CSS FY20-JAX-0001_VCS.pdf

CALIBRATION STANDARDS SPECIFICATION

PROCUREMENT PACKAGE

VACUUM

SENSOR CALIBRATOR

DEPARTMENT OF THE NAVY

METROLOGY AND CALIBRATION PROGRAM

CSS FY20-JAX-0001

MARCH 2025

DISTRIBUTION STATEMENT C. DISTRIBUTION AUTHORIZED TO U. S. GOVERNMENT AGENCIES AND

THEIR CONTRACTORS TO PROTECT PUBLICATIONS REQUIRED FOR OFFICIAL USE OR FOR

ADMINISTRATIVE OR OPERATIONAL PURPOSES ONLY. OTHER REQUESTS FOR THIS DOCUMENT SHALL BE REFERRED TO THE NAVAIR METCAL PROGRAM OFFICE, BLDG 1403, 22113 FORTIN CIRCLE, PATUXENT

CALIBRATION STANDARDS SPECIFICATION

PROCUREMENT PACKAGE

VACUUM

SENSOR CALIBRATOR

Prepared for:

NAVAIR Metrology and Calibration (METCAL) Program

Prepared by:

Devin Harants

METCAL Branch

Fleet Readiness Center Southeast Enterprise Ave, Bldg. 6G 1st Floor

Jacksonville FL 32212-0016

DEPARTMENT OF THE NAVY

METROLOGY AND CALIBRATION PROGRAM

Table of Contents

1.0 SCOPE

1.1 General

1.2 Usage

1.3 Design activity

1.4 Classification

2.0 APPLICABLE DOCUMENTS

2.1 Reference documents

2.2 Order of precedence

3.0 REQUIREMENTS

3.1 Equipment components

3.2 Design and construction

3.3 Electrical power sources and connections

3.4 Enclosure physical characteristics

3.5 Environmental requirements

3.6 Safety

3.7 Marking and identification

3.8 Maintainability

3.9 Performance requirements

1.0 SCOPE

1.1 General. This document specifies the minimum requirements for a Vacuum Sensor Calibrator. It is intended to be used by Navy personnel in shore-based laboratories. The equipment will be used to calibrate vacuum sensor arrays by method of comparison to the output of a vacuum standard. For the purpose of this Calibration Standards Specification (CSS), the Vacuum Sensor Calibrator herein shall be referred to as the VSC.

1.2 Usage. Equipment covered by this CSS is intended for use in testing equipment and systems in controlled environments in which Military equipment is operated.

The requirements of this CSS are tailored to the intended use of the equipment.

Specific requirements of MIL-PRF-28800G, as identified in this CSS, are invoked according to the class of equipment.

1.3 Design activity. This VSC product is specific to Navy calibration requirements.

Maximum use of commercial-off-the-shelf items is desired. The overall product design, packaging, and life-cycle configuration management is under the cognizance of the Navy.

1.4 Classification. Test equipment specified herein is categorized by class, (requirements arising from the intended operational environment), as specified herein. The class is assigned by the most severe environmental condition expected for the equipment.

1.4.1 Class. The VSC shall conform to Class 4 requirements in accordance with MIL- PRF-28800G for Navy shore-based laboratory use as specified in this CSS, except where de-rated in specific categories in this CSS.

2.0 APPLICABLE DOCUMENTS

2.1 Reference documents. The following documents form a part of this specification to the extent specified herein. Unless otherwise indicated, the issues of these documents shall be those in effect on the date of this solicitation.

DEPARTMENT OF DEFENSE SPECIFICATIONS

MIL-PRF-28800G - Test Equipment for use with Electrical and Electronic Equipment, General Specification for

MIL-PRF-38793 Manuals, Technical: Calibration Procedures Preparation of.

(Copies of DoD specifications are available online at http://assist.daps.dla.mil/quicksearch/ or from the Standardization Document Order Desk, 700 Robbins Avenue, Building 4D, Philadelphia, PA 19111-5094.)

DEPARTMENT OF DEFENSE STANDARDS

MIL-STD-130 - Standard Practice of Identification Marking of U.S. Military Property

MIL-STD-1472 - Human Engineering

(Copies of DoD Standards are available online at http://assist.daps.dla.mil/quicksearch/ or from the Standardization Document Order Desk, 700 Robbins Avenue, Building 4D, Philadelphia, PA 19111-5094.)

