ASTM F2046-00(2022)

Standard Specification for Tachometers, Various

ABSTRACT
This specification covers various tachometers capable of measuring rotational shaft speed. Special requirements for tachometer types used in naval shipboard applications. The materials for all parts shall be selected for long-term compatibility with the environment in which the tachometer will be installed or used. Qualification testing and quality conformance testing shall be performed.
SCOPE
1.1 This specification covers various tachometers capable of measuring rotational shaft speed.  
1.2 Special requirements for tachometer types used in naval shipboard applications are included in Supplement S1.  
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.  
1.4 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: 47.020.70 - Navigation and control equipment
• 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 F2046-00(2022), Standard Specification for Tachometers, Various defines requirements for a wide range of tachometers used to measure rotational shaft speed. This international ASTM standard applies to diverse tachometer types, including those used for critical naval shipboard applications, and guides the selection of materials, performance requirements, testing, and documentation. The specification covers both electric and fiber-optic tachometers, ensuring long-term compatibility, reliability, and environmental resilience, essential in industrial, marine, and military environments.

Key Topics

• Tachometer Types: The standard covers various types, including centrifugal, chronometric, electrical (AC and DC), digital contact, photoelectric, frequency responsive, and vibrating resonant reed tachometers.
• Naval Applications: Supplement S1 details additional requirements for noncontact electric and fiber-optic tachometers for naval shipboard systems, including construction, environmental durability, and compliance with relevant military standards.
• Material Selection: All tachometer components must be made from materials compatible with their intended environment, including resistance to corrosion, fungus, and fire hazards.
• Performance Criteria: The standard outlines key performance parameters such as accuracy, repeatability, damping, resistance to vibration and shock, and electromagnetic interference (EMI) tolerance.
• Testing & Quality Assurance:
  • Qualification and quality conformance testing
  • Adherence to industry and military testing methods
  • Maintenance of test records for at least three years
• Acquisition & Documentation: Specifications must be clear in acquisition documents, including required range, mounting method, materials, testing, marking, and packaging.

Applications

ASTM F2046-00(2022) is widely applicable across industries where accurate rotational speed measurement is critical:

• Naval & Shipboard Systems: Provides guidance for selecting and qualifying tachometers used in propulsion, gas and steam turbines, and auxiliary machinery, ensuring performance under harsh maritime conditions.
• Industrial Machinery: Supports maintenance and operational safety in rotating equipment such as motors, pumps, and generators, where precise speed monitoring prevents failures and optimizes performance.
• Aerospace & Defense: Ensures tachometers meet stringent military and environmental specifications for use in defense systems and equipment.
• Research & Testing Laboratories: Standardizes performance and installation requirements, promoting repeatability and comparability of test data.

The standard’s guidance on environmental resistance, durability, and precise marking ensures reliability in applications subject to temperature extremes, humidity, vibration, and salt spray.

Related Standards

Implementing ASTM F2046-00(2022) is often complemented by adherence to other related industry and military standards, including:

• ASTM D3951: Practice for Commercial Packaging - referenced for product delivery and packaging requirements.
• MIL-STD-461: Electromagnetic Interference Characteristics - for controlling EMI in subsystems and equipment.
• MIL-STD-167-1: Mechanical Vibrations - ensures shock and vibration requirements for shipboard equipment.
• MIL-S-901: Shock Testing of Shipboard Systems - applicable for testing high-impact resistance.
• MIL-C-5015 & MIL-C-83522: Specifications for electrical and fiber-optic connectors.
• ANSI/ISA S37.1: Defines transducer nomenclature and terminology used in sensor technologies.

By referencing these standards, ASTM F2046 ensures consistency, compatibility, and performance in a wide range of operational environments.

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Keywords: ASTM F2046, tachometers, rotational speed measurement, shipboard tachometer, fiber-optic tachometer, industrial tachometer, military standards, quality assurance, vibration testing, EMI compliance, naval applications, packaging standards, connector specifications.

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:F2046 −00 (Reapproved 2022) An American National Standard
Standard Specification for
Tachometers, Various
This standard is issued under the fixed designation F2046; 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.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope (1)Centrifugal;
(2)Centrifugal, flexible drive;
1.1 Thisspecificationcoversvarioustachometerscapableof
(3)Chonometric;
measuring rotational shaft speed.
(4)Electrical, alternating current (ac) voltage responsive,
1.2 Specialrequirementsfortachometertypesusedinnaval
direct drive;
shipboard applications are included in Supplement S1.
(5)Electrical reactance;
1.3 The values stated in SI units are to be regarded as (6)Electrical, magnetovoltmeter, direct drive;
(7)Electrical, magnetovoltmeter;
standard. The values given in parentheses are mathematical
conversions to inch-pound units that are provided for informa- (8) Frequency responsive, electrical control box and
voltmeter, direct drive;
tion only and are not considered standard.
(9)Frequency sensitive, electrical, nonrotating magnetic
1.4 This international standard was developed in accor-
pickup, direct drive, consists of a magnetic pickup, transducer,
dance with internationally recognized principles on standard-
and indicator;
ization established in the Decision on Principles for the
(10)Photoelectric;
Development of International Standards, Guides and Recom-
(11)Digital contact;
mendations issued by the World Trade Organization Technical
(12)Centrifugal, flexible drive; and
Barriers to Trade (TBT) Committee.
(13)Vibrating resonant reed.
2. Referenced Documents
5. Ordering Information
2.1 ASTM Standards:
5.1 Thebuyershallprovidethemanufacturerwithallofthe
D3951Practice for Commercial Packaging
pertinent application data in accordance with the acquisition
requirements, 5.2.
3. Terminology
5.2 Acquisition Requirements—Acquisitiondocumentsshall
3.1 Definitions:
specify the following:
3.1.1 SI (Le Systeme International d’Unites) Units, n—units
(1)Title, number, and date of this specification;
of measurement recognized by the Comite’ International des
(2)Quantity of tachometers required;
Poids et Mesures (CIPM).
