The document discusses different types of comparators used for measurement. It describes direct measurement which uses a calibrated standard directly, and comparison measurement which sets a comparator to a reference value using a standard and then measures deviations. It also discusses the functional requirements, types (mechanical, optical, electric, pneumatic), components (dial indicators, contact points), and operating principles of specific comparators like the Johansson Mikrokator, Sigma comparator, and mechanical optical comparator.
What is a Comparator in Metrology ? | Types of Comparators
January 5, 2018 by
In Metrology, The comparator is a Precision Instrument, which is used to compare the dimensions of the given component with the actual working standard.
The Comparator is an indirect type of precision measurement because it will not measure the dimension, it will indicate the difference in measurement between the given component and working standard, and another magnification instrument is needed to measure this difference with accuracy. Still Didn’t get it? Let’s talk about The principle
Principle and operation of Comparator
The comparator (which will have a dial indicator) will be used along with the gauge blocks. Gauge blocks are also known as Slip Gauge (You already knows right?)
Now you need to Arrange the slip gauges to a dimension of which the workpiece should have.
The Slip gauges will have the working standard dimension, but the workpiece will have a deviation from this working standard.
The workpiece dimension may be less than or greater than this(Slip gauge) dimension What is a Comparator in Metrology ? | Types of Comparators
January 5, 2018 by
In Metrology, The comparator is a Precision Instrument, which is used to compare the dimensions of the given component with the actual working standard.
The Comparator is an indirect type of precision measurement because it will not measure the dimension, it will indicate the difference in measurement between the given component and working standard, and another magnification instrument is needed to measure this difference with accuracy. Still Didn’t get it? Let’s talk about The principle
Principle and operation of Comparator
The comparator (which will have a dial indicator) will be used along with the gauge blocks. Gauge blocks are also known as Slip Gauge (You already knows right?)
Now you need to Arrange the slip gauges to a dimension of which the workpiece should have.
The Slip gauges will have the working standard dimension, but the workpiece will have a deviation from this working standard.
The workpiece dimension may be less than or greater than this(Slip gauge) dimensionWhat is a Comparator in Metrology ? | Types of Comparators
January 5, 2018 by
In Metrology, The comparator is a Precision Instrument, which is used to compare the dimensions of the given component with the actual working standard.
The Comparator is an indirect type of precision measurement because it will not measure the dimension, it will indicate the difference in measurement between the given component and working standard, and another magnification instrument is needed to measure this difference with accuracy. Still Didn’t get it? Let’s talk about The principle
Principle and operation of Comparator
The comparator (which will have a dial indicator) will be used along with the gauge blocks. Gauge blocks are also known as Slip Gauge (You already knows right?)
Now you need to Arrange the slip gauges to a dimension of which
What is a Comparator in Metrology ? | Types of Comparators
January 5, 2018 by
In Metrology, The comparator is a Precision Instrument, which is used to compare the dimensions of the given component with the actual working standard.
The Comparator is an indirect type of precision measurement because it will not measure the dimension, it will indicate the difference in measurement between the given component and working standard, and another magnification instrument is needed to measure this difference with accuracy. Still Didn’t get it? Let’s talk about The principle
Principle and operation of Comparator
The comparator (which will have a dial indicator) will be used along with the gauge blocks. Gauge blocks are also known as Slip Gauge (You already knows right?)
Now you need to Arrange the slip gauges to a dimension of which the workpiece should have.
The Slip gauges will have the working standard dimension, but the workpiece will have a deviation from this working standard.
The workpiece dimension may be less than or greater than this(Slip gauge) dimension What is a Comparator in Metrology ? | Types of Comparators
January 5, 2018 by
In Metrology, The comparator is a Precision Instrument, which is used to compare the dimensions of the given component with the actual working standard.
The Comparator is an indirect type of precision measurement because it will not measure the dimension, it will indicate the difference in measurement between the given component and working standard, and another magnification instrument is needed to measure this difference with accuracy. Still Didn’t get it? Let’s talk about The principle
Principle and operation of Comparator
The comparator (which will have a dial indicator) will be used along with the gauge blocks. Gauge blocks are also known as Slip Gauge (You already knows right?)
Now you need to Arrange the slip gauges to a dimension of which the workpiece should have.
The Slip gauges will have the working standard dimension, but the workpiece will have a deviation from this working standard.
The workpiece dimension may be less than or greater than this(Slip gauge) dimensionWhat is a Comparator in Metrology ? | Types of Comparators
January 5, 2018 by
In Metrology, The comparator is a Precision Instrument, which is used to compare the dimensions of the given component with the actual working standard.
