 0105 0 01 y 0 0095 2 0 009 0 0085 0 008 0 0075 0 007 0 0065 Signal V 0 008 CCD Timer lt 1 second 0 006 1 1 1 1 I 1 58 91159 59 2 59 4 59 6 59 8 60 60 2 60 4 60 6 60 8 61 61 2 61 4 61 6 Elapsed Time min 5 O M y ry 7 J 1300 Update Interval Average Elapsed Time min 69 5073 Apply Time Scale Recent Mins gt Time Min Time Max Clear Graph A J 57 J60 Auto Avgs 3 Al Selection Latch Time Min Time Max Add Comment 7 m Colour Q Visible So No End of Recording 4 643nm Comment Voltage Min Voltage Max 710 006 70 012 Autoscale Voltage zero Status Stopped Recording J 81 174 Go WL nm Arrow Scanning Jj 10 Jog
17. bJack acquisition device Each analog input output and digital pin can be given a label and saved to a configuration file which is automatically loaded on program initialization The settings file is kept in the program s application directory and is called IO Settings ini It can be opened in notepad to edit values however its formatting 1s not user friendly and therefore the I O tab should be used as its primary editor Refer to the LabJack U12 user manual for more information E VM200 YUY Spectrometer ALO Photodiode SECOND Y ES Analog Output O E Analog Output 1 B Im v y 9 v A A A A gt v v gt gt 4 A 4 4 A v C A 0XW 0WO 0WO 00W89 0W 0Wo 0 WW 0 WW YTT WOW TUTVU U 09 Zero Stopped Recording Go Stop J 81 174 ie Figure 12 The I O tab Features include 4 x 12 bit single ended analog inputs 10V range 2 x 10 bit analog outputs 0 5V range 5V supply voltage 1 x5V supply pin 500 mA maximum current 16 x Digital I O lines All digital I O pins are CMOS output VM92 Spectrometer Page 20 of 36 Software Manual Ports IOO 103 TTL Input Short Circuit amp Overvoltage Protected Ports DO D12 TTL Input No Protection Ports D13 D15 Schmitt Trigger Input No Protection LabJack DB25 Pin Diagram The following displays the assignment of each of the 25 pins for the DB25 case connector 13 44
18. comes available after a dialogue notifies the user The user should ensure the USB connection from the computer to the electronics case is properly mated and click Find Instrument again If the COM port of the device is known but the software still cannot find it the VM92 Spectrometer Page 30 of 36 Software Manual user can manually select the COM port using the drop down box and try to zero the device If the electronics case 1s connected and the software still cannot find it try disconnecting the USB connection closing the software plugging the USB back in and re loading the software Error Log As can be seen from Figure 21 above the error log contains information about an error that occurred during operation of the instrument In this case the error was caused by a physical interruption of the USB cable from the instrument s stepper control electronics to the laptop computer running the software The error window allows the user to scroll through past messages which are all time stamped Refer to the Error Log section under the Overview heading for more information about where the logs are automatically saved Spectrometer Wavelength Calibration Spectrometer Wavelength Calibration 1200 lines mm Al Step ar Ru l Calculate jo 7 1820 1820 A2 Step X2 ax Coeff Grab Cursor j2s37 Jaa25 Grab 22605654 piota 43 Step 43 ax 2 Coeff Cursor Value A j404 412331 Grab
19. e CCD To compensate for this a CCD centre offset option has been included in the software to allow the user to compensate for this effect The entered offset 1s 1n nanometres VM92 Spectrometer Page 33 of 36 Software Manual Photodiode Acquisition Settings Photodiode Acquisition Settings Photodiode Channel Photodiode Gain 0 1 Diff z 2 10 x Figure 25 The Photodiode Acquisition settings This section allows the user to select the acquisition channel and gain of the LabJack acquisition device to which the photodiode signal line is connected Note that the built in BNC connector on the LabJack is connected to AIO only so the default 0 1 Diff setting 1s recommended The gain for the chosen channel can also be selected here The user should choose a signal range that corresponds with the expected maximum signal levels to get the most out of the available 12 bit resolution Note that the gain only applies to differentially wired inputs Various Settings Various Settings 500 Hard Limit Min 100 J Step Period ms J 20000 Hard Limit Max o Measured Step Period ms 500 Backlash 4685 Current Step W Start Scans From Hard Limit Min Figure 26 The Various Settings section of the Settings tab Hard Limit Min This is the absolute minimum offset in steps from the zero position the stepper motor is allowed to go After the zero routine the stepper motor goes to a park position somewher
