Vernier Height Gauge
- Vernier height gauge is similar to vernier caliper but in this instrument, the graduated bar is held in a vertical position and it is used in conjunction with a surface plate. A Vernier height gauge is a measuring device used either for determining the height of something or for the repetitive marking of items to be worked on. The pointer is sharpened to allow it to act as a scriber and assist in marking on workpieces. The figure below shows the details and working arrangement of a Vernier height gauge.
- Height gauge, also called Vernier height gauge, is a widely used benchtop tool.
- A height gauge is a measuring device used either for determining the height of something or for the repetitious marking of items.
- It is much more capable than calipers but not as complex as a coordinate measuring machine (CMM).
- Vernier height gauges, however, greatly rely on users’ skills.
- The first electronic height gauge emerged during the mid-1980s.
- These measuring tools are used in metalworking or metrology to either set or measure vertical distances.
Definition of vernier height gauge:
Vernier height gauge is a special type of vernier instrument which is used to measure heights of different engineering objects up to high precision and accuracy during many of industrial jobs where measuring process is required.
Construction of Vernier height Gauge:
A vernier height gauge consists of
Diagram Of Vernier Height Gauge :
- This also uses the same principle of vernier caliper and is used especially for the measurement of height. It is equipped with a special base block, sliding jaw assembly, and a removable clamp.
- The upper and lower surfaces of the measuring jaws are parallel to the base, which makes it possible to measure both over and under surfaces.
- A scribing attachment in place of measuring jaw can be used for scribing lines at a certain distance above the surface.
- Specification of a vernier height gauge is made by specifying the range of measurement, type of scale required, and any particular requirement regarding the type of vernier desired.
Procedure Of Using Vernier Height Gauge :
1. Take the material (sample) for which the value must be measured.
2. Check the vernier and the main scale must coincide at 0
3. After checking the 0 marks put the sample piece and slowly leaves the measuring jaw over the piece
4. Tight the screw and measure the main scale also vernier scale reading
5. The line coincides with the main scale that the VSR
6. By adding MSR with VSR*L
Specification Of Vernier Height Gauge:
The important features of vernier height gauge are :
- all the parts are made of good quality steel or stainless steel.
- The beam should be sufficiently rigid and square with the base.
- The measuring jaw should have clear protection from the edge of the beam at least equal to the projection of the base from the beam.
- The upper and lower ganging surfaces of the measuring jaw shall be flat and parallel to the base.
- The scriber should also be of the same nominal depth as measuring jaw so that it may be reversed.
- The projection of the jaw should be at least 25 mm.
- The slider should have a good sliding fit for all along the full worship length of the beam.
- Height gauge can also be provided with a dial gauge instead of the vernier. This provides easy and exact reading of slider movement by dial gauge which is larger and clear.
Types Of Height Gauge :
- Vernier Height Gauge
- Digital Height Gauge or Electronic Height Guage – The digital height gauge has an easy to read display that can be very quickly set to any dimension. The readout display is in in. (0.002 mm), and it has a zero function that allows the zero to be set at any position on the job or workpieces. This type of height gage is becoming very popular because it eliminates or reduces the errors common to height gages having vernier scales.
- Dial Height Gauge
Sources of Errors in Vernier Height Gauges
Errors occur due to
- Slide arm does not parallel with the base
- The unclean and damaged base which causes inaccuracy.
- Worn-out scriber.
- Improper calibration. The zero marks of the vernier and main scale should coincide when the base of the scriber makes flat contact with the
Precautions While Using A Vernier Height Gauge
- The base should be held firmly to the surface plate to avoid tipping.
- The height gauge and surface plate should be cleaned properly before use.
- Care should be taken to avoid heating by warmth from the hands, especially in the case of long height gauges.
- The height gauge should be moved slowly and gently over the surface plate.
- The scriber should be clamped as near as possible to the beam to reduce vibration and increase accuracy.
- They should be kept in their cases when not in use.
Advantages of Vernier Height Guage :
- It can be used in different ways: one set of jaws can be used to determine inner measurements, while the other set can be used to measure exterior measurements.
- It is the simplest and quickest of the vernier instruments to use, and it is also quite cheap.
The disadvantages of Vernier Height Gauge :
- The main disadvantage is that the readings are highly dependent on the operator’s ability, and its accuracy is limited by the vernier scale.
- It can only be used to measure small objects.
Applications of Vernier Height Gauge :
- These are used to mark out lines and widely used on surface plates and on machine tables.
- The height gauge with an indicator attachment is used for checking of surface holes.
- The height gauge with a scribe attachment is used to mark reference lines and locations on castings and forgings.
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