Pressure gauges. Presentation on the topic “pressure gauge”: a box is immersed in liquid, the larger it becomes

Instruments for measuring atmospheric pressure

Physics Presentation

7th grade

Sharonova S.M.

Pressure is a physical quantity that shows the acting force per unit area of a surface perpendicular to this surface. Pressure is defined as P = F / S, where P is pressure, F is pressure force, S is surface area. From this formula it is clear that pressure depends on the surface area of the body acting with a certain force. The smaller the surface area, the more pressure.

The unit of measurement for pressure is newton per square meter(H/m2). We can also convert pressure units N/m2 to pascals, a unit of measurement named after the French scientist Blaise Pascal, who developed the so-called Pascal's Law.

1 N/m2 = 1 Pa.

Torricelli. His mercury tube was the first barometer.

The cup barometer is an improved version of the Torricelli barometer.

For scientific and everyday purposes, you need to be able to measure atmospheric pressure. For this there are special devices- barometers. The very first device for measuring atmospheric pressure was invented...

No matter what size cup of mercury you take, no matter what diameter the tube is, the mercury will always rise to the same height - 760 mm. The barometric tube can be given different shape, only one thing is important, one end of the tube must be closed so that there is no air from above.

You can fill the tube with any liquid other than mercury, but you must remember to change its length.

Water barometers were built by Pascal (Rouen, 1646) ...

... and Otto von Guericke (Magdeburg, 1660)

The largest water barometer, 12 m high, was constructed in 1987 by Bert Bolle, curator of the Barometer Museum in Martensdijk, the Netherlands, where it is installed.

Mercury barometers provide accurate readings but require great care when handling them. The modern barometer is made liquidless!

It's called an aneroid barometer. Metal barometers are less accurate, but not as bulky or fragile.

Internal structure of an aneroid.

This barometer is called a barometric altimeter or altimeter.

An aneroid barometer is a very sensitive instrument. For example, going up to the top floor of 9 storey building, due to the difference in atmospheric pressure on different heights we will detect a decrease in atmospheric pressure of 2-3 mmHg. Art.

A barometer can be used to determine the flight altitude of an aircraft.

The idea of Pascal's experiment formed the basis for the design of the altimeter. It determines the altitude above sea level by changes in atmospheric pressure.

When observing the weather in meteorology, if it is necessary to record fluctuations in atmospheric pressure over a certain period of time, they use recorder- barograph.

To measure pressure, different units are used: mm of mercury, physical atmospheres,

in the SI system

Pascals.

All living organisms are adapted to live at certain values of atmospheric pressure. Humans and most animals do not tolerate high altitude conditions well, but some birds reach significant heights in flight. The condor bird can rise to a height of up to 9000m, mountain jackdaws - up to 8200m, vultures and hawks - up to 6000-7000m, eagle - up to 5000m, other birds stay at an altitude of no more than 4000m.

The largest water barometer, 12 m high, was constructed in 1987 by Bert Bolle, curator of the Barometer Museum in Martensdijk, the Netherlands, where it is installed.

Can a person produce a pressure of 1000 atm? Yes, by sticking a needle into the fabric!

Remember the experience of Otto von Guericke - 1654 in the city of Magdeburg. It turns out that " Magdeburg hemispheres“every person has: the heads of the femurs are held in the pelvic joint by atmospheric pressure.

How can a driver help a friend and pour gasoline from his car into the gas tank of another? There is such a simple device - a siphon. Its work is based on the action of atmospheric pressure.

The structure of the Earth's atmosphere resembles a multi-story building.

The first “floor” is the troposphere: up to 11 km high at sea level, it contains 4/5 of the mass of all air, the temperature drops with height, and clouds form here.
The second “floor” is the stratosphere: up to 55 km above sea level, contains 1/5 of all air, the kingdom of cold with a temperature of about minus 40 degrees Celsius, the ozone layer is located here.
The third “floor” is the mesosphere: up to 200 km above sea level, the air is very rarefied, the pressure is 1/25000 of normal atmospheric pressure.

The fourth “floor” is the thermosphere: unprecedented heat of about 1000-2000 degrees Celsius, air density is extremely low, falling meteors ignite here.
The fifth “floor” is the exosphere: the outer shell of the atmosphere, up to 600 km high, the strongest air rarefaction; even higher, signs of air particles can be traced to an altitude of more than 1000 km.

ABOUT STRANGE FISH - STICKED

This fish sticks to the shark with such force that it is impossible to tear it off. This live hook is still used in Australia to catch sharks and large fish, and in South America– turtles. With the help of stick fish, fish weighing up to 18 kg are caught. There are metal vacuum lifting devices. These suction cups are metal or rubber bowls similar to Magndeburg hemispheres with a diameter of 50 to 600 mm; they can lift loads weighing up to 700 kg. By attaching several suction cups to an object, you can lift a load weighing up to 10 tons!