(3)Range;
3.1.2 tachometer, n—an instrument capable of generating,
(4)Manufacturer’s part number;
transmitting, and indicating information or signal that can be
(5)When qualification inspection is required;
convened into a function of rotational speed.
(6)Final disposition of qualification test samples;
(7)Type of electrical connection;
4. Classification
(8)Mounting method;
4.1 Design Types—The following are among the types of
(9)Environmental requirements;
tachometers available:
(10)Materials;
(11)Size and weight restrictions;
This specification is under the jurisdiction ofASTM Committee F25 on Ships
(12)Critical service life requirements;
and Marine Technology and is the direct responsibility of Subcommittee F25.10 on
(13)Performance requirements;
Electrical.
(14)Surface finish requirements;
Current edition approved Oct. 1, 2022. Published October 2022. Originally
(15)Cleaning requirements;
approved in 2000. Last previous edition approved in 2017 as F2046–00 (2017).
DOI: 10.1520/F2046-00R22.
(16)When certification is required;
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
(17)Marking requirements;
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
(18)Packaging requirements; and
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. (19)Preservation requirements.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
F2046−00 (2022)
6. Materials and Manufacture 11. Number of Tests and Retests
11.1 Test Specimens—The number of test specimens to be
6.1 Material Selection—The materials for all parts shall be
subjected to qualification testing shall depend on the tachom-
selected for long-term compatibility with the environment in
eter design. If each range is covered by a separate and distinct
which the tachometer will be installed or used.
design, a test specimen for each range will require testing. In
6.2 Material Inspection—Themanufacturershallberespon-
instances in which a singular design series may cover multiple
sible for ensuring that materials used are manufactured,
ranges and types, it is recommended that three test specimens
examined, and tested in accordance with the specifications and
betestedprovidedtheelectricalandmechanicalsimilaritiesare
standards as applicable.
approved by the buyer. In no case, however, should less than
three units, one unit each representing low, medium, and high
7. Physical Properties
ranges, be tested, regardless of design similarity.
7.1 Size and Weight—The buyer may have intended appli-
12. Test Methods
cations where size and weight are limited. Size and weight
12.1 Tests—All tests shall be performed in accordance with
limitations shall be specified in the acquisition requirements.
ASTM, American Society of Mechanical Engineers (ASME),
or industry standards as specified.
8. Performance Requirements
12.2 Test Data—All test data shall remain on file at the
8.1 Service Life—Thebuyermayhaveaminimumspecified
manufacturer’sfacilityforreviewbythebuyeruponrequest.It
serviceliferequirement.Criticalserviceliferequirementsshall
isrecommendedthattestdataberetainedinthemanufacturer’s
be specified in the acquisition requirements.
filesforatleastthreeyearsoraperiodoftimeacceptabletothe
8.2 Tachometer Performance—Performance tolerances are
buyer and manufacturer.
usually specified in percentage of range span. The following
13. Quality Assurance Provisions
performance characteristics and environmental exposures may
or may not be important to each buyer’s intended application.
13.1 Warranty:
(1)Accuracy,
13.1.1 Responsibility for Warranty—Unless otherwise
(2)Repeatability,
specified, the manufacturer is responsible for the following:
(3)Damping,
(1)All materials used to produce a unit and
(4)Temperature,
(2)Manufacturer will warrant his product to be free from
(5)Humidity,
defect of workmanship to produce the unit.
(6)Salt spray,
(7)Vibration,
14. Certification
(8)Shock, and
14.1 When specified in the purchase order or contract, the
(9)Electromagnetic interference (EMI).
buyer shall be furnished certification that samples representing
each lot have been either tested or inspected as directed in this
9. Workmanship, Finish, and Appearance
specification, and the requirements have been met. When
specified in the purchase order or contract, a report of the test
9.1 Cleaning, Finish, and Appearance—Any special
results shall be furnished.
cleaning, surface finish, and appearance requirements shall be
specified in the acquisition requirements.
15. Product Marking
15.1 User-specified product marking shall be listed in the
10. Inspection
acquisition requirements. The minimum data to be clearly
10.1 Classification of Inspections—The inspection require-
marked on each tachometer shall include the following:
ments specified herein are classified as follows:
(1)Manufacturer’s name,
(1)Qualification testing, and
(2)Manufacturer’s part number,
(2)Quality conformance testing.
(3)Serial number or lot number,
(4)Date of manufacture, and
10.2 Qualification Testing—Qualification test requirements
(5)Range.
shall be specified, where applicable. Test methods should be
identified for each design and performance characteristic
16. Packaging and Package Marking
specified. Test report documentation requirements should also
be specified. 16.1 Packaging of Product for Delivery—Product shall be
packaged for shipment in accordance with Practice D3951.
10.3 Quality Conformance Testing—Quality conformance
16.2 Anyspecialpreservation,packaging,orpackagemark-
inspection is accomplished when acceptance and qualification
ing requirements for shipment or storage shall be identified in
testing is satisfied by a previous acquisition or when the
the acquisition requirements.
product has demonstrated reliability in similar applications.
Quality conformance inspection is usually less intensive than
17. Keywords
acceptance and qualification, often verifying that samples of a
production lot meet a few critical performance requirements. 17.1 tachometer
F2046−00 (2022)
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 this standard
(Specification F2046) and this supplement, the requirements of this supplement shall take precedence
for equipment acquired by this supplement.This document supersedes MIL-T-16049C, Tachometers:
Electrical; Self-Generating; Mechanical, Fixed Mounting, and Hand Held; and Vibrating Reed, for
new ship construction. This document also supersedes MIL-T-24797, Tachometers, Fiber Optic,
(Naval Shipboard Use), (Metric) General Specification for, for new ship construction.