20. e above the limit switch During normal operation it is not only impractical to operate the grating drive close to the limit switch for optical reasons since it is in a negative order anyways but also for mechanical reasons The limit switch is close to the hard stop and telling the motor to step in this region risks bumping the grating drive into the hard stop The value has been set at Resonance Ltd to a default of 500 steps VM92 Spectrometer Page 34 of 36 Software Manual Anything below less than this number risks potentially running the grating into a hard stop When a wavelength 1s entered for the beginning end or Go location this limit determines the minimum wavelength 1t snaps to Hard Limit Max This is the absolute offset in steps from the zero position the stepper motor 1s allowed to go This is set as a filter to prevent the grating drive motor from driving it into a hard stop It has been set at Resonance Ltd to a default value of 20 000 Anything greater than this number risks potentially running the grating into a hard stop When a wavelength 1s entered for the beginning end or Go location this limit determines the maximum wavelength it snaps to Backlash The stepper motors used as explained in the Overview section at the beginning incur a certain amount of mechanical lash when changing direction due to their gearing The software ensures the lash 1s taken up by always arriving at a position from t
21. e or less than 5 V For an accurate analog output 1t is recommended that the analog output voltage should be read using an available analog input so the user can exactly control the set voltage Note Analog output ranges from 0 5 V 10 bit resolution with 5 V being the supply voltage 5 V pin supplies a maximum current of 500 mA VM92 Spectrometer Page 22 of 36 Software Manual CCD Mode This mode employs the CCD as the detector for the spectrometer The tab 1s structured similarly to the Photodiode and Time Series tabs The wavelength scanning recording functions are replaced with store subtract dark functions and the x axis can be toggled to display pixel number or wavelength CCD Tab I vM200 YUY Spectrometer Photodiode Time Series Chart Recorder CCD I O Settings WL nm 125 010 Signal V 0 995 CCD Timer E 1 second 3000 Cursors oim Plot 1 123 764 169 2500 5S Plot 2 2950 Plot2 112 615 301 Erots 2000 Plot 3 113 92 188 gt 1750 EI Plot 4 Plot 4 113 446 190 E IX 2 amp 12907 Cursor Mover 1000 AUS B oU gt 50 si Integration Time ms 5 j OO ee A el eS M EE Or TA A A A AA 300 dale abul sa aae aaa able alas ID als SiS d Il 12 123 224 5201255 DOS dea es deel LC 0 eil Ee le Ig e Averages Wavelength nm A5 gt Bae Spec Vis gt Spectrum Parameters Apply Intensity Scale MM e StreDak Dark Ploti MEM i
22. ed if needed The sliding switch to the right of each box allows the user to use a value from the list box or a manually entered temporary constant above VM92 Spectrometer Page 28 of 36 Software Manual The operators themselves are selectable via drop down boxes and 4 choices are given add subtract multiply and divide When the Calculate Result button 1s pressed the operations are carried out on the 4 plots and a Result plot is created and graphed on the tab which called the function When a data operation 1s in progress the status indicator will display Calculating result to let the user know the operation is in progress Figure 19 above shows the data manipulation window and the selected function Plot 1 is to be added to Plot 2 The First two plots in the equation are meaningless since they are being multiplied by a constant of 0 Figure 20 below shows the resulting spectrum in yellow graphed with Plot 1 and 2 to show that the operation was successful si zip Photodiode Time Series Chart Recorder CCD I O Settings WL nm 109 994 Signal V 1 426 CCD Timer lt 1 second Wavelength 39 Voltage ajy Cursors x Plot 1 100 008 Y Plot 2 Plot 2 100 008 Y Plot 3 Plot 3 100 008 BA Plot 4 Plot 4 103 Y Result Result 100 008 oo l l Cursor Mover 200 1005 001 10S 07102 7192 5 01085 105 ie 10 3 IUS ass a 065 p 1075 0108 te Ss 10s Vibes Lig ere Wavel
23. ength nm gt BEA 0 J 100 00833 scan A SIEP A Apply Voltage Scale Apply Wavelength Scale 2011 3 14 Date V Min V Max WLMin WL Max 18 04 36 Time Jo J5 Scan Speed Step Size Plot 3 AAN y 100 008330 Scan Min Autoscale Voltage Autoscale Waveleng Plota ENM 109 993593 Scan Max Result Step I Speed nm s AN S sci Save Plot Plot 1 coma emer 1918 e Avgs 3 Total 1 20V Gain es Rl Zero Status Calculation Calculation Complete 100 008 008 Go WL nm Arrow Arrow Scanning J10 Jog nm 10 Jog nm Y Stepper Q Photodiode 2 CCD 4109 99359 Scan Maximum Plot2 ENIM Figure 20 The result of performing an addition operation of Plot Plot2 The Result spectrum is graphed along with Plot 1 and Plot2 for demonstration purposes The result spectrum is also padded according to the source scans used in the operations That 1s if the start and end wavelengths of the scans do not match the result spectrum will range from the lowest of the scan wavelengths to the highest of the scan wavelengths and will pad the scans so they all match this range before operating on them The CCD is exempt from this additional feature since there are always the same number of pixels and the beginning and end wavelengths are simply a function of the calibration polynomials It wouldn t make sense to manipulate spectra of different regions for the CCD mode of operation VM92 Spectrom
