ASTM F2071-00(2022)

Standard Specification for Switch, Position Proximity (Noncontact) or Limit (Mechanical Contact), Fiber-Optic

ABSTRACT
This specification covers the requirements for the proximity and limit of fiber-optic position switches. This specification does not include switches that transfer an optical signal from one path to another by an external force or energy applied to the switch. The fiber-optic switches meet physical property requirements stipulated for enclosure, optoelectronic module, external configuration, and size and weight. The switches shall also adhere to minimum specified service life requiements. Other critical performance requirements shall be specified in the acquisition order as deemed important to the purchaser.
SCOPE
1.1 This specification covers the requirements for fiber-optic position switches (proximity and limit). This specification does not include switches that transfer an optical signal from one path to another by an external force or energy applied to the switch.  
1.2 Special requirements for naval shipboard applications are included in the Supplement.  
1.3 The values stated in SI units are to be regarded as standard. The values given in parentheses are mathematical conversions to inch-pound units that are provided for information only and are not considered standard. Where information is to be specified, it shall be stated in SI units.  
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 30-Sep-2022
• ICS: 33.180.20 - Fibre optic interconnecting devices
• Technical Committee: F25 - Ships and Marine Technology
• Drafting Committee: F25.10 - Electrical

Relations

• Refers: ASTM D3951-18(2023) - Standard Practice for Commercial Packaging
• Effective Date: 01-Oct-2023
• Refers: ASTM D3951-18 - Standard Practice for Commercial Packaging
• Effective Date: 01-May-2018
• Refers: ASTM D3951-15 - Standard Practice for Commercial Packaging
• Effective Date: 01-Dec-2015
• Refers: ASTM D3951-10 - Standard Practice for Commercial Packaging
• Effective Date: 15-Aug-2010
• Refers: ASTM D3951-98(2004) - Standard Practice for Commercial Packaging
• Effective Date: 10-Nov-1998
• Refers: ASTM D3951-98 - Standard Practice for Commercial Packaging
• Effective Date: 10-Nov-1998

Overview

ASTM F2071-00(2022), published by ASTM International, is the standard specification for fiber-optic position switches-both proximity (noncontact) and limit (mechanical contact) types. This standard outlines essential requirements for these switches, which are used to detect or monitor position via changes in fiber-optic properties. The specification sets out criteria for key components, operational characteristics, physical properties, and service life, ensuring reliable and consistent performance, particularly in mission-critical applications such as naval shipboard systems. It does not cover switches that re-route optical signals using external force or energy.

Key Topics

• Switch Types & Components:

  • Proximity switches: Detect object presence by noncontact optical means.
  • Limit switches: Employ a mechanical component-such as pin, lever, roller, or tether-to sense positional changes physically, interrupting or completing the optical path.
  • System architecture: Comprises a sensor head, optoelectronics module (handling the optical transmission/reception and signal conditioning), and fiber-optic cabling.

• Performance and Quality Requirements:

  • Minimum service life criteria to ensure long-term reliability.
  • Physical properties-such as enclosure configuration, material selection (corrosion-resistant, noncombustible), external size, and weight limitations.
  • Electrical and optical performance: Operational features include response time, voltage specifications, light transmittance changes, and environmental exposure tolerance.
  • Inspection and test protocols: First-article and conformity tests ensure compliance throughout manufacturing.

• Marking, Packaging, and Documentation:

  • Required markings include the manufacturer's name, part/serial number, and component identification.
  • Packaging must provide adequate protection and adhere to industry best practices for shipping and storage.
  • Acquisition documents specify unique application needs, including environmental and quality assurance considerations (ISO 9001 compatibility).

Applications

Fiber-optic position and proximity switches covered by ASTM F2071 are critical in settings demanding high reliability, such as:

• Shipboard and marine equipment: The standard includes supplementary criteria for naval applications, emphasizing durability under harsh environmental conditions, shock, vibration, and electromagnetic interference (EMI) resilience.
• Industrial automation: Facilitates precise position sensing in automated machinery where electrical interference or hazardous environments prevent traditional electrical contacts.
• Aerospace, defense, and critical infrastructure: Provides position feedback in control systems requiring immune-to-EMI operation or where mechanical wear of traditional contacts is unacceptable.
• Safety and monitoring systems: Used in applications where noncontact switching improves reliability and reduces maintenance.