DEPARTMENT OF DEFENSE HANDBOOKS

MIL-HDBK-781 - Reliability Test Methods, Plans, and environments for Engineering Development, Qualification and Production

(Copies of DoD Handbooks are available online at http://assist.daps.dla.mil/quicksearch/ or from the Standardization Document Order Desk, 700 Robbins Avenue, Building 4D, Philadelphia, PA 19111-5094.)

NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY

NIST Special Publication 811 - Guide for the Use of the International System of Units (SI)

(Copies of NIST documents are available online at http://physics.nist.gov/cuu/pdf/sp811.pdf or Standards Information Center, 100 Bureau Drive, Stop 2100 Gaithersburg, MD 20899-2100 or Email: ncsci@nist.gov Phone: (301) 975-4040.)

AMERICAN NATIONAL STANDARDS INSTITUTE (ANSI)

ANSI/ISA S82.02.01-1999 - Electric and Electronic Test, Measuring, Controlling, and Related Equipment: General Requirements

ANSI-Y32.2 - Graphic Symbols For Electrical and Electronic Diagrams

ANSI-Y32.16 - Standard Reference Designations for Electrical and Electronics Parts and Equipment

(Copies of ANSI documents are available from http://webstore.ansi.org/ or ANSI Attn:

Customer Service Department, 25 W 43rd Street, 4th Floor, New York, NY, 10036

AMERICAN SOCIETY OF MECHANICAL ENGINEERS (ASME)

ASME B1.20.1 - Pipe Threads, General Purpose, Inch

ASME 2769 Rev C - Heat Treatment of Parts in a Vacuum http://webstore.ansi.org/

(Copies of ASME documents are available from www.asme.org or ASME Information Central Orders/Inquiries, P.O. Box 2300, Fairfield, NJ 07007-2300.)

ELECTRONIC INDUSTRIES ASSOCIATION (EIA)

EIA RS-310 - Racks, Panels and Associated Equipment

(Copies of EIA documents are available online at http://www.eia.org or Electronic Industries Association, 2500 Wilson Blvd, Arlington, VA 22201.

INSTITUTE OF ELECTRICAL AND ELECTRONICS ENGINEERS (IEEE)

IEEE 260.1 - IEEE Standard Letter Symbols for Units of Measurement (SI Units, Customary Inch-Pound Units, and Certain Other Units)

(Copies of IEEE documents are available from http://www.ieee.org or IEEE Service Center, 445 Hoes Lane, Piscataway, NJ 08854-1331.)

INTERNATIONAL ELECTROTECHNICAL COMMISSION (IEC)

IEC/IEEE 60488-1 - Standard for Higher Performance Protocol for the Standard Digital Interface for Programmable Instrumentation

IEC/IEEE 60488-2 - Standard Digital Interface for Programmable Instrumentation

IEC 61010-1 - Safety Requirements for Electrical Equipment for Measurement, Control and Laboratory Use (General Requirements)

(Copies of IEC documents are available online at http://www.iec.ch/ or EC publications are available in the US from the Sales Department. American National Standards Institute, 11 West 42nd Street,113 Floor, New York, NY 10036, USA.)

INTERNATIONAL ORGANIZATION FOR STANDARDIZATION (ISO)

ISO 1609 - Vacuum technology-Dimension of non-knife edge flanges

ISO 7779 - Measurement of Airborne Noise Emitted by Information Technology and Telecommunications Equipment

(Copies of ISO documents are available online at http://www.iso.org/iso/home.html or International Organization for Standardization (ISO) 1, ch. de la Voie-Creuse, Case postale 56, CH-1211 Geneva 20, Switzerland) http://www.eia.org/ http://www.iec.ch/ http://www.iso.org/iso/home.html

LAN EXTENSIONS FOR INSTRUMENTATION (LXI) CONSORTIUM

LXI Standard Revision 1.3-2008 - LAN Extensions for Instrumentation (LXI) Standard

(Copies of LXI documents are available online at http://www.lxistandard.org or LXI Consortium, PO Box 1016, Niwot, CO 80544-1016.)

STANDARD COMMANDS FOR PROGRAMMABLE INSTRUMENTS (SCPI)

CONSORTIUM

SCPI Volume I -1999 - Standard Commands for Programmable Instruments (SCPI)

(Copies of SCPI documents are available online at http://www.ivifoundation.org or IVI Foundation Corporate Office, PO Box 1016, Niwot, CO 80544-1016.)