24. ently entered parameters of Scan Minimum Scan Maximum Speed and Resolution as explained above Stop Scan Will stop a scan in progress and record the end wavelength as the wavelength the scan indeed stopped at and not the intended maximum wavelength which was never reached Add Comment During a scan the user can input comments that are written to an array attached to the scan data When the scan is saved to file a column is dedicated to any comments that were entered while the scan was running Once a comment has been written the Add Comment button un clicks To write the same comment for every consecutive increment use the Latch button When Latch is selected the comment button will not VM92 Spectrometer Page 9 of 36 Software Manual unclick until Latch 1s un clicked This 1s useful for indicating certain periods of data over many increments of a scan Save The save function writes a csv file renamed to a xls file extension so it opens natively in Microsoft Excel A pop up window will appear prompting the user to enter the file name and path A header is written which contains all the pertinent program settings that affect the scan followed by the data A comment box is supplied for the user to enter in any pertinent information about the data to be saved and will appear in the file header The column format is displayed below Wavelength nm Signal V Signal Averaged Calculate Result Launche
25. eter Page 29 of 36 Software Manual Settings Tab This section of the application allows the user to modify some very important parameters essential to the proper operation of the instrument Each setting will be explained below I M200 YUY Spectrometer j25a Joss Grab 26 0564 soo 2011 08 03 17 35 00 312 Error 1073807194 occurred at Property Node arg 8 in VISA Configure Serial Port Instr vi gt 615 VM200 Shipping Beta vi Possible reason s VISA Hex OxBFFFOOA6 The connection For the given session has been lost 2011 08 03 17 35 00 078 Error 1073807194 occurred at Property Node arg 8 in VISA Configure Serial Port Instr vi gt 615 VM200 Shipping Beta vi Possible reason s VISA Hex OxBFFFO046 The connection For the given session has been lost 2011 08 03 17 34 59 906 Error 1073807194 occurred at Property Node arg 8 in VISA Configure Serial Port Instr vi gt 615 M200 Shipping Beta vi Figure 21 The Settings tab Save Settings Saves all entered parameters in this tab to an INT file in the application s root directory See the Overview section at the beginning of this manual for more information Find Instrument This is where the stepper COM port is selected if the program could not find it automatically When the software is started it pings all available COM ports to identify the control electronics box If nothing is found the Find Instrument button be
26. he same direction The Backlash parameter 1s the number of steps to go below a wavelength when scanning from a longer wavelength to a shorter wavelength before it steps back up to the intended wavelength If there appears to be some repeatability 1ssues with wavelength positioning a greater backlash value can be used The default set at Resonance Ltd and tested to be sufficient 1s 5000 steps Start Scans From Hard Limit Min This toggle overrides the backlash setting and applies the maximum amount of backlash possible at the start of every scan or Go command This option 1s meant to provide the greatest repeatability by forcing the drive system to start from the same position every time a new position or scan 1s requested Step Period ms This parameter controls the rate at which the application sends serial commands to the microprocessor controlling the stepper grating drive motor A value as short as possible will result in the fastest scan rates however a value too low will result in missed serial transmissions and therefore uneven step rates The default value set at Resonance Ltd was set to 100 ms It was observed that 50 ms could potentially work however this was cutting it close and some serial commands were not sent to the control case properly which caused pauses while scanning A longer value could be used to perform a scan that must be extremely uniform and a longer value would allow the stepper motor and mechan
27. hed with the LabJack board and valid data has been processed Finally the CCD LED is lit when valid pixel data has been processed Depending on the mode of operation the relevant LEDs should all appear green after successful initialization which occurs automatically Stepper Zeroing Before any functions or operations can be carried out the spectrometer must first be zeroed The user will find that all other buttons are grayed out until zeroing has been completed Invoking this function asks the stepper motor to search for a limit switch in order to calibrate itself to a known position The location of the switch is defined as the 0 step position which is converted to a wavelength according to the 3 order polynomial The wavelength at the zero position will be negative to indicate the grating is actually rotated below 0 order VM92 Spectrometer Page 6 of 36 Software Manual Wavelength Positioning The Go and Stop buttons are used to send the spectrometer to a desired wavelength A wavelength can be entered into the Go WL nm box where 1t will snap to the nearest step position When Go is pressed the system will command the grating to move to that position The Stop button can be used to halt the stepper at its current location before it reaches the desired location Arrow Key Jogging Arrow Scanning The arrow key jog feature moves the diffraction grating a specified increment every time the left or r
