Purchase_Description_19E-129A-PH_Rev._1_dated_30_August_2018.pdf

19E-129A-PH

30 August 2018

Revision 1

PURCHASE DESCRIPTION

FOR

LUMINANCE SPHERE SOURCE

1.0 SCOPE: This purchase description identifies the performance requirements for an integrating sphere source used for luminance measurements. The Luminance Sphere Source will be used as a uniform light source for all Air Force luminance measurements, and shall be maintained at a Correlated Color Temperature (CCT) of 2856K and/or 3100K. The Luminance Sphere Source shall maintain a monitor detector to accurately monitor luminance at the exit port of the sphere to hold the luminance scale, and shall have fully automated output controls with minimal luminance gaps when switching between lamps. Any necessary controllers, power supplies, and shipping containers must be supplied with the Luminance Sphere Source.

2.0 REQUIREMENTS: The following will discuss the minimum performance, design, functional, environmental, reliability requirements and quality assurance provisions for this Luminance Sphere Source. The Luminance Sphere Source shall be capable of generating Luminance outputs at the exit port from 2 to 20,000 foot-Lamberts (fL) at 2856 Kelvin. The output at the exit port shall be capable of fully automatic control via software adjustments, based on the measurement of the monitor detector.

3.0 SALIENT CHARACTERISTICS:

3.1 Integrating Sphere Dimensions:

3.1.1 Integrating Sphere Size: The integrating sphere shall have a diameter of no greater than 12 inches. Lamp housings and external support structures and cages for shipping protection are not included in the integrating sphere diameter.

3.1.2 Exit Port Size: The integrating sphere shall have one circular exit port with a diameter of at least 3 inches. Exit port sizes greater than 3 inches are acceptable provided that the Luminance Sphere Source can meet Luminance Output and Output Uniformity specifications listed within this Purchase Description.

3.2 Luminance Sphere Source Output:

3.2.1 Luminance Output: The Luminance Sphere Source shall be capable of generating a luminance output from 2 fL to 20,000 fL at 2856K.

3.2.2 Correlated Color Temperature: The Luminance Sphere Source shall be capable of generating an output at a constant CCT of 2856K, and optionally shall be capable of also maintaining a constant CCT of 3100K. The CCT must be maintained to within 25K of the set point when constant current is supplied to the lamps when operating across the full range of luminance outputs.

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3.3 Spectral Distribution: The Luminance Sphere Source shall have a spectral distribution profile that is similar to that of the CIE standard Illuminant A across the visible spectrum of light from 380 nm to 780 nm.

3.4 Monitor Detector: The Luminance Sphere Source shall have an internal monitor detector which is capable of monitoring luminance at the exit port of the integrating sphere to within 2.0% of actual luminance output. The detector shall be properly baffled and shielded from direct view of any lamps in order to prevent erroneous readings.

3.5 Internal/External Lamps: The Luminance Sphere Source shall have a sufficient number of lamp sources and/or attenuators necessary to generate luminance across the entire range with minimal gaps in attainable luminance values. Any gaps in coverage must be detailed in supporting documentation. The wattage, type, and standard part number for supply of all bulbs should be provided in supporting documentation. The Air Force shall be capable of replacing the bulbs in all lamps when necessary.

3.6 Power Supply Requirements: All power supplies necessary to drive each lamp at the proper constant current necessary to maintain a CCT at 2856K or 3100K shall be provided as part of a complete system. The specifications for the power supplies shall be provided in supporting documentation.

3.6.1 Interchangeability: All power supplies shall be interchangeable between each Luminance Sphere Source system. The part number(s) of all power supplies shall be supplied in supporting documentation.

3.7 Automated Variable Output Control: Automated output control capability shall be provided. This shall be accomplished either through a dedicated physical control unit on which direct output levels are entered or through use of an integrated software program that controls the output levels.

3.7.1 Automated Lamp Control: Automated lamp on/off control shall be provided. This capability shall include proper ramping to the set constant current and proper ramping from the set current to zero in order to prevent shock to the bulbs. The automated lamp control shall be provided in conjunction with automated optical attenuator control in order to automate the full range of luminance output.

3.7.2 Automated Optical Attenuator Control: An automated optical attenuator shall be provided in order to adjust luminance output to the desired set point. This capability shall be provided in conjunction with automated lamp control in order to automate the full range of luminance output.

3.8 User Interface: Operations shall be performed using automated measurement software provided by the manufacturer or with the use of front panel controls.

3.8.1 Controller: A dedicated controller shall be provided to operate any control software provided as necessary to operate the Luminance Sphere Source.

3.8.1.1 Operating System: Microsoft Windows 10

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3.8.2 General Software: The contractor shall provide full command set and operating control codes to operate with the following:

3.8.2.1 Operating System: Microsoft Windows 10

3.9 Calibration: The Luminance Sphere Source shall be capable of storing all calibration coefficients within the internal memory in order to maintain traceability of luminance output levels. The calibration coefficients must be accessible to the user in order to update these coefficients as required.

3.9.1 Luminance Detector: The User must be capable of updating any coefficients necessary in order to maintain the accuracy of the luminance monitor detector to within 2% of the actual sphere output.