The Comparator is an indirect type of precision measurement because it will not measure the dimension, it will indicate the difference in measurement between the given component and working standard, and another magnification instrument is needed to measure this difference with accuracy. Still Didn’t get it? Let’s talk about The principle
Principle and operation of Comparator
The comparator (which will have a dial indicator) will be used along with the gauge blocks. Gauge blocks are also known as Slip Gauge (You already knows right?)
Now you need to Arrange the slip gauges to a dimension of which
Comparators: Constructional features and operation of mechanical, optical, electrical/electronics and pneumatic comparators, advantages, limitations and field of applications
Principles of interference, concept of flatness, flatness testing, optical flats, optical interferometer and laser interferometer.
Surface texture measurement: importance of surface conditions, roughness and waviness, surface roughness standards specifying surface roughness parameters- Ra, Ry, Rz, RMS value etc., surface roughness measuring instruments – Tomlinson and Taylor Hobson versions, surface roughness symbols
These may be used as reference standards for transferring the dimension of the unit of length from the primary standard to gauge blocks of lower accuracy and for the verification and graduation of measuring apparatus. These are high carbon steel hardened, ground and lapped rectangular blocks, having cross sectional area 0f 30 mm
10mm. Their opposite faces are flat, parallel and are accurately the stated distance apart. The opposite faces are of such a high degree of surface finish, that when the blocks are pressed together with a slight twist by hand, they will wring together. They will remain firmly attached to each other. They are supplied in sets of 112 pieces down to 32 pieces. Due to properties of slip gauges, they are built up by, wringing into combination which gives size, varying by steps of 0.01 mm and the overall accuracy is of the order of 0.00025mm. Slip gauges with three basic forms are commonly found, these are rectangular, square with center hole, and square without center hole.
Comparators: Constructional features and operation of mechanical, optical, electrical/electronics and pneumatic comparators, advantages, limitations and field of applications
Principles of interference, concept of flatness, flatness testing, optical flats, optical interferometer and laser interferometer.
Surface texture measurement: importance of surface conditions, roughness and waviness, surface roughness standards specifying surface roughness parameters- Ra, Ry, Rz, RMS value etc., surface roughness measuring instruments – Tomlinson and Taylor Hobson versions, surface roughness symbols
These may be used as reference standards for transferring the dimension of the unit of length from the primary standard to gauge blocks of lower accuracy and for the verification and graduation of measuring apparatus. These are high carbon steel hardened, ground and lapped rectangular blocks, having cross sectional area 0f 30 mm
10mm. Their opposite faces are flat, parallel and are accurately the stated distance apart. The opposite faces are of such a high degree of surface finish, that when the blocks are pressed together with a slight twist by hand, they will wring together. They will remain firmly attached to each other. They are supplied in sets of 112 pieces down to 32 pieces. Due to properties of slip gauges, they are built up by, wringing into combination which gives size, varying by steps of 0.01 mm and the overall accuracy is of the order of 0.00025mm. Slip gauges with three basic forms are commonly found, these are rectangular, square with center hole, and square without center hole.
Observation of Io’s Resurfacing via Plume Deposition Using Ground-based Adapt...Sérgio Sacani
Since volcanic activity was first discovered on Io from Voyager images in 1979, changes
on Io’s surface have been monitored from both spacecraft and ground-based telescopes.
Here, we present the highest spatial resolution images of Io ever obtained from a groundbased telescope. These images, acquired by the SHARK-VIS instrument on the Large
Binocular Telescope, show evidence of a major resurfacing event on Io’s trailing hemisphere. When compared to the most recent spacecraft images, the SHARK-VIS images
show that a plume deposit from a powerful eruption at Pillan Patera has covered part
of the long-lived Pele plume deposit. Although this type of resurfacing event may be common on Io, few have been detected due to the rarity of spacecraft visits and the previously low spatial resolution available from Earth-based telescopes. The SHARK-VIS instrument ushers in a new era of high resolution imaging of Io’s surface using adaptive
optics at visible wavelengths.
Comparing Evolved Extractive Text Summary Scores of Bidirectional Encoder Rep...University of Maribor
Slides from:
11th International Conference on Electrical, Electronics and Computer Engineering (IcETRAN), Niš, 3-6 June 2024
Track: Artificial Intelligence
https://www.etran.rs/2024/en/home-english/
Remote Sensing and Computational, Evolutionary, Supercomputing, and Intellige...University of Maribor
Slides from talk:
Aleš Zamuda: Remote Sensing and Computational, Evolutionary, Supercomputing, and Intelligent Systems.