TACHOMETERS: ELECTRIC AND FIBER OPTIC, FIXED MOUNTING
S1. Scope S2.2 Government Documents:
S2.2.1 Military Standards:
S1.1 This supplement covers single-range noncontact elec-
MIL-STD-461Electromagnetic Interference Characteristics
tric and fiber-optic tachometers capable of generating,
of Subsystems and Equipment, Requirements for the Control
transmitting, and indicating information or signal that can be
of
converted into a function of rotational speed. The subject
tachometers may be used in shipboard systems, such as gas MIL-STD-167-1 Mechanical Vibrations of Shipboard
generators, power turbines, propulsion shafts, and gas steam Equipment (Type I—Environmental and Type II—Internally
turbine generators.
Excited)
S1.2 Vibrating reed resonant-type tachometers are not cov-
S2.2.1 Military Specifications:
ered in this specification.
MS3452Connector, Receptacle, Electric, Box Mounting,
S1.3 The values stated in SI units are to be regarded as
Rear Release, Crimp Contact, AN Type
standard. The values given in parentheses are mathematical
MS3456Connector, Plug, Electrical, Rear Release, Crimp
conversions to inch-pound units that are provided for informa-
Contact, AN Type
tion only and are not considered standard.
MIL-C-5015Connectors, Electrical, Circular Threaded, AN
Type General Specification for
S2. Referenced Documents
MIL-M-24794Material, Index Matching, Fiber Optics
S2.1 Commercial Documents:
MIL-F-49291Fiber, Optical, (Metric), General Specifica-
S2.1.1 ASTM Standards:
tions for
B117 Practice for Operating Salt Spray (Fog) Apparatus
MIL-C-83522Connectors, Fiber Optic, Single Terminus,
D3951 Practice for Commercial Packaging
General Specification for
S2.1.2 ANSI/ISA Standards:
ANSI/ISAS37.1 (R-1982)Electrical Transducer Nomencla- MIL-C-83522/16Connector, Fiber Optic, Single Terminus,
ture and Terminology Plug, Adapter Style, 2.5 mm Bayonet Coupling, Epoxy
ANSI/ASQC Q9001-1994 Quality Systems—Model for
MIL-C-83522/17Connector, Fiber Optic, Single Terminus,
Quality Assurance in Design, Development, Production,
Adapter, 2.5 mm Bayonet Coupling, Bulkhead Panel Mount
Installation, Inspection, Testing, and Servicing
MIL-C-83522/18Connector Fiber Optic, Single Terminus,
S2.1.3 Electronic Industries Association (EIA) Standards:
Adapter, 2.5 mm Bayonet Coupling, PC Mount
RS-422Electrical Characteristics of Balanced Voltage Digi-
MIL-C-85045Cables, Fiber Optic, (Metric), General Speci-
tal Interface Circuit
fication for
455-22 FOTP-22Ambient Light Susceptibility of Fiber
MIL-S-901Shock Tests, H.I. (High Impact), Shipboard
Optic Components
Machinery, Equipment, and Systems, Requirements for
455-34FOTP-34InterconnectionDeviceInsertionLossTest
S3. Terminology
S3.1 Definitions—Terms marked with “ANSI/ISA S37.1”
are taken directly from ANSI/ISA S37.1 (R-1982) and are
included for the convenience of the reader.
Available fromAmerican National Standards Institute (ANSI), 25 W. 43rd St.,
4th Floor, New York, NY 10036, http://www.ansi.org.
4 5
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.
F2046−00 (2022)
S3.1.1 ambient conditions, n—conditions, such as pressure S3.1.14 sensor head, n—the transduction element of a fiber
and temperature, of the medium surrounding the case of a optic tachometer that detects rotational speed by means of
sensor. changes in optical properties.
ANSI/ISA S37.1 S3.1.15 sheath, n—the protective covering of a sensor
element.
S3.1.2 calibration, n—test during which known values of
S3.1.16 signal conditioner, n—an electronic device that
measurandsareappliedtothesensorandcorrespondingoutput
makes the output signal from a transduction element compat-
readings are recorded under specific conditions.
ible with a readout system.
ANSI/ISA S37.1
S3.1.17 span,n—thealgebraicdifferencebetweenthelimits
S3.1.3 environmental conditions, n—specified external
of the measurement range.
conditions,suchasshock,vibration,andtemperature,towhich
S3.1.18 static error band, n—the maximum deviation from
a sensor may be exposed during shipping, storage, handling,
astraightlinedrawnthroughthecoordinatesofthelowerrange
and operation.
limit at specified sensor output, and the upper range limit at
ANSI/ISA S37.1
specified output expressed in percentage of sensor span.
S3.1.4 error, n—the error for a given value of the input
S3.1.19 supporting surface, n—surfaceonwhichtheequip-
variable (measurand) is the difference between the measured
ment is placed.
value of the output signal and the expected value of the output
S3.1.20 tachometer, n—an instrument capable of
signal.Theexpectedvalueoftheoutputsignalforanyvalueof
generating, transmitting, and indicating information or signal
themeasurandshallberepresentedbyastraightlinewhoseend
that can be converted into a function of rotational speed.
points are given by:
S3.1.21 target, n—description including items such as
S3.1.4.1 The specified value of the output signal at the
material, size, multiple reflectors, and surface features shall be
minimum input value of the measurand (for example, 4 mAat
as specified in the acquisition requirements.
the minimum specified rotational speed).
S3.1.22 warm-up time, n—the time required for a sensor to
operate within specified accuracy, repeatability, and other
S3.1.4.2 The specified value of the output signal at the
maximum input value of the measurand (for example, 20 mA critical parameters after being energized from a cold (ambient)
state.
at the maximum specified rotational speed).
