Least count is the smallest value any instrument can read or measure. You may hear of vernier calliper of least count 0.02 mm, which means the minimum value vernier can measure is 0.02 mm.
You can’t measure a value less than 0.02 mm with this vernier calliper. The same thing applied to all other instruments, a usual scale of least count of 1 mm, can measure a minimum length of 1 mm only.
Vernier Caliper is a widely used linear measurement instrument with the least count of 0.02 mm. It is used to measure linear dimensions like length, diameter, depth.
Let’s discuss common Mechanical measuring instruments with their least count (Considering least count of commonly used instruments, you may find changes in special cases)
Instruments
Least count
Vernier Caliper
0.02 mm
Digital Caliper
0.01 mm
Outsite Micrometre
0.01 mm
Vernier Micrometre
0.001 mm
Digital Micrometre
0.001 mm
Vernier Depth gauge
0.02 mm
Vernier Height Gauge
0.02 mm
Electronic Height Gauge
0.001 or 0.0001 mm
Glass scale
0.1 mm
Steel scale
1 mm
Bevel Protractor
5′ (5 second)
Depth Micrometer
0.01 mm
Digital Protractor
0.1 degree
Pressure gauge
1 bar
Digital Pressure gauge
0.01 bar
Pressure Calibrator
0.001 bar or 0.0001 bar
Laser Interferometer
0.1 nm (nanometre)
Dial gauge
0.01 mm
Measuring tape
1 mm
There is a lot more, please comment below if you are looking for the least count of any instrument.
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Material science has always a topic of research and fascination, about how a single atom has so many properties that can alter the whole tensile as well as the ultimate strength of a material such as cement or concrete which is used build skyscrapers …yes the same you watch in Hollywood movies.
What is the difference between moment and torque is the question that pops up in most of our minds?
In physics, they signify the same thing but in mechanics, they hold slightly different meanings. Both have the same unit i.e. N-m but torque is a movement force whereas the moment Is a static force. Torque is used where there is rotation involved whereas moment Is used where there is no rotation.
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Application of moment and torque for varied and interesting to observe. I hope everyone has played on a seesaw at least once in their life. What if I tell you that you can keep the saw balanced by having a 120 kg person one side and a 50kg person on the other side?
Photo by Mike Anderson
It seems difficult to accept but if you place them in such a way that the lighter person is at 3m from the center and the healthy person is at 1m. They both will apply the same moment and the seesaw will be balanced.
In rural areas, people still use the concept of the moment to churn milk. By providing a torque to the handle with the help of the rope the wooden stick rotates about its axis and thus, in turn, churns the milk. Learn more about torque and moment in our online course Strength of Machine
A similar concept of torque is used in old dams where the force of the falling water rotated the water wheel. The water wheel was connected to a dynamo thus generating electricity by the principle of conversion of kinetic energy into potential energy.
The International System of Units (SI)has become the fundamental basis of scientific measurement worldwide. This system is an extension and refinement of the metric system, which is more superior and convenient than other systems. It provides one basic unit for each physical quantity. So, the 7 units of measurement are follow
1. Mass
The basic fundamental unit of mass is “Kg”. We also measure mass in Gram, Pound, Metric ton, Stone, Microgram, Carat, etc.
Photo by Victor Freitas
2. Time
The basic fundamental unit of Time is “Sec(s)”. We also express time in seconds, minutes, hours, days, weeks, years, etc
Photo by Moose Photos
3. Electric Current –
The basic fundamental unit of Electric Current is “Ampere(A)”.
Photo by Pok Rie
4. Amount of Substance –
The amount of Substance is a dimensionless expression of the number of particles in a particle or object. The basic fundamental unit of Amount of Substance is “Mole”. The amount of substance all called material quantity.
5. Illumination
The SI unit of Illumination is “Candela”. Candela is denoted by symbol ‘cd’. Some other units are lux, lumen, etc.
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6. Distance
The SI unit of Distance is “Meter”. Distance also measures in mm, cm, km, yard, inch, foot, feet, etc.
Photo by Krivec Ales
7. Temperature
The SI unit of temperature is “kelvin”, expressed as the word “K”.Temperature 0 K is known as “absolute zero.”
We use two types of scale in measuring temperature that is –
1.Relative scales [Fahrenheit (°F) and Celsius (°C)]
This seven basic quality tools, which can assist an organization for problem solving and process improvements. Learn this awesome skill Free Here.
Video of Seven QC tools
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The first who introduce the seven basic tools is Dr. Kaoru Ishikawa (1968).
Check Sheets
Check sheets are sheets that are designed in advance to collect the necessary data easily and systematically, which allows the efficient checking off all items for inspection and verification.
Check sheets are tools for collecting data. They are designed specifically for the type of data to be collected. Check sheets aid in the systematic collection of data.
Some examples of check sheets are daily maintenance check sheets,
attendance records, production log books, etc
Histogram
The histogram is a very useful tool to describe a sense of the frequency distribution of observed values of a variable.
Histograms or Frequency Distribution Diagrams are bar charts showing the distribution pattern of observations grouped inconvenient class intervals and arranged in order of magnitude.
histogram by wiki
It should be designed properly for those working into the operation
the process can easily utilize and understand them.
Pareto Analysis
Pareto Analysis introduced by an Italian economist Vilfredo Pareto,
who worked with income and other unequal distributions in the 19th century,
he noticed that 80% of the wealth was owned by only 20% of the
population. Which means the majority of defects are caused by a few defective items later, the Pareto principle was developed by Juran in 1950.
Fishbone Diagram
Kaoru Ishikawa is considered by many researchers to be the founder and the first promoter of the ‘Fishbone’ diagram (or Cause-and-Effect Diagram) for root cause analysis and the concept of Quality Control (QC) circles.
A Cause-and-Effect Diagram is a tool that shows a systematic relationship
between a result or a symptom of an effect and its possible causes.
Scatter Diagram
When solving a problem or analyzing a situation one needs to know the relationship between two variables.
Scatter diagram is a powerful tool to draw the distribution of information
in two dimensions, which helps to detect and analyze a pattern
relationships between two quality and compliance variables (as an
independent variable and a dependent variable), an understanding if there is a relationship between them, so what kind of relationship is (Weak or strong and positive or negative).
Flowcharts
A Flowchart visualizes a picture including the inputs, activities, decision points, and outputs for using and understanding easily concerning the overall objective through the process.
Photo by Christina Morillo
Control Charts
Control chart or Shewhart control chart was introduced and developed by Walter A. Shewhart in the 1920s at the Bell Telephone Laboratories and is likely the most “technically sophisticated” for quality management (Montgomery, 2009).
Photo by Lukas
Control charts are a special form of “run chart that illustrates the amount and nature of variation in the process over time”.
Also, it can draw and describe what has been happening in the process.
