22E-584A-DC DC Voltage Reference Standard Purchase Description Rev 7.pdf

22E-584A-DC

January 26, 2023

Revision #7

DIRECTORATE OF METROLOGY

PURCHASE DESCRIPTION

FOR

DC VOLTAGE REFERENCE STANDARD

1.0 SCOPE: This purchase description describes a DC Voltage Reference Standard Unit (unit), which contains four DC voltage standards (standard), contained in one rack mountable kit. This is intended as a replacement for the Fluke 734A/AF, which the unit shall have to match in form, fit, and function, as will be outlined in this purchase description. It will be used by the Air Force’s Precision Measurement Equipment Laboratories (PMELs) to serve as the primary DC voltage reference standard, maintain traceability to the Intrinsic Josephson Junction, and disseminate the volt to the rest of the Air Force. Each individual DC Voltage Standard shall have a 10V, 1V, and 0.1V tap. The standards shall be of sufficient quality and uncertainty, as described below. All specifications will apply to each DC voltage standard; each unit will contain four separate standards. The unit shall be capable of charging and auxiliary power capabilities for the four standards. Each DC Voltage Reference Standard requires six months of stability data from the manufacturer.

2.0 WORKLOAD: This item will support the following workload: voltage calibrators, multi-function calibrators, digital multimeters, multi-product calibrators, and precision DC sources. Weapon Systems include the following: B2A, MM3, RASCAL, B1B, C17, CV22, and M86.

3.0 PERFORMANCE REQUIREMENTS: The DC Voltage Reference Standard Unit will contain four independent DC voltage standards, contained in one rack mountable kit. Each DC Voltage Standard shall have a 10V, 1V, and 0.1V tap. The 10V tap shall have an accuracy of +/-1ppm, the 1V tap shall have an accuracy of +/-2ppm, and the 0.1V tap shall have an accuracy of +/-5ppm at k=2.

Output Voltage Stability 30 Days (±μV/V)

10 V 1 ppm 1 V 2 ppm

0.1 V 5 ppm

3.1 INTERNAL BATTERY: At full charge, the internal battery of each standard operates for a minimum of 72 hours at 23 ±5 °C, with 0 mA to 0.1 mA total current drain at the outputs.

3.2 UNIT ENCLOSURE: The unit shall have an AC power bus inside the enclosure that powers each of the 4 standards with only one AC line cord.

4.0 FUNCTIONAL REQUIREMENTS: Listed in this purchase description are the Air Force minimum functional requirements which are to be satisfied.

4.1 COMPATIBILITY: This item must be compatible with equipment currently in use by the Air Force in the Direct Current/Low Frequency measurement area, which is the Fluke 734A/AF mountable rack and Programmable Josephson Junction. The unit should be able to be intercompared between itself and the Fluke 734A/AFs existing in the Air Force. Each individual standard shall be capable of fitting into existing Fluke 734A/AF unit case.

Dimensional limits are provided in section 5.1.

4.2 SPECIAL HARDWARE/SOFTWARE REQUIREMENTS: Any special equipment, fixtures, tools, standards, etc., required to establish Air Force self-sufficiency for calibration and not common to a secondary calibration laboratory shall be supplied with the unit. Any unique accessories including software required for calibration of this item shall be furnished by the manufacturer. Units that fail calibration and are recommended to be aligned or adjusted, either manually or using an automated alignment/adjustment software, the special hardware, manual instructions, software, software instructions and software licenses (where required by the manufacturer, and shall be valid for the life of the instrument) needed to perform the alignment/adjustment process shall be included with the unit. A list of peripheral support TMDE equipment required to accomplish the calibration/alignment/adjustments of the unit shall be provided with the unit. The support TMDE for the unit shall consist of equipment that is currently available in the market place. The unit shall not require support equipment that has been obsoleted and no longer supportable by the manufacturer and/or is not otherwise obtainable/supportable by the Air Force.

4.3 WORKMANSHIP: The workmanship shall be first class, of neat general appearance, and shall comply with standard commercial practices. The standards of workmanship shall be such that the unit shall comply with the requirements of this description.