S3.1.5 noncontact tachometer, n—any type of tachometer
S4. Design Classification
that senses or responds to rotational speed without physical
contact or mechanical connection to the shaft being measured. S4.1 Electric Types:
S4.1.1 Designation—Tachometers shall be classified by a
S3.1.6 operating environmental conditions,
series of designations which shall be assigned and listed in the
n—environmental conditions during exposure to which a
format following.
sensor must perform in some specified manner.
Example: F2046-20M-BK-A
ANSI/ISA S37.1
F2046 20M BK A
S3.1.7 optical, adj—involving the use of light-sensitive
Specification Range Mounting Indicator
devices to acquire information.
(see S4.1.2) (see S4.1.3) (see S4.1.4)
S3.1.8 optical fiber—a very thin filament or fiber, made of
S4.1.2 Range—Electric tachometer ranges shall be selected
dielectricmaterials,thatisenclosedbymaterialoflowerindex
from the standard ranges listed in Table S4.1.
of refraction and transmits light throughout its length by
S4.1.3 Mounting—Tachometer indicators shall be either
internal reflections.
bulkhead mounted (designator—BK) or panel (designator—
S3.1.9 optoelectronics module, n—a component of the fiber
PL) mounted.
optic tachometer that contains the optical source and detector, S4.1.4 Indicator—Tachometer indicators shall be either
and signal conditioner devices necessary to convert the sensed
analog (designator—A) or digital (designator—D).
rotational speed to a specified output signal. S4.2 Fiber-Optic Type:
S4.2.1 Designation—The sensor classification shall consist
S3.1.10 output, n—electrical or numerical quantity, pro-
ofaseriesofdesignationswhichshallbeassignedandlistedin
ducedbyasensorormeasurementsystem,thatisafunctionof
the form following.
the applied measurand.
Example: F2046-DC-A-1
S3.1.11 range, n—measurandvalues,overwhichasensoris
F2046 dc A 1
intended to measure, specified by their upper and lower limits.
Specification Input power Optoelectronics Sensor mount-
ANSI/ISA S37.1
S4.2.2 module ing configura-
type S4.2.3 tion S4.2.4
S3.1.12 repeatability, n—ability of a sensor to reproduce
output readings when the same measurand value is applied to
S4.2.2 Input Power—The input power required to operate
it consecutively, under the same conditions, and in the same the optoelectronics module shall be designated as follows:
direction.
dc—28-V direct current (Vdc)
ac—115-V alternating current (Vac)
ANSI/ISA S37.1
S3.1.13 sensor element, n—that part of the sensor that S4.2.3 Optoelectronics Module—The mounting of the ta-
responds directly to the measurand. chometer’s optoelectronics module type shall be designated as
ANSI/ISA S37.1 follows:
F2046−00 (2022)
TABLE S4.1 Standard Ranges for Electric Tachometers
0—1000 R/MIN
0—5000 R/MIN
Range, R/MIN Designation
0—10 000 R/MIN
0–100 10A
0—20 000 R/MIN
0–200 20A
0–500 50A
50–500 50M S5. Ordering Information
0–1000 10B
100–1000 10M
S5.1 The buyer shall provide the manufacturer with all of
0–2000 20B
the pertinent application data shown in S5.2. If special appli-
200–2000 20M
cation operating conditions exist that are not shown in the
0–3000 30B
300–3000 30M
acquisition requirements, they shall also be described.
0–4000 40B
S5.2 Acquisition Requirements—Acquisition documents
0–5000 50B
500–5000 50N
shall specify the following:
0–10 000 10C
(1)Title, number, and date of this specification;
1000–10 000 10N
(2)Type and quantity required;
0–20 000 20C
1000–20 000 20N
(3)Whether panel or bulkhead mounting is required;
0–30 000 30C
(4)Range required;
0–50 000 50C
5000–50 000 50P (5)National Stock Numbers (NSNs) if available;
0–100 000 10D
(6)When self-contained red illumination is required;
500–100 000 10P
(7)Whether tachometer, control box, and indicator should
1000–100 000 10R
5000–100 000 10T
be other than drip-proof construction;
(8)Number of additional indicators, if required;
(9)When qualification testing is required;
(10)Disposition of qualification test samples;
(11)Analog or digital indicator requirement;
Type A—Bulkhead mounted (see S7.3.1)
(12)Special levels of preservation-packaging and packing
Type B—Console mounted (see S7.3.2)
required; and
S4.2.4 Sensor Mounting Configuration—The tachometer’s
(13)Product marking and labeling required.
sensor shall be mounted according to the following mount
S5.2.1 Fiber-Optic Requirements—In addition to the re-
requirementtype.Themassperunitlengthofthesensormount
quirements outlined in S5.2, acquisition documents for fiber-
configuration shall be no greater than 0.02 kg/mm. The
optic tachometers should specify the following:
dimensions of the tachometer’s sensor head shall be in accor-
(1)Classification (see S4.2.1):
dance with Fig. S4.1.
(a)Input power,
S4.2.4.1 Mass—Unless otherwise specified, the mass of the
(b)Optoelectronics module,
optoelectronics module shall be not greater than 5 kg.
(c)Signal output, and
S4.2.4.2 Target—The target description including items
(d)Range.
such as material, size, multiple reflectors, and surface features
(2)Whether bulkhead or console mounting is required.
shall be as specified in the acquisition requirements.
S4.2.5 Range—Thefiber-optictachometerrangeisaninter- (3)Type and quantity of indicator(s) required.
(4)Whether junction box should be other than drip-proof
nal selection within the optoelectronics module with the
following ranges: construction.
FIG. S4.1Sensor Head Construction
F2046−00 (2022)
TABLE S7.1 Dimensions and Weight (Indicators)
S6. Materials and Manufacture
Nominal Scale
S6.1 Metals—Unless otherwise specified herein, all metals Height Max, Width Max, Depth Max, Weight Max,
Length Min,
in. in. in. lbs
used in the construction of the tachometer shall be corrosion
in.
