Bar is a unit of pressure. Calculator for converting pressure in bar to MPa, kgf and psi. Thermal efficiency and fuel economy

10.11.2020

Different manufacturers use different designations and standards to indicate the water resistance of watches. Some waterproof watch manufacturers use bars (bar), others in meters, and still others in atmospheres. There are also many ISO standards that determine the water resistance and water resistance of not only watches, but also other devices. This article will help you deal with all these subtleties.

First, let's look at the units of measure for water resistance.

Bar

Bar - international designation: bar. The term comes from the Greek word βάρος, which means heaviness. The bar is a non-systemic unit of pressure, that is, it is not included in any measurement system. The value of a bar is approximately equal to one atmosphere. That is, the pressure of "one bar" is the same as the pressure of one atmosphere.

Atmosphere

Well, everything is clear from the name, and, perhaps, from the school physics course. This pressure is equal to the force with which the layer of air above the earth presses on the earth itself. In nature, pressure is of course constantly changing, but in physics it is generally accepted that the pressure of one atmosphere is equal to the pressure of 760 millimeters of mercury (mmHg). Pressure in atmospheres is abbreviated as "atm" or "atm".

m or meters

Most often, the water resistance of watches is indicated in meters, but these are not the meters that you can dive under water. This is the equivalent of the pressure measured by the water column. For example, at a depth of 10 meters, water will press with a force of one atmosphere. That is, a pressure value of 10 m is equal to a pressure of one atmosphere.

So, there are different systems for indicating the water resistance of watches - in meters, bars and atmospheres. But they all mean about the same thing: 1 bar is equal to 1 atmosphere and is approximately equal to immersion by 10 meters.

1 bar = 1 atm = 10 m

Watch water resistance standards

There are many different standards by which the water resistance of watches and other electronic devices(eg phones). Waterproof watches are very popular among hikers, climbers and extreme sports enthusiasts.

Watch water resistance standard ISO 2281 (GOST 29330)

This standard was adopted in 1990 to standardize the water resistance of watches. It describes the procedure for checking the water-resistance of a watch during a test run. The standard specifies the requirements for water pressure, or air, at which the watch must maintain its tightness and performance. However, the standard states that it can be carried out selectively. This means that not all watches produced according to this standard undergo mandatory water resistance testing - the manufacturer can selectively check individual items. This standard is used for watches not specifically designed for diving or swimming, but only for watches for daily use with possible short-term immersion in water.

Testing a watch against this water resistance standard consists of the following steps:

Immerse the watch in water to a depth of 10 cm for one hour.
Immersion of the watch in water to a depth of 10 cm with a water pressure of 5 N (Newtons) perpendicular to the buttons or to the crown for 10 minutes.
Immersion of the watch in water to a depth of 10 cm with temperature changes between 40°C, 20°C and again 40°C. At each temperature, the clock is within five minutes, the transition between temperatures is no more than five minutes.
Immersion of watches in water in a pressure chamber and exposure to their nominal pressure for which they are designed for 1 hour. Do not allow condensation inside the watch and water penetration into the case.
Checking watches with an excess of nominal pressure by 2 atm.

Well, additional checks that are not directly related to the water resistance of the watch:

The watch must not exhibit a flow rate exceeding 50 µg/min.
No strap test required
No corrosion test required
No negative pressure test required
Magnetic field and shock resistance test not required

ISO 6425 standard - diving and diving watches

This standard was developed and adopted in 1996 and is designed specifically for watches that require increased water resistance, such as watches for diving, spearfishing and other types of underwater work.

All watches produced under the ISO 6425 standard are subject to a mandatory water resistance test. That is, unlike the ISO 2281 standard, where only individual watches are tested for water resistance, in the ISO 6425 standard, absolutely all watches are tested at the factory before they are sold.

Moreover, the check is also performed with an excess of the calculated indicators by 25%. That is, watches designed for diving up to 100 meters will be tested at a pressure as at a depth of 125 meters.

According to the ISO 6425 standard, all watches must pass the following water resistance tests:
Prolonged stay under water. The watch is immersed in water to a depth of 30 cm for 50 hours. The water temperature can vary from 18°C to 25°C. All mechanisms must continue to function, no condensation should appear inside the watch.
Check for condensation in the watch. The watch heats up to 40°C - 45°C. After that, cold water is poured onto the watch glass for 1 minute. Watches that have condensation on the glass on the inside of the glass must be destroyed.
Resistance of crowns and buttons to increased water pressure. The watch is placed in water and pressurized in water 25% above its rated water resistance. Within 10 minutes in such conditions, the watch should maintain its tightness.
Prolonged exposure to water under pressure exceeding the calculated pressure by 25%, for two hours. The clock must continue to work, maintain tightness. There must be no condensation on the glass.