IN Lately in medicine they began to use a “liquid scalpel”, i.e. tissue incision during surgery is carried out with a thin stream of saline solution under a pressure of about 120 atmospheres.

LET'S THINK ABOUT "5"?

1. What is the difference between the change in air density with height and the density of water at different sea depths? 2. Which barometer is more sensitive: mercury or oil? Why? 3. Is it possible to measure the pressure on board? space station a mercury barometer, or an aneroid?

4. What type of barometer should be used to measure internal pressure spaceship when it is moving with the engine off? Why?

Option 7-3-1
1. Determine the area of one tractor caterpillar, which, with a mass of 3880 kg, exerts a pressure on the ground of 4 N/sq.cm? 2. For a smaller piston hydraulic machine area 5 sq.cm. a force of 2500 N acts. What load is lifted by the machine with a large piston whose area is 200 sq.cm? 3. What pressure does a layer of kerosene 0.6 meters high exert on the bottom of the vessel? 4. With what force does the air press on a table with an area of 0.7 square meters? Why do we not experience the action of this force when we lift the table? 5. Water is poured into one elbow of communicating vessels to a height of 10 cm; to what height should mercury be poured into the other elbow in order to achieve equilibrium of the liquids in the vessel’s elbows?
Everyone decides their own option

Option 7-3-2.

1. What pressure does it exert on the ground? Brick wall 2.5 meters high?

2. The pump pumps oil into Hydraulic Press under pressure 30 N/sq.cm. With what force does the press compress the pressed part if the area of the press piston is 0.08 sq.m.?

H. The tank with kerosene has a side hole, closed with a plug with an area of 8 sq. cm. What force must keep the plug from flying out if the hole is at a depth of 1.8 meters?

4. Determine the force with which the atmosphere presses on window glass with an area of 1.5 sq.m. Why doesn’t the glass shatter into pieces from such terrible force?

5. Water is poured into one elbow of communicating vessels to a height

6 cm. To what height should you pour kerosene into the other elbow to achieve equilibrium of liquids in the legs of the vessel?

Option 7-3-3.

1. A tractor having a support area of two tracks of 2.4 sq.m. produces a pressure on the ground equal to 5 N/cm2. Determine the mass of the tractor.

2. The area of small piston of hydraulic machine is 10 times less area second piston. What force must be applied to the large piston to keep a 1 kg load on the small piston in balance?

3. The pipe can withstand pressure of 500,000 N/sq.m. To what height can water be supplied through this pipe?

4. With what force does the atmosphere press on a person whose skin surface area is 2 square meters? Why does a person not notice the effect of this force on himself?

5. In communicating vessels of the same shape there are 10 cubic meters. cm of water and 10 cc. kerosene. What is the difference in fluid levels in the right and left vessels?

Option 7-3-4.

1. Find the area of the piston, which, under pressure on it compressed air 48 N/sq.cm. develops a force of 120,000 N.

2. A cubic vessel with a volume of 1 cubic meter. filled with water. Determine the pressure at the bottom of the vessel.

H. In a cylinder under a piston with an area of 0.1 sq.m. there are 9 kg of water. What is the pressure on the bottom of the cylinder if a 1 kg weight is placed on the piston in stages?

4. Air pressure at an altitude of 10 km is 26000 Pa. With what force does the air in an airplane squeeze out a window glass with an area of 800 sq. cm?

5. There are 10 cubic cm in communicating vessels of the same shape. water and 3 cc. mercury What is the difference in fluid levels in the right and left vessels?

Option 7-3-5.

1. What should be the area of the skis so that a person weighing 70 kg exerts a pressure of no more than 0.5 N/cm2 on the snow?

2. Hydraulic machine piston with an area of 2 cm2. is lowered by a force of 150 N. What is the weight of the load lifted by the second piston of area 8 cm2?

H. The fountain's water rises to a height of 5 m. What is the water pressure in the pipe supplying water to the fountain?

4. What force of atmospheric pressure acts on a notebook sheet with an area of 350 sq. cm? Why doesn't this sheet tear under the influence of such enormous force?

5. On one side of the communicating vessels, water was poured to a height of 4 cm, and on the other, an unknown liquid was poured, which needed to be poured to a height of 5 cm before reaching equilibrium in the communicating vessels. What kind of liquid is this?

Answers

task\option

7 - 3 - 1

7 - 3 - 2

7 - 3 - 3

7 - 3 - 4

7 - 3 - 5

density 800 kg/m 3, most likely it is kerosene

Grebenshchikov V.E. PSM-21
Measuring instruments
pressure

Content
1.What is pressure? Kinds.
2. Classification of measuring instruments
pressure
A. Two-pipe pressure and vacuum gauge
b. Deadweight pressure gauges
V. Differential pressure gauges
g. Recording pressure gauges
d. Pressure gauges precise measurements
e. Digital pressure gauges
and. Electric contact pressure gauges
h. Micromanometers
And. Pressure meters, draft pressure meters, draft meters
j. Pressure transducers KRT5
l. Pressure switches

1.What is pressure? Kinds.