4.4 QUALITY ASSURANCE: This item shall be inspected and evaluated at destination. It will be evaluated with test equipment with parameters equal to or better than those required to assure specified performance requirements are met. The test equipment used is traceable to the intrinsic Josephson Junction when/where required. Evaluations will be performed to assure the item meets the requirements of this purchase description. Such evaluation at destination does not relieve the contractor of performing all inspections and quality checks at the point of fabrication. In addition to all elements of this purchase description, all commercially available components provided with this item and the item itself shall, as a minimum, satisfy all commercially published performance specifications (and must be provided by the contractor). Evaluations will also be performed to assure the item meets the requirements of the commercially published performance specifications.

4.5 ENVIRONMENT, SAFETY, AND OCCUPATIONAL HEALTH: A combination of the system manual, other documentation, and/or the system itself shall identify potential environment, safety and occupational 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.

4.6 STABILITY DATA: Provided by the manufacturer, each unit shall come with no less than 6 months of quantitative, stability data specific to the actual performance of each standard.

5.0 MECHANICAL & PHYSICAL REQUIREMENTS:

5.1 DIMENSIONS AND WEIGHT: The unit shall be no larger than the following dimensions:

Dimensional and Weight Limits Standard Dimensions Unit Dimensions

Height 5.28 in 7 in Width 3.85 in 18 in Depth 16 in 20 in including handles

Weight 15 lbs 80 lbs

5.2 MODEL AND SERIAL NUMBER IDENTIFICATION: Every unit will have a model and serial number, in addition to warranty information display visible on the unit itself. Each standard shall also have a unique model and serial number, in addition to warranty information displayed on the standard itself.

5.3 CARRYING/SHIPPING CASE: Five (5) reusable shipping cases shall be supplied that can hold one unit, any auxiliary power source, all accessories, and manuals each. Each case shall be rugged, rigid, waterproof, and capable of withstanding shock and vibration from day-to-day shipping.

5.3.1 QUALITY: Each case will be inspected by the Air Force and shall be free from any defects (i.e. poor molding fabrication, loose materials, damaged or improperly assembled cases, peeling, or chipping of plating or finish, nicks or burrs of metal parts, and post molding warping) which affect the durability, strength, safety, or serviceability. The finish of the exposed edges/surfaces shall be smooth and free of sharp or jagged surfaces. The container shall be labeled with identifying information (AFMETCAL, part number, etc.). The container shall also have the required shipping regulation labeling, i.e. battery.

5.3.2 CLASPS: Heavy duty, corrosion resistant clasps or latches shall be attached to the case. The clasps or latches shall prevent any separation of the closure or unlocking of the clasps when the case is subject to shipping conditions. A quantity of no less than two clasps shall be provided per case.

5.3.3 HINGE: The cases hinges shall have corrosion/erosion resistant properties and allow for easy opening and closing of the case. A quantity of no less than two hinges shall be provided per case.

5.3.4 CUSHIONING: The top and bottom shells of each case shall be lined with black polyurethane foam cushioning material. The minimum thickness shall be 2.0 inches (5.08 cm). The foam shall be cut to fit the unit and shall have at least 2 inches of foam separating it from the case on each surface plane.

5.3.5 HANDLES: The unit shipping/carrying case shall have at least two, heavy duty handles.

5.3.6 LOADING: The shipping/carrying case shall be tested with not less than 100 pounds. This will simulate an in-transit loading scenario. The case shall then be inspected thoroughly for damage.

5.3.7 SHIPPING/HANDLING: Damage, accuracies, and/or stability shall not be altered from the normal handling and normal transportation of the unit.

5.3.8 COMMERCIAL AIR TRANSPORTABILITY: The unit and shipping case shall be suitable for commercial air transport and shall meet all shipping regulations that apply.

5.4 MANUALS:

5.4.1 OPERATOR’S MANUAL: An operator’s manual shall be provided with the unit.

5.4.2 MAINTENANCE MANUAL: A maintenance manual shall be provided with the unit that details any applicable adjustment procedures.

6.0 FACILITY REQUIREMENTS:

6.1 OPERATING ENVIRONMENT/STORAGE: Shall be operable in a temperature range of at least 15 C to 30 C. Shall be storable in a temperature range of at least -25 C to 45 C.

6.2 ELECTRICAL POWER AND CONNECTIONS: Unit shall operate under an input range of 100V to 250V.