Immersion in water to a depth of 30 cm with a change in water temperature from 40°C to 5°C and again 40°C. The transition time from one dive to another should not exceed 1 minute.

A 25% overpressure provides a safety margin to prevent wetting during dynamic increases in pressure or changes in water density, for example sea water is 2 to 5% denser than fresh water.

Watches that have passed ISO 6425 testing are marked with the inscription DIVER "S WATCH L M. The letter L indicates the diving depth in meters guaranteed by the manufacturer.

Water Resistant watch table

Watch water resistance (Water Resistant)	Purpose	Restrictions
Water Resistant 3ATM or 30m	for everyday use. Withstands light rain and splashes	not suitable for showering, swimming, diving.
Water Resistant 5ATM or 50m	Withstand short-term immersion in water.	swimming is not recommended.
Water Resistant 10ATM or 100m	Water sports	do not use for diving and snorkeling
Water Resistant 20ATM or 200m	Professional water sports. Scuba diving.	duration of stay under water no more than 2 hours
Diver's 100m	ISO 6425 minimum requirement for scuba diving	This marking is worn by obsolete watches. Not suitable for long dives.
Diver's 200m or 300m	Suitable for scuba diving	Typical markings for modern diving watches.
Diver's 300+m for mixed gas diving.	Suitable for long-term scuba diving with mixed gas in scuba gear.	They are additionally marked DIVER'S WATCH L M or DIVER'S L M

IP water resistance standard

The IP standard adopted for various electronic devices, including smart smart watches, regulates two indicators: protection against dust ingress and protection against liquid ingress. The marking according to this standard is IPXX, where instead of "X" there are numbers indicating the degree of protection against dust and water ingress into the case. The numbers may be followed by one or two characters that carry auxiliary information. For example, a sports watch with an IP68 rating is a dust-proof device that can withstand long-term immersion in pressurized water.

First digit in the code IPXX indicates the level of protection against ingress of dust. Sports GPS trackers and smartwatches tend to use the most high levels dust protection:

5 dust-proof, some dust may enter the case, but this does not interfere with the operation of the device.
6 Dust-proof, dust does not get inside the device.

The second digit in the IPXX code indicates the level of water protection. Changes from 0 to 9 - the higher the number, the better the water resistance:

0 No protection
1 Vertically dripping water must not interfere with the operation of the device.
2 Vertically dripping water must not interfere with the operation of the device if it is tilted up to 15° from the working position.
3 Rain protection. Water flows vertically or at an angle up to 60°.
4 Protected against splashes falling in any direction.
5 Protected against water jets from any direction.
6 Protection against sea waves or strong water currents. Water entering the housing must not impair the operation of the device.
7 Short-term immersion to a depth of 1 m During short-term immersion, water does not enter in quantities that impair the operation of the device. Permanent work in immersed mode is not expected.
8 Long-term immersion to a depth of more than 1 m Completely waterproof. The device can work in immersed mode.
9 Long-term pressure immersion. Completely waterproof under pressure. The device can work in immersed mode with high pressure water.

Common watch water resistance designations

Watches not waterproof

This is a watch that is not designed to be used in water. Try not to keep them in damp places and keep them away from accidental water or splashes, steam, etc.

Please note that non-water resistant watches usually do not have any special markings on the dial or case back.

Normal water resistance - up to 30 m -3 ATM - 3 bar - 3 bar

On such hours there is an inscription "WATER RESISTANT" ("water-resistant"). This means that the watch is able to withstand the static pressure of a 30-meter water column (3 atmospheres), but does not mean that they can dive to a depth of 30 m. The meaning of this inscription is that the watch will not be damaged by drops when washing, rainy season etc. . The design of these watches allows them to be used in Everyday life- for example, when washing your face or in the rain, but you should not swim, take a bath or wash your car in such a watch.

Normal water resistance - up to 50 m- 5 ATM - 5 bar - 5 bar

On such watches there is an inscription "WATER RESISTANT 50M" or "50M" (or "5 bar"). This means that the watch can withstand the static pressure of a 50-meter water column (5 atmospheres), but does not mean that it can dive to a depth of 50 m. Such water resistance allows you to work with water in the watch. This watch cannot be used for diving, diving, windsurfing, etc.