Pressure - effective force located on the surface of the body, divided by
area of this surface. In the SI system it is measured in Pa (Pascals).
Metrologists measure pressure in units of measurement - millibars, which
equals 100 Pa.
Absolute pressure is a value measured relative to a pressure equal to
absolute zero. In other words, the pressure is relative to absolute
vacuum.
Barometric pressure is the absolute pressure of the earth's atmosphere.
This type of pressure gets its name from the measuring device
barometer, which is known to determine atmospheric pressure in
a certain point in time at a certain temperature and at
a certain altitude above sea level. Relative to this pressure
excess pressure and vacuum are determined.
Excessive pressure occurs if there is a positive
the difference between the measured pressure and the barometric pressure. That is
excess pressure is the amount by which the measured pressure is greater
barometric A pressure gauge is used to measure this type of pressure.

Vacuum or otherwise vacuum pressure is the value by which
the measured pressure is less than barometric. If excess pressure
is denoted in positive units, then vacuum in negative units.
For example, a 40PC015V1A sensor capable of measuring vacuum has a range
measured pressure from -103 to 0 kPa. Instruments capable of measuring this type
pressure are called vacuum gauges.
Differential pressure occurs when one pressure is compared
relative to the other, and neither of them is equal to the barometric one.
Excess pressure and vacuum are measured relative to barometric
pressure. If we measure these quantities relative to any other
quantities, then we get a differential one.

2.Classification of pressure measuring instruments

Two-pipe pressure and vacuum gauge
Double-pipe pressure and vacuum gauges MN21 are designed
for measuring excess, absolute pressure, and
also pressure differences between liquids and gases.
Operating principle and pressure and vacuum gauges
two-pipe is based on the law of communicating
vessels. The device is a curved
U-shaped glass tube permanent
section filled with working fluid.
The liquid is a sensitive element,
responsive to changes in pressure. For
gas pressure measurements as a working
liquids use water to measure
liquid pressure - mercury. Under influence
measured pressure changes height
balancing column of liquid, such
the measured pressure is determined by
readings of the position of the working fluid level in
one or two tubes.

The instrument scale is a rectangular plate on which
A uniform scale is applied, graduated in mm.
Double-pipe pressure and vacuum gauges MN21 have 5 modifications,
differing in measurement ranges, design and overall dimensions
sizes. In pressure and vacuum gauges mod. 5, designed for
measurements of low absolute and differential pressures,
an inclined tube is used.

Deadweight pressure gauges

Deadweight piston pressure gauges are
devices in which the measured pressure
is balanced by the force created
calibrated weights acting
on a freely moving piston.
The main part of the device is
vertical column, in cylindrical
the channel in which the piston is located.
The most common pressure gauges are with
unsealed piston. Between him and
there is a small gap in the cylinder,
the space under the piston is filled
special oil, which is under
pressure enters the gap and provides
lubrication of rubbing surfaces. At
pressure measurement to reduce friction
between the cylinder and the piston the last
driven by an electric motor.
Pressure gauges of this type are characterized by high
accuracy and wide measurement range
(from 0.098 to 250 MPa). Deadweight piston
pressure gauges have upper limits
measurements 0.1; 0.6; 1; 2.5; 6; 10; 60; 100;
250 MPa and accuracy classes 0.02, 0.03 or
0.05. High accuracy of these devices
requires good care behind them and
strict adherence to the rules
operation.

MP-250 deadweight pressure gauge
Overpressure gauge
deadweight piston MP-250 class
accuracy 0.05 (hereinafter according to
text - pressure gauge) is intended
for verification and calibration
measuring instruments
pressure (deformation
pressure gauges, sensors,
registrars, etc.). And
for direct
measurement of excess
pressure in the connected
systems.
Specifications
pressure gauges comply with GOST
8291-83.
The pressure gauge is designed for
work at temperature
ambient air from 10 to
30 °C and relative
humidity no more than 80%

MVP-2.5 pressure-vacuum tester, deadweight piston (accuracy class 0.02)

Pressure and vacuum gauge
deadweight piston MVP-2.5 (in
hereinafter pressure-vacuum gauge)
accuracy class 0.02
intended for verification
exemplary deformation
pressure gauges with upper
measurement limits no more
0.25MPa (2.5 kgf/cm2) and
exemplary deformation
vacuum gauges, as well as for
direct measurement
excess pressure and
vacuum.
The pressure and vacuum gauge is designed
for operation at temperatures
environment from 10 to
30°C and relative humidity
no more than 80%.

Differential pressure gauges

Differential pressure gauge
(differential manometer) is
showing (arrow
or digital) device
differential measuring
(difference) pressure. IN
depending on what is being measured
parameters are distinguished
differential pressure gauges:
changeover meters, flow meters and
level gauges Beyond simple
showing performance,
differential pressure gauges can be
signaling and
self-peeping.