WORLD WIDE WEB (W3C) CONSORTIUM

SVG Specification 1.1 - 2003 - Scalar Vector Graphics (SVG) 1.1 Specification

(Copies of W3C documents are available online at http://www.w3.org)

NATIONAL INSTITUTE OF OCCUPATIONAL HEALTH AND SAFETY (NIOSH)

DHHS (NIOSH) Publication Number 94-1100 0 - Applications Manual of the Revised NIOSH Lifting Equation

(Copies of this document are available online at https://doi.org/)

2.2 Order of precedence. In the event of conflict between the text of this CSS and the references cited herein, the text of this specification shall take precedence.

Nothing in this CSS, however, supersedes applicable laws and regulations unless a specific exemption has been obtained.

3.0 REQUIREMENTS

3.1 Equipment components. Parts, materials, and process shall be as specified herein and shall permit the test equipment to meet all applicable requirements of its class.

3.1.1 Finish. The equipment shall be the finish normally provided by the manufacturer.

3.1.2 Color. The equipment shall be the color normally provided by the manufacturer

3.1.3 Interchangeability. A model number shall be designated for all units provided.

All units and the replaceable assemblies, subassemblies, and parts comprising the unit shall be interchangeable on a noninterference basis.

http://www.lxistandard.org/ http://www.ivifoundation.org/ http://www.w3.org/ https://doi.org/10.26616/NIOSHPUB94110revised092021

3.1.4 Restricted materials. Test equipment furnished to the Navy that uses material restricted for Navy use, as specified herein and in MIL-PRF-28800G, requires approval prior to procurement.

3.1.4.1 Material restricted for Navy use. The materials and parts specified in a through e shall not be used in equipment for the Navy except as specified herein.

a. Mercury, including mercury batteries

b. Radioactive material

c. Lithium electrochemical cells

d. Helium-3

e. Cadmium, except batteries

3.1.4.2 Other restricted materials and gases. Test equipment shall not contain materials that promote the premature failure of the equipment or that present a health hazard under normal use or storage conditions as specified herein.

3.1.4.2.1 Organic materials. Test equipment shall not contain materials prone to organic decay or that act as a nutrient for the growth of multi-celled organisms.

3.1.4.2.2 Flammable materials. Test equipment shall not contain materials that ignite into flames at operating or storage temperatures.

3.1.4.2.3 Explosive materials. Test equipment shall not contain materials that explode at operating or storage temperatures.

3.1.4.2.4 Carcinogens. Certain chemicals have been identified by the Occupational Safety and Health Administration (OSHA) in CFR Title 29 Part 1910 as cancer-producing substances (carcinogens). Test equipment shall not contain carcinogenic materials.

3.1.4.2.5 Helium. Helium shall not be used as pressurizing gas in sealed units containing electron tubes. When necessary to use helium for leak detection purposes, exposure shall be limited to the time necessary for the test, followed by thorough purging.

3.1.4.3 Combination of materials. The equipment shall contain no combination of materials that cause deterioration of any material contained in the equipment due to the effects of outgassing.

3.1.4.4 Recycled, recovered, environmentally preferable, or biobased materials.

Recycled, recovered, environmentally preferable, or biobased materials should be used to the maximum extent possible, provided that the material meets or exceed the operational and maintenance requirements, and promotes economically advantageous life cycle costs.

3.2 Design and construction. The test equipment shall be designed and constructed to permit compliance with all applicable requirements of its class, as defined in this CSS as well as the performance, accuracy, and other requirements in this CSS.

3.2.1 Operator adjustments. The equipment shall include built-in adjustments or compensating devices for any function or parameter that would exceed the specified tolerance within the calibration interval defined in 3.9.2 Calibration interval. Under all specified service conditions the variation of any adjustment or control shall produce the desired control action to bring the equipment within tolerance.

3.2.2 Operator controls. Operating controls and indicators shall be readily accessible to the operator from the front of the equipment. The readings presented on the controls and indicators shall be available to the operator without conversion or calculation.

3.2.3 Connectors, electric. Provision shall be made to ensure that connectors will be mated only with the appropriate counterparts. Where design considerations require close proximity of connectors of similar configuration, the mating connectors shall be suitably coded or marked. The live or hot side of unmated connectors shall be protected against shorting.

3.2.4 Wiring, internal. Internal wiring practices shall be such that the wiring shall not be damaged during normal maintenance, transportation and calibration.