11th International Conference on Electrical, Electronics and Computer Engineering (IcETRAN), Niš, 3-6 June 2024
Inter-Society Networking Panel GRSS/MTT-S/CIS Panel Session: Promoting Connection and Cooperation
https://www.etran.rs/2024/en/home-english/
Phenomics assisted breeding in crop improvementIshaGoswami9
As the population is increasing and will reach about 9 billion upto 2050. Also due to climate change, it is difficult to meet the food requirement of such a large population. Facing the challenges presented by resource shortages, climate
change, and increasing global population, crop yield and quality need to be improved in a sustainable way over the coming decades. Genetic improvement by breeding is the best way to increase crop productivity. With the rapid progression of functional
genomics, an increasing number of crop genomes have been sequenced and dozens of genes influencing key agronomic traits have been identified. However, current genome sequence information has not been adequately exploited for understanding
the complex characteristics of multiple gene, owing to a lack of crop phenotypic data. Efficient, automatic, and accurate technologies and platforms that can capture phenotypic data that can
be linked to genomics information for crop improvement at all growth stages have become as important as genotyping. Thus,
high-throughput phenotyping has become the major bottleneck restricting crop breeding. Plant phenomics has been defined as the high-throughput, accurate acquisition and analysis of multi-dimensional phenotypes
during crop growing stages at the organism level, including the cell, tissue, organ, individual plant, plot, and field levels. With the rapid development of novel sensors, imaging technology,
and analysis methods, numerous infrastructure platforms have been developed for phenotyping.
Salas, V. (2024) "John of St. Thomas (Poinsot) on the Science of Sacred Theol...Studia Poinsotiana
I Introduction
II Subalternation and Theology
III Theology and Dogmatic Declarations
IV The Mixed Principles of Theology
V Virtual Revelation: The Unity of Theology
VI Theology as a Natural Science
VII Theology’s Certitude
VIII Conclusion
Notes
Bibliography
All the contents are fully attributable to the author, Doctor Victor Salas. Should you wish to get this text republished, get in touch with the author or the editorial committee of the Studia Poinsotiana. Insofar as possible, we will be happy to broker your contact.
The ability to recreate computational results with minimal effort and actionable metrics provides a solid foundation for scientific research and software development. When people can replicate an analysis at the touch of a button using open-source software, open data, and methods to assess and compare proposals, it significantly eases verification of results, engagement with a diverse range of contributors, and progress. However, we have yet to fully achieve this; there are still many sociotechnical frictions.
Inspired by David Donoho's vision, this talk aims to revisit the three crucial pillars of frictionless reproducibility (data sharing, code sharing, and competitive challenges) with the perspective of deep software variability.
Our observation is that multiple layers — hardware, operating systems, third-party libraries, software versions, input data, compile-time options, and parameters — are subject to variability that exacerbates frictions but is also essential for achieving robust, generalizable results and fostering innovation. I will first review the literature, providing evidence of how the complex variability interactions across these layers affect qualitative and quantitative software properties, thereby complicating the reproduction and replication of scientific studies in various fields.
I will then present some software engineering and AI techniques that can support the strategic exploration of variability spaces. These include the use of abstractions and models (e.g., feature models), sampling strategies (e.g., uniform, random), cost-effective measurements (e.g., incremental build of software configurations), and dimensionality reduction methods (e.g., transfer learning, feature selection, software debloating).
I will finally argue that deep variability is both the problem and solution of frictionless reproducibility, calling the software science community to develop new methods and tools to manage variability and foster reproducibility in software systems.
Exposé invité Journées Nationales du GDR GPL 2024
2. Comparison Between Direct &
Comparison Measurement
Direct
Measurement
Comparison
measurement
calibrated
standard directly
gives the
measured value
a comparator has to be set to
a reference value (usually
zero setting) by employing a
standard. Once it is set to this
reference value, all
subsequent readings indicate
the deviation from the
standard.
accuracy of the
standard,
accuracy of
scale, least count
of the scale, and
accuracy of
reading the scale.
accuracy of the standard used
for setting the comparator,
least count of the standard,
sensitivity of the comparator,
and accuracy of reading the
scale.
3. Functional Requirements of Comparators
• A comparator should have a high degree of accuracy and precision
• The scale should be linear and have a wide range. Since a
comparator, be it mechanical, pneumatic, or electrical, has a
means of amplification of signals, linearity of the scale within the
measuring range should be assured.