Handheld Digital Differential Pressure Gauge
series 477.
● For easy data download option
USB contains cable and software
security;
● Choice of nine
English/Metric technical
units;
● The memory stores 40 previous
indications;
● Positive measurements,
negative and differential
pressure;
● Audible and visual emergency
overpressure signals;
● Operates up to 100 hours from one
9 volt batteries;
Combines the features needed for
pressure measurements quickly, easily and more accurately
records data. Firstly, you can immediately
choose from nine most widely used units
pressure without wasting time and risking mistakes
tedious conversion of units. Next, the function
non-volatile memory allows you to save up to 40
readings - convenient for HVAC technicians
(heating, ventilation and air conditioning) and
gives reading profiles air flow for channel with
pitot tube. Models are FM certified with
intrinsically safe for hazardous locations to Class 1, Div. 1,
Group A, B, C, D, T4.
When working in areas with poor lighting there is a function
display backlight. She automatically
switches off after 20 minutes to minimize
battery discharge. Electronic zeroing made simple
touching one key to completely reset
any minimum pressure differences. HOLD key
(hold) records the current pressure in order to
determine the general situation when the readings
fluctuate. We even turned on the emergency sound
overpressure warning signal plus
visual Emergency Signal in case
the ambient noise level is too high to
hear a beep. Sound signal Also
confirms that the reading has been preserved, which excludes
the need to pay attention to the display during
measurements on the channel profile.
A new option for the 477 series is the USB interface. IN
combinations with the possibility of data recording in a series
477 user can now quickly and conveniently download
saved readings to any USB compatible
device. Data manipulation can be done easily
in numerous electronic processing devices
text or spreadsheet programs. USB
models are equipped with a USB cable and a CD with software
provision.

Differential U-shaped pressure gauges
These inexpensive pressure gauges measure positive, negative and
differential pressures. U-shaped pressure gauges combine obvious accuracy,
which has a simple U-shaped tube, with the strength being rigid and durable
plastic construction. The pressure gauge posts are made of flexible, durable transparent
tubes with an outer diameter of 0.375".
They can be easily cleaned.
To ensure maximum color contrast behind the indicator tube
there is a recess white. The scales are extruded on polystyrene, which has the shape
keeping the gauge posts absolutely straight. Durable for clarity
white scales have black divisions and numbers.
A large number of models and characteristics,
including versions with safety
overpressure traps, options with
full scale range from 8" to 36" for water and
mercury All pressure gauges are suitable for full
pressures up to 100 Pa - to determine speed and
static pressures, leakage, efficiency
fan and blower, filter resistance
and gas pressure. The pressure gauge is ideal when
Transportability and direct reading are required.
Small divisions (scales) 1/10 inch water
column (or 2 mm water column in metric
units) are printed for better legibility
black on a white scale. Easy to read,
even from a distance, they are covered for durability
acrylic. All models come with one bottle
per ¾ ounce fluorescent concentrate
green color with special wetting agent
substance for W/M models (water/mercury) or
¾ ounce bottle of red measuring oil
for D models.

Differential U Shape Flexible Twist Gauge
Convenient twist-up pressure gauge,
measuring with laboratory precision.
The pressure gauges correspond in accuracy to the most
high-quality laboratory U-shaped pressure gauges – also for
ease of carrying the pressure gauge U-shaped
pressure gauges are rolled up to a compact size
pressure gauge size and withstand
quite rough handling of the U-shape
pressure gauge.
Simply unfold the pressure gauge and install the U-shaped pressure gauge to measure
differential pressure. Magnetic
U-shaped pressure gauge clamps securely
hold the pressure gauge on any steel
surfaces. Pressure gauge can be installed
obliquely, securing one side with a nail.
To start working with the pressure gauge, turn
U-shaped pressure gauge connectors per one
turnover When pressure is applied, it occurs
upward displacement of the level in one shoulder by
some value measured in inches and
shift the level down by some
a value measured in inches.
Pressure gauges cover a wide range of pressures - from 4-0-4 inches to
60-0-60 inches. Use these U-shaped pressure gauges to determine
speed and static pressure, for leak detection, testing
fans and blowers, calibration of control devices, testing
gas pressure and many other applications. All models of U-shaped pressure gauges
have flexible vinyl arms and a flexible steel scale calibrated to
inches of water when using water and inches of mercury when
use of mercury. Pressure gauges are suitable for measuring pulsating
total pressure up to 50 Pa and vacuum not exceeding 20 C.