1 1 1
4 ⁄2 5 ⁄2 5 ⁄2 55
resistant. Dissimilar metals shall not be used in close physical
1 1
67 ⁄2 7 ⁄2 66
contact with each other unless suitably finished to prevent
electrolytic corrosion.
S6.2 Flammable Materials—Materialsusedintheconstruc-
S7.1.5 Mounting—Theindicatorshallbedesignedforpanel
tion of the tachometer shall, in the end configuration, be
or bulkhead mounting.
noncombustible or retardant in the most hazardous conditions
S7.1.6 Operating Characteristics—The tachometers shall
of atmosphere, pressure, and temperature to be expected in the
instantaneously and continuously indicate information or a
application.
signal that can be converted into a function of the speed of
S6.3 Fungus-Resistant Materials—Materials used in the
rotation in r/min of the rotating part being measured. The
construction of the tachometer shall be fungus-inert materials.
tachometers shall indicate, without change or adjustment,
S6.4 Solvents, Adhesives, and Cleaning Agents—If any
regardlessofthedirectionofrotationofthedrivingpartonthe
chemicals or cements are used in bonding of internal tachom-
same scale.
eter components, no degradation of these components shall
S7.2 Fiber-Optic Tachometers—The fiber-optic tachometer
result during in-service use.
shall be a noncontact device capable of converting a rotational
S6.5 Refractive Index Matching Gels, Fluids, or
speed to a continuous output signal throughout a specified
Compounds—Refractive index matching gels, fluids, or com-
measurement range.Afiber-optic tachometer shall consist of a
pounds for fiber-optic tachometers shall be in accordance with
sensor head, optoelectronics module, and fiber-optic cable
MIL-M-24794.
connector at both ends. The optoelectronics module translates
the optical input from the sensor head to a continuous linear
S7. Physical Properties
proportionalanalogelectricalsignalorotheroutputsignalsuch
S7.1 Electric Tachometers—Electric tachometers shall be a
as optical and digital.
noncontact design and shall provide an output proportional to S7.2.1 Sensor Head—The sensor head(s) shall be passive
thecontinuousinstantaneousshaftspeed.Tachometersshallbe
and detect shaft rotation through change in optical properties.
for fixed mounted type of installations in which ranges from The beam interruption sensing mechanism shall consist of two
100 to 100000 r/min are encountered. Unless otherwise
sensor heads. One sensor head shall be used to transmit, and
specified, the sensor, control box, and indicator shall be of one sensor head shall be used to receive an optical signal
drip-proof construction.
(generated from the optoelectronics module) across an air gap.
S7.1.1 Sensor—The sensor shall produce a signal by mag- Neither electrical nor electronic components shall be used in
neticpulse,lightpulse,orothernoncontactmethodforinputto
the construction of the sensor head. The configuration and
the control box. The method of mounting or adapting the physicaldimensionsofthesensorhead(s)shallbeasspecified.
sensor may be varied to suit the machinery details.
S7.2.2 Optoelectronics Module Mounting—The optoelec-
S7.1.2 Control Box—The control box shall include the tronics module mounting shall be either bulkhead or console
necessary electronics to process the sensor signal for driving
mounted as specified.
the indicator. The sensor and control box may be combined in S7.2.2.1 Bulkhead Mounted (Type A)—The optoelectronics
a single unit.
module shall be housed in a junction box.
S7.1.3 Indicator—Theindicatorshallbecapableofpanelor S7.2.2.2 Console Mounted (Type B)—The optoelectronics
bulkhead mounting.The indicator shall be analog or digital, as
module shall be packaged in a circuit card that is a modular
specified in the acquisition requirements. The analog indicator subassemblyofacontrolconsole.Designandtestrequirements
shall be a nominal 4 ⁄2- or 6-in. round scale with a 250°
for the optoelectronics module shall be as specified.
minimum arc. The digital indicator may be a round or S7.2.3 Fiber-Optic Cable—For integrity, the cable shall
rectangular liquid crystal or light-emitting diode display with haveanouterdiameterofafour–fibercableinaccordancewith
readoutnumeralsaminimumof1cminheight.Astopshallbe MIL-C-85045. In the cable, there shall be no less than two
provided in analog indicators to prevent the indicating pointer times the number of fibers needed for operation of the sensor.
fromgoingpastfull-scalereading.Analogindicatorsshallhave The cable shall be supplied with a stuffing tube, packing
self-contained red illumination. assembly, and an O-ring, installed on each end of the cable to
S7.1.3.1 Dial and Pointer for Analog Indicators—The dial accomplish watertight penetration into the sensor head and
shall be of a corrosion-resistant material that will not warp at optoelectronics module. Exposed single-fiber OFCC shall not
90°C. The dial shall have a dull white finish with scale be used over distances greater than 1 m. The length of cable
markings, numerals, and pointer a dull black. Dial and pointer shall be as specified.
assembly shall be of commercial design.
S7.2.3.1 Optical Fiber—Optical fiber used to transmit light
S7.1.3.2 Display or Indicator Windows—The display shall betweentheoptoelectronicsunitandthesensorheadshallbein
be protected by a window of high-quality plastic, free from accordance with MIL-F-49291.
flaws and defects, that does not cause parallax error. S7.2.3.2 Fiber-Optic Connectors, Receptacles, and Bulk-
S7.1.4 Dimensions and Weights (Maximum)—Dimensions head Adapters—Fiber-optic connectors, receptacles, or bulk-
and weights of the indicator shall be as shown in Table S7.1. head adapters used shall be in accordance with MIL-C-83522
F2046−00 (2022)
and MIL-C-83522/16,17,18, respectively. Connectors shall be S7.2.6.2 dc Input and Frequency Output—The receptacle
assembled at both ends of the fiber-optic cable between the mounted to the optoelectronics module shall be Classification
sensor head and the optoelectronics module. The connectors
MS3452W14S-5PX in accordance with MS3452. Receptacle
and receptacles shall be mounted inside the sensor head or
Pin “A” shall be +28–Vdc power input, Pin “B” shall be
optoelectronics module.