The versatility of fiber-optic switches, including their resistance to corrosion, fire, and electromagnetic interference, makes them suitable for environments with severe operational demands.

Related Standards

For comprehensive specification and quality control, several relevant standards are referenced or associated:

• ASTM D3951: Practice for commercial packaging of components.
• ISO 9001: Quality management systems for manufacturing and servicing.
• NEMA 250: Standard for enclosures for electrical equipment (for environmental protection).
• Military Standards: Supplementary naval criteria reference MIL-STD-461 (EMI), MIL-STD-167-1 (Mechanical vibration), and MIL-S-901 (Shock).
• EIA 455 (FOTP): Test procedures for optical transmittance and ambient light susceptibility of fiber optic components.

Summary

ASTM F2071-00(2022) provides a robust framework for specifying, acquiring, and verifying fiber-optic position and limit switches in demanding applications. By standardizing design, performance, and quality assurance criteria, it supports safety, reliability, and effective integration in industrial, shipboard, and advanced technological environments. For engineers, manufacturers, and procurement professionals, adherence to this standard assures optimal lifecycle performance and regulatory compliance for fiber-optic switching solutions.

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation:F2071 −00 (Reapproved 2022) An American National Standard
Standard Specification for
Switch, Position Proximity (Noncontact) or Limit
(Mechanical Contact), Fiber-Optic
This standard is issued under the fixed designation F2071; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 2.2 ISO Standards:
ISO 9001Quality System—Model for QualityAssurance in
1.1 This specification covers the requirements for fiber-
Design/Development, Production, Installation, and Ser-
optic position switches (proximity and limit). This specifica-
vicing
tion does not include switches that transfer an optical signal
fromonepathtoanotherbyanexternalforceorenergyapplied
3. Terminology
to the switch.
3.1 Definitions:
1.2 Special requirements for naval shipboard applications 3.1.1 closed switch, n—the light path is complete; signal
are included in the Supplement.
from transmitter to receiver is complete.
3.1.2 closed switch with positive alarm, n—the light path is
1.3 The values stated in SI units are to be regarded as
complete. Signal level indicates that the end faces of the
standard. The values given in parentheses are mathematical
sensing element are dirty and require maintenance for contin-
conversions to inch-pound units that are provided for informa-
ued proper operation.
tion only and are not considered standard. Where information
is to be specified, it shall be stated in SI units.
3.1.3 fiber-optic position switch, n—a device that converts
measured position, via changes in fiber-optic properties, to an
1.4 This standard does not purport to address all of the
output that is a function of the applied measurand. The
safety concerns, if any, associated with its use. It is the
fiber-optic position switch normally consists of a sensor head,
responsibility of the user of this standard to establish appro-
optoelectronics module, and connectorized fiber-optic cable.
priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use. 3.1.4 limit switch, n—a switch that senses a change in
1.5 This international standard was developed in accor- position via mechanical contact.
dance with internationally recognized principles on standard-
3.1.5 open switch, n—the light path is blocked; signal from
ization established in the Decision on Principles for the
transmitter to receiver is not complete.
Development of International Standards, Guides and Recom-
3.1.6 optical transmittance change, n—thechangeinoptical
mendations issued by the World Trade Organization Technical
power level introduced by an environmental, mechanical, or
Barriers to Trade (TBT) Committee.
other induced stress.
3.1.7 optoelectronics module, n—unit of the fiber-optic
2. Referenced Documents
position switch that contains the optical transmitter and
2.1 ASTM Standards:
receiver, and signal conditioning electronics, necessary to
D3951Practice for Commercial Packaging
convert the sensed position to the specified output signal. The
optoelectronics module may be an expansion card for a
microprocessor-based system, or a stand-alone unit.
This specification is under the jurisdiction ofASTM Committee F25 on Ships
3.1.8 proximity switch, n—a switch that senses a change in
and Marine Technology and is the direct responsibility of Subcommittee F25.10 on
position via noncontact means.
Electrical.
Current edition approved Oct. 1, 2022. Published October 2022. Originally
3.1.9 sensor head, n—unit of the fiber-optic position switch
approved in 2000. Last previous edition approved in 2017 as F2071–00 (2017).
that detects position via changes in optical properties. The
DOI: 10.1520/F2071-00R22.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Available from International Organization for Standardization (ISO), ISO
Standards volume information, refer to the standard’s Document Summary page on Central Secretariat, BIBC II, Chemin de Blandonnet 8, CP 401, 1214 Vernier,
the ASTM website. Geneva, Switzerland, http://www.iso.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
F2071−00 (2022)
optoelectronics module interrogates the sensor head to deter- fiber-optic cable allows completion of the light path to a
mine the position of the measurand. An optical signal is fiber-optic receiver in the optoelectronics module. Dependent
transmitted from the optoelectronics module to the sensor upon the configuration of the switch, the mechanical contact
head.Theopticalpathiseithercompleteorblocked,depending device either completes or breaks the light path upon detection
on the status of the item being measured, giving an indication
of the object.
of the position or status of the item back to the optoelectronics
module.
5. Ordering Information
3.1.10 steady-state supply voltage, n—an input voltage that
5.1 The purchaser should provide the manufacturer with all
does not deviate from a specified nominal tolerance (for
of the pertinent application data. Recommended data is shown
example, 65%).
in 5.2. If special application operating conditions exist that are
3.1.11 tether valve limit switch, n—a limit switch used to
not shown in the acquisition requirements, they should also be
detect valve position via a tether line connected to the valve
described.
handle.
5.2 Acquisition Requirements—Acquisition documents
3.1.12 transient supply voltage, n—a voltage superimposed
should specify the following:
on the steady-state supply voltage that is greater than the
(1)Title, number, and date of this specification,
specified steady-state tolerance and has a very rapid rise and
(2)Manufacturer’s part number,
fall.
(3)Switch type required (see 4.3),
(4)Unique or special enclosure requirements (see 7.1),
4. Classification
(5)Type of optoelectronics module (see 7.2). If control
4.1 Designation—Most switch manufacturers use enclosure or console mounted, specify requirements,
designations,systematicnumberingoridentifyingcodes.Once
(6)Length of fiber-optic cable required,
understood, these designations could aid the purchaser in
(7)Type of electrical connection (see 7.4),
quickly identifying the switch type, electrical power ratings, (8)Whentheelectricalconnectionmatingplugisnottobe
and other characteristics.
provided (see 7.4),
(9)System operating characteristics,
4.2 Design—Fiber-optic position switches typically consist
(10)Materials,
of an assembly with three major components: optical sensor
(11)Environmental requirements,
head, fiber-optic cables, and optoelectronics module. The
(12)Quantity of switches required,
optoelectronics module shall be interchangeable between any
(13)Size and weight restrictions (see 7.5),
of the sensor types.
(14)Critical service life requirements (see 8.1),
4.3 Types—The following are common types of fiber-optic
(15)Performance requirements (see 8.2),
position switches:
(16)Special surface finish requirements (see 9.1),
Proximity
(17)Special workmanship requirements (see 9.2),
Limit, pin actuated
(18)When certification is required (see 13),
Limit, lever actuated
