Measuring Tools.pptx

WHAT IS MEASURING INSTRUMENTS? A measuring instrument is a device for measuring a physical quantity. Measurement is the activity obtaining and comparing physical quantities of real-world objects and events. Measuring instrument’s use, are the means by which these relations of numbers is obtained. TWO TYPES OF MEASUREMENTS

1. The English system of measurement grew out of the creative way that people measured for themselves. For example, people measured shorter distances on the ground with their feet. 2. Metric system based on the meter. The most common units in the automotive industry are the centimeter and millimeter. Millimeters are used to express close tolerances of engine measurements. Metric system is based on divisions of ten.

SOME EXAMPLE OF MEASURING INSTRUMENTS

CALIPER

is a device used to measure the distance between two opposite sides of an object.

MICROMETE R

Instrument that measure the thickness or the diameter of relatively small parts.

DEPTH GAUGE

It is a gauge for measuring the depth of holes, grooves, or concavities.

VOLT METER

A voltmeter is an instrument used for measuring electrical potential difference between two points in an electric circuit.

WATTMETER

is an instrument for measuring the electrical power (or the supply rate of electrical energy) in watts of any given circuit.

instrument measuring the rotation speed of a shaft or disk as in a motor or other machine tachometer can also be used to measure flow of liquid by attaching a wheel with inclined vanes

OSCILLOSCOPE

commonly used to observe the exact wave shape of an electrical signal. Oscilloscopes are usually calibrated so that voltage and time can be read as well as possible by the eye.

THREAD SNAP GAUGE snap guage are often quantity of workpiece must be inspected. The snap guage has fauranvils or jaws, the first one or pair are using upper limitof the part and the inner set adjusted to the lower limit of the part.

DIAL INDICATOR instrument used to accurately measure small linear distances and are frequently use in industrial and mechanical processes.

FEELER GAUGE

used to measure gap with or clearance between surface and bearings.

VERNIER CALIPER It is a precision tool used to measure a small distance with high accuracy.

TELESCOPIC FEELER GAUGE

It is also known as tongue guage, and it consist of long feeler guage inside a cover with tongue or curved edge,

POKER GAUGE This guage is used to measure propeller stem shaft clearance, also known as propeller wear down.

BRIDGE GAUGE

Bridge guages are used to measure the amount of wear of main engine bearing. Typically the upper bearing keep is removed and clearance is measured for the journal.

BORE GAUGE

A dial or vernier bore guage measure a boar directly.

TELESCOPIC GAUGE these are range of gauges that are used to measure bore size, by transferring the internal dimension to a remote measuring tool.

THERMOMETER

A thermometer is a device that measures temperature or a temperature radiant.

WEIGHING SCALE SPRING WEIGH SCALE

D I G I TA L W E I G H I N G SCALE

Weighing scales are devices to measure weight or calculate mass.

SPRING BALANCE It measures weight by balancing the force due to gravity againts the force on a spring,

RULERS AND TAPE

The most common method of obtaining simple measurements of length is by the ruler or tape

SUNDIAL

The sundial was invented in ancient Egypt and was also used in ancient China, Greece, and Rome. Sundials consist of a shadowmaker known as a gnomon, which casts a shadow onto a surface below, usually marked with the hour. As the sun moves through the sky, the shadow moves accordingly, indicating the time of day.

CANDLES Candles are simple timetelling devices which work simply by burning at a fixed rate. To indicate the time, candles are marked with hours.

HOURGLASS The hourglass tells time roughly in terms of an amount of sand which pours through a small hole at a nearly fixed rate. As the name implies, the sand in most hourglasses pours for one hour. Egg timers, which run out in 3 to 5 minutes, are small versions of hourglasses. Hourglasses were once used in navigation.

WATERCLOCK

The water clock was a clock commonly used in ancient and medieval times. It works by maintaining a steady flow of water.

MECHANICAL CLOCK

The mechanical clock was an improvement of the water clock developed around 1280. Mechanical clocks work by hanging a weight from a string and using an escapement to make the clock tick at a nearly fixed rate.

PENDULUM The next significant improvement in time measurement was the pendulum clock. Galileo Galilei discovered the principle of the pendulum in 1581 and Christian Huygens invented the pendulum clock in 1656. Until the 1930s, the most accurate clocks were pendulum clocks.

CHRONOMETER Navigators needed a very accurate portable seaworthy clock in order to measure longitude on long sea voyages. John Harrison built the H4 Chronometer in 1761 for this purpose. Chronometers like this were used on ships until they were replaced by more accurate quartz clocks in the 1970s

ATOMIC CLOCK

The atomic clock is the most accurate clock currently in use. The first atomic clock was built in 1949 at the U.S. National Bureau of Standards (NBS). The first accurate atomic clock, based on the transition of the cesium-133 atom, was built by Louis Essen in 1955 at the National Physical Laboratory in the UK. This led to the internationally agreed definition of the second being based on atomic time. With an accuracy of 1 part in 10^15 or 0.1 ns per day, the NIST-F1, built in 1999 at the National Institute of Standards and Technology (NIST, formerly NBS), is the world's most accurate clock.

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