3.2.5 Internal cooling. The equipment shall be capable of operating without interruption for at least 24 hours at the maximum operating temperature for the applicable class. Cooling devices used in the equipment shall be an integral part of the equipment and not degrade any aspect of performance or safety.

3.2.6 Front panel display indicators. Front panel/control panel display indicators designed to present change-of-state information to the operator shall be distinguishable at a distance of 1 m in a maximum ambient light level of 100 foot-candles (fc) and a minimum light level of 10 fc. All display indicators shall be discernible at viewing angles from 0 to 45 degrees.

3.2.7 Self-test capability. The VSC shall perform an automatic diagnostic self-test at startup. The self-test shall determine operational readiness and isolate faulty modules. The information provided by the self-test shall indicate operational readiness. If failure occurs, the associated lowest replaceable unit (LRU) causing the malfunction shall be identified.

3.3 Electrical power sources and connections.

3.3.1 Electrical power source. The equipment shall operate from the input power conditions specified herein. When multiple power source requirements are invoked, the equipment shall operate within each required range without changing manually operated devices such as tapped transformers (variable setting transformers) and other similar devices for compensation. When multiple power source requirements are invoked, all selectable power setting controls shall be externally accessible.

3.3.1.1 Power consumption. The maximum power for operation of a VSC component that requires an external single phase 120 Vrms power source shall not exceed 1500 watts.

3.3.1.2 Nominal power source. The equipment shall operate at 120 Vrms single-phase 60 Hz source.

3.3.1.2.1 Steady-state conditions. The performance and accuracy of the equipment shall not be adversely affected when operated under any combination of conditions a through c. For definitions of voltage waveform factor and harmonics, see MIL-PRF-28800G paragraph 6.6.12.

a. The steady-state voltage-tolerance shall be ±10%.

b. The steady-state frequency-tolerance shall be ±5%.

c. The deviations in waveform characteristics shall be as follows.

1. Waveform deviation factor of ±10 percent or less

2. Total harmonics of ±10 percent or less

3. Individual harmonics of ±5 percent or less

4. Crest factor of 1.27 to 1.56

3.3.1.2.2 Transient-state conditions. Operation of the equipment during voltage and frequency transients shall be in accordance with a and b for transients that recover to within the steady-state tolerance band within 500 ms. The equipment performance may be impaired during the transient. Transient values are derived from, and referenced to, the nominal values specified for voltage and frequency.

a. Voltage transients within the range of ±10 percent to ±30 percent shall not cause the operation of the equipment to be impaired for longer than 30 seconds following the transient and not cause loss of information stored in a volatile memory. Testing shall be in accordance with MIL- PRF-28800G paragraph 4.5.5.6.3.

b. Frequency transients within the range of ±5 percent to ±10 percent shall not cause the operation of the equipment to be impaired for longer than 30 seconds following the transient and not cause loss of information stored in a volatile memory. Testing shall be in accordance with MIL- PRF-28800G paragraph 4.5.5.6.4.

3.3.1.2.3 Interruption of power source. Voltage or frequency interruptions shall not cause damage to the equipment. A power source interruption is when the voltage falls in the range of 0 to 70% of nominal or frequency falls in the range of 0 to 90% of nominal. Equipment performance is not required during interruption of the power source. After power interruptions of any duration, the equipment shall automatically resume operation at either the last operating condition before interruption, or a default power-up condition.

3.3.1.2.4 DC internal power source. The equipment shall be designed to operate from external power source only. Internal power sources shall only be used for memory backup as specified below.

3.3.1.2.4.1 Battery restrictions. Battery restrictions shall apply as follows:

a. Mercury Batteries. For Navy applications, the use of mercury batteries is restricted and shall not be used in equipment.

b. Lithium batteries. S9310-AQ-SAF-010 establishes the safety guidelines for the usage of lithium batteries. The use of lithium batteries is prohibited without prior authorization. S9310-AQ-SAF-010 promulgates the exception requirements for approving the usage of lithium batteries. If equipment does not qualify for an exception, then a request for approval for the use of lithium batteries shall be submitted at the time of submission of proposals. Approval shall apply only to the specific model proposed. The lithium ion rechargeable cell manufacturer, part number, configuration (number of cells in series), nominal voltage, and rated capacity shall specified at the time of submission of proposals. The equipment shall incorporate safety precautions of UL 60950-1 and a label containing the following caution and battery information shall be affixed to the outside of the unit:

3.3.2 Battery information. If batteries are used in the equipment, instructions shall be provided that describe the procedure for battery replacement, including the part number of the battery and description of the replacement process. If lithium batteries are used, proper disposal procedures shall be contained in the Use and Installation Manual and the Maintenance and Service Manual.