−28–Vdc power input, Pin “C” shall be case ground, and Pins
S7.2.4 Electrical Input Power Requirements—Nominal “D” and “E” shall be frequency signal outputs. The mating
steady-state power supply requirements for ac shall be 115V plug shall be Classification MS3456WI4S-5SX in accordance
68V,60Hz 6 2 Hz, single phase. Nominal steady-state with MS3456.
power supply requirements for dc shall be 28V 6 4.5 V. The
S7.2.6.3 ac Input and Current or Voltage Output—The
tachometer shall meet all performance requirements specified
receptacle mounted to the optoelectronics module shall be
herein while operating with specified power supply voltages
Classification MS3452W14S-5PX in accordance with
and their tolerances.
MS3452.ReceptaclePins“A”and“B”shallbe115–Vacpower
S7.2.5 Output Signal—The output signal of the tachometer
input,Pin“C”shallbecaseground,Pin“D”shallbea+mAor
shall be directly proportional to the speed being measured. A
Vdc signal output, and Pin “E” shall be a −mA or Vdc signal
means shall be provided for internal selection (within the
output.ThematingplugshallbeClassificationMS3456W14S-
optoelectronics module) between the following output signals:
5SX in accordance with MS3456.
true current source of 4mAto 20 mA, 0mAto 1 mA, 0mAto
S7.2.6.4 ac Input and Frequency Output—The receptacle
2 mA, 0 to 5 mA; true voltage source of 0V to 5V or 0V to
mounted to the optoelectronics module shall be Classification
10V dc, and frequency (including TTL compatibility). A
MS3452W14S-5PX in accordance with MS3452. Receptacle
means shall also be provided for internal indication of the
Pins “A” and “B” shall be 115–Vac power input, Pin “C” shall
output signal selected.The complexity of this adjustment shall
be case ground, Pins “D” and “E” shall be frequency signal
be such that one individual working alone is capable of
outputs. The mating plug shall be Classification
performing this adjustment. The adjustment shall not require
MS3456W14S-5SX in accordance with MS3456.
electrical disconnection.
S7.2.6.5 Digital Output—The connector assembly for a
S7.2.5.1 Current Output—The 0– or 4–mA output shall
digital output signal shall be as specified.
correspond to the lower speed range value and the 1–, 2–, 5–,
S7.2.7 RPM Range Selection—A means shall be provided
or 20–mA output shall correspond to the upper speed range
for internal selection (within the optoelectronics module)
value. The current output shall remain accurate regardless of
between the following r/min ranges: 0 to 1000, 0 to 5000, 0 to
external load resistance variations over a range of 0Ω to 250
10000, and 0 to 20000. A means shall also be provided for
Ω.
internal indication of the r/min range selected.The complexity
S7.2.5.2 Voltage Output—The 0–Vdc output shall corre-
of this adjustment shall be such that one individual working
spond to the lower speed range value, and the 5– or 10–Vdc
aloneiscapableofperformingthisadjustment.Theadjustment
output shall correspond to the upper speed range value. The
shall not require electrical disconnection.
voltageoutputshallremainaccurateregardlessofexternalload
S7.2.8 Low-Intensity Alarm Indication—The optoelectron-
resistances greater than 100000Ω.
ics module shall have a red LED which shall light when the
S7.2.5.3 Optical Output—When an optical output is
intensity of the tachometer’s optical signal falls below a preset
required, all requirements shall be as specified.
level.TheLEDshallbelocatedoneitherthetoporfrontofthe
S7.2.5.4 Digital Output—When an electrical digital output
moduleasitwouldbemountedduringtypicalusage.TheLED
isrequired,allrequirementsshallbeasspecified.Theelectrical
shall be visible in typical fluorescent room lighting. The
characteristics shall be in accordance with EIA Standard
optoelectronics alarm will allow for an indication that mainte-
RS-422 for balanced voltage digital interface circuitry or as
nance is required before a false output signal from the
specified. The data format shall be as specified.
tachometer.
S7.2.6 Electrical Connectors—Asingleelectricalconnector
S7.2.8.1 Low-Intensity Alarm Set Point Adjustment—A
andmatingpluginaccordancewithMIL-C-5015shallbeused
means shall be provided for adjusting the low-intensity alarm
to interface the input power and linear output signal to the
setpointovernolessthanonehalfofthedynamicrangeofthe
optoelectronics module. The appropriate connector assembly
tachometer. A means of securing this adjustment shall be
and pin designations for each of the possible tachometer
provided.The low-intensity alarm set point shall be capable of
configurations shall be as follows:
adjustment by one individual without the necessity for any
S7.2.6.1 dc Input and Current or Voltage Output—The
electrical disconnection. Alarm set point adjustments shall be
receptacle mounted to the optoelectronics module shall be
labeled and shall be accessible when the optoelectronics
Classification MS3452W14S-5PX in accordance with
enclosure cover is removed.
MS3452. Receptacle Pin “A” shall be +28–Vdc power input,
S7.2.9 Sensitivity Adjustment—The tachometer shall have a
Pin “B” shall be −28–Vdc power input, Pin “C” shall because
sensitivity adjustment for increasing or decreasing the electri-
ground, Pin “D” shall be a +mAor Vdc signal output, and Pin
“E”shallbea−mAorVdcsignaloutput.Thematingplugshall calpulseheightoftheopticalsignaloverthedynamicrangeof
thetachometer.Thetachometer’ssensitivityshallbeadjustable
be Classification MS3456W14S-SSX in accordance with
MS3456. by one individual without the necessity for any electrical
F2046−00 (2022)
disconnection. Sensitivity adjustments shall be labeled and S8.10 Steady-State Supply Voltage and Frequency (ac) or
shallbeaccessiblewhentheoptoelectronicsenclosurecoveris Supply Voltage (dc) (Fiber Optic Only)—The tachometer shall
exhibit no damage and shall be in accordance with the
removed.
requirements of S8.2 during each of the specified test condi-
S7.2.10 Fuses—The optoelectronics module shall not be
tions.
fused.
S8.11 Transient Voltage and Frequency (ac) or Voltage (dc)
(Fiber Optic Only)—The tachometer shall exhibit no damage
S8. Performance Requirements
and reference measurements shall be in accordance with the
S8.1 Accuracy, Repeatability, and Damping—The accuracy
requirements of S8.2 following each of the transient condi-
ofthetachometershallbenolessthan1%offull-scalereading
tions.
at any part of the scale at any ambient temperature between
S8.12 Insulation Resistance (Fiber Optic Only)—The insu-
5°C and 65°C.The accuracy requirement shall be met during
lationresistanceoftheoptoelectronicsmoduleshallnotbeless
three calibration cycles to demonstrate repeatability.The accu-
than 10 MΩ.
racy requirements shall be met within2softhe sensor
S8.13 Power Interruption (Fiber Optic Only)—The ta-
receiving an input signal and at any temperature between 5°C
chometer shall exhibit no damage and shall be in accordance
and 65°C to demonstrate damping requirements. with the requirements of S8.2 when power is reapplied
following each of the power interruption intervals.
S8.2 Reference Measurement—The referenced accuracy of
S8.14 Short Circuit (Fiber Optic Only)—The tachometer
eachoftheoutputsignalsofthefiberoptictachometershallbe
shall exhibit no damage and shall be in accordance with the
within 61.0% of the output span. Measurements shall be
requirements of S8.2 following the short-circuit test.
made at 10, 50, and 90% intervals of span without any
S8.15 Line Voltage Reversal (dc Input) (Fiber Optic
alignments or adjustments.
Only)—Thetachometershallexhibitnodamageandshallbein
S8.3 Magnetizing—The materials used in the construction
accordance with the requirements of S8.2 following the line
ofthetachometersshallhavesuchcharacteristicsthatnoerror,
voltage reversal test.
either temporary or permanent, in excess of the errors permit-
S8.16 Temperature (Fiber Optic Only)—During the tem-
ted under the accuracy requirements specified for the appli-
perature test, monitored tachometer output shall show no
cable type will be introduced when the tachometer is tested as
deviationgreaterthan 61%oftheoutputspan.Followingthis
specified in S12.2.3. Posttest reference measurements shall
test, the tachometer shall be in accordance with the require-
meet the requirements of S8.2.
ments of S8.2.
S8.4 Accelerated Life—Thetachometersshallbecapableof
S8.17 Humidity (Fiber Optic Only)—The tachometer shall
demonstrating reliable operation within the accuracy require-
be in accordance with the requirements of S8.2 without any
mentswhensubjectedtotheconditionswithintheperformance
alignments or adjustments. After testing is completed, there
parameters yet configured to induce accelerated life conditions
shallbenoevidenceofphysicaldegradation,suchascorrosion
(see S12.2.4).
of metal parts or distortion of plastic parts.
S8.5 Sensitivity (Fiber Optic Only)—The ratio of the ta-
S8.18 Enclosure (Fiber Optic Only)—There shall be no
chometer output in percent change of span to speed input in
evidence of water penetration into the tachometer components
percentage change of span shall not be less than 0.75 or more either during or at the conclusion of the enclosure test. During
than 1.25. the enclosure test, monitored tachometer output shall show no
deviation greater than 61 % of the output span. The tachom-
S8.6 Response Time (Fiber Optic Only)—The time for the
eter shall be in accordance with the requirements of S8.2
tachometer output signal to indicate a steady-state speed (that
following the enclosure test.
is, 5000, 10000, or 20000 r/min) shall not be greater than 2 s
S8.19 Salt Spray (Fiber Optic Only)—Following this test,
after the test standard attains a steady-state speed.
the tachometer shall show no appreciable corrosion or other
S8.7 Warm-Up Time (Fiber Optic Only)—The tachometer
damage,eitheroptical,mechanical,orelectricalthatwillaffect
shall attain an output value within 61% of the output span.
its operation, and it shall be in accordance with the require-
Output shall reach this band in no more than 1 min after the
ments of S8.2.
tachometer is energized and shall remain in this band.
S8.20 Vibration—Tachometers shall conform to the vibra-
S8.8 Dynamic Range (Fiber Optic Only)—The dynamic
tion requirements of MIL-STD-167-1 (see S12.2.20). Moni-
range of the tachometer shall be no less than 35 dB for
tored tachometer output during all phases of the vibration test
tachometers using the beam interruption sensing mechanism.
shall show no deviation greater than 61% of the output span.
The dynamic range of the tachometer shall be no less than 16
Pretest and posttest reference measurements shall be in accor-
dB for tachometers using the reflection and magneto-optic
dance with the requirements of S8.2. The tachometer shall
sensing mechanism.
shownoevidenceofphysicaldamagethatimpairsitsoperation
S8.9 Ambient Light Susceptibility (Fiber Optic Only)—This as a result of the vibration test.
testisapplicablefortachometersusingthereflectionandbeam
S8.21 Shock—Tachometers shall conform to the shock re-
interruption sensing mechanism only. Monitored tachometer quirements of Type A, Class I, Grade A for lightweight
outputduringtheambientlightsusceptibilitytestshallshowno
equipmentofMIL-S-901.Monitoredtachometeroutputduring
deviation greater than 61% of the output span. all phases of the shock test shall show no evidence of physical
F2046−00 (2022)
TABLE S10.1 Qualification Testing
damage greater than 61% of the output span. Pretest and
posttest reference measurements shall be in accordance with Examination Electrical Fiber-Optic Require-
Test
and Test Tachometers Tachometers ments
the requirements of S8.2. The tachometer shall show no
General examination X X S10.6
evidence of physical damage that impairs its operation as a
Accuracy and repeatability X X S8.1 S12.2.1
result of the shock test.
Damping X S8.1 S12.2.1
S8.22 Electromagnetic Interference (EMI) Emission and Reference measurement X X S8.2 S12.2.2
Magnetizing X X S8.3 S12.2.3
Susceptibility—Tachometers shall conform to the electromag-
Accelerated life X S8.4 S12.2.4
netic interference requirements of MIL-STD-461 (see
Sensitivity X S8.5 S12.2.5
S12.2.22). The tachometers shall be in accordance with MIL- Response time X S8.6 S12.2.6
Warm-up time X S8.7 S12.2.7
STD-461requirementsCE101,CE102,CS101,CS114,CS116,
Dynamic range X S8.8 S12.2.8
RE101, RS101, RS103, and RS105. Monitored tachometer
Ambient light susceptibility X S8.9 S12.2.9
Steady-state voltage X S8.10 S12.2.10
output during all phases of the EMI test shall show no
frequency
deviation greater than 61% of the output span. Pretest and
Transient voltage frequency X S8.11 S12.2.11
posttest reference measurements shall be in accordance with
Insulation resistance X S8.12 S12.2.12
Power interruption X S8.13 S12.2.13
the requirements of S8.2.
Short circuit X S8.14 S12.2.14
Line voltage reversal X S8.15 S12.2.15
S9. Workmanship, Finish, and Appearance
Temperature X S8.16 S12.2.16
Humidity X S8.17 S12.2.17
S9.1 Cleaning and Surface Finishes—Surfaces of castings,
Enclosure X S8.18 S12.2.18
forgings, molded parts, stampings, and machined and welded
Salt spray X S8.19 S12.2.19
parts shall be free of defects such as cracks, porosity,
Vibration X X S8.20 S12.2.20
undercuts, voids, and gaps as well as sand, dirt, fins, sharp Shock X X S8.21 S12.2.21
Electromagnetic X X S8.22 S12.2.22
edges, scale, flux, and other harmful or extraneous materials.
interference
External surfaces shall be smooth and edges shall be either
rounded or beveled. There shall be no burn-through. There
shall be no warpage or dimensional change as a result of heat
TABLE S10.2 Qualification Conformance Testing
from welding operation.
Examination Electrical Fiber-Optic Require-
Test
and Test Tachometers Tachometers ments
S10. Inspection
General examination X X S10.6
Accuracy and X X S8.1 S12.2.1
S10.1 Inspection System—The manufacturer shall provide
repeatability
and maintain an inspection system acceptable to the buyer for
Damping X S8.1 S12.2.1
supplies and services covered by this specification.The testing
Dynamic range X S8.8 S12.2.8
Insulation resistance X S8.12 S12.2.12
set forth in this specification shall become a part of the
Temperature X S8.16 S12.2.16
manufacturer’s overall inspection system or quality program.
Enclosure X S8.18 S12.2.18
The manufacturer’s quality system shall comply with the
requirements of ANSI/ASQC 9001-1994. Certification and
registration is highly desired but not required.
limited to the examinations that may be performed without
S10.2 Classification of Inspections—The inspection re-
disassemblingtheunits.Examinationshallalsoincludeacheck
quirements specified herein are classified as follows:
of all adjustments. The manufacturer shall be responsible for
(1)Qualification testing and
ensuring that materials used are manufactured, examined, and
(2)Quality conformance testing.
tested in accordance with the specifications and standards as
S10.3 Qualification Testing—One sample tachometer shall
applicable.
be subjected to the examination and tests specified in Table
S10.1. Failure of any tachometer to meet the requirements of
S11. Number of Tests and Retests
this specification shall be cause for rejection.
S11.1 The number of tests and retests, if any, shall be
S10.4 Quality Conformance Testing—Each tachometer
specified in the acquisition requirements.
shall be subjected to the tests specified in Table S10.2. The
results of each examination and test shall be compared to the
S12. Test Methods
requirementsofthisspecification.Ifanytachometerfailsinthe
examination or in any test, it shall be rejected. S12.1 Test Conditions—Unless otherwise specified herein,
S10.5 Order of Inspection—The sample tachometers shall the fiber-optic tachometer(s) shall be fully assembled and
be subjected to the inspections specified in Table S10.1 and energized throughout the duration of each test procedure.
Table S10.2 in the order listed except that the steady-state Except where the following factors are the variables, the tests
supply voltage and frequency inspection may be performed specifiedinS10.2shallbeconductedwiththeequipmentunder
concurrently with the temperature inspection. the following operating environmental conditions:
S10.6 General Examination—Each tachometer shall be (1)Ambient temperature shall be 25°C 6 5°C,
givenathoroughexaminationtodetermineconformancetothe (2)Relative humidity shall be ambient,
requirements of this specification with respect to material, (3)Supply voltage shall be 115 V (nominal) for input
finish, workmanship, construction, assembly, dimensions, power designation ac or 28 V (nominal) for input power
weight, and marking of identification. Examination shall be designation dc,
F2046−00 (2022)
(4)Supply frequency shall be 60 Hz (nominal) for input (2)Measure both the shaft speed and the optoelectronics
power designation ac or dc for input power designation dc, module output signal.
(5)Distance from sensor head to target shall be 10 mm for (3)Increase the shaft speed by an amount not greater than
fiber-optic tachometers using reflection and beam interruption 1% of the output span.
sensing mechanisms, and (4)Measureboththenewshaftspeedandtheoptoelectron-
(6)Distance from sensor head to target shall be 2 mm for ics module output signal.
fiber-optictachometersusingmagno-opticsensingmechanism. (5)Calculate the change in both shaft speed and the
optoelectronics module output signal as a percentage of the
S12.2 Test Methods:
output span.
S12.2.1 Accuracy—The tachometer shall first be operated
(6)
...