(19)Special marking requirements (see 14),
Limit, lever and roller
(20)Special packaging or package marking requirements
Limit, tether valve
(see 15),
4.3.1 Fiber-Optic Proximity Switches—The fiber-optic
(21)When ISO 9001 quality assurance system is not
proximity switch sensor head receives the light beam from the
required (see 16.1), and
light source in the optoelectronics module via a fiber-optic
(22)Special warranty requirements (see 16.1).
cable.The sensor head emits the light beam to detect an object
in a specific location. The sensor head also receives the light
6. Materials and Manufacture
beam reflection from the object, typically via a wide angle
6.1 Position Switches—Materialsforthefiber-opticposition
receiving lens, and is detected by the light beam receiving
switchesshallbecorrosionresistantandnoncombustibleorfire
device in the optoelectronics module. When the object moves
retardant.
into the sensing site, the light beam is reflected into the
receiving lens completing the fiber-optic light path. It is
important to consider contrasting light levels between reflec- 7. Physical Properties
tionsfrombackgroundobjectswhennoobjecttobedetectedis
7.1 Enclosure—If case sealing is required, the mechanism,
present and reflections from the object to be detected, when
materials, and process shall be described. The same should
selecting a fiber-optic proximity switch.
apply to the electrical connector. Resistance to cleaning sol-
4.3.2 Fiber-Optic Limit Switches—The fiber-optic limit
vents should likewise be stated. Unique or special enclosure
switch sensor head houses the mechanical contact device that
requirements shall be specified in the acquisition requirements
sensesthepositionoftheobjecttobedetected.Themechanical
(see 5.2).
contact device is typically a pin or plunger, lever, roller, lever
and roller, or tether valve. The fiber-optic limit switch sensor 7.2 Optoelectronics Module—The optoelectronics module
head receives the light beam from the light source in the shall contain the optical and signal conditioner devices neces-
optoelectronics module via a fiber-optic cable. The same sarytoconvertthesensorheadoutputtothespecifiedelectrical
F2071−00 (2022)
output. Optoelectronics modules shall be designed in consid- 9. Workmanship, Finish, and Appearance
eration of their mounting method (type): bulkhead mounted,
9.1 Finish and Appearance—Any special surface finish and
control enclosure mounted, or console mounted (microproces-
appearance requirements shall be specified in the acquisition
sor expansion card).
requirements (see 5.2).
7.3 External Configuration—The outline drawing shall
9.2 Workmanship—Any special workmanship requirements
show the configuration with dimensions in SI units (inch-
shall be specified in the acquisition requirements (see 5.2).
poundunits)iftheyarenotspecified.Theoutlinedrawingshall
include limiting dimensions for electrical and fiber-optic con-
10. Number of Tests and Retests
nections if they are not specified. The outline drawing shall
10.1 The number of test specimens to be subjected to
indicate the mounting method with hole size, center location,
first-articleandconformancetestsshallbespecifiedandshould
andotherpertinentdimensions.Wherethreadedholesareused,
depend on the fiber-optic position switch design.As guidance,
thread specifications shall be provided.
foreachswitchcoveredbyaseparateanddistinctdesign,atest
7.4 Electrical Connection—An electrical interface connec-
specimenforeachdesignshouldrequiretesting.Ininstancesin
tor receptacle and mating plug shall be provided with each
which a singular design series may cover multiple switch
optoelectronicsmoduleofthepositionswitchunlessotherwise
configurations, a minimum of three test specimens should be
specified in the acquisition requirements (see 5.2). Other
tested, provided the electrical, optical, and mechanical simi-
possible electrical interface connections include pigtails and
larities are approved by the purchaser. It is recommended that
terminal boards.
one unit be tested for each switch configuration regardless of
design similarity.
7.5 Size and Weight—The purchaser may have intended
applications in which size and weight are limited. Size and
