The master height gauge is used for setting height gauges and provides a high precision standard.
The master height gauge is basically a stack of gauge blocks with robust housing. They can be used with riser blocks.
Riser blocks are used to adjust the height. With master height gauges it can increase measuring capacity up to 600 mm.
Master height gauges can be used as a height standard to measure hole location, the width of groove, pitches, etc.
To check concentricity universal measuring instrument is a more accurate device.
2. Which of the following is true for master height gauges?
This is a stack of slip gauge blocks
Can store readings in memory
Less skilled labour
Has statistical production control
Answer.1. This is a stack of slip gauge
Explanation:-
The master height gauge is basically a stack of gauge blocks with robust housing. They can be used with riser blocks.
Since it is used as the standard for setting the height gauge hence it cannot store measurements in memory
3. Which of the following is incorrect about master height gauges?
Can provide a high precision standard
It has a digital readout
Has a sliding attachment
Built-in microprocessor
Answer.4. Built-in-microprocessor
Explanation:-
Master Vernier Height Gage is the ultimate in height gage design. It is a rugged and reliable tool that gives precise and dependable measurements over long ranges. This tool is accurate, has the easiest reading vernier style, is stronger, and is offered in greater ranges than other height gages.
There is no microprocessor and micro switch in master height gauges. A master height gauge has a rectangular column with a sliding attachment. It can be connected to statistical process control (SPC) equipment for analysis, data collection, and hard-copy documentation.
4. What is the difference between surface gauge and height gauge?
Only surface gauge is used on a surface plate
Height gauge has a heavy base
The height gauge is more accurate than the surface gauge
The surface gauge has a smooth and flat base
Answer.3. The height gauge is more accurate than the surface gauge
Explanation:-
A surface gauge is used for general marking off. It is not used to measure things, but to mark off work. Although a surface gauge is not as accurate as a height gauge, it is often used as a marking-off tool. Surface gauges have adjustable heights. The base of a surface gauge is heavy and rests on the marking-off surface. The V-shaped bottom can be used for cylindrical objects.
In the toolroom, the distinction between a height gauge and a surface gauge is that a height gauge has a measuring head (whether vernier, fine rack and pinion with dial, or linear encoder with digital display), whereas a surface gauge has only a scriber point. Both are typically used on a surface plate and have a heavy base with an accurately flat, smooth underside.
5. Which attachment is needed to check squareness and parallelism with master height gauge?
Dial test indicator
Gauge block
Slip rings
Micrometer
Answer.1. Dial test indicator
Explanation:-
If dial test indicator or lever is attached to master height gauge then this unit can be used to check parallelism and squareness.
Dial indicators are commonly used to determine parallel and square alignments of machine units and to check the runout of spindles. The dials should be sufficiently large so that the graduations are clearly visible. For checking square and parallel alignment of machine tools, dial indicators with 0.001-inch graduations are normally satisfactory. However, indicators used in checking runout of spindles, spindle tapers, and spindle sleeve noses should have 0.0001 inches or 0.0005-inch graduations. In all cases, dial indicators should be securely clamped to substantial holders or posts to avoid vibration and deflection. When testing with dial indicators, the initial pressure applied should be kept to the minimum of 0.005 inches.
7. Which of the following option is correct for given statements?
Statement 1: Power blocks are used to adjust the height Statement 2: Functioning of master height gauges is slower than electronic digital readout height gauge.
Both statements are true
Both statements are false
Statement 1 true and statement 2 is false
Statement 2 is true and statement 1 is false
Answer.4. Statement 2 is true and statement 1 is false
Expalantion:-
Riser blocks are used to adjust the height. With master height gauges it can increase measuring capacity up to 600 mm.
The digital master height gauge can be equipped with a contact probe for the precision inspection of finished parts. The readout display can provide measurements accurate to .0001 in. or at the touch of a button to 0.002 mm.
An electronic height gauge is used in this case because the degree of sensitivity and accuracy and speed obtained is greater than that can be obtained with an ordinary dial test indicator. The height gauge is coupled to an electronic amplifier. Also, it requires more skilled operators.
8. How much measuring capacity can be increased by using riser blocks with a master height gauge?
500 mm
600 mm
700 mm
800 mm
Answer.2. 600 mm
Explanation
Master height gages are available in models 6, 12, 24. and 36 inches and their range may be increased by the use of riser blocks under the base. With master height gauges it can increase measuring capacity up to 600 mm.
9. What precautions should be taken while using the master height gauge?
Clean the surface
Turn dial indicator to zero
Move the dial indicator over the nearest disk
All of the above
Answer.4. All of the above
Explanation:-
To Use a Precision Height Gauge
Clean the surface plate and the feet of the height gauge.
Clean the bottom of the work to be checked and place it on the surface plate, using parallels and an angle plate if required.
Insert plugs into the holes to be checked.
Mount a dial indicator on the movable jaw of a master height gauge.
Adjust the height gauge until the dial indicator registers across the top of the plug.
Turn the dial of the indicator to zero.
Move the dial indicator over the nearest disk of the precision height gauge and raise the column by turning the micrometer until the dial indicator reads zero.
Check the micrometer reading. This reading will indicate the distance from the surface plate to the top of the plug.
Subtract half the diameter of the plug from this reading.
10. Which of the following statement is correct for features of master height gauge?
Statement 1: The scriber and base are designed for direct reading from zero Statement 2: Special master bar design and the balanced design and weight of the base eliminates vibration
Both statements are true
Both statements are false
Statement 1 true and statement 2 is false
Statement 2 is true and statement 1 is false
Answer.1. Both statements are true
Explanation:-
Features of the master height gauge
The scriber and base are designed for direct reading from zero (bottom of base).
Black lines and figures against Starrett’s satin chrome finish make reading the marking and number easy.
Flush fitting of the vernier scales to the main scale means that these are in the same plane, which eliminates parallax. Vernier scales are adjustable.
Long, 50-division vernier scales feature permits just half as many bar graduations as conventional single vernier tools. These widely spaced graduations make possible easy reading to .001 or 0.02mm without needing a magnifying glass.
Additional remote fine adjustment located on top of the bar for sizes 36 (900mm) and larger – a convenient feature when working in higher ranges.
Special master bar design and the balanced design and weight of the base eliminates vibration – especially helpful with fully extended scribers
Master bars on models up to 24 and 600mm are hardened and stabilized
The base is hardened, ground and lapped square with the bar, and has finger grooves to provide ease of movement.
The vertical bar is positioned near the center of the base for balance and stability.
The versatile tool will scribe lines, mount dial indicators or electronic probes, and accept depth attachments.