Water resistant up to 100 m- 10 ATM - 10 bar - 10 bar

The watch is labeled "WATER RESISTANT 100M" or "100M" (or 10 bar). This also means that the watch can withstand the static pressure of a 100-meter water column, but note that you cannot dive to a depth of 100 meters in it. In practice, this water resistance allows the watch to be exposed to water or even submerged in water, but does not allow the watch to withstand the pressure of water when swimming in a pool or sea, where waves can hit the watch.

Water resistant up to 200 m- 20 ATM - 20 bar - 20 bar

Watches with such water resistance are called "diver" ("diver's watches"). You can safely swim in the sea or in the pool while wearing this watch, but you need to be careful when taking a pressure shower or diving into the water. In addition, it is best to avoid bathing in hot water, as hot water can damage the lubricating oil inside the watch.

Conversion table for pressure units. Pa; MPa; bar; atm; mmHg.; mm w.st.; m w.st., kg / cm 2; psf; psi inches Hg; in.st.

Note, there are 2 tables and a list. Here's another useful link:

Conversion table for pressure units. Pa; MPa; bar; atm; mmHg.; mm w.st.; m w.st., kg / cm 2; psf; psi inches Hg; in.st.

	In units:
	Pa (N / m 2)	MPa	bar	atmosphere	mmHg Art.	mm w.st.	m w.st.	kgf / cm 2
	Should be multiplied by:
Pa (N / m 2)	1	1*10 -6	10 -5	9.87*10 -6	0.0075	0.1	10 -4	1.02*10 -5
MPa	1*10 6	1	10	9.87	7.5*10 3	10 5	10 2	10.2
bar	10 5	10 -1	1	0.987	750	1.0197*10 4	10.197	1.0197
atm	1.01*10 5	1.01* 10 -1	1.013	1	759.9	10332	10.332	1.03
mmHg Art.	133.3	133.3*10 -6	1.33*10 -3	1.32*10 -3	1	13.3	0.013	1.36*10 -3
mm w.st.	10	10 -5	0.000097	9.87*10 -5	0.075	1	0.001	1.02*10 -4
m w.st.	10 4	10 -2	0.097	9.87*10 -2	75	1000	1	0.102
kgf / cm 2	9.8*10 4	9.8*10 -2	0.98	0.97	735	10000	10	1
	47.8	4.78*10 -5	4.78*10 -4	4.72*10 -4	0.36	4.78	4.78 10 -3	4.88*10 -4
	6894.76	6.89476*10 -3	0.069	0.068	51.7	689.7	0.690	0.07
Inches Hg / inches Hg	3377	3.377*10 -3	0.0338	0.033	25.33	337.7	0.337	0.034
inches w.st. / inchesH2O	248.8	2.488*10 -2	2.49*10 -3	2.46*10 -3	1.87	24.88	0.0249	0.0025

Conversion table for pressure units. Pa; MPa; bar; atm; mmHg.; mm w.st.; m w.st., kg / cm 2; psf; psi inches Hg; in.st.

To convert pressure in units:	In units:
	pounds per sq. pound square feet (psf)	pounds per sq. inch / pound square inches (psi)	Inches Hg / inches Hg	inches w.st. / inchesH2O
	Should be multiplied by:
Pa (N / m 2)	0.021	1.450326*10 -4	2.96*10 -4	4.02*10 -3
MPa	2.1*10 4	1.450326*10 2	2.96*10 2	4.02*10 3
bar	2090	14.50	29.61	402
atm	2117.5	14.69	29.92	407
mmHg Art.	2.79	0.019	0.039	0.54
mm w.st.	0.209	1.45*10 -3	2.96*10 -3	0.04
m w.st.	209	1.45	2.96	40.2
kgf / cm 2	2049	14.21	29.03	394
pounds per sq. pound square feet (psf)	1	0.0069	0.014	0.19
pounds per sq. inch / pound square inches (psi)	144	1	2.04	27.7
Inches Hg / inches Hg	70.6	0.49	1	13.57
inches w.st. / inchesH2O	5.2	0.036	0.074	1

Detailed list of pressure units:

