Diploma Measurement and Metrology Study Material
Dear friends
We have added Diploma Measurement and Metrology Study Material for the unit 2 – Linear and Angular Measurements
| Join Diploma Exam Corner | |
| Study Materials | Click here |
| Telegram Channel | Click here |
| YouTube | Click here |
| All Govt Jobs | Click here |
Subject: Measurements and Metrology Scheme: N
Unit 2 – Linear and Angular Measurements
Three Marks
- What are the Linear Measuring Instruments?
Linear Measuring instruments are used to measure the lengths, diameter, heights and thickness. This may be internal or external. In linear measuring instruments spaced lines are used for measurements.
- What are the angular measuring instruments?
The angle is a measurement that we can measure between the two lines which meet at one point. Angular measurements are playing a very crucial role in measurements. The best example is that the Ships and the Aeroplanes will navigate with the help of The precise angular directions of the landing area.
Bevel Protractor, Sine bar, Combination set,, angle gauges are used for angular measurement
- What is a caliper? Mention its types
Calipers are used to transfer the distance between the faces of a product to a scale or micrometer or vernier caliper. Clipers are meant for end measurements. They transfer end measurement to line measurement.
Calipers are classified into three major types. They are (i) Outside Caliper (ii) Inside Caliper (iii) Jenny Caliper
- What is a combination set?
Combination set is a set of steel rule, square head, protractor head and center head. Combination set is general used in layout and inspection head.
Steel Rule: Used for linear measurements
Square head: used for measuring Perpendicular and flatness measurements
Protractor head: Used for measuring angles
Center head: Used for finding the center line of cylindrical objects
- What is feeler gauge?
Feeler gauges are used for measuring the clearance between two mating parts. Feeler gauge consists of strips of sheet of different thickness. These strips are assembled together in a holder. Feeler gauges are mostly used in automobile sector.
- What is Pitch screw gauge?
Pitch screw gauges are used to measure the pitch of a thread. It consists of a number of threaded blades of different standard pitches. They are available for 50O AND 60O included thread angle.
- What is the least count of Vernier Caliper and Micrometer?
The least count in vernier caliper is defined as the difference between the values of a main scale division and vernier scale division.
Least Count (Vernier Caliper) = 1 Main Scale Division – 1 Vernier Scale Division
Least Count (Vernier Caliper) = 0.02mm
The Least Count in Scre gauge is the minimum distance that can be measured accurately by the instrument
Least count (Screw gauge) = Pitch / No. of thimble divisions
- What are the sources of error in micrometer?
The possible sources of Error in micrometer are
- The anvil surfaces are not flat
- The anvil surface are not parallel
- Zero error
- Applying too much pressure on the thimble
- Wear of anvil surfaces and ratchet mechanisms
- Mention the Indian Standard on Slip gauges?
The Indian standard on slip gauges are the slip gauges are made from high grade steel with coefficient of thermal expansion 11.5 x 106 per degree Celsius between 1O and 30OC
The commonly available slip gauges are M45, M87, M33 AND M112
- What is Bevel Protractor? Mention its Types
Bevel Protractor is one of the angle measuring instruments. Bevel protractor is used to measure the angle of a given surface or object. There are different types of Bevel protractor. They are (i) Vernier Bevel Protractor (ii) Universal Bevel Protractor (iii) Optical Bevel Protractor
- What is sine bar? Write its types
- Sine bar is an angular measuring instrument
- A sine bar consists of a steel bar and two rollers
- Sine Bars used along with slip gauges for the measurement of angles.
- Sine bars used to measure the angles of a given object or surface very accurately
- What is the principle of sine bar?
Sine bar is based on the laws of trigonometry. To set or find the angle, one roller of the sine bar is placed on the surface plates. The combination of slip gauges is inserted under the second roller.
Sin θ = Oppsite side (h) / Hypotenuse side (L)
Angle of the given object θ = sin -1 (h /L)
- What are the applications of Sine bar?
- Locating any work to a given angle
- Checking or measuring unknown angles
- When the component is heavy size
- What is Autocollimator?
Autocollimator is an optical instrument and a special form of telescope. Autocollimator is used to measure smaller angle of differences, changes, deflections and plane surfaces.
- What is Comparator? Write its uses
Comparator is a precision instrument used to compare the component with a working standard. Slip gauges are generally used as working standards. Comparators are needed when identical parts are produced on a very large scale.
- Write the classification of Comparator.
Comparators are classified into the following types
- Mechanical Comparator
- Electrical & Electronic Comparator
- Optical Comparator
- Pneumatic Comparator
- Electro Mechanical Comparator
- What are the advantages of Mechanical Comparator?
Advantages of Mechanical Comparator
- They are cheaper compared to other types of comparator
- They do not need external agency such as electricity or compressed air
- They have linear scale
- They are easy to handle
- What is Pneumatic comparator? List its types
A pneumatic comparator is a precision device operated using a pneumatic system or compressed air. Like other mechanical, optical, and electrical comparators, pneumatic comparators are also used to analyze the dimensional difference between the workpiece to be measured and the standard workpiece
Types:
- Air flow or velocity type
- Back pressure type
| Check N Scheme Mechanical Department Study Materials | |
| Strength of Materials | Click here |
| Manufacturing Technology – 1 | Click here |
| Thermal Engineering – 1 | Click here |
| Metrology & Measurements | Click here |
