Types of Gauges MCQ Quiz in मल्याळम - Objective Question with Answer for Types of Gauges - സൗജന്യ PDF ഡൗൺലോഡ് ചെയ്യുക

Explanation:

William Taylor developed a concept relating to the gauging of components.

According to Taylor's Principle:

• GO gauges are designed to check the maximum metal conditions i.e. Minimum hole limit and Maximum shaft limit.
• GO gauges should check as many related dimensions (form, size, location/positions) as possible.  
• NO-GO gauges are designed to check the minimum metal conditions i.e. Maximum hole limit and Minimum shaft limit.
• NO-GO should check one dimension at a time.

Additional Information

To check the allowance of any hole and shaft system gauges are used. They are:

Plug Gauge: To check holes.

Ring Gauges: To check shafts.

The plug and ring gauges are further divided into GO gauges and NO-GO gauges which correspond to the Maximum Material Limit (MML) and Minimum Material Limit (MML) of the component.

Explanation:

Since plug gauge dimensions are to be determined, thus we have to check dimensions of hole.

Now,

‘Go’ gauge is always designed for maximum material limit of component.

Thus,

Plug go-gauge size = 30 – 0.1 = 29.9 mm

And. ‘NO-GO’ gauge is designed for minimum material limit condition, ie. Maximum size of hole.

Hence,

‘No-Go’ plug gauge size = 30 + 0.3

Explanation:

Angular measurement involves the measurement of angles of tapers and similar surfaces. Examples:

• Bevel protector
• Sine Bar
• Spirit level
• Clinometer
• Autocollimators

​Bevel protector:

• Bevel protector is used for measuring the angles between two faces of components.

• It has a base plate or stock whose surface has a high degree of flatness and surface finish.
• The stock is placed on the workpiece whose angle is to be measured. It is normally used as a reference base for measuring angles.
• An adjustable blade attached to a circular dial is made to coincide with the angular surface.
• It can be swiveled to the required angle and can be locked.

Sine bar

• A sine bar is a precision measuring instrument for checking and setting of angles.
• The size of a sine bar is specified by its length.
• The length of the sine bar is the distance between the centers of the rollers.
• A sine bar is used to measure angles based on the sine principle.
• Its upper surface forms the hypotenuse of a triangle formed by a steel bar terminating in a cylinder near each end.
• When one of the cylinders, called a roller, is resting on a flat surface, the bar can be set at any desired angle by simply raising the second cylinder.
• The required angle is obtained when the difference in height between the two rollers is equal to the sine of the angle multiplied by the distance between the centers of the rollers.

\(\sin \theta = \frac{h}{L}\)

Autocollimator

• An autocollimator is an optical instrument that is used to measure small angles with very high sensitivity.
• The autocollimator has a wide variety of applications including precision alignment, detection of angular movement, verification of angle standards, and angular monitoring over long periods.
• An autocollimator is essentially an infinity telescope and a collimator combined into one instrument.

Micrometer

• A micrometer is a precision instrument used to measure a job, generally within an accuracy of 0.01 mm.
• Micrometers used to take the outside measurements are known as outside micrometers.

Concept:

sin θ = (Total height of combined gauge)/(Length of sine bar)

Here θ is the taper angle.

Calculation:

\(sin \;30=\frac{A}{C}\)

\(sin \;30=\frac{A}{200}\)

Total height of combined gauges = 200 × sin 30° = 200 × (1/2) = 100 mm

Concept:

• Master gauges are used in many diverse applications, but none of these comprises the direct measurement of production parts.
• Master gauges are reference standards, used for setting, checking the accuracy, adjusting or calibrating different types of measuring instruments, including the limit types of fixed gauges.

Concept:

Vernier gear tooth caliper 

• A vernier gear tooth caliper as shown in the figure consists of two vernier perpendicular to each other.
• It is used for measuring the chordal thickness of a gear tooth at the pitch circle of the gear.
• The horizontal vernier caliper is used for measuring the tooth thickness of a gear.
• Its working is similar to an outside vernier caliper.
• The vertical vernier caliper is used for measuring the distance from the top of a tooth (addendum circle) to the pitch circle of the gear.
• Various tables which give these distances and the chordal tooth thicknesses for gears of various diametral pitches and a different number of teeth are supplied with a vernier gear tooth caliper.

Explanation:

Limit gauges are used in inspection because they provide a quick means of checking.

The Go and No-Go principals of gauging are that the Go end of the gauge must go into the feature of the component being checked and the No-Go end must not go into the same feature.

There are different types of cylindrical plug gauges.

• Ring gauges are used to measure the outside diameter of the shaft.
• The ‘GO’ ring gauge is of a size corresponding to the high (maximum) limit of the shaft, while the ‘No-Go’ gauge corresponds to the low (minimum limit).

Roundness is the measure of how closely the shape of an object approaches that of a mathematically perfect circle. By the ring gauge, one cannot measure how much the shape is meeting the shape of a perfect circle.

Additional Information

Explanation:

Feeler gauge:

• A feeler gauge is a tool used to measure gap widths.
• Feeler gauges are mostly used in engineering to measure the clearance between two parts.
• They consist of a number of small lengths of steel of different thicknesses with measurements marked on each piece.

There are different types of cylindrical plug gauges used for the different purposes..

Explanation:

Telescopic Gauge:

• A telescopic gauge is a measuring tool with spring-loaded plunges used together with a micrometer to measure the inside of holes or bores.
• The shape of this gauge is as T (English Letter) with knurling on the backside of the handle.

Feeler Gauge:

• It is also known as a thickness gauge.
• Feeler gauges are often used to measure the clearance between the components.
• They consist of a number of small lengths of steel of different thicknesses with measurements marked on each piece.
• These gauges are excellent for the measurement of narrow slots, measuring clearance, determining small spacing, and determining the fit between mating parts.

​

Radius Gauge:

• It is also known as Fillet Gauge.
• These gauge types are used to check the concave and convex radii on corners or shoulders.
• It is also useful for layout work and inspection of components in various industries. It is used as a template when grinding cutting tools.

​

Sine Bar:

• A sine bar is used to measure angles based on the sine principle.
• Its upper surface hypotenuse of the right-angled triangle formed by a steel bar terminating in a cylinder near each end.

Concept:

When a shaft is electroplated, the final diameter gets increased.

D_f = D_i + 2t

When a hole is electroplated, the final diameter gets decreased.

D_f = D_i - 2t

where t = plating thickness.

Calculations:

Given:

Basic size = D ⇒  \(25\begin{array}{*{20}{c}} { + 0.020}\\ { + 0.010} \end{array}mm\)

Plating = t ⇒  \({30^{ \pm 2}}\ microns\ ={0.03^{ \pm 0.002}} \ mm \;[\because 1\;micron\;= \;10^{-3}\;mm]\)

t_max = 0.03 + 0.002 ⇒ 0.032 mm.

⇒ (D_i)_max = 25 + 0.02 ⇒ 25.02 mm.

D_f = D_i + 2t

⇒ (D_f)_max = (D_i)_max + 2t_max

⇒ (D_f)_max = 25.02 + 2 × 0.032

⇒ (D_f)_max = 25.084 mm.

Thus, the size of the GO gauge is 25.084 mm.