28. ical drive to settle before a reading is taken VM92 Spectrometer Page 35 of 36 Software Manual Measured Step Period ms Useful while setting the Step Period parameter this value 1s the actual measured time the application took from one loop to the next If the measured step period is greater than the set step period the application 1s being asked to execute faster than 1t 1s able to and therefore may drop some serial transmission commands which will delay the stepper motor from time to time This value should always be equal to the set step period and indicates proper operation VM92 Spectrometer Page 36 of 36 Software Manual
29. ight arrow key is depressed The increment in nanometres is specified by the input box to the right of the Arrow Scanning button and 1s called Jog nm The arrow keys can be held down to continually scan the system and simply released to stop scanning Setting the system on a wavelength peak 1s made easy using this mode in conjunction with the chart recorder Note that in this mode no backlash compensation will take place leaving the system susceptible to positioning inaccuracy Once a peak has been found using this quick and dirty method a formal Go request should be made to the wavelength which will include a backlash compensation routine Note that the control remains disabled and grayed until the system has been zeroed and is also deactivated during a scan Exit The Exit button found in the GUI s top right corner attempts to properly stop all running processes and close the executable leaving the hardware devices in a state ready for proper initialization when the software is started again for another session Note that in order to close properly the current CCD integration must complete and since integrations can be 10 s of minutes the user may have to wait that long for it to complete VM92 Spectrometer Page 7 of 36 Software Manual Photodiode Mode If the user selects the photodiode as the detector after being prompted at program initialization the software will run in photodiode mode This mea
30. ily the 3 scan it is whatever scan is selected in the respective Scan column The Auto column when checked will automatically increment the scan number box to 1ts immediate left after a secan has been completed This will bump out the previous scan and increment to the next When all boxes are checked it will make sure only the 4 latest scans are always shown Deselecting a box will mean that unless the user changes it manually performing a new scan will never increment the scan assigned to its respective plot This is very useful to designate a certain plot to hold a reference scan The Avg column selects whether to apply a running average to the respective plot The sample length or Avgs as denoted in the software is how many samples are to be averaged together to produce a point This parameter can only be an odd integer and the software will filter even entries A side effect of a typical running average is a shift in data by 2 the sample length rounded down That is if a peak was displayed on a eraph and a running average of 11 was applied the peak would shift to the right by 5 samples The software compensates for this by deleting the first 5 points on the graph This 1s the reason only odd numbers are permitted The user should be aware that during a scan if the plot is being averaged no data will appear until there are more data points than half the average value since they are being chopped off the beginni
31. low Elapsed Time min signal V signal Averaged Graphing Controls The graphing controls are exactly the same as those used for the Photodiode tab and therefore that section of the manual should be referenced Instead of being labeled as scans the data acquired in Time Series mode is with respect to time and therefore called records One important change from the Photodiode tab to the Time Series tab is the addition of some controls in the bottom right corner which affect the manually applied graph x axis time limits Apply Voltage Scale Apply Time Scale V Min V Max Time Min Time Max Jo Js Jo 100 I Ma VM92 Spectrometer Page 15 of 36 Software Manual Auto Max The Auto Max button will continually set the time axis limit to the total elapsed time so the graph will always show the most recent information Note that this will only take effect 1f Apply Time Scale is enabled Recent This toggle in conjunction with the input box Mins will set the time axis lower limit to a value such that only the recent x minutes of data will be displayed where x 1s the time in minutes entered in Mins Note that this will only take effect if Apply Time Scale 1s enabled VM92 Spectrometer Page 16 of 36 Software Manual Chart Recorder Tab The Chart Recorder mode is always functioning and is meant to aid the user in wavelength positioning and also to log d
