Handbook 44 – 2020 5.51. Wire- and Cordage-Measuring Devices

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Table of Contents

Page

Section 5.51. Wire- and Cordage-Measuring Devices...................................................... 5-11

A. Application .................................................................................................................................................. 5-11

A.1. General................................................................................................................................................5-11

A.2. Additional Code Requirements...........................................................................................................5-11

S. Specifications............................................................................................................................................... 5-11

S.1. Units....................................................................................................................................................5-11

S.2. Design of Indicating Elements............................................................................................................5-11

S.2.1. Graduations...........................................................................................................................5-11

S.2.2. Indicator................................................................................................................................5-11

S.2.3. Zero Indication......................................................................................................................5-11

S.3. Design of Measuring Elements...........................................................................................................5-12

S.3.1. Sensitiveness.........................................................................................................................5-12

S.3.2. Slippage. ...............................................................................................................................5-12

S.3.3. Accessibility..........................................................................................................................5-12

S.4. Marking Requirements. .........................................................................................................................5-12

S.4.1. Limitation of Use. .................................................................................................................5-12

S.4.2. Operating Instructions...........................................................................................................5-12

S.4.3. Indications.............................................................................................................................5-12

S.5. Design Accuracy....................................................................................................................................5-12

N. Notes............................................................................................................................................................. 5-12

N.1. Testing Medium....................................................................................................................................5-12

N.2. Minimum Test.......................................................................................................................................5-12

T. Tolerances......................................................................................................................................................... 5-12

T.1. Tolerance Values...................................................................................................................................5-12

UR. User Requirements........................................................................................................................................ 5-13

UR.1. Installation Requirements. ..................................................................................................................5-13

UR.1.1. Installation. ...........................................................................................................................5-13

UR.2. Use Requirements. ..............................................................................................................................5-13

UR.2.1. Limitation of Use. .................................................................................................................5-13

UR.2.2. Return to Zero.......................................................................................................................5-13

UR.2.3. Operation of Device..............................................................................................................5-13

UR.2.4. Cleanliness............................................................................................................................5-13
5.51. Wire- and Cordage-Measuring Devices Handbook 44 – 2020

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Handbook 44 – 2020 5.51. Wire- and Cordage-Measuring Devices

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Section 5.51. Wire- and Cordage-Measuring Devices

A. Application

A.1. General. – This code applies to mechanisms and machines designed to indicate automatically the length of 

cordage, rope, wire, cable, or similar flexible material passed through the measuring elements.

A.2. Additional Code Requirements. – In addition to the requirements of this code, Wire- and Cordage-Measuring 

Devices shall meet the requirements of Section 1.10. General Code.

S. Specifications

S.1. Units. – A wire- or cordage-measuring device shall indicate lengths in terms of feet, yards, or meters, or 

combinations of units of the same measurement system, and shall have minimum increments with values that do not 

exceed the equivalent of 0.1 meter or 0.1 yard.

(Amended 1989)

S.2. Design of Indicating Elements.

S.2.1. Graduations.

S.2.1.1. Length. – Graduations shall be so varied in length that they may be conveniently read.

S.2.1.2. Width. – In any series of graduations, the width of a graduation shall in no case be greater than 

the width of the minimum clear interval between graduations, and the width of main graduations shall be not 

more than 50 % greater than the width of subordinate graduations. Graduations shall in no case be less than 

0.2 mm (0.008 in), nor more than 1.0 mm (0.04 in), in width.

S.2.1.3. Clear Interval between Graduations. – The clear interval between graduations shall be at least 

as wide as the widest graduation, and in no case less than 0.8 mm (0.03 in).

S.2.2. Indicator.

S.2.2.1. Symmetry. – The index of an indicator shall be symmetrical with respect to the graduations, at 

least throughout that portion of its length associated with the graduations.

S.2.2.2. Length. – The index of an indicator shall reach to the finest graduations with which it is used, 

unless the indicator and the graduations are in the same plane, in which case the distance between the end of 

the indicator and the ends of the graduations, measured along the line of the graduations, shall be not more 

than 1.0 mm (0.04 in).

S.2.2.3. Width. – The index of an indicator shall not be wider than the narrowest graduations with which 

it is used, and shall in no case exceed 0.4 mm (0.015 in).

S.2.2.4. Clearance. – The clearance between the index of an indicator and the graduations shall in no case 

be more than 1.5 mm (0.06 in).

S.2.2.5. Parallax. – Parallax effects shall be reduced to the practicable minimum.

S.2.3. Zero Indication. – Primary indicating elements shall be readily returnable to a definite zero indication.
5.51. Wire- and Cordage-Measuring Devices Handbook 44 – 2020

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S.3. Design of Measuring Elements.

S.3.1. Sensitiveness. – If the most sensitive element of the indicating system utilizes an indicator and 

graduations, the relative movement of these parts corresponding to a measurement of 30 cm (1 ft) shall be not 

less than 6 mm (1⁄4 in).

S.3.2. Slippage. – The measuring elements of a wire- or cordage-measuring device shall be so designed and 

constructed as to reduce to the practicable minimum any slippage of material being measured and any lost motion 

in the measuring mechanism.

S.3.3. Accessibility. – A wire- or cordage-measuring device shall be so constructed that the measuring 

elements are readily visible and accessible, without disassembly of any supporting frame or section of the main 

body, for purposes of cleaning or removing any foreign matter carried into the mechanism by the material being 

measured.

S.4. Marking Requirements.

S.4.1. Limitation of Use. – If a device will measure accurately only certain configurations, diameters, types, 

or varieties of materials, or with certain accessory equipment, all limitations shall be clearly and permanently 

stated on the device.

S.4.2. Operating Instructions. – Any necessary operating instructions shall be clearly stated on the device.

S.4.3. Indications. – Indicating elements shall be identified by suitable words or legends so that the values of 

the indications will be unmistakable.

S.5. Design Accuracy. – Indications of length shall be accurate whether the values of the indications are being 

increased or decreased.

N. Notes

N.1. Testing Medium. – Wherever feasible, a wire- or cordage-measuring device shall be tested with a steel tape not 

less than 10 mm (3

/8 in) in width and at least 15 m (50 ft) in length. When a device cannot be tested in this manner 

because of the design of the device, it shall be tested with a dimensionally stable material appropriately marked and 

compared at frequent periodic intervals with a steel tape in order to assure that any marked interval is not in error by 

more than 1⁄3 of the tolerance of the device at that particular interval.

(Amended 1981)

N.2. Minimum Test. – Tests shall be conducted at a minimum initial increment of 5 m (20 ft) and appropriate 

increments up to at least 15 m (50 ft).

T. Tolerances

T.1. Tolerance Values. – Maintenance and acceptance tolerances shall be as shown in Table 1. Maintenance and 

Acceptance Tolerances for Wire- and Cordage-Measuring Devices.
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UR. User Requirements

UR.1. Installation Requirements.

UR.1.1. Installation. – A wire- or cordage-measuring device shall be securely supported and firmly fixed in 

position.

UR.2. Use Requirements.

UR.2.1. Limitation of Use. – A wire- or cordage-measuring device shall be used to measure only those 

materials that it was designed to measure, and in no case shall it be used to measure a material that a marking on 

the device indicates should not be measured.

UR.2.2. Return to Zero. – The primary indicating elements of a wire- or cordage-measuring device shall be 

returned to zero before each measurement.

UR.2.3. Operation of Device. – A wire- or cordage-measuring device shall not be operated in such a manner 

as to cause slippage or inaccurate measurement.

UR.2.4. Cleanliness. – The measuring elements of a wire- or cordage-measuring device shall be kept clean to 

prevent buildup of dirt and foreign material that would adversely affect the measuring capability of the device.

Table 1.

Maintenance and Acceptance Tolerances for Wire- and Cordage-Measuring Devices

Indication of Device

(feet)

Acceptance and Maintenance Tolerances

On Underregistration

(inches)

On Overregistration

(inches)

20

Over 20 to 30

Over 30 to 40

Over 40 to 50

Over 50

 6

 8

10

12

Add 2 inches per indicated 10 feet

3

4

5

6

Add 1 inch per indicated 10 feet
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