Differential inclined
pressed pressure gauges
Pressed pressure gauges series
Mark II are available as inclined type,
and the type with vertical
location of the meter.
Curved located
vertical pressure gauge tube
Model 25 provides more
wide ranges with lighter
reading increments at low
reading values. Model 25
great for general use
applications. Inclined model
pressure gauge provides linear
calibration and beauty
resolution over the entire range.
Inclined pressure gauge model
ideal for measuring
air speed and measurements in
air filter. Both types
pressure gauges are capable of measuring
pressure higher and lower
atmospheric, as well as for
differential measurements
pressure (pressure difference).

Hospital patients who
sensitive to dust or
bacteria, require placement in
carefully controlled blocks
environment. Complex
filtration systems are removed
particles from incoming
forced air. Pressure gauge
differential pressure
monitors pressure drop across
filter system for
determining the moment when
maintenance required.
Mark II pressure gauge measures
positive pressure in
room so that there is
confidence in exceeding
pressure above atmospheric and
preventing intrusion
unfiltered air when
the door opens. If
a double type reading is desirable,
instead of Mark II maybe
pressure gauge used
differential pressure
And to provide visual
or audible warning about
upcoming problems
can be installed
relays/pressure gauges.

DM 3583M differential pressure gauge
Designed for proportional
converting pressure difference to output
unified mutual signal
inductance.
Converters (differential pressure gauges) are used in
control systems, automatic
regulation and management of technological
processes when measuring liquid flow,
gas or steam by the pressure difference in the constrictions
devices, differences between vacuum and
excess pressure, liquid level according to
hydrostatic column pressure,
under atmospheric, excess or
vacuum pressure.
Transducers are designed to measure
parameters of non-aggressive gases and liquids at
ambient temperature from minus 30
degrees to plus 50 degrees Celsius and
relative humidity up to 95 percent.
Converters are available with upper
measurement limits corresponding to the following range:
1.6; 2.5; 4.0; 6.3; 10; 16; 25 kPa (160; 250; 400;
630; 1000; 1600; 2500 kgf/m2) 40; 63; 100; 160;
250; 400; 630 kPa (0.4; 0.63; 1.0; 1.6; 2.5; 4.0;
6.3 kgf/cm2).
The lower limit of measurement is zero.
Converters with upper rated
measurement limits 1.6; 2.5; 4.0 kPa (160; 250;
400 kgf/m2) are intended only for maximum
permissible operating overpressure 16
MPa (160 kgf/cm2)
Converters with upper limits
measurements 1.6 and 2.5 kPa (160 and 250 kgf/m2)
are intended only for conversion to

Bellows differential pressure gauge
showing DSP-160M1
To measure pressure drop on gas meters,
gas filters, as well as other gas equipment.
Industries: gas supply, heat power,
chemical industry.
Wednesday: natural gas, nitrogen, argon, air, and others
non-aggressive gases.
Operating principle: Differential manometer design
consists of two parts - a bellows block and
showing part.
The operating principle is based on the use
deformation of the elastic system (bellows,
coil springs,
torque tube) when exposed to
measured pressure difference. Mechanism
showing part assembled
in a round case with a diameter of 160 mm and represents
is a tribco-sector mechanism, on the axis of which
installed
indicating arrow. Differential pressure gauge scale
uniform with a value of one division of 1 mbar (10 mm.
water Art.).
The differential pressure gauge can withstand an overload exceeding the maximum limit for 1 hour on the positive input side
nominal pressure drop by 50%. The differential pressure gauge holds for 1 minute on the positive side or
minus
input exposure to pressure equal to the maximum permissible operating excess pressure. Easy to install
differential pressure gauge. Insensitive to working environment pollution. In terms of resistance to temperature and
ambient humidity differential pressure gauge
It has Climatic performance U2 according to GOST 15150-69. According to the degree of protection from environmental influences
The differential pressure gauge meets the requirements for IP55 performance (protected from dust and water) according to
GOST 14254-96.
The design provides for installation on a round post with a diameter of 40mm or on a bracket with bolt fastening
M14x1.5. Full average service life of at least 12 years.

Self-recording pressure gauges

Intended for
measurement and continuous
records in time on
disk diagram
excessive and
vacuum,
differential
liquid pressure and
gaseous non-aggressive
environments, incl. gaseous
oxygen.
Chart disk drive
from an electric motor or from
clock mechanism. Time
one revolution of the diagram
disk 24 hours. Execution according to
Pressure records: single and
two-note. Class
accuracy: 1; 1.5. Working
ambient temperature
Wednesday: -10 to +600С.

DM-2001 self-recording pressure gauge

Recording pressure gauge DM-2001
used to measure
excess pressure of gaseous
and liquid non-aggressive media in
various industries
industry and continuous
records in time on disk
diagram (diagram discs,
registration number 2109). Sign up for
chart disc is produced with
using a writing unit brand UPS23/D1. The letter "D" means that
The disk has been modified. Action
pressure gauge DM2001 is based on
balancing the measured
pressure elastic deformation
single-turn tubular spring,
moving the free end
which multiplying
mechanism is converted into an angular
moving the writing pen
readings on the chart disc.
The disk rotates with
with help mechanical drive.