11. Inspection
weightrestrictionsshallbespecifiedintheacquisitionrequire-
ments (see 5.2).
11.1 Classification of Inspections —The inspection require-
ments specified herein are classified as follows:
8. Performance Requirements
(1)First-article tests (see 11.2)
8.1 Service Life—The purchaser may have a minimum (2)Conformance tests (see 11.3)
specified service life requirement that may be critical. Critical
11.2 First-Article Tests—First-articletestrequirementsshall
service life requirements shall be specified in the acquisition
bespecified,whereapplicable.First-articletestmethodsshould
requirements (see 5.2).
be identified for each design and performance characteristic
8.2 Switch Performance—Critical performance require- specified.
ments shall be specified in the acquisition requirements (see
11.3 Conformance Tests—Conformance testing is accom-
5.2). The following performance characteristics and environ-
plished when first-article tests were satisfied by a previous
mental exposures may or may not be important to each
acquisition or the product has demonstrated reliability in
purchaser’s intended application.
similar applications. Conformance tests are usually less inten-
(1)Warm-up time,
sive than first-article tests, often verifying that samples of a
(2)Steady-state supply voltage and frequency (ac),
production lot meet a few critical performance requirements.
(3)Steady-state supply voltage (dc),
(4)Response time,
12. Test Data
(5)Transient supply voltage and frequency (ac),
12.1 Test Data—Test data shall remain on file at the manu-
(6)Transient supply voltage (dc),
facturer’s facility for review by the purchaser upon request. It
(7)Change in optical transmittance,
isrecommendedthattestdataberetainedinthemanufacturer’s
(8)Dynamic range,
filesforatleastthreeyearsoraperiodoftimeacceptabletothe
(9)Ambient light susceptibility,
purchaser and manufacturer.
(10)Temperature,
(11)Humidity,
13. Certification
(12)Salt spray,
13.1 When specified in the acquisition requirements (see
(13)Insulation resistance,
5.2), the purchaser shall be furnished certification that samples
(14)Power interruption,
representing each lot have been either tested or inspected as
(15)Short circuit,
directed in this specification and the requirements have been
(16)Line voltage reversal (dc powered),
met.
(17)Output,
(18)Mechanical life,
14. Product Marking
(19)Enclosure,
(20)Vibration, 14.1 Special purchaser specified product marking shall be
(21)Shock, listed in the acquisition requirements (see 5.2). The minimum
(22)Electromagnetic interference (EMI), and data to be clearly marked on each switch shall include the
(23)Power system harmonic distortion. following:
F2071−00 (2022)
14.1.1 Sensor Head: 15.2 Special packaging or package marking requirements
(1) “FIBER-OPTIC POSITIONS SWITCH—SENSOR for shipment or storage shall be identified in the acquisition
requirements (see 5.2).
HEAD,”
(2)Manufacturer’s name,
16. Quality Assurance
(3)Manufacturer’s serial number or lot number, and
16.1 Quality System—A quality assurance system in accor-
(4)Manufacturer’s part number.
dancewithISO9001shallbemaintainedtocontrolthequality
14.1.2 Optoelectronics Module:
of the product being supplied effectively, unless otherwise
(1) “FIBER-OPTIC POSITION SWITCH—
specified in the acquisition requirements (see 5.2).
OPTOELECTRONICS MODULE,”
16.2 Responsibility for Warranty—Unless otherwise
(2)Manufacturer’s name,
specified, the manufacturer is responsible for the following:
(3)Manufacturer’s serial number or lot number,
(1)All materials used to produce a unit and
(4)Manufacturer’s part number, and
(2)Workmanship to produce the unit.
(5)Excitation voltage.
Special warranty requirements shall be specified in the
acquisition requirements (see 5.2).
15. Packaging and Package Marking
17. Keywords
15.1 Packaging of Product for Delivery—Productshouldbe
packagedandmarkedforshipmentinaccordancewithPractice 17.1 fiber-optic position switch; limit switch; optoelectron-
D3951. ics module; position switch; proximity switch; sensor head
SUPPLEMENTARY REQUIREMENTS
The following supplementary requirements established for U.S. Naval shipboard application shall