32. m 1 to 100 The Vis column directly to the right selects whether the plot 1s visible or not By clicking the round green button the user can choose which plots to display and therefore which scans The Spectrum Parameters to the right of the Vis column displays the parameters associated with a given scan selectable by the vertical radio selection box These parameter fields will show the values for the selected plot If the 3 radio button is selected the parameters for the gr plot will be shown and remember the 3d plot 1s not necessarily the aa scan it is whatever scan is selected in the respective Spec column The Realtime check box toggles whether plot 1 should display the latest acquired spectrum or a stored spectrum of specified index The Avg column selects whether to apply a running average to the respective plot The sample length or Avgs as denoted in the software is how many samples are to be averaged together to produce a point This parameter can only be an odd integer and the software will filter even entries A side effect of a typical running average is a shift in data by 2 the sample length rounded down That is if a peak was displayed on a eraph and a running average of 11 was applied the peak would shift to the right by 5 samples The software compensates for this by deleting the first 5 points on the graph This 1s the reason only odd numbers are permitted The user should be aware tha
33. ng of the data array It could appear as though nothing is happening until enough points are acquired to have something to graph The bottom right of the Photodiode tab allows the user to set the autoscale or manually applied limits for the wavelength and signal axes When in manual mode the limits can be changed using the increment arrows on the controls themselves or a new value can be typed in When focus is lost from the control preferably by pressing enter the new values are instantly applied to their respective axis Note that for usability purposes the values are not checked to see if they make sense Therefore for example the user could enter in a maximum value that is actually lower than the current minimum value which will cause the graph to incorrectly display data Changing the lower value to something lower will naturally solve this problem The graph palette at the bottom right corner of the graph can also be used to zoom in on a section data quickly and easily All apply autoscale buttons must be un clicked in order for this function to work Simply click on the middle button on the VM92 Spectrometer Page 12 of 36 Software Manual palette and choose a selection type A region may now be drawn on the graph to define the zoom area Refer to Figure 7 below for an illustration Flor 101 1 425 Plot 3 Plot 3 102 0 004 EY Plot 4 Plot 4 103 0 004 ES Result Result 104 1 005 Cursor Mover
34. nm Q Stepper Y Photodiode a CCD Figure 10 The Chart Recorder tab Update Interval ms This specifies the length of time between signal acquisitions in milliseconds ms VM92 Spectrometer Page 17 of 36 Software Manual Add Comment The user can add comments to the chart record data When the record is saved to file a column is dedicated to any comments that were entered during the recording Once a comment has been written the Add Comment button un clicks To write the same comment for every consecutive increment use the Latch button When Latch is selected the comment button will not unclick until Latch 1s un clicked This is useful for indicating certain periods of data over many increments of a scan The colour of comments can be changed by clicking the box to the left of the Colour label and will only affect future comments All comments can also be shown or hidden by using the Visible button Clear Graph This flushes the saved chart recorder data held in memory and will reset the recorder to start over All annotations will also be cleared This function may have to be performed if the application has been open for hours or if the update interval 1s set to be low such that large amounts of data accumulates in memory which could slow down the application Average Like all the other tabs this function applies a running average to all the plotted data on the chart recorde
35. ns the CCD tab will be grayed out and all functions pertaining to the CCD will be disabled This leaves the user access to the Time Series Chart Recorder and I O tabs Settings 1s always avallable Each of these tabs will be explained below Photodiode Tab From this tab the spectrometer can be positioned to any precise wavelength or also scanned from a fixed starting wavelength to a fixed ending wavelength The photodiode signal 1s plotted on the graph fe vM2nn VI IV Snectrometer Photodiode Time Series Chart Recorder CCD 1 0 Settings WL nm 129 999 Signal 0 015 CCD Timer lt 1 second 0 11 Wavelength amp ui por Voltage alje 0 09 0 08 Cursors IX 1Y DE 7 Plot 1 100 155 0 007 o HOr gt 0 06 Plot 2 100 155 0 007 E ua Ei 3 gt Plot 3 100 155 0 006 0 04 E Plot 4 Plot 100 958 0 005 0 03 Y Result 0 02 Result 100 155 DS m Cursor Mover AS 1021 21215 ze Sizes des 1255 184 Ls d 159 le 125937 ee 7127 5 128 128 5 led da 120 Wavelength nm BH T TAGS E ER pni Vis Scan Parameters Apply Voltage Scale nas K Ploti MN 13 _ 5 2011 08 03 Date V Min V Max WLMin WL Max J 129 99947 Scan Maximum Plot 2 nu e 17 04 49 Time oor loo T j T doo Scan Speed Step Size Plot 3 nu E 100 154690 Scan Min Plot4 MEN 1129 999469 Scan Max EN d