Recording differential pressure gauge DSS-711-M1 (flow meter)

Differential pressure gauges
(differential pressure gauges) - flow meters
bellows are intended for
measuring the flow of liquids and
gaseous media according to the method
variable pressure drop in
standard constriction devices.
DSS-711-M1 - differential pressure gauge
recorder with drive
chart disk from
electric motor. Chart
discs of differential pressure gauges-flow meters with
quadratic dependence uneven.

Pressure gauges for precise measurements

Pressure gauges for precise measurements
(pressure and vacuum gauges, vacuum gauges) –
MTIF, MVTIf, VTIf. Accuracy class -
0.4; 0.6; 1.0. Intended for
non-aggressive pressure measurements

steam and gas, including oxygen and
freon.
Belong to deformation
pressure gauges - their base is tubular
Bourdon spring. Peculiarity
production of standard pressure gauges
(working standards) from conventional
technical pressure gauges, consists in
compliance with higher requirements,
requirements for materials, technology
manufacturing, pressure gauge design,
providing more accurate
adjustment. At the exemplary - reference
pressure gauge is used tubular
the spring is usually larger
there are additional options
adjusting the scale range and its
uniformity. For the manufacture of
exemplary sensitive elements
pressure gauges use alloys with more
high elasticity characteristics
(for example, beryllium bronze).

MPTI, VPTI, MVPTI class t.1, class t.0.6, class t.0.4

Pressure gauges, vacuum gauges and
pressure and vacuum gauges indicating
for precise MPTI measurements,
VPTI, MVPTI are intended for
measurement of excess and
vacuum pressure
non-aggressive,
non-crystallizing liquids,
gas and steam, including
oxygen and applications in the fields
state
metrological control and
supervision (GMKiN) and
state system
industrial devices and
automation equipment (GSP).

MTPSd-100 ship pressure gauge

Ship pressure gauges
(ship) MTPSd-100OM2 are designed for
measurement of excess
fluid pressure
(diesel fuel, oil,
water, sea water), gases and
water vapor, temperature
which at the sampling site
there shouldn't be any pressure
more than 60°C, in the ambient
vapor-rich environment
lubricating oil, diesel
fuel and sea water.
Devices can be manufactured
for pressure measurement
freons grades 12, 13. 22.
142, 502 and oxygen.

Digital pressure gauges Yokogawa MT210 / MT210F / MT220 Digital pressure gauges

MT220 and MT210 Yokogawa are
high-precision digital pressure gauges and
used for checking instruments,
measuring excess, absolute and
pressure drop. Pressure gauge
differential pressure allows
measure both absolute, excess, and
pressure drop. MT220 as opposed to MT210
It has additional functions digital
multimeter with an accuracy of 0.01% of the measured value
values and 24V DC output. current, which allows
carry out verification and calibration
pressure converters without involving
other Yokogawa MT220 devices at the same time
can immediately show deviations in readings
calibrated sensor from the real value
pressure. Digital pressure gauges have
built-in memory for measured values,
have a standard exchange interface with
computer (RS232C or GP-IB) and can be
additionally equipped with digital-analog
output and output of the comparator. Thanks to
it is possible to build
automated documentation schemes and
verification based on MT210 and MT220 devices.

Electrical contact pressure gauges DM2005 signaling pressure gauge, explosion-proof.

Designed to measure
excess and vacuum
pressures of various media in the range
0-4 kgf/cm² and external control
electrical circuits from
direct signaling device
actions.
Medium being measured: liquid, steam, gas,
including propane and butane. To order
it is possible to design the device for
measurements in liquid and
oxygen gas.

Micromanometers MMN 2400 micromanometer

Multi-range micromanometer with
inclined tube MMn-2400
designed to measure
excess vacuum
pressure and pressure difference
non-aggressive to steel, brass and
polyethylene gases up to
240 kgf/cm2 at static
pressure no more than 1000 kgf/m2
Operating principle: measurable
pressure balances
working column pressure
liquid that forms in
measuring tube.
As a working fluid in
MMn-2400 uses ethyl
technical alcohol. Scale
applied to the bottle
measuring tube L=300 mm.
Scope of application: control
industrial ventilation
premises, environmental
emission control of various
production, technological
control of gas and dust flows,
aerodynamic research.

Pressure meters, draft pressure meters, draft meters Multi-limit pressure meters ADN/ADR

ADN meter (ADR) –
small-sized product
which combines functions
primary sensor and secondary
device. The meter is built on
modern element base with
using technology
laser calibration
and microprocessing
measurement results.
Applications: as pressure meters
and thrust gauges in automation
protection of gas boilers and burners,
as converters
pressure in the circuits
power regulation and
vacuum, for indication
water level in the boiler drum and
for position control
flaps Acceptable limit
main error,
expressed as a percentage of
range of instrument readings, not
exceeds 2.5%.

