Purchase Description 24E-556A-IN Rev. 1 dated 12 April 2024.pdf

24E-556A-IN

12Apr2024

Rev1

DIRECTORATE OF METROLOGY

PURCHASE DESCRIPTION

FOR

Subtractive Double Monochromator

1. Scope This purchase description identifies the requirements for a Subtractive Double Monochromator. This standard shall be used to calibrate silicon detectors, InGaAs detectors, germanium detectors, FEL lamps, and deuterium lamps at the Air Force Primary Standards Laboratory. The standard shall have the necessary equipment that allows the standard to be operated remotely.

2. Performance Requirements

2.1. Monochromator Configuration: Double subtractive monochromator.

2.2. Wavelength Range: 0.2 – 2.2μm.

2.3. Wavelength Accuracy: 0.05%. The difference between the true wavelength and the item’s wavelength setting.

2.4. Wavelength Precision: 0.01%.

2.5. Wavelength Resolution: 0.05nm.

2.6. Focal Length: 254 mm.

2.7. F/Number: f/4.

2.8. Variable Chopper Range: 10 – 350Hz.

2.9. Variable Chopper Output: TTL Compatible BNC.

2.10. Filter Wheel: The filter wheel has sufficient filter positions to cover a wavelength region of 0.2 to 30 μm, and shall also provide shutter and open positions.

2.11. Monochromator Dispersion: at least 4 nm/mm.

2.12. Diffraction grating(s): The monochromator shall have sufficient diffraction gratings necessary to cover the range (2.2). The Air Force shall be capable of replacing the diffraction gratings when necessary.

2.13. Diffraction grating size: Each diffraction grating shall have dimensions of 68mm x 68mm.

2.14. Diffraction grating groove density: 600 g/mm.

Attachment 1

Rev1

2.15. Diffraction Grating Blazed Wavelength: Over the wavelength range of 0.2 – 0.35μm, diffraction grating shall be blazed at 0.3μm. Over the wavelength range of 0.35 – 1.1μm, the diffraction grating shall be blazed at 0.5μm. Over the range of 1.1 – 2.2μm, the diffraction grating shall be blazed at 1.6um.

2.16. Diffraction grating mount: The monochromator shall have two turrets, which each turret consisting of a replaceable tri-grating mount. Each tri-grating mount shall have diffraction gratings that ensure the wavelength range (2.1) and blazed wavelength (2.15) requirements.

2.17. Slit Width Range: The monochromator shall have a middle slit between the two diffraction gratings, as well as an entrance slit an exit slit. At a minimum, each slit shall be adjustable to widths of 0.5mm, 1.25mm, 2.5mm.

2.18. Warm-up Time: The monochromator shall meet all specifications contained in this purchase description after a warm-up time not to exceed 60 minutes.

3. Functional Requirements

3.1. Automated Control: The user shall be able to control the item using remote operations.

3.2. Additional Hardware: Additional hardware required to make this item function as identified by this purchase description shall be required and provided by the vendor.

3.3. I/O Communications Interface: The item shall be equipped with an IEEE-488 interface, and/or a USB interface, and/or a RS-232 interface with a RS-232 to USB dongle. The item shall be provided with the necessary cables to allow for remote communication.

3.4. Remote Interface/Programming: The item shall be programmable via an interface connection (3.3) by an external controller.

3.5. Software Development Kit (SDK): The item shall include a Windows 10 compatible .NET DLL library with methods and properties to access the item’s controller. The SDK shall allow for the remote setting and reading wavelength set point, chopper frequency set point, filter wheel position, and diffraction grating position. The SDK shall allow for the calibration of the item to ensure the specified accuracy (2.3)

4. Mechanical and Physical Requirements: The item shall be constructed of materials that meet the requirements of this specification and in accordance with the best commercial practices for industry approved equipment. The item shall be designed and manufactured to maximize reliability, maintainability, accuracy of operation, and ease of operation. All parts such as shafts, bearings, regulators, switches, controls, etc., shall have proper clearance and adjustments. They shall work together so that the equipment will supply the rated requirements without unnecessary strains, vibrations, or overheating. They shall be able to withstand the conditions met in shipping, storage, installation, and service. All materials and parts of this equipment shall be capable of withstanding the environmental requirements of this specification.

4.1. Power Requirements: The item shall have a dedicated power supply that powers the filter wheel, wavelength drive motors, and associated electronics, and shall operate at 115 VAC, ± 10%. 50 – 60 Hz, 450W Max. The item shall be supplied with a power cord.

4.2. Filter Wheel: The item shall have a filter wheel installed in the monochromator that shall cover the wavelength region (2.2) and have open and closed positions.

4.3. Chopper: The item shall have a chopper installed in the monochromator, and a reference BNC shall output a TTL level squarewave synchronous with the optical chopper.

4.4. Commercial Parts: Commercial parts and materials that are used shall have properties consistent with a precision laboratory instrument.

Rev1

4.5. Materials: Materials used in electronic cable and connector technology shall conform to applicable requirements in MIL-STD-454 and MIL-STD-1587 NOTI. These materials shall be selected such that they degrade by a mechanism other than elimination and shall be resistant to corrosion and reductions in performance.

4.6. Metals: Metals shall be of the corrosion-resistant type or shall be metallurgically processed or suitably treated to resist corrosion due to atmospheric conditions likely to be met in storage, service, or transportation. Dissimilar metals in close contact with each other shall not be present.

Selection of metals shall be in accordance with the applicable requirement of MIL-STD-889B.

4.7. Individual Unique Identifier Designation: The item shall be clearly labeled with a model number, serial number, and manufacturer’s name. Unique item identification labeling shall follow Item Identification and Valuation requirements as stated in the contract.

4.8. Operating Environment:

4.8.1. Operating Temperature: 23 °C ± 5 °C, at a minimum.

4.8.2. Operating Humidity: 25 to 50 % RH, at a minimum.

4.9. Facility Requirements: No additional facility requirements shall be necessary for proper operation of the monochromator. Equipment shall be air cooled or closed loop water cooled. No external gas or water supply shall be required for operation of the item to withing the performance requirements outlined in this purchase description.

4.10. Workmanship: The workmanship shall be first class, of neat general appearance in compliance with standard commercial practices. The standards of workmanship shall be such that the item complies with the requirements set forth in this purchase description.

5. Operator’s Manual: A manual for the item and the SDK shall be provided upon delivery.

6. ENVIRONMENT, SAFETY and OPERATIONAL HEALTH: A combination of the system manual, other documentation, and/or the system itself shall identify potential environment, safety and operational health hazards and how they are mitigated when the design itself cannot mitigate them.

This will be accomplished through stating the hazard and accompanying mitigation through the use of safety devices, use of warnings or use of special operational procedures to counter such hazards.

Attachment to Purchase Description

24E-556A-IN

Subtractive Double Monochromator

DATA REQUIREMENTS

MANUALS: A complete user and service manual and calibration procedure shall be provided with each unit in contractor format. Manuals shall be on CD/DVD-ROM in Indexed Portable Document Format (iPDF). The manuals shall comply with Data Item Description (DID) DI-TMSS-80527C and the Contract Data Requirements List (DD Form 1423).