ASTM_F_2071_-_00_2011.pdf

Designation:F207100(Reapproved 2011)An American National StandardStandard Specification forSwitch,Position Proximity(Noncontact)or Limit(Mechanical Contact),Fiber-Optic1This standard is issued under the fixed designation F2071;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This specification covers the requirements for fiber-optic position switches(proximity and limit).This specifica-tion does not include switches that transfer an optical signalfrom one path to another by an external force or energy appliedto the switch.1.2 The values stated in SI units are to regarded as thestandard.The values given in parentheses are for informationonly.Where information is to be specified,it shall be stated inSI units.1.3 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.1.4 Special requirements for naval shipboard applicationsare included in the Supplement.2.Referenced Documents2.1 ASTM Standards:2D3951 Practice for Commercial Packaging2.2 ISO Standards:ISO 9001 Quality SystemModel for Quality Assurance inDesign/Development,Production,Installation,and Ser-vicing33.Terminology3.1 Definitions:3.1.1 closed switchthe light path is complete;signal fromtransmitter to receiver is complete.3.1.2 closed switch with positive alarmthe light path iscomplete.Signal level indicates that the end faces of thesensing element are dirty and require maintenance for contin-ued proper operation.3.1.3 fiber-optic position switcha device that convertsmeasured position,via changes in fiber-optic properties,to anoutput that is a function of the applied measurand.Thefiber-optic position switch normally consists of a sensor head,optoelectronics module,and connectorized fiber-optic cable.3.1.4 limit switcha switch that senses a change in positionvia mechanical contact.3.1.5 open switchthe light path is blocked;signal fromtransmitter to receiver is not complete.3.1.6 optical transmittance changethe change in opticalpower level introduced by an environmental,mechanical,orother induced stress.3.1.7 optoelectronics moduleunit of the fiber-optic posi-tion switch that contains the optical transmitter and receiver,and signal conditioning electronics,necessary to convert thesensed position to the specified output signal.The optoelec-tronics module may be an expansion card for a microprocessor-based system,or a stand-alone unit.3.1.8 proximity switcha switch that senses a change inposition via noncontact means.3.1.9 sensor headunit of the fiber-optic position switchthat detects position via changes in optical properties.Theoptoelectronics module interrogates the sensor head to deter-mine the position of the measurand.An optical signal istransmitted from the optoelectronics module to the sensorhead.The optical path is either complete or blocked,dependingon the status of the item being measured,giving an indicationof the position or status of the item back to the optoelectronicsmodule.3.1.10 steady-state supply voltagean input voltage thatdoes not deviate from a specified nominal tolerance(forexample,65%).3.1.11 tether valve limit switcha limit switch used todetect valve position via a tether line connected to the valvehandle.1This specification is under the jurisdiction of ASTM Committee F25 on Shipsand Marine Technology and is the direct responsibility of Subcommittee F25.10 onElectrical.Current edition approved April 1,2011.Published April 2011.Originallyapproved in 2000.Last previous edition approved in 2006 as F2071 00(2006).DOI:10.1520/F2071-00R11.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.3Available from International Organization for Standardization(ISO),1 rue deVaremb,Case postale 56,CH-1211,Geneva 20,Switzerland.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 3.1.12 transient supply voltagea voltage superimposed onthe steady-state supply voltage that is greater than the specifiedsteady-state tolerance and has a very rapid rise and fall.4.Classification4.1 DesignationMost switch manufacturers use designa-tions,systematic numbering or identifying codes.Once under-stood,these designations could aid the purchaser in quicklyidentifying the switch type,electrical power ratings,and othercharacteristics.4.2 DesignFiber-optic position switches typically consistof an assembly with three major components:optical sensorhead,fiber-optic c