3.3.3 Electrical power connections. The requirements specified herein shall apply to equipment rated at 10 amperes (A) rms, or less. The equipment shall operate with a ground at the primary power source on either or neither side of the single phase input power line.

THIS UNIT CONTAINS LITHIUM BATTERIES

Battery Manufacturer:

Battery Part Number:

3.3.3.1 Input power cable. The input power cable shall be a detachable power cable normally provided by the manufacturer.

3.3.3.2 Input power switch. The operator shall be able to energize the equipment from the front panel. A standby capability may be incorporated to activate and deactivate the equipment. If such a capability is provided, suitable warnings shall be placed in the operating and service manuals and on the equipment to warn the operator of possible shock hazards during servicing, due to partially activated power supplies.

3.3.3.3 Excessive current drain protection. An automated safety mechanism (circuit breaker/fuse) shall be incorporated to automatically disconnect the equipment in the event of current being drawn that is in excess of the equipment rating.

The mechanism shall be available from the control panel or an exterior panel.

3.3.3.4 Indicators. Visual indication shall be provided on the front panel to indicate when the equipment is energized.

3.4 Enclosure physical characteristics. A commercial-off-the-shelf (COTS) enclosure, normally provided by the manufacturer, that meets the requirements herein shall be acceptable.

3.4.1 Dimensions. Dimensions of each enclosure shall not exceed 72 inches in height, 28 inches in width and 25 inches in depth.

3.4.2 Weight. If the weight exceeds 20 kilograms (kg) (44 pounds), the unit shall include wheels or other method to move the unit up to 60 feet. Additionally, a label containing the following cautionary note and weight information shall be affixed to the outside of the unit:

3.4.3 Mechanical stability. The equipment shall be designed to preclude tipping during normal handling and operation. Testing shall be in accordance with MIL- PRF-28800G paragraph 4.5.7.4. This requirement is not applicable to test equipment smaller than 2000 cc with a weight less than 2.5 kg, and excludes equipment that has a depth of 4.5 or more times the height, or that has a height of less than 100 mm.

3.4.3.1 Enclosure orientation. Equipment shall be mechanically stable when positioned in its normal orientation on a bench for horizontal viewing of the front panel, and when placed in its alternate orientation on the floor or deck for vertical viewing

TWO-PERSON LIFT

THIS UNIT EXCEEDS 20KG (44 LBS) AND

REQUIRES TWO PERSONS TO MOVE

of the front panel. The size and weight limitations of 3.4.1 and 3.4.2 apply to this requirement.

3.4.4 Enclosure requirements. The degree of protection provided by the enclosure shall allow the equipment to pass the environmental tests applicable to the specified class.

3.4.4.1 Cover. The enclosure shall have a cover.

3.4.4.2 Latches. When latches are incorporated in the equipment design, latches shall incorporate a quick-opening mechanism.

3.4.4.3 Component protection. Panels shall be designed to conform to the bench handling requirement as specified in MIL-PRF-28800G paragraph 3.9.5.3.

3.4.4.4 Handles. Unless otherwise specified, one or more handles shall be provided.

The number and location of handles shall be such that the load distribution per handle shall not exceed 20kg. Handles shall be located above the equipment center of gravity to ensure carrying stability. Handles shall permit compliance with the enclosure orientation provisions specified above in 3.4.3.1.

3.4.4.5 Corners. All corners shall be designed to preclude injury to personnel or damage to material. All corners shall be adequately reinforced to protect the instrument from damage during shipping, handling and storage.

3.4.4.6 Connections and controls. All external electrical connections (except power connections) and operating controls shall be on the control panel. Electrical power connections shall be on the rear.

3.4.4.7 Chassis fasteners. The chassis shall be securely fastened within the enclosure conforming to the maintainability requirements of 3.9.

3.4.4.8 Pressure equalizing valve. A mechanism for equalizing air pressure within the enclosure with the external ambient pressure, when the enclosure is sealed, shall be provided. The mechanism provided shall not protrude beyond the enclosure.

3.5 Environmental requirements. The VSC environmental performance requirements shall be as specified herein and in MIL-PRF-28800G table II, for Class 4 equipment.