• A comparator is required to have high amplification. It should be
able to amplify changes in the input value, so that readings can be
taken and recorded accurately and with ease.
• A comparator should have good resolution, which is the least
possible unit of measurement that can be read on the display device
of the comparator.
• It should have good readability which include size of graduations,
dial contrast, and parallax.
• There should be a provision incorporated to compensate for
temperature effects
4. Types of Comparators
The comparators differ principally in the method used for
amplifying and recording the variation measured. Most
commonly available comparators are of the following types:
1. Mechanical comparators
2. Mechanical-Optical comparators
3. Electric and Electronic comparator
4. Pneumatic comparators
5. Fluid displacement comparator machines
6. Projection comparators
7. Multi-check comparator
8. Automatic gauging
5. Dial Indicator
It is primarily used to compare
workpieces against a master.
The basic features of a dial
gauge consist of a body with a
circular graduated dial, a
contact point connected to a
gear train, and an indicating
hand that directly indicates the
linear displacement of the
contact point.
The contact point is first set
against the master, and the dial
scale is set to zero by rotating
the bezel.
6. Dial Indicator
• Now, the master is removed and the workpiece is set below the
contact point; the difference in dimensions between the master and
the workpiece can be directly read on the dial scale. Dial gauges
are used along with V-blocks in a metrology laboratory to check
the roundness of components.
• Dial indicators are versatile instruments because their mountings
adapt them to many methods of support. Interchangeable contact
points adapt them to varied measurement situations.
7. Dial Indicator: Contact Points
•Contact points are
available in various hard
and wear-resisting materials
such as boron carbide,
sapphire, and diamond.
Contact points made of
hardened steel are also
often used
•The standard or spherical
contact point is the most
preferred one because it
presents point contact to the
mating surface irrespective
of whether it is flat or
cylindrical.
8. Dial Indicator: Contact Points
• It becomes less reliable when gauging spherical components
because sphere-to sphere contact makes the highest point of contact
difficult to find. Another limitation is that it can take only limited
gauging pressure, as high gauging pressure will leave an indent on
the workpiece
• A button-type contact point can be used if light contact pressure on smaller
components is required.
• A tapered point is convenient for component surfaces that cannot be
accessed by either standard or flat contact points.
• The use of contact points on spherical surfaces presents some
problems. Only a flat point is suitable in such cases. It gives reliable
readings for cylindrical surfaces too.
• Paradoxically, flat contact points are not preferred for flat surfaces.
9. Dial Indicator: Contact Points
• On the one hand, the presence of a thin air film can lead to
minor errors; on the other hand, a higher area of contact with
the component may result in rapid wear and tear of the contact
point.
10. PRECAUTIONS TO BE TAKEN
1.A dial indicator is a delicate instrument as the slender spindle
can be damaged easily. The user should avoid sudden contact
with the workpiece surface, over-tightening of contact points,
and side pressure.
2. Any sharp fall or blow can damage the contact points or upset
the alignment of bearings, and hence should be avoided.
3. Standard reference surfaces should be used. It is not
recommended to use non-standard attachments or accessories
for reference surfaces.
4. The dial indicator should be cleaned thoroughly before and
after use. This is very important because unwanted dust, oil,
and cutting fluid may seep inside the instrument and cause
havoc to the maze of moving parts.
5. Period calibration of the dial gauge is a must.
11. Mechanical Comparator
Systems of Displacement amplification Used in
Mechanical Comparators
1. Rack and Pinion
2. Cam and gear train
3. Lever with toothed sector
4. Compound levers
5. Twisted taut strip
6. Lever combined with band wound around drum
7. Reeds combined with optical display
8. Tilting mirror projecting light spots
12. Systems of Displacement amplification Used in
Mechanical Comparators
Rack & Pinion Cam and Gear Train
Lever with the toothed Gear Twisted Taut Strip
13. Advantages of Mechanical Comparator
1. Usually cheaper in comparison to other
amplifying devices.
2. Do not depend on external supple such as
electricity or air.
3. They have linear scale.
4. Robust , Compact easy to handle.
14. Disadvantages of mechanical
Comparator
1. Due to more moving parts, fricton is more
and hence less accuracy.
2. Any slackness in the moving parts reduces
accuracy.
3. The mechanism has more inertia and are
sensitive to vibration.
4. Range is limited as the pointer moves over
the fixed scale.
16. • This type of comparator, which was developed by the
Johansson Ltd Company of USA, uses this principle in an
ingenious manner to obtain high mechanical magnification.