Pressure converters KRT5
Application area:
Heating points, heat metering units,
CHP, distribution networks (water, steam, gas and
etc.), pumping stations with adjustable
electric drive, control systems and
regulation of technological processes,
oil and gas pumping stations, enterprises
food, chemical and gas industries.
Purpose: for measurement and continuous
overpressure conversion
(pressure) neutral to titanium and
stainless steel environment
(gas, steam, liquid) into a unified
output signal direct current or
voltage.
Used as an input device
in secondary equipment of systems
automatic control, regulation and
technology management
processes, testing equipment
(hydrotesters, etc.), dispatching,
telemechanical information-measuring complexes,
adjustable asynchronous thyristor
electric drives, etc.

Pressure switches

Purpose: for control and
on/off control
pressure of liquid and gaseous
media in refrigeration units,
used on ships,
railway and road
transport, as well as in
stationary installations and others
systems and devices.
Controlled Environments:
freons, air, oils and others
non-aggressive environments. For
devices DEM102-1-01A, DEM1022-05A controlled environment
It could be ammonia.

Slide 1

Slide 2

* Atmosphere (Greek “atmos” - steam, air and “sphere” - ball) is the air shell surrounding the Earth. The atmosphere extends to a height of several thousand kilometers from the Earth's surface. The surface of the Earth is the bottom of the ocean of air. The surface of the Earth and all bodies on it experience pressure from the entire thickness of air. This pressure is called atmospheric pressure.

Slide 3

* Confirmation of the existence of atmospheric pressure. The existence of atmospheric pressure can explain many phenomena that we encounter in life. Let's look at some of them. The figure shows a glass tube, inside of which there is a piston that fits tightly to the walls of the tube. The end of the tube is lowered into the water. If you lift the piston, then water will rise behind it. This happens because when the piston rises, an airless space is formed between it and the water. Water rises into this space under pressure from outside air following the piston.

Slide 4

* In 1654, Otto Guericke in the city of Magdeburg, in order to prove the existence of atmospheric pressure, performed such an experiment. He pumped the air out of the cavity between the two metal hemispheres folded together. The pressure of the atmosphere pressed the hemispheres so tightly against each other that eight pairs of horses could not tear them apart.

Slide 5

*Torricelli experience. Atmospheric pressure was first measured by the Italian scientist Evangelista Torricelli in the experiment that bears his name. The pressure of a column of mercury 1 mm high is equal to: 1 mm Hg = 133.3 Pa 1 hPa (hectopascal) = 100 Pa.

Slide 6

* Torricelli noticed that the height of the mercury column in the tube changes, and these changes in atmospheric pressure are somehow related to the weather. If you attach a vertical scale to a tube of mercury, you get the simplest mercury barometer (Greek “baros” - heaviness, “metreo” - measure) - a device for measuring atmospheric pressure. Conclusion:

Slide 7

* Students write in their notebook: The unit of atmospheric pressure is 1 mm Hg. Art. Relationship between Pa and mm. Hg P= ρgh = 13,600 kg/m3 9.8 N/kg 0.001 m = 133.3 Pa 1 kPa = 1000 Pa 1 hPa = 100 Pa 760 mmHg ≈ 101 300 Pa ≈ 1013 hPa Units of atmospheric pressure.

Slide 8

Atmosphere pressure in wildlife, flies and tree frogs can stay on window glass thanks to tiny suction cups in which a vacuum is created and atmospheric pressure holds the suction cup on the glass. Sticky fish have a suction surface consisting of a series of folds that form deep “pockets”. When you try to tear the suction cup away from the surface to which it is stuck, the depth of the pockets increases, the pressure in them decreases, and then the external pressure presses the suction cup even harder. *

Slide 9

* The elephant uses atmospheric pressure whenever it wants to drink. His neck is short, and he cannot bend his head into the water, but only lowers his trunk and draws in air. Under the influence of atmospheric pressure, the trunk fills with water, then the elephant bends it and pours water into its mouth. The suction effect of the swamp is explained by the fact that when you raise your leg, a rarefied space is formed under it. The excess of atmospheric pressure in this case can reach 1000 N/per foot area of an adult. However, the hooves of artiodactyl animals, when pulled out of a quagmire, allow air to pass through their incision into the resulting rarefied space. The pressure from above and below the hoof is equalized, and the leg is removed without much difficulty.

During the classes

1. Organizational moment.

2. Stage: repetition.

Teacher: Hello guys!

Today we have a presentation lesson. In previous lessons, you were convinced that atmospheric pressure exists, and you learned that atmospheric pressure can be measured using a device invented by the Italian scientist Evangelista Torricelli.

3. Stage: Aneroid barometer.

And now we will find out how the aneroid barometer works.

What is an aneroid barometer and what is it intended for?

In practice, an aneroid barometer is used to measure atmospheric pressure. It is called liquid-free because it does not contain mercury.