3.5.1 Warm-up. The VSC shall comply with the specified performance requirements after a maximum 4 hour warm-up period proceeded by a 1-hour not operating temperature stabilization period.

3.6 Safety. The equipment shall meet the safety requirements of IEC 61010-1. For safety, all accessible surfaces of the equipment shall be at ground potential.

The power cable shall include a safety ground conductor. Disconnecting the safety ground shall also disconnect the power conductors for drawer assemblies.

3.7 Marking and identification. Marking and identification of test equipment shall be as specified herein.

3.7.1 Marking. Test equipment shall be marked in a manner that does not adversely affect safety or performance.

3.7.1.1 Reference designations. Reference designations shall be used to identify each part for its particular circuit application. Subminiaturized and non-repairable assemblies need not be marked with reference designations. Reference designator usage shall be in accordance with IEEE 315.

3.7.1.2 Warning markings. Warning markings shall warn of the location, the nature, and the extent of a hazard. Letters of warning markings shall be of clearly legible gothic capitals. Warning markings shall have high contrast between the letter and background colors. The markings shall be as permanent as normal life expectancy of the test equipment, and located as close as possible to the point of danger. Warning markings indicating circuits of more than 500 Vdc or Vrms shall read:

DANGER HIGH VOLTAGE (maximum applicable voltage) VOLTS

Markings shall be in accordance with IEC 61010-031, which requires the warning and caution markings specified in a through c:

a. The precautionary signal word shall be at least 2.5 mm high.

b. The text shall be at least 1.5 mm high and contrasting in color to background.

c. If molded or stamped in a material, text shall be at least 2.0 mm high and, if not contrasting in color, a depth or raised height of at least 0.5 mm.

3.7.1.3 Panel markings and processes. Panel markings shall enable the operator to identify the functions and use of all items requiring operator intervention.

3.7.2 Equipment identification. All equipment, excluding small accessory items contained within a reusable pouch or container, shall be identified with the items specified herein.

a. Manufacture name

b. Equipment model number with installed options

c. Equipment nomenclature

d. Serial number

3.7.2.1 Identification plate. An equipment identification plate shall be affixed to the test equipment enclosure when the enclosure also serves as the transit case. The identification plate shall contain the information provided herein. The identification plate shall be permanently affixed.

3.7.2.1.1 Identification plate, single case. The identification plate for a single case shall contain the information provided in a through d.

a. Configuration model number or equipment model number with installed options

b. Configuration or equipment nomenclature

c. Configuration or manufacturer CAGE

d. Configuration serial number

3.7.2.1.2 Identification plate, supplemental. When accessories are required to meet the requirements of the CSS and the combination is given a part or model number designation that differs from that of the main unit, there shall be a supplemental identification plate containing the information in a and b. The plate shall be placed on the accessory container, as applicable. Whether or not a configuration model designation is assigned to the accessory or group of accessories, all major accessories shall be marked as in c:

a. Part number of main unit and all accessories (excluding cables and adapters) comprising the equipment configuration.

b. Model configuration number: (Model number assigned to the equipment configuration).

c. Part of number (or p/o): Model number assigned to the equipment configuration or main unit model number, as applicable.

d. Serial number (or s/n): Serial number assigned to the equipment comprising the set or the serial number of the primary instrument if a separate s/n is not assigned to the set

3.7.2.1.3 Identification plate, material. The following materials with minimum thickness of 1/32 inch are recommended.

a. Brass

b. Corrosion resistant steel

c. Aluminum alloy

3.7.2.1.4 Identification plate, marking. The plate background color shall be black. It shall have a minimum character size of 1/8 inch. All characters shall be permanent using best commercial practices for laser engraving, etching, or photosensitive marking of material.

3.7.2.2 Reusable pouch or container. If a reusable pouch or container is provided, containers shall be marked "accessories for use with" (test equipment nomenclature or model number), or, "maintenance aids for use with" (test equipment nomenclature or model number), as applicable.

3.7.2.3 Nomenclature assignment. The nomenclature assignment shall be provided by the Government. The complete system shall be assigned the nomenclature “Vacuum Sensor Calibrator” and any sensor components that perform measurements of the vacuum level in the test volume shall be assigned the nomenclature “Vacuum Sensor.”