1 Pa (N / m 2) \u003d 0.0000102 Atmosphere "metric" / Atmosphere (metric)
1 Pa (N/m 2) = 0.0000099 Atmosphere (standard) = Standard atmosphere
1 Pa (N / m 2) \u003d 0.00001 Bar / Bar
1 Pa (N / m 2) \u003d 10 Barad / Barad
1 Pa (N / m 2) \u003d 0.0007501 Centimeters of mercury. Art. (0°C)
1 Pa (N / m 2) \u003d 0.0101974 Centimeters in. Art. (4°C)
1 Pa (N / m 2) \u003d 10 dyne / square centimeter
1 Pa (N/m 2) = 0.0003346 Foot of water / Foot of water (4 °C)
1 Pa (N / m 2) \u003d 10 -9 Gigapascals
1 Pa (N / m 2) \u003d 0.01
1 Pa (N / m 2) \u003d 0.0002953 Dumov Hg / Inch of mercury (0 °C)
1 Pa (N / m 2) \u003d 0.0002961 Inches of mercury. Art. / Inch of mercury (15.56 °C)
1 Pa (N / m 2) \u003d 0.0040186 Dumov w.st. / Inch of water (15.56 °C)
1 Pa (N / m 2) \u003d 0.0040147 Dumov w.st. / Inch of water (4 °C)
1 Pa (N / m 2) \u003d 0.0000102 kgf / cm 2 / Kilogram force / centimetre 2
1 Pa (N / m 2) \u003d 0.0010197 kgf / dm 2 / Kilogram force / decimetre 2
1 Pa (N / m 2) \u003d 0.101972 kgf / m 2 / Kilogram force / meter 2
1 Pa (N / m 2) \u003d 10 -7 kgf / mm 2 / Kilogram force / millimeter 2
1 Pa (N / m 2) \u003d 10 -3 kPa
1 Pa (N / m 2) \u003d 10 -7 Kilopound force / square inch / Kilopound force / square inch
1 Pa (N / m 2) \u003d 10 -6 MPa
1 Pa (N / m 2) \u003d 0.000102 Meters w.st. / Meter of water (4 °C)
1 Pa (N / m 2) \u003d 10 Microbar / Microbar (barye, barrie)
1 Pa (N / m 2) \u003d 7.50062 Microns of mercury / Micron of mercury (millitorr)
1 Pa (N / m 2) \u003d 0.01 Milibar / Millibar
1 Pa (N/m 2) = 0.0075006 Millimeter of mercury (0 °C)
1 Pa (N / m 2) \u003d 0.10207 Millimeters of w.st. / Millimeter of water (15.56 °C)
1 Pa (N / m 2) \u003d 0.10197 Millimeters w.st. / Millimeter of water (4 °C)
1 Pa (N / m 2) \u003d 7.5006 Millitorr / Millitorr
1 Pa (N/m2) = 1N/m2 / Newton/square meter
1 Pa (N / m 2) \u003d 32.1507 Daily ounces / sq. inch / Ounce force (avdp)/square inch
1 Pa (N / m 2) \u003d 0.0208854 Pounds of force per sq. foot / Pound force/square foot
1 Pa (N / m 2) \u003d 0.000145 Pounds of force per sq. inch / Pound force/square inch
1 Pa (N / m 2) \u003d 0.671969 Poundals per sq. foot / Poundal/square foot
1 Pa (N / m 2) \u003d 0.0046665 Poundals per sq. inch / Poundal/square inch
1 Pa (N / m 2) \u003d 0.0000093 Long tons per sq. foot / Ton (long)/foot 2
1 Pa (N / m 2) \u003d 10 -7 Long tons per sq. inch / Ton(long)/inch 2
1 Pa (N / m 2) \u003d 0.0000104 Short tons per sq. foot / Ton (short)/foot 2
1 Pa (N / m 2) \u003d 10 -7 Tons per sq. inch / Ton/inch 2
1 Pa (N / m 2) \u003d 0.0075006 Torr / Torr

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1 megapascal [MPa] = 10 bar [bar]

Initial value

Converted value

pascal exapascal petapascal terapascal gigapascal megapascal kilopascal hectopascal decapascal decipascal centipascal millipascal micropascal nanopascal picopascal femtopascal attopascal newton per sq. newton meter per sq. centimeter newton per sq. millimeter kilonewton per sq. meter bar millibar microbar dynes per sq. centimeter kilogram-force per sq. meter kilogram-force per sq. centimeter kilogram-force per sq. millimeter gram-force per sq. centimeter ton-force (short) per sq. ft ton-force (short) per sq. inch ton-force (L) per sq. ft ton-force (L) per sq. inch kilopound-force per sq. inch kilopound-force per sq. inch lbf/sq. ft lbf/sq. inch psi poundal per sq. ft torr centimeter of mercury (0°C) millimeter of mercury (0°C) inch of mercury (32°F) inch of mercury (60°F) centimeