ASME B89-1-7-2009 pdf free
ASME B89-1-7-2009 pdf free.Performance Standard for Steel Measuring Tapes.
4 GENERAL REQUIREMENTS
All steel measuring tapes covered by this Standard shall conform to the requirements in paras. 4.1 through 4.9.
4.1 Straight and Parallel
Steel measuring tapes shall be made so that when stretched out on a flat surface the edges are nominally straight and parallel.
4.2 Ease of Reading
All steel measuring tapes shall be clearly marked to facilitate easy and correct reading.
4.3 Background
The graduations and numbering shall be in sharp visual contrast with the background.
4.4 Compatibility
There shall be compatibility between the legibility of graduations and the size and form of numbers, when related to the distance at which the measuring tape is normally read.
4.5 Measurement Units
Unit names and symbols displayed on metric measuring tapes covered by this Standard shall be consistent with TEF.E/ASTM SI lO-2(X12.
4.6 Graduation Requirements
Along the nominal length, the measuring tape shall carry clear, regular, and indelible graduations and numbering, to ensure simple and unambiguous reading. Some unnumbered graduations may extend beyond the major graduation marks at the ends of the measuring tape. Graduations extending to the left of zero and to the right of the last inalor graduation are not to be considered part of the tape for calibration purposes.
4.6.1 Graduation Quality. When the graduations are lines, they shall be isually straight, perpendicular to the axis of the measuring tape, and all of the same thickness. The thickness of each line shall be constant throughout its length. The lines shall be such that they form a distinct and clear graduation and that their thickness does not cause inaccuracy of measurement.
Certain sections of the measuring tape, especially towards the ends, may be subdivided into submuitiples of the graduation interval adopted for the whole measure. in that case, the thickness of the lines may be less in the areas of reduced graduation intervals than in the rest of the measuring tape.
4.6.2 Arrangement. The measuring tape shall be divided by graduations of units consistent with the SI system or U.S. Customary system. The Si units shall be in meters, centimeters, millimeters, and multiples or subdivisions thereof. The U.S. Customary units shall be in feet, inches, arid multiples or subdivisions thereof, to include decimal or fractional divisions.
4.6.3 Length of Graduations. In general, as the subdivision of length becomes smaller, the subdivisions should be indicated by using graduations of shorter length. However, in no case should the length of graduations be less than 0.7 mm or 0.03 in.
4.6.4 Width. The graduation marks shall not be wider than 50% of the distance between two consecutive minor graduations.
4.7 Additional Markings
All markings, other than graduations and numbering, should be so positioned and of such a size as not to interfere with the legibility of the steel measuring tapes.
4.8 Numbering
4.8.1 SIze of Numbers. The size of the numbers denoting the major graduations shall be as large as practical without reducing the legibility of the graduations. All digits shall be of a style that distinctly differentiates one number from another.ASME B89-1-7 pdf download.