3.8 Maintainability. Maintainability shall be as specified herein.

3.8.1 Fault isolation. The design of the equipment shall permit isolation of faults, and repair down to the component item or lowest replaceable unit with the maintenance provisions furnished.

3.8.2 Calibration interval. The interval between calibrations shall be 12 months minimum. The equipment shall be within all accuracy requirements specified herein with an 85 percent or greater confidence factor following its full calibration interval.

3.8.3 Reliability. The design of the equipment shall be such that under normal use and operation the equipment does not fail within 10,000 hours of operation with a statistical certainty of 90%.

3.8.4 Preventive maintenance. Preventive maintenance shall not require more than 15 minutes per a 30-day period. Preventive maintenance shall not require breaking of the equipment seams where calibration seals would normally be placed.

3.8.5 Maintenance provisions. Equipment shall be as follows to facilitate maintenance:

a. Accessibility for maintenance. The equipment shall be designed to ensure that maintenance access can be accomplished utilizing ordinary tools as defined by MIL-PRF-28800G paragraph 6.6.33. The equipment shall be constructed so that no damage to any component shall occur and no permanent distortion to any structural member shall be caused during maintenance and calibration (performance verification and adjustment/alignment).

b. Maintenance and calibration aids. If required, circuit board extenders, special adapters, special tools, and patch or interface cables required for maintenance or calibration shall be provided. They shall be identified as a set with a unique part number. Stowage shall be in a reusable pouch or container.

c. Accessibility for repair. The equipment shall be designed so that subassemblies and chassis components can be removed without removing other hardwired subassemblies or components. There shall be no need to unsolder cables or interconnecting wiring. Assemblies designed primarily to distribute power and signals to other components are excluded from this requirement. When motherboards are used, they shall be accessible from both sides to facilitate troubleshooting or repair.

d. Accessibility for adjustment. The equipment design shall permit adjustments to be made without removing any component, printed circuit cards, or subassembly. The use of extender cards is permitted.

(Example: Access will be provided to potentiometers that control the accuracy of specified parameters.)

3.8.6 Washability. The equipment shall conform to all requirements after being washed, and there shall be no evidence of deterioration when tested in accordance with MIL-PRF-28800G paragraph 4.5.7.1.2.

3.9 Performance requirements. The VSC shall provide the performance capabilities as listed below.

3.9.1 Ports. All ports shall be designed so that they can be isolated from all other ports and isolated from the VSC test volume. The VSC will be equipped with sufficient ports and any necessary adapters such that it will be able to connect appropriately for each of the following arrangements;

3.9.1.1 Simultaneous connections for one NW16 (DN16 ISO-KF) fitting and two NW25 (DN25 ISO-KF) fittings.

3.9.1.2 Simultaneous connections for two 1/2 inch Rohr fittings and one NW25 (DN25 ISO-KF) fitting.

3.9.1.3 One 1/8 inch NPT fitting.

3.9.1.4 One 1/4 inch MFL fitting.

3.9.2 Range. The VSC shall provide indications of the absolute vacuum in the test volume from the range of 10-4 to 1,000 Torr at the uncertainty specified in 3.9.4.

3.9.3 Resolution. The VSC shall have a minimum resolution of 10-5 Torr.

3.9.4 Uncertainty. The VSC shall have a minimum uncertainty of ±0.12%iv.

3.9.5 Pumping. The VSC shall provide vacuum pumping to the test volume at a capacity greater than or equal to 10 liters/minute.

3.9.6 Accessories. The following accessories specified herein shall be provided with each VSC.

3.9.6.1 Vacuum Hose. The VSC will include two accessory ISO-KF thin wall metal hoses at least 12 inches long but no longer than 24 inches with end fittings size NW16 (DN16 ISO-KF) for one hose and NW25 (DN25 ISO-KF) for the second hose.

3.9.6.2 Centering Rings. The VSC will include four accessory centering rings with two of each size NW16 (DN16 ISO-KF) and NW25 (DN25 ISO-KF). The centering rings will be equipped with seals of a material appropriate for the full range of the VSC.

3.9.6.3 Clamps. The VSC will include four accessory flange wing nut clamps, two of size NW16 (DN16 ISO-KF) and two of size NW25 (DN25 ISO-KF).

3.9.6.4 Adapters. The VSC will include three accessory adapters, two of size 1/2 inch Rohr to an ISO-KF flange (size NW16 or NW25) and one of size 1/8 inch NPT to an ISO-KF flange (size NW16 or NW25).