Now let’s find out how this device works.

frame
corrugated box
glass
scale
spring plate
arrow

Open the textbook on page 105 and read about the device.

Now look at the side view and try to name the parts of the device.

Student:

metal box with a wavy surface.
Spring.
Transmission mechanism
Pointer arrow.

Will the barometer show the same pressure on the first and second floors of our school?

Student: The pressure on the first floor will be higher than on the second floor.

Teacher: Why do you think?

Student: With altitude, pressure decreases.

For every 12 m rise, the pressure decreases by 1 mmHg. Art. Therefore, they can be called altimeters.

Teacher: What pressure do we consider normal? And what does it equal?

Student: Atmospheric pressure equal to the pressure of a column of mercury 760 mm high at a temperature of 0°C is callednormal atmospheric pressure. Normal atmospheric pressure is 101,300 Pa=1013 hPa.

Teacher: Guys, look at the scale of the aneroid barometer. State the measuring limit of the device.

Student: 720mmHg. – 780mmHg

Teacher: What is the division price of the device?

Student: 1mmHg.

Teacher: Close your eyes, listen to me and imagine what I will talk about. I will ask you riddles, the one who knows the answer will tell you the answer.

First - shine
Behind the shine is a crackling sound,
Behind the crackling is a splash.
(Lightning, thunder, rain)
Fluffy cotton wool
Floating somewhere.
The lower the wool,
The closer the rain comes.
(Cloud)
Colored rocker
Hanging over the forest.
(Rainbow)
White smoke pulled at the forelock,
The oak tree shook on the field.
He knocked on the gate.
Hey, open up! Who's there?
(Wind)
Flies - is silent,
Lying down - silent.
When he dies, then he will roar.
(Snow)
He will tell everyone
Although without a tongue,
When it's clear
And when there are clouds.
(Barometer)

Teacher: What do these riddles have in common?

Student: We are talking about atmospheric phenomena.

Teacher: Everything that was discussed in the riddles exists on earth only because the earth has an atmosphere. But in solar system not all planets have an atmosphere.

Space painted in black color,
Because there is no atmosphere
There is neither night nor day,
There is no earthly blue here,
The views here are strange and wonderful,
And the stars are all visible at once,
Both the Sun and the Moon.
V. P. Lepilov, Astrakhan.

4. Stage: Pressure gauges.

Teacher: Let's move on to the second part of the lesson. Pressure gauges.

Pressure gauges are used to measure pressures greater or less than atmospheric pressure.

There are 2 types of pressure gauges: liquid and metal. Let's consider the device of a liquid pressure gauge.

Double bend glass tube.
Rubber tube.
Scale.

Operating principle of a liquid pressure gauge.

The deeper the box is immersed in the liquid, the greater the difference in the heights of the liquid columns in the pressure gauge elbows becomes, and, consequently, the greater the pressure produced by the liquid.

Teacher: Open your textbook to page 109 and read about the construction of a metal pressure gauge. And tell us the principle of its operation.

Student: As the pressure increases, the tube straightens.

When the pressure decreases, the tube, due to its elasticity, returns to previous position, and the arrow goes to zero division scales.

5. Stage – Consolidation.

Teacher: A Now let's check how you have mastered the topic. Prepare pieces of paper, sign and number them from 1 to 10. Write only the end of the sentence.

Conceptual dictation.

1. A metal barometer, translated from Greek as liquid-free, is called.... ...aneroid

The number 2 in the figure indicates... corrugated box
The number 4 in the figure indicates... scale
Atmospheric pressure equal to the pressure of a column of mercury 760 mm high at a temperature of 0°C is called... normal
Atmospheric pressure decreases by 1 mm for each rise... 12 m
A device for measuring pressures greater or less than atmospheric pressure is called... pressure gauge
In the vessel in Figure B the pressure is ... atmospheric less
The pressure gauge in the figure is called... metal
Number 1 in the figure indicates... Metal tube
The number 3 in the figure indicates... arrow

At the end of the lesson, the pieces of paper are collected and a self-test is carried out using ready-made answers on the screen. Who answered 5? At 4?

6. Stage – Lesson summary.

Teacher: So, guys, we got acquainted with devices for measuring pressure. Name these devices?

Student: Barometer and pressure gauge.

Teacher: Choose two of the 4 proposed words that relate to barometers.

Student: Aneroid and Torricelli

Teacher: . Which one do you think is more convenient to use? Why?

Student: Barometer- aneroid.

Teacher: What pressure gauges do you know?

Student: Liquid and metallic.

Teacher: Which one is more practical to use? Why? Where in your life have you seen the use of pressure gauges?

Student: Measuring pressure when filling gas cylinders in the press.

This concludes the lesson. Thank you everyone for your work, everyone who answered correctly today will receive a grade - excellent, the rest of the grades will be clarified after checking the dictation.