scale Flashcards
What is scale?
Scale is the ratio of map distance to ground distance.
What is enlarged scale?
Smaller objects are drawn in larger dimensions than their actual dimensions (e.g., 100:1).
What is full scale?
Objects are drawn in the same dimension as their actual dimensions (e.g., 1:1).
What is reduced scale?
Larger objects are drawn in smaller dimensions than their actual dimensions (e.g., 1:100).
What is the designation of scales?
Full scale: 1:1
Reduction scale: 1:X
Enlargement scale: X:1
What is Representative Fraction (RF)?
The ratio of the length in the drawing to its corresponding length of an object, when both lengths are in the same unit.
What is Representative Scale?
The ratio of the length of the drawing to the actual length of the object represented.
What is the formula for RF?
RF= Actualsizeofthecomponent/
Sizeofthecomponentinthedrawing
What are the types of scales
Plain scale
Diagonal scale
Vernier scale
Comparative scale
Scale of chords (for angles
What is the length and width of a plain scale?
Length: 15 cm (can be up to 30 cm)
Width: 5 mm
What does a plain scale represent?
Either two units or a unit and a subdivision
What is the height of the plain scale in drawing?
10 mm
What is a comparative scale?
A graphical device to compare or convert one variable into another
What does a comparative scale compare?
Similar units in different systems, e.g., meters and yards, kilometers and miles, or temperatures in °C and °F
What is the datum of the Fahrenheit scale?
It starts at 32°F instead of 0.
What is the formula to convert Fahrenheit to Celsius?
C=
What is the formula to convert Celsius to Fahrenheit?
.
What type of scale has the same RF but is graduated to read different units?
Comparative scale
Which scale is used for dimensions up to a single decimal?
Plain Scale
What is a diagonal scale used for?
To represent 3 units of measurement.
What is the smallest distance between consecutive divisions on a plain scale
0.5 mm
What is the principle of a diagonal scale?
it relies on a “diagonal” to divide a small distance into further equal parts and is based on the principle of similar triangles.
For which dimensions is a diagonal scale used?
Dimensions up to two decimal places.
What is the purpose of a vernier scale?
To divide a small dimension into a number of equal parts, allowing smaller measurements than possible by plain scales.
What are the parts of a vernier scale?
Secondary scale (vernier scale, VS) and primary scale (main scale, MS).
What is the smallest measurement that can be measured from an instrument?
Least count.
What is the height of a vernier scale in a drawing?
5 mm.
What is the smallest measurement on the main scale called?
Main scale division (MSD).
What is a direct vernier scale?
A vernier scale and main scale that read in the same direction.
What is the relationship between divisions on the vernier and main scale in a direct vernier?
n divisions on the vernier correspond to n-1 divisions on the main scale.
What is a retrograde vernier scale?
A vernier scale that reads in the opposite direction of the main scale.
What is the relationship between divisions on the vernier and main scale in a retrograde vernier?
n divisions on the vernier correspond to n+1 divisions on the main scale.
What is the formula for calculating n in a vernier scale?
n = MSD / Fractional part of MSD.
What is a scale of chords used for?
To construct or measure angles in the absence of a protractor.
What is the scale used for survey maps called?
Graphical scale.
What is an engineering scale?
A scale numerically represented on the drawing sheet to create full-size, reduced-size, or enlarged-size drawings.
How are engineering scales designated?
From M1 to M8.
Table of scale
..
Inking pen is used for drawing -
Straight lines
