5 Discovery Way, Acton, MA 01720 Phone: (978)263-3584, Fax: (978)263-5086 Web Site: www.piacton.com Operating Instructions Princeton Instruments Model VM-502 0.2 Meter Vacuum Monochromator VM-502 s/n: SD3 s/n: Rev. 5.
PRINCETON INSTRUMENTS CORPORATION VM-502 Operating Instructions CONTENTS Section I. General Description ................................................................................................1 1.1 Description.......................................................................................................................1 1.2 Specifications...................................................................................................................1 Section II. Instrument Setup..........
Section I. General Description 1.1 Description The Princeton Instruments Model VM-502 is a nominal 0.2 meter vacuum scanning monochromator, with an optimum wavelength range in the vacuum ultraviolet region. However, with other gratings and coatings, the instrument is useful from the extreme UV to the infrared. The Model VM-502 is designed to use an aberration-corrected concave holographic grating, which provides and aperture ratio of f/4.5.
If specified, standard fixed width slits 1m high are supplied to customer’s specified width. Movable Diverter Mirror (optional): A movable diverter mirror is provided to divert the beam from the V slit position to the straight through position. A knob in the instrument cover allows the mirror to be moved under vacuum conditions Slit Chamber Isolation Valve (optional): Vacuum valves are provided to isolate the slit chambers form the main instrument chamber.
Section II. Instrument Setup 2.1 General Description: The instrument is shipped completely assembled, tested and ready for immediate installation. If the instrument is to be stored before use, contact Princeton Instruments for storage instructions. For shipping purposes, some optical components are covered, and mechanical components are tied or placed in specific positions. The following procedure is recommended to prepare the instrument for use. 2.
2.4 Pumping System Mounting: The instrument is now ready for mounting to a pumping system. The VM-502 and Pumping Port Size drawings (pages 18 and 19, respectively) show the location and dimensions of a pumping port in the instrument base. The instrument may be supported by the pumping port or by the three pads provided.
3. Make sure that power supply is switched OFF and connect it to POWER connector on the SD3. Connect the line cord provided with the SD3 to the power supply and the AC line. The power supply will operate with line voltages between 100 and 250 volts AC 50/60 Hz and provides +5 volts DC for the SD3 control logic and +24 volts DC for the motor drives. Pin # 1 2 3 4 Description +5V GND GND +24V Table 2: Power Input Pin Arrangement: 4. Connect the SD3 to a computer.
2.6 Software Installation: Each VM-502 monochromator ships with the Actono Monochromator Control Software CD CD. If you have not purchased Princeton Instruments' SpectraSense or WinSpec/32 software, use this CD to install the Monochromator Control Software on your computer. The following instructions briefly describe the installation process. For greater detail, refer to the Monochromator Control Software manual on the CD. 1. Locate your Monochromator Control Software CD. 2.
2.7 System Operation It is important that the VM-502 be connected to the computer and be initialized before the controlling software is started. If the VM-502 is part of a system that includes a Princeton Instruments SpectraHub Detector Interface and a single point detector such as a PMT or a Silicon Diode detector, then the entire system will be controlled through the Princeton Instruments SpectraSense software.
Section III. Instrument Operation 3.1 Bilateral Slit Assemblies: 1. Slit Width: The slit width of each bilateral slit assembly is adjustable from 0.005 millimeters to 3 millimeters (5 to 3,000 micrometers) by a micrometer knob located on the slit housing. The micrometer knob is graduated in 0.01 millimeter (10 micrometer) increments. One counterclockwise revolution of the micrometer knob increases the slit width 0.25 millimeters (250 micrometers).
3. Place the shipping grating cover supplied over the face of the grating. Loosen the one 8-32 clamp screw in the base of the grating assembly and remove the complete grating holder assembly. Reverse the procedure when reinstalling the grating assembly. NOTE: To ensure proper positioning, make sure that the grating assembly is properly seated before tightening the 8-32 clamp screw. The clamp screw should be tightened the same torque to ensure proper positioning.
3.7 Slit Chamber Air Inlet Valves: (optional) An air inlet valve is supplied to bring the slit chamber to atmospheric pressure and is located on the side of the slit housing. The valve is open when the handle is in line with the valve body, and closed when the handle is 90 degrees to the valve body.
Section IV. Controlling the VM-502 with the SD3 SpectraDrive Controller 4.1 Description The Princeton Instruments SD3 SpectraDrive Controller is used with the Acton VM Monochromators in conjunction with Acton Monochromator Control Software to provide the electronic drive for wavelength positioning, diverter mirror control and filter positioning. The SD3 also provides the link between the monochromator and the computer. Both USB and RS-232 are supplied as standard interfaces. 4.
Monochromator Wavelength Movement Commands GOTO Goes to a destination wavelength at maximum motor speed. Accepts destination wavelength in nm as a floating point number with up to 4 digits after the decimal point or whole number wavelength with no decimal point. Same as GOTO (For compatibility with software written for previous Acton models.) NM Goes to a destination wavelength at constant nm/min rate specified by last NM/MIN command.
The following command is used for grating installation by Acton part #: INSTALL Installs new grating parameters into the non-volatile memory of the monochromator. Uses the part # of the grating to specify the parameters. e.g. 1-120-500 5 INSTALL places a 1200 g/mm grating blazed at 500 nm into the second grating position on #5. The following commands are used for grating installation by grating parameters: SELECT-GRATING Specifies the grating number to be installed 1 - 9.
Calibration Commands: INIT-OFFSET Sets the offset value for the designated grating. Default values are 25600 for all gratings. The grating designator used with this command is grating# - 1. e.g. 25590. 0 INIT-OFFSET for setting offset on grating #1. NOTE: This command requires a decimal point after the offset value. For the new parameters of this command to take effect, the monochromator must be initialized with the MONO-RESET command or by turning the power off and back on.
The following are the Start-Up parameters and their default values: Default Values: GRATING #1 WAVELENGTH 0.0 nm SCAN SPEED 200.0 nm/min INITWAVELENGTH Sets an initial wavelength for the SD3 after initialization. INIT-SRATE Sets an initial scan rate for the SD3. e.g. 435.84 INIT-WAVELENGTH e.g. 200.
Section V. Care of the Instrument 5.1 Main Chamber (Instrument) The main chamber should be kept sealed at all times, and under vacuum if possible. Only vacuum-compatible material should be exposed to the vacuum of the instrument. When operating the instrument in the vacuum ultraviolet region, the vacuum should be better than 5 x 10-5 Torr. 5.2 Bilateral Slits The knife edges that form the slit aperture are mounted on Ball Slides and therefore require no lubrication.
Appendix A.