36. onvert it to a step position and automatically copy this value to the Step box In order to calibrate then the user simply has to choose 3 known wavelengths position 3 cursors at each peak corresponding to the wavelengths and press grab for each wavelength making sure to select the right cursor between each grab Calculate This button takes the entered 3 wavelengths and 3 step positions and calculates 3 coefficients These coefficients are held in the column directly to the right of the 3 wavelengths and step positions box Make sure to zero after the coefficients are changed Conversions Section This section is meant to be an aid for the wavelength calibration section and allows the user to convert step positions to wavelengths and vice versa Conversions Jo Wavelength D Step Position Jo Step Position O Wavelength Convert This button as explained above will take a wavelength or step position and convert it to its complement using the active coefficients entered in the far right column of the Spectrometer Wavelength Calibration section of the Settings tab VM92 Spectrometer Page 32 of 36 Software Manual CCD Wavelength Calibration CCD WL Calibration CCD ax Coeff WL correction m y jj CCD Centre Offset 4 236 ax Coeff T 14 236 Offset 1E 6 ax 2 Coeff Y LL ax Coeff 10 014 Pixel Width mm ju ax 2 Coeff Figure 24 The CCD Waveleng
37. ow for an illustration Flor 2 101 1 426 7 Plot 3 Plot 3 102 0 004 EY Plot 4 Plot 4 103 0 004 ES Result Result 104 1 005 Cursor Mover 105 106 107 108 109 110 K igth nm Ems Scan Parameters Date Time En Autoscale Voltage Autoscale Wavelength l Scan Max Figure 18 The CCD zoom area controls VM92 Spectrometer Page 27 of 36 Software Manual Data Manipulation One feature of the software 1s the ability to apply mathematical operations to 1 or more plots to produce a result spectrum This function allows the user to perform mathematical operations on any of the 4 displayed plots All 4 plots can be involved in the operation or just 1 or more plots with or without constants The calculation follows the mathematical order of operations respecting the parentheses around the values To access this function Calculate Result needs to be pressed on the Photodiode or CCD tabs A separate window will pop up asking the user for the parameters of the operation El VM200 VUV Spectrometer Photodiode Time Series Chart Recorder CCD 1 0 Settings WL nm 109 994 Signal V 1 426 CCD Timer lt 1 second Wavelength LL Voltage 394 Cursors IX 100 008 1 406 100 008 1 411 100 008 1 426 7 M LEF 1 vy ALI bs gt V V v X Fl gt Data Manipulation B x Bi Plot 1 amp Plot 2 2 El 5 Plot 1 El
38. r These different regions can even be stitched together as one continuous spectrum using the software s multiple graphing abilities where up to 4 plots can be graphed at once Photodiode Input Gain The input signal for the photodiode BNC connector is a differential voltage reading connected to the programmable instrument amplifier of the analog to digital converter inside the LabJack case This allows the user to select various gains The gains are listed in the chart below and can be selected in the Settings tab 8 o 425 VM92 Spectrometer Page 3 of 36 Software Manual Settings File Settings ini The software uses a single settings file to store important parameters The file 1s found in the program s root directory which changes depending on your operating system but for Windows XP by default is C Program Files VM200Y and is named Settings ini It can be edited in notepad simply by double clicking and the various parameters directly changed In the program s graphical user interface GUI the tab called Settings allows the user to edit and save all the program s parameters without manually opening the INI file Whenever the settings file is written to from within the Settings tab of the GUI a backup copy is placed in the program s Mata directory and given a date and time stamp The Mata directory 1s a folder named data contained in the path to the program executable by default C Program Files V
39. r graph The Samples as denoted in the software is how many data points are to be averaged together to produce an averaged point This parameter can only be an odd integer and the software will filter even entries A side effect of a typical running average is a shift in data by Y2 the sample length rounded down That is if a peak was displayed on a graph and a running average of 11 was applied the peak would shift to the right by 5 samples The software compensates for this by deleting the first 5 points on the graph This is the reason only odd numbers are permitted The user should be aware that during a scan if the plot 1s being averaged no data will appear until there are more data points than half the average value since they are being chopped off the beginning of the data array It could appear as though nothing 1s happening until enough points are acquired to have something to graph Save The save function writes a csv file renamed to a xls file extension so it opens natively in Microsoft Excel The user has the option of saving all or a selection of data If Selection is chosen the user must enter a minimum starting and maximum ending time to define the region of data to be saved A pop up window will appear prompting the user to enter the file name and path A header is written which contains all the pertinent program settings that affect the scan followed by the data A comment box 1s supplied for the user to enter in any
40. s another window in which mathematical operations can be applied to various plots to generate a result spectrum The new spectrum will be graphed automatically when the window is closed See the section Data Manipulation for more information Revert Restores the plots that were visible before Calculate Result was pressed Cursors Cursors can be added or removed and told to snap to a plot or to be freely movable The X and Y columns indicate the position of the cursor and can also be edited to place the cursor at an exact location A context menu allowing the user to change cursor attributes such as point style colour and X Y scales can be accessed by right clicking in the cursor window Figure 5 below VM92 Spectrometer Page 10 of 36 Software Manual D Timer lt 1 second Wavelength amp as ena Voltage Cursors X Y Plot 1 100 1 426 Y Plot 2 Plot 2 101 1 426 Y Po gt visible Items Po ES Plo Snap To b E Attributes Color d Re Cursor SEvle Bring to Center Point St Go bo Cursor T m E i ine Style Create Cursor P Line Width kk Cl Delete Cursor EE a ESSE LE 110 e SENE Bae m Figure 5 The Photodiode tab cursor controls Graphing Controls The software is tailored for repeating scans and therefore allows the user to plot up to 4 scans on the same graph as well as a Result plot which
41. t during a scan if the plot is being averaged no data will appear until there are more data points than half the average value since they are being chopped off the beginning of the data array It could appear as though nothing is happening until enough points are acquired to have something to graph The bottom right of the CCD tab allows the user to set the autoscale or manually applied limits for the wavelength and signal axes When in manual mode the limits can be changed using the increment arrows on the controls themselves or a new value can be typed in When focus is lost from the control preferably by pressing VM92 Spectrometer Page 26 of 36 Software Manual enter the new values are instantly applied to their respective axis Note that for usability purposes the values are not checked to see if they make sense Therefore for example the user could enter in a maximum value that is actually lower than the current minimum value which will cause the graph to incorrectly display data Changing the lower value to something lower will naturally solve this problem The graph palette at the bottom right corner of the graph can also be used to Zoom in on a section data quickly and easily All apply autoscale buttons must be un clicked in order for this function to work Simply click on the middle button on the palette and choose a selection type A region may now be drawn on the graph to define the zoom area Refer to Figure 18 bel
42. th Calibration settings There is a 3 order polynomial which converts the pixel number to wavelength based on the currently set wavelength Because the dispersion will change with the angle of the diffraction grating and therefore wavelength the 1 coefficient of this polynomial ax Coeff needs to be modified by the current centre wavelength It is called the centre wavelength because the set wavelength will be incident upon the centre of the CCD To modify this 1 coefficient yet another 3 order polynomial on the right 1s used to calibrate it against centre wavelength The result is a CCD spectrometer system which can remain accurate over a large range of wavelengths and which can set any particular wavelength to the centre of the CCD instead of being confined to certain regions of calibration Calibrating the CCD is a complex task and involves a lot of trial and error tweaking The coefficients shipped with the instrument should not be tampered with unless Resonance Ltd 1s consulted CCD Centre Offset Due to potential variations in the CCD positioning during the manufacturing process and the combined effect of the shifting dispersion with respect to wavelength of the grating and the non linear spectral response of the CCD it 1s possible that the set wavelength may not fall on the centre pixel of the CCD as expected If this occurs a shift in the wavelength calibration may be observed when scanning to various spectral regions with th