3.9.2 Lamp Operating Current: The User must be capable of updating the operating current necessary to maintain operation at a constant color temperature of 2856K and/or 3100K for each individual lamp.

3.9.3 Interchangeability: The each integrating sphere must be interchangeable with each provided controller and set of power supplies. The user must be capable of calibrating any of the supplied integrating spheres with any set of power supplies and controller, provided that the user enters the correct lamp currents and other coefficients into the system memory prior to calibration.

3.10 Shipping Requirements: The integrating sphere shall be protected from potential damage during shipment through use of an external cage structure or through use of a sphere internal to the system. The Luminance Sphere Source shall be supplied with a dedicated reusable hard-sided shipping case(s) and appropriate cushioning foam inserts in order to minimize potential damage during shipment. The integrating sphere and lamps shall be contained in a shipping case separate from the power supplies and system controller to minimize potential damage to the integrating sphere. The systems will be regularly transported to USAF calibration facilities for recalibration via commercial shipment. The weight of the packaged systems and their dimensions shall be provided in supporting documentation.

4.0 PHYSICAL/MECHANICAL REQUIREMENTS:

4.1 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 system complies with the requirements set forth in this purchase description.

4.2 Selected Components: Matched and selected components shall be kept to an absolute minimum. Use of specially built non-standard components other than switches and similar individual assemblies shall be avoided.

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

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4.4 Metals: Metals shall be of corrosion resistant type or suitably treated to resist corrosion due to atmosphere conditions likely to be met in storage, services or transportation.

Dissimilar metals in intimate contact shall be kept to a minimum.

4.5 Mounting: The integrating sphere shall be capable of being mounted along its optical axis.

4.6 Protective Covers: The exit port of the integrating sphere shall be covered appropriately to avoid dust intrusion. Any unused ports shall be covered appropriately in such a manner to maintain proper optical design and baffle placement when the port is not in use.

4.7 Accessories: All accessories, connectors and cables necessary for normal operation and calibration of the equipment shall be supplied.

4.8 Power Requirements: These power requirements apply to any controllers and power supplies provided as part of a complete Luminance Sphere Source.

4.8.1 Electrical Power and Connections: 110V ± 10%, 60Hz ±5%

4.8.2 Electrical Safety: Equipment shall be designed such that it shall not be of any hazard to itself or to any person operating it using reasonable precautionary procedures.

4.8.3 Power Cord: Each item that requires power shall be supplied with one assembled power cord, 3 to 6 feet in length, and connectable to a standard 15 Amp, 120VAC, local power source.

4.9 Operating Environment/Storage:

4.9.1 Operating Temperature Range: The unit shall perform to full specifications at 22.8°C +/-3.3°C.

4.9.2 Operating Humidity Range: The unit shall perform to full specifications from 20 to 50 % RH.

4.9.3 Storage Conditions: The unit shall be capable of surviving in standard shipping conditions without damage to the instrument.

5.0 CALIBRATION:

Calibration of the Luminance Sphere Source shall be accomplished by comparison to external standards traceable to a National Metrology Institute (NMI) or other AFMETCAL approved laboratory when required. Any unique hardware and software accessories required for calibration of this item, to the specifications of this purchase description and to all commercial specifications, shall be furnished by the contractor. Unique hardware and software accessories are defined as software packages, licenses, cables, and other equipment that are specifically required for calibration of the Luminance Sphere Source and not otherwise commonly found in a calibration laboratory.

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6.0 TESTING:

This item shall be inspected and tested at destination, as specified elsewhere in this contract.

This item shall be checked with test equipment with parameters equal to or better than those required to assure that specified performance requirements are met. Test equipment used has first echelon certification directly traceable to a National Metrology Institute (NMI) or other AFMETCAL approved laboratory when required. Tests shall be performed to assure the item meets the requirements of this purchase description. Such testing at destination does not relieve the contractor of performing all inspections and quality checks at the point of fabrication, as specified elsewhere in this contract, or as necessary, to ensure performance, as specified herein. In addition to all elements of this purchase description, all commercially published components provided with this system must, as a minimum, satisfy their commercially published performance specifications (and must be provided by the contractor).

7.0 LICENSING:

Where licensing issues apply to any part of the Luminance Sphere Source, such licensing and associated documents shall be obtained and provided by the contractor. Licenses shall not contravene federal law, federal procurement regulations, or the requirements of this acquisition.

8.0 MODEL AND SERIAL NUMBER IDENTIFICATION (IUID):

Each individual component of the system (integrating sphere, power supply(s), controller, shipping cases, etc.) shall be clearly labeled with a model, serial number, and manufacturer’s name. Unique item identification labeling shall follow the Item Identification and Valuation clause as stated in the contract.

Attachment:

Data Requirements

Attachment to Purchase Description 19E-129A-PH

Photometric Calibration System - Luminance

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).

CALIBRATION CERTIFICATE: A calibration certificate, traceable to the National Institute of Standards and Technology (NIST) or other national metrology institutes (NMIs) shall be provided with each instrument. The calibration certificate shall comply with Data Item Description (DID) DI-QCIC-80798C and the Contract Data Requirements List (DD Form 1423).