apply when specified in the contract or purchase order. When there is conflict between the standard
F25(FOSW)M-99 and this supplement, the requirements of this supplement shall take precedence for
equipment acquired by this supplement. This document supersedes MIL-S-24798, Switch, Position,
Proximity (Non-Contact) or Limit (Mechanical Contact), Fiber Optic, for new ship construction.
S1. SWITCH, POSITION, PROXIMITY (NONCON- S1.2.3 NEMA Standards:
TACT) OR LIMIT (MECHANICAL CONTACT), FIBER- 250 Enclosures for Electrical Equipment (1000 Volts Maxi-
OPTIC
mum)
S1.2.4 Military Standards:
S1.1 Scope
MIL-C-83522 Connectors, Fiber Optic, Single Terminus,
S1.1.1 This specification supplement covers the require-
General Specification for
ments for fiber-optic position switches (proximity and limit)
MIL-C-83522/16 Connector, Fiber Optic, Single Terminus,
designedtomeettherequirementsforuseonboardnavalships.
Plug,Adapter Style, 2.5 Millimeter Bayonet Coupling, Epoxy
This specification does not include switches that transfer an
MIL-C-83522/17 Connector, Fiber Optic, Single Terminus,
optical signal from one path to another by an external force or
Adapter, 2.5 Millimeter Bayonet Coupling, Bulkhead Panel
energy applied to the switch.
Mount
S1.1.2 The values stated in SI units are to be regarded as
MIL-C-83522/18 Connector, Fiber Optic, Single Terminus,
standard. The values given in parentheses are mathematical
Adapter, 2.5 Millimeter Bayonet Coupling, PC Mount
conversions to inch-pound units that are provided for informa-
MIL-PRF-49291 Fiber, Optical (Metric), General Specifica-
tion only and are not considered standard.
S1.2 Referenced Documents tion for
S1.2.1 ASTM Standards: MIL-S-901 Shock Tests, H.I. (High-Impact); Shipboard
D542 Test Methods for Index of Refraction of Transparent Machinery, Equipment and Systems, Requirements for
Organic Plastics MIL-STD-167-1 Mechanical Vibrations of Shipboard
D570 Test Method for Water Absorption of Plastics
Equipment (Type I-Environmental and Type II-Internally Ex-
S1.2.2 Electronic Industries Association (EIA) Standards:
cited)
455-20 FOTP-20 Measurement of Change in Optical Trans-
MIL-STD-461 Electromagnetic Interference Characteristics
mittance
of Subsystems and Equipment, Requirements for the Control
455-22 FOTP-22 Ambient Light Susceptibility of Fiber
of
Optic Components
455-34FOTP-34InterconnectionDeviceInsertionLossTest
Available from National Electrical Manufacturers Association (NEMA), 1300
N. 17th St., Suite 900, Arlington, VA 22209, http://www.nema.org.
4 6
Available from IHS Markit Ltd, https://www.ihs.com/products/eia- Available from DLA Document Services, Building 4/D, 700 Robbins Ave.,
standards.html. Philadelphia, PA 19111-5094, http://quicksearch.dla.mil.
F2071−00 (2022)
MIL-STD-1399, Section 300 Interface Standard for Ship- (13)Special marking requirements (see S1.14);
board Systems, Electric Power, Alternating Current (14)Special packaging or package marking requirements
S1.3 Terminology (see S1.15); and
S1.3.1 Terminology is consistent with that of Section 3 and (15)Special warranty requirements (see S1.16.1).
the referenced documents.
S1.5.3 First-Article Tests—The purchaser should include
S1.4 Designation
specific instructions in acquisition documents regarding ar-
S1.4.1 Designation—For this specification, fiber-optic posi-
rangements for tests, approval of first-article test results and
tionswitchdesignationsshallbeassignedasspecifiedinS1.5.2
time period for approval, and disposition of first articles.
and listed in the format below:
Invitations for bids should provide that the purchaser reserves
Example: F25(FOSW)M-1-B-DC
the right to waive the requirement for samples for first-article
F25(FOSW)M-99 1 B DC
inspectiontothosemanufacturersofferingaproductwhichhas
Specification Type Optoelectronics Power Supply
been previously acquired or tested by the purchaser, and that
S1.4.2 Module S1.4.4
manufacturersofferingsuchproducts,whowishtorelyonsuch
S1.4.3
productionortest,mustfurnishevidencewiththebidthatprior
S1.4.2 Type—The following designators have been estab-
purchaser approval is presently appropriate for the pending
lished for the various types of fiber-optic position switches:
contract. The manufacture of items before purchaser approval
1—Proximity position switch sensor head,
should be specified as the responsibility of the manufacturer.
2—Pin-actuated limit position switch sensor head,
S1.6 Materials
3—Lever-actuated limit position switch sensor head,
4—Lever and roller limit position switch sensor head,
S1.6.1 Metals—Unless otherwise specified herein, all met-
5—Tether valve limit position switch sensor head, and
als used in the construction of the proximity or limit position
6—Special (see S1.5.2).
switch shall be corrosion resistant. Dissimilar metals shall not
S1.4.3 Optoelectronics Module—The optoelectronics mod-
be used in contact with each other unless suitably finished to
ule shall be designated as follows:
prevent electrolytic corrosion.
A—Bulkhead mounted,
S1.6.2 Flammable Materials—Materials used in the con-
B—Control enclosure mounted, and
struction of the proximity or limit position switch shall be
C—Console mounted (microprocessor or programmable
noncombustible or fire retardant in the most hazardous condi-
logic controller expansion card).
tions of atmosphere, pressure, and temperature to be expected
S1.4.4 Electrical Power Supply—The electrical interface
in the application. Fire-retardant additives may be used pro-
wiring shall be determined by the power supply as follows:
vided they do not adversely affect the specified performance
AC—Four-wire system used with a 115-V (nominal) alter-
requirementsofthebasicmaterials.Fireretardanceshallnotbe
nating current (ac) supply.
achieved by use of nonpermanent additives to the basic
DC—Four-wire system used with a 28-V (nominal) direct
material.
current (dc) supply.
S1.6.3 Fungus-Resistant Materials—Materials used in con-
S1.5 Ordering Information
structionoftheswitchsensorheadandoptoelectronicsmodule
S1.5.1 The purchaser shall provide the manufacturer with
shall not support the growth of fungus.
all of the pertinent application data shown in accordance with
S1.6.4 Solvents, Adhesives, and Cleaning Agents—When
S1.5.2.Ifspecialapplicationoperatingconditionsexistthatare
chemicalsorcementsareusedinbondingofinternalproximity
not shown in the acquisition requirements, they shall also be
or limit position switch components, no degradation shall
described.
result during in-service use.
S1.5.2 Acquisition Requirements—Acquisition documents
shall specify the following: S1.6.5 Refractive Index Matching Gels, Fluids, or
Compounds—Refractive index matching gels, fluids, or com-
(1)Title, number, and date of this specification;
(2)Part designation (see S1.4.1); poundsshallnotproducetoxic,corrosive,orexplosivebyprod-
ucts. The material is subject to a toxicological data and
(3)Special type position switch (see S1.4.2) description
and unique requirements; formulations review and inspection, for safety of material, by
the purchaser. The index matching material shall be either
(4)National Stock Number (NSN) if available;
(5)Sensor head mounting requirements (see S1.7.2); silicone or aliphatic hydrocarbon material and shall be clear
(6)Requirements when Type B or Type C optoelectronics and transparent. The index matching material shall have an
module is specified (see S1.7.3.2 and S1.7.3.3); indexofrefractionof1.46 60.01astestedinaccordancewith
(7)Optoelectronics module mounting method if other than Test Methods D542, when exposed to operating temperature
specified herein (see S1.7.3); extremes between −28°C and +85°C. The index matching
(8)Type of fiber-optic connectors, receptacles, and bulk- material shall not flow at elevated temperatures. The index
head adapters, if other than specified herein (see S1.7.4); matching material shall remain clear and transparent when
(9)Fiber-optic cable length required (see S1.7.6); tested for water absorption in accordance with Test Method
(10)Critical dimensions of the switch (see S1.7.13); D570. The index matching material shall have a shelf life not
(11)Quantity of switches required; less than 36 months at 25°C 6 5°C. The 36-month period
(12)When first-article tests are required (see S1.12.2); commences on the date of adhesive manufacture.
F2071−00 (2022)
S1.7 Physical Properties MIL-C-83522/16, 17, and 18, respectively, or equal. Connec-
tors shall be assembled at both ends of the fiber-optic cable
S1.7.1 Design and Construction—The switch shall consist
between the sensor head and the optoelectronics module.
of an assembly with three major components: optical sensor
S1.7.7 Local Status Indication—The switch optoelectronics
head, fiber-optic cable, and optoelectronics module. The opto-
electronicsmoduleshallbeinterchangeablebetweenanyofthe module shall have three indicator light-emitting diodes
(LEDs): (1) a green LED that indicates the switch is closed
sensor head types (see S1.4.2).
when illuminated, (2) a red LED that indicates the switch is
S1.7.2 Sensor Head—The sensor head shall meet the re-
open when illuminated, and (3) a yellow LED that indicates a
quirements specified herein. Sensor head mounting require-
switch is closed with alarm level condition when illuminated.
ments shall be as required for the switch application and
The LEDs shall be located on either the top or front of the
specified in the acquisition requirements (see S1.5.2). It is
module as it would be mounted during usage. The LEDs shall
recommended that the sensor head be installed such that
be visible in fluorescent room lighting. One LED and only one
sufficient clearance is provided for repair and maintenance of
LED shall be lit at all times when the optoelectronics unit is
the unit.
energized.
S1.7.3 Optoelectronics Module—The optoelectronics mod-
S1.7.8 Low-Intensity Alarm Set Point Adjustment—The
ule shall contain the optical and signal conditioner devices
switch shall provide an indication of a degradation in the
necessary to convert the sensor head output to the specified
intensity of the transmitted optical signal via an alarm output.
electrical output. The module shall be bulkhead mounted,
Theoptoelectronicsmoduleshallprovideameansforadjusting
control enclosure mounted, or console mounted as specified in
thelow-intensityalarmsetpointbyoneindividualandwithout
the acquisition requirements (see S1.5.2).
the necessity for an electrical disconnection.The low-intensity
S1.7.3.1 Bulkhead Mounted (Type A)—Bulkhead-mounted
alarm set point adjustments shall be labeled and shall be
optoelectronicsmodulesshallbehousedinajunctionbox.The
accessible when the optoelectronics enclosure cover (for
junction box maximum dimensions shall be 280mm L by
mounting Type A and Type B) is removed. The low-intensity
205mmWby 130mm D (11in. Lby 8in.Wby 5in. D).The
alarm level set point shall allow tamperproof sensitivity
junction box material shall be brass. The junction box shall
adjustment over the entire dynamic range of the optoelectron-
meet all test criteria in NEMA Standard 250 for Type 4X
ics module. The optoelectronics module low-intensity alarm
enclosures. The optoelectronics module shall be subjected to
shall allow for an indication that maintenance is required
all first-article tests as specified (see S1.12.1) before mounting
before a false open switch indication.
in the junction box.
S1.7.9 Electrical Overload Protection and Isolation—The
S1.7.3.2 Control Enclosure Mounted (Type B)—Control
optoelectronics module shall be provided with overload and
enclosure-mounted optoelectronics modules are intended for
short circuit protection. As a minimum, ac switches shall be
use within an environmental protective enclosure as part of a
protected from continuous overloads up to 6-A rms. Interrup-
motor controller or other system. The optoelectronics module
tionoftheoperatingvoltageshallberequiredtorestorenormal
shallbemountedinanenclosureasspecifiedintheacquisition
operation of the switch after an overload has been detected.A
requirements(seeS1.5.2).Theoptoelectronicsmoduleshallbe
meansofisolatingtheoptoelectronicsmodulefromshippower
subjected to all first-article tests as specified (see S1.12.1)
shall be provided on the unit.
before mounting in the enclosure.
S1.7.10 Wire Colors:
S1.7.3.3 Console Mounted (Type C)—Console-mounted
S1.7.10.1 ac Switches—Wire colors shall be as follows:
(microprocessor or progra
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