43. tively in Microsoft Excel A pop up window will appear prompting the user to enter the file name and path A header is written which contains all the pertinent program settings that affect the scan followed by the data A comment box is supplied for the user to enter in any pertinent information about the data to be saved and will appear in the file header The column format is displayed below Calculate Result Launches another window in which mathematical operations can be applied to various plots to generate a result spectrum The new spectrum will be graphed automatically when the window is closed See the section Data Manipulation for more information Revert Restores the plots that were visible before Calculate Result was pressed VM92 Spectrometer Page 24 of 36 Software Manual Cursors Cursors can be added or removed and told to snap to a plot or to be freely movable The X and Y columns indicate the position of the cursor and can also be edited to place the cursor at an exact location A context menu allowing the user to change cursor attributes such as point style colour and X Y scales can be accessed by right clicking in the cursor window Figure 16 below AE D Timer lt 1 second Cursors A Y EJ Plot 1 Floti 8 4095 Bl Plok2 106 42 264 8 MI El Visible Items p BAFI Snap To Attributes d Color Cursor Style Bring to Center Point Style
44. to arrive from the positive direction In this way the mechanical lash 1s taken up and accurate wavelength positioning can be expected Photodiode Vs CCD Mode Upon initialization of the software the user 1s prompted to select the detector used for the session photodiode or CCD Once a selection has been made functions tabs and controls relevant to the other detector will be grayed out Furthermore the mode of operation cannot be changed during the current session and therefore the executable must be exited and restarted if another detector is to be chosen The photodiode is a single element detector which outputs a voltage proportional to the incident intensity of light Its signal 1s read using a LabJack U12 analog to digital converter in differential mode which allows for a programmable gain to better utilize the available 12 bits of resolution Being a single element only one wavelength at a time can be measured and therefore positioning accuracy directly depends on the grating drive s accuracy The CCD detector is a 1 x 2048 pixel array which allows an entire spectrum to be acquired and displayed without moving the diffraction grating The span is approximately 70 nm but if repeatable results are an absolute must there is no better alternative than a fixed hardware setup such as this The grating can of course be moved to different wavelengths so the CCD can display different regions of the full capable spectrum of the spectromete
45. ual Global Functions I M200 YUY Spectrometer Photodiode WL nm 643 486 lt 1 second Signal V 0 008 CCD Timer Time Series Chart Recorder CCD I O Settings 0 2 Wavelength 8 13 0 18 Voltage alla 0 16 l Cursors x Y 0 14 EY Plot 1 wi 008 0 12 Plot 1 71 2532 0 008 042 Plot 2 106 191 1 426 gt i Plot 5 gt 0 08 Plot 3 5 56139 0 004 i E Plot 4 0 06 Plot 4 256 506 0 004 Y Result 0 04 RU Result 225 813 1 005 0 02 4 i JL JUE NIP SEES os i i Cursor Mover 100 50 0 50 100 150 200 250 300 350 400 450 500 550 600 650 K Wavelength nm Scan Vis c Scan Parameters Plot M n 2011 08 03 Date Plot 2 ANAN Jo s 11 37 18 Time Jo 30 2 100 3200 Plot3 MEM 2 1 vio 81 174152 ScanMin z Autoscale Voltage _Autoscale Wavelength Plot4 FMM vis 643 486448 Scan Max 1 1 Lu 1 1 5 10 15 20 Result 0 39531 Speed nm s esult KAYA E p StepInc leave Plot Plot 1 Result Auto 1 20V Gain Result Apply Voltage e Apply Wavelength Scale V Min WL Min WL Max 1 81 174152 Scan Minimum 643 48645 Scan Maximum Scan Speed Step Size 1 1 0 039531 Resolution Avgs 33 Total 1 slits 200 micron pressure 2 2e 5 mbar zero Status Scan Completed Jj 81 174 Go WL nm J 10 Jog nm Q Stepper Q Photodiode 23 CCD Figure 2 The global controls available at all times highlighted
46. v 2011 08 03 Date l P Plot2 BN gt ED e 17 36 31 Time o Tor T p n se A E Subtract Dark IUS VV J 3 9 B 125 009812 M Autoscale Intensity Autoscale Wavelength Plot4 BN a 9 j 1300 Int Time E Result PAY n Averages r 2 Save Plot Current Calculate Avgs 43 Total 4 Result ARE i WON 1 an ee ea Figure 15 The CCD tab Store Dark Stores the latest spectrum in memory This spectrum can be subtracted from any future or stored spectra by toggling the Subtract Dark button Subtract Dark Subtracts the saved dark spectrum from a stored or realtime current spectrum The button affects all graphed spectra simultaneously VM92 Spectrometer Page 23 of 36 Software Manual X Axis Selects which units to apply to the x axis Pixel number or wavelength is available Wavelength is displayed in nanometres Store Spectrum Stores the latest spectrum in memory for the purposes of graphing and data manipulation Stored spectra can be graphed simultaneously over current spectra or operated on to produce a result spectrum see the Data Manipulation section Integration Time ms Specifies the length in milliseconds the CCD waits until reading out the intensities of its pixels to produce a spectrum Averages Specifies how many spectra to acquire and average to produce a final resulting spectrum Save The save function writes a csv file renamed to a xls file extension so it opens na
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