INFORMATION SHEET # 2
LO1. Select measuring instruments
Measuring Tools used for the purpose of measuring dimensions,
measuring tools are imperative for implementing any work with precision. The
measuring tools are also used largely for carrying out different types of
measurements.
Importance of measuring tools
Measuring tools are essential
for examining a finished product or semi- finished product. The inspection or
examination operations include checking, or testing an object based on the
required dimensions given on a diagram or a sketch. Again the measurements
taken must be accurate.
Types of measuring tools
1. T-Square is used a guide in drawing horizontal lines and in measuring up to 48” straight line.
2.
Triangles are used for drawing vertical and oblique lines. They
are usually made of celluloid or plastic and come in various sizes. The most
commonly used triangles are the 45 degree and the 30 degree x 60 degree. Illustrations below show
the proper use of drawing lines and measuring angles using the T-square and
triangle.
3. Ruler is the most popular type of measuring tool. It is usually
6 or 12 inches in length. It is needed for measuring sizes and distances.
4. Triangular Scale is used in general drawing. Its main purpose is to
reproduce the dimension in full size or to reduce or enlarge them on a drawing.
5.
Protractor is used for measuring and
setting of angles other than those obtainable with the triangles.
6. Tape or tape ruler is a concave, spring-steel blade ranging from
1/4" to 1" wide and 6 to about 300 feet in length, coiled inside a
carrying case. Metric tape ruler comes in comparable widths and lengths up to
10 meters. It provides an easy means for accurately measuring curved surfaces.
How to Take Care of Drafting Measuring Tools
Tools will last longer when
properly kept and maintained. A good worker or draftsman keeps and takes care
of these tools. The following are some pointers:
1.
Be sure to inspect tools before using them. This is to check if they are in
working condition.This can be detected when there is ease and speed when in
use.
2.
After using a tool, clean it thoroughly with a damp cloth. Wipe it dry with
another piece of cloth before keeping it.
3.
When not in use, the T-square is preferably hung by inserting the hole to a
nail (attached to a wall) at the end of its blade.
4.
Do not abuse or misuse any piece of drawing instruments.
5.
Avoid throwing tool to anybody instead hand it over
6.
Avoid setting off the distances individually by moving the scale to a new position
each time, because slight errors in the measurements may accumulate and give
rise to a large error.
7.
Avoid unnecessary sliding of T-square or triangles across the drawing. Pick up
the triangle by their tips and tilt the T-square blade upward slightly before
moving.
8. Report defective tool and
any hazard to instructor immediately.