The basic principle is also referred to as the ‘Abramson
movement’ after H. Abramson who developed the comparator
• The two halves of the thin metal strip, which carries the light
pointer, are twisted in opposite directions. Therefore, any pull
on the strip will cause the pointer to rotate. While one end of
the strip is fixed to an adjustable cantilever link, the other end
is anchored to a bell crank lever,as shown in the figure.
• The other end of the bell crank lever is fixed to a plunger. Any
linear motion of the plunger will result in a movement of the
bell crank lever, which exerts either a push or a pull force on
the metal strip
Johansson Mikrokator
17. . Accordingly, the glass pointer will rotate either clockwise or
anticlockwise, depending on the direction of plunger
movement.
The comparator is designed in such a fashion that even a
minute movement of the plunger will cause a perceptible
rotation of the glass pointer.
A calibrated scale is employed with the pointer so that any
axial movement of the plunger can be recorded conveniently
The relationship of the length and width of the strip with the
degree of amplification.
Thus, dθ /dl ∝ l/nw2, where dθ/dl is the amplification of the
mikrokator, l is the length of the metal strip measured along
the neutral axis, n is the number of turns on the metal strip, and
w is the width of the metal strip.
A slit washer is provided to arrest the rotation of the plunger
along its axis.
Johansson Mikrokator
19. • It is a simple but ingenious mechanical comparator
developed by the Sigma Instrument Company, USA.
• A linear displacement of a plunger is translated into the
movement of a pointer over a calibrated scale.
• The plunger is the sensing element that is in contact with
the work part. It moves on a slit washer, which provides
frictionless linear movement and also arrests rotation of the
plunger about its axis.
• A knife edge is screwed onto the plunger, which bears upon
the face of the moving member of a cross-strip hinge. This unit
comprises a fixed member and a moving block, connected by
thin flexible strips at right angles to each other.
Sigma Comparator
20. • Whenever the plunger moves up or down, the knife edge drives the
moving member of the cross-strip hinge assembly. This deflects an
arm, which divides into a ‘Y’ form. The extreme ends of this Y-arm are
connected to a driving drum by means of phosphor-bronze strips. The
movement of the Y-arm rotates the driving drum and, in turn, the
pointer spindle. This causes the movement of the pointer over a
calibrated scale.
• The magnification of the instrument is obtained in two stages. In the
first stage, if the effective length of Y-arm is L and the distance from
the hinge pivot to the knife edge is x, then magnification is L/x. The
second stage of magnification is obtained with respect to the pointer
length R and driving drum radius r. The magnification is given by R/r.
• Therefore, overall magnification is given by (L/x) × (R/r).
• Magnification is 3000 to 5000 and LC 0.1 micrometer
Sigma Comparator
22. • This is also termed as Cooke’s Optical Comparator. As the
name of the comparator itself suggests, this has a mechanical part
and an optical part. Small displacements of a measuring plunger
are initially amplified by a lever mechanism pivoted about a
point, as shown in Fig.
• The mechanical system causes a plane reflector to tilt about its
axis. This is followed by a simple optical system wherein a
pointed image is projected onto a screen to facilitate direct
reading on a scale.
• The plunger is spring loaded such that it is biased to exert a
downward force on the work part. This bias also enables both
positive and negative readings, depending on whether the plunger
is moving up or down.
Mechanical Optical Comparator
23. • The scale is set to zero by inserting a reference gauge below
the plunger. Now, the reference gauge is taken out and the work
part is introduced below the plunger. This causes a small
displacement of the plunger, which is amplified by the
mechanical levers.
• The amplified mechanical movement is further amplified by
the optical system due to the tilting of the plane reflector. A
condensed beam of light passes through an index, which
normally comprises a set of cross-wires.
Mechanical Optical Comparator
24. • This image is projected by another lens onto the plane mirror.
The mirror, in turn, reflects this image onto the inner surface of a
ground glass screen, which has a scale. The difference in reading
can be directly read on this calibrated screen, which provides the
linear difference in millimetres or fractions of a millimetre.
• Optical magnifications provide a high degree of precision in
measurements due to the reduction of moving members and
better wear-resistance qualities.
• mechanical amplification = l2/l1 and optical amplification = 2
(l4/l3).
• The multiplication factor 2 in the optical amplification because if the mirror
is tilted by θ°, then the image is tilted by 2θ° over the scale. Thus, the overall
magnification of thesystem is given by 2 × (l4/l3) × (l2/l1).
Mechanical Optical Comparator