PD_18E-187A-DC_Rev_4_Data_Atch.pdf

28 August 2018

18E-187A-DC

REV 4

PURCHASE DESCRIPTION

AFPSL - High Voltage Resistive Divider

1. SCOPE: This Purchase Description (PD) describes a High Voltage Resistive Divider with durable, long-lasting Shipping Container. The High Voltage Resistive Divider will be used by the U.S. Air Force Primary Standards Laboratory (AFPSL) in the calibration of High Voltage Test, Measurement, and Diagnostic Equipment (TMDE) such as power supplies, voltmeters, voltage dividers and probes. The following will discuss the minimum performance, design, environmental, and reliability requirements, as well as the quality assurance provisions for this High Voltage Resistive Divider. The High Voltage Resistive Divider shall be of primary standards laboratory caliber / metrology-grade quality and uncertainty, as described below, that it may be used as an Air Force Primary Measurement Standard and Transfer Standard for many calibration procedures.

2. COMPONENT: Listed in this PD are the Air Force minimum functional requirements which are to be satisfied. Proposals offering a High Voltage Resistive Divider against the requirements of this purchase description will be evaluated for acceptability.

3. COMPATIBILITY: This item must be compatible with equipment currently in use by the

Air Force in the High Voltage measurement area. Items such as power supplies, voltmeters, voltage dividers, probes, and other High Voltage TMDE shall be supportable with this High Voltage Resistive Divider without limitation due to lack of capability of the High Voltage Resistive Divider.

4. PERFORMANCE REQUIREMENTS:

4.1. Specifications: The High Voltage Resistive Divider shall meet or exceed the following measurement specifications with a 95% confidence level for 1 year measurement uncertainties. Items that are available commercially shall also meet the specifications published by the manufacturer.

4.2. Functions: Alternating Voltage (60Hz) and Direct Voltage.

4.3. Input Voltage Range: The High Voltage Resistive Divider shall be capable of measuring voltages up from 1000 V to 100 kV.

4.4. Output Voltage: There shall be two output taps provided with the following characteristics:

4.4.1. Output #1 Voltage: 10 Volts at 100,000 Volts input.

4.4.2. Output #1 Ratio: 10,000:1

4.4.3. Output #2 Voltage: 1 Volt at 100,000 Volts input.

4.4.4. Output #2 Ratio: 100,000:1

4.5. Input Impedance: The Input Impedance of the High Voltage Resistive Divider shall be ≥

150 MΩ.

4.6. Linearity of Ratio: Shall not be worse than ±0.005% from maximum to minimum in the range of 2kV to 100kV of applied Direct Voltage. Shall not be worse than ±0.025% from maximum to minimum in the range of 2kV to 100kV of applied Alternating Voltage.

4.7. Accuracy of Direct Voltage Ratio: ±60 ppm or better.

4.8. Accuracy of Alternating Voltage Ratio: ±300 ppm or better.

4.9. Ratio Stability: Shall not be worse than ±0.003% short term, ±0.005% per year.

4.10. Voltage Frequency: The High Voltage Resistive Divider shall be capable of voltage measurements for frequencies ranging from DC to 60 Hz.

4.11. Initial Calibration: The initial DC calibration for the High Voltage Resistive Divider shall be performed by the National Institute of Standards and Technology (NIST) or other National Metrology Institute (NMI) approved by AFMETCAL. The initial AC calibration for the High Voltage Resistive Divider shall be performed by an NMI approved by

AFMETCAL.

4.11.1. Initial Calibration Method: The High Voltage Resistive Divider shall be calibrated by making measurements of the ratio between the voltage applied to the high-voltage terminal and that at the 1 Volt and 10 Volt Output Taps with DC Voltage and AC Voltage (RMS) at a frequency of 60Hz.

4.11.1.1. DC Voltage Calibration: The DC Voltage Calibration shall be performed at 10, 50, 75, and 100 kV. A Voltage Ratio shall be given for elapsed times of 3, 6, and 9 minutes for each voltage on both Output Taps.

4.11.1.2. AC Voltage Calibration: The AC Voltage Calibration shall be performed at

RMS voltages of 2, 5, 10, 50, 75, and 100 kV at 60 Hz on each. A 60 Hz Voltage Amplitude Ratio shall be given for an elapsed time of 5 minutes for each voltage on Output Taps.

4.12. Applied Voltage Sustainability: The High Voltage Divider should be able to maintain its ratio value within the proposed short-term uncertainty with the maximum applied voltage for at least one hour. The purpose of this is to minimize the risk of any resistor failure within the divider stack as a result of exposure to sustained maximum applied voltage.

5. GENERAL, MECHANICAL & PHYSICAL REQUIREMENTS:

5.1. Dimensions and Weight: The High Voltage Resistive Divider shall be no larger than 40 inches (101.6 cm) height, 25 inches (63.5 cm) depth, and 25 inches (63.5 cm) wide. Weight shall not exceed 60 lbs. (27.2 kg) maximum.

5.2. Output Connectors: The High Voltage Resistive Divider shall have BNC type output connectors for each output tap and a 5-way binding post for a ground connection.

5.3. Input Connector: The High Voltage Resistive Divider shall have an input connector capable of safely accepting DC Voltages up to 100,000V and AC RMS Voltages up to 100,000V @ 60 Hz.

5.4. Transportation Container(s): The High Voltage Resistive Divider shall be provided with

(a) reusable Transportation Container(s) suitable for repeated use shipping via military and commercial land/air carrier.

5.4.1. Outside Dimensions: Each no larger than 46 inches (116.8 cm) height, 35 inches (88.9

cm) depth, and 35 inches (88.9 cm) wide.

5.4.2. Shock Absorption: The Transportation Container(s) shall be shock absorbent, making use of technology such as shock absorbing frames, protective foam, and/or permanent case liner made of material sufficient to allow a secure fit of the High Voltage Resistive Divider in order to prevent damage to the High Voltage Resistive Divider during repeated use shipping via military and commercial land/air carrier.

5.4.3. Handles: If a two-man lift is necessary, a minimum of four (4) lift handles shall be provided.

5.4.4. Latches: Minimum of two (2) recessed latches shall be provided to secure the cover of the Transportation Container(s) to the base. The latches shall be of sufficient strength to maintain the integrity of the Transportation Container(s) with the High Voltage Resistive Divider inside during a two-man lift.

5.4.5. Construction: The Transportation Container(s) shell material shall have minimum strength equivalence to that of HMW Polyethylene with an industrial frame structure.

5.5. Operating Environment: The High Voltage Resistive Divider shall perform to all specifications within the following environment:

5.5.1. Temperature Range: 22.8 ºC ±3.3 ºC (73 ±6 ºF)

5.5.2. Humidity Range: 20% to 50% RH

5.6. Storage Environment: Damage to the unit shall not occur as a result of storage in the following environment:

5.6.1. Temperature Range: 5 ºC to 60 ºC (41 ºF to 140 ºF)

5.6.2. Humidity Range: 15% to 80% RH

5.7. Commercial Parts: Commercial parts and materials that are to be supplied shall have properties consistent with a precision laboratory instrument.

5.8. Accessories and Adapters: Any and all ancillary equipment/items and accessories (not otherwise specified) needed to perform as described shall be provided by the contractor.

This would include, but is not limited to, special tools, cables, fixtures, adapters and Standards.

5.9. Design and Construction: The equipment shall be designed and constructed of materials that meet the requirements of this specification and in accordance with the best commercial practices for industry approved equipment. It shall be designed and manufactured to achieve 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 material and parts of this equipment shall be capable of withstanding the environmental requirements of this specification.

5.10. 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 whenever possible.

5.11. Metals: Metals shall be of corrosion resistant type or suitably treated to resist corrosion due to atmospheric conditions likely to be met in storage, service or transportation.

Dissimilar metals in close contact shall not be present. Selection of metals shall be in accordance with the applicable requirement of MIL-STD-889B.

5.12. Circuit Boards: Frequent shipping will require that all circuit boards be sufficiently secured by their connectors and be held in place by securing screws or other such hold-down devices.

5.13. Individual Unique Identifier Designation: This 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.

6. SAFETY: The High Voltage Resistive Divider shall be designed such that it will not be of any hazard to itself or to any person operating it using reasonable precautionary procedures.

7. WORKMANSHIP: The workmanship shall be first class, of neat general appearance, and comply with standard commercial practices. The standard of workmanship shall be such that the High Voltage Resistive Divider and Transportation Container conform to the requirements set forth in this PD. All components, subassemblies and final assembly shall comply with the examination and test in Section 11.

8. INTERCHANGEABILITY: All replaceable assemblies, subassemblies, components, and parts of a designated model provided under a single contractor or ordered from any one manufacturer shall be fully interchangeable without interference or degradation of performance.

9. QUALITY ASSURANCE: This item shall be inspected and tested at destination, as specified elsewhere in this contract. This item will be checked with test equipment with parameters equal to or better than those required to assure specified performance requirements are met. Test equipment used is traceable to the National Institute of Standards and Technology when/where required. Tests will 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 available components provided with this system must, as a minimum, satisfy their commercially published performance specifications.

Attachment: Data Requirements

Attachment to Purchase Description 18E-187A-DC

High Voltage Resistive Divider

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).