pressure and temperature

Question 1

is the analysis of an applied force by a fluid (liquid or gas) on a
surface.

Answer 1

PRESSURE MEASUREMENT

Question 2

is typically measured in units of force per unit of surface area. Many techniques
have been developed for the measurement of pressure and vacuum

Answer 2

Pressure

Question 3

is a pressure gauge used to measure pressures lower than the ambient
atmospheric pressure, which is set as the zero point, in negative values (e.g.: −15 psig or
−760 mmHg equals total vacuum).

Answer 3

vacuum gauge

Question 4

Other methods of pressure measurement involve sensors that can transmit the pressure reading
to a remote indicator or control system

Answer 4

(telemetry).

Question 5

The oldest type is the liquid column (a
vertical tube filled with mercury) manometer invented by Evangelista Torricelli in 1643. The
U-Tube was invented by Christiaan Huygens in 1661.

Answer 5

liquid column manometer

Question 6

compare pressure to the hydrostatic force per unit area at the base of a column of fluid.

Answer 6

Hydrostatic gauges

Question 7

s counterbalance the pressure of a fluid with a spring (for
example tire-pressure gauges of comparatively low accuracy) or a solid weight, in which case it is
known as a deadweight tester and may be used for calibration of other gauge

Answer 7

Piston-type gauge

Question 8

consist of a column of liquid in a tube whose ends are exposed to different pressures. The column will rise or fall until its weight (a force applied due to gravity) is in
equilibrium with the pressure differential between the two ends of the tube (a force applied due
to fluid pressure

Answer 8

Liquid-column gauges

Question 9

has a larger reservoir instead of one side of the U-tube

and has a scale beside the narrower column

Answer 9

A single-limb liquid-column manometer

Question 10

types of manometers

Answer 10

o Simple manometer
o Micromanometer
o Differential manometer
o Inverted differential manometer
o McLeod gauge

Question 11

isolates a sample of gas and compresses it in a modified mercury manometer
until the pressure is a few millimetres of mercury. The technique is very slow and unsuited to
continual monitoring, but is capable of good accuracy.

Answer 11

McLeod gauge

Question 12

are based on a metallic pressure-sensing element that flexes elastically under the
effect of a pressure difference across the element

Answer 12

Aneroid gauge

Question 13

uses the principle that a flattened tube tends to straighten or
regain its circular form in cross-section when pressurized. This change in cross-section may be
hardly noticeable, involving moderate stresses within the elastic range of easily workable
material

Answer 13

Bourdon pressure gauge

Question 14

A second type of aneroid gauge uses deflection of a flexible membrane that separates regions of
different pressure. The amount of deflection is repeatable for known pressures so the pressure
can be determined by using calibrate

Answer 14

Diaphragm

Question 15

These gauges use the attraction of two magnets to translate differential pressure into motion of
a dial pointer. As differential pressure increases, a magnet attached to either a piston or rubber
diaphragm moves

Answer 15

Magnetic coupling

Question 16

works by measuring the amount a rotating ball is slowed by the viscosity of the gas being measured. The ball is made of steel and is magnetically levitated inside a steel tube closed at one end and exposed to the gas to be measured at the other

Answer 16

spinning-rotor gauge

Question 17

the originator of the era of precision thermometry. He invented
the mercury thermometer (first practical, accurate thermometer) and Fahrenheit scale (first
standardized temperature scale to be widely used

Answer 17

Daniel Gabriel Fahrenheit,

Question 18

, also known as thermometry, describes the process of measuring a
current local temperature for immediate or later evaluation. Datasets consisting of repeated
standardized measurements can be used to assess temperature trend

Answer 18

Temperature measurement

Question 19

early devices able to measure relative change in temperature, but subject also to confounding with
atmospheric pressure changes.

Answer 19

thermoscopes.

Question 20

One of the most common devices for measuring temperature. This consists of a
glass tube filled with mercury or some other liquid, which acts as the working fluid. Temperature
increase causes the fluid to expand, so the temperature can be determined by measuring the
volume of the fluid

Answer 20

glass thermometer

Question 21

is an electrical device consisting of two dissimilar electrical conductors forming electrical junctions at differing temperatures. A temperature-dependent voltage as a result of the thermoelectric effect, and this voltage can be
interpreted to measure temperature. Thermocouples are a widely used type of temperature sensor

Answer 21

thermocouple

Question 22

is a type of resistor whose resistance is dependent on temperature, more so than
in standard resistors. The word is a portmanteau of thermal and resistor

Answer 22

thermistor

Question 23

also called resistance temperature detectors (RTDs), are sensors used
to measure temperature. Many RTD elements consist of a length of fine wire wrapped around a
ceramic or glass core but other constructions are also used.

Answer 23

Resistance thermometer

Question 24

is a type of remote-sensing thermometer used to measure the temperature of a
surface. In the modern usage, it is a device
that from a distance determines the temperature of a surface from the amount of the thermal
radiation it emits

Answer 24

A pyrometer

Question 25

is a device used to determine the electron temperature, electron density, and
electric potential of a plasma. It works by inserting one or more electrodes into a plasma, with a
constant or time-varying electric potential between the various electrodes or between them and
the surrounding vess

Answer 25

Langmuir probe

Question 26

sometimes called infrared light, is electromagnetic radiation (EMR) with
longer wavelengths than those of visible light. It is therefore generally invisible to the human
eye, although IR at wavelengths up to 1050 nanometers (nm)s from specially pulsed lasers can
be seen by humans under certain condition

Answer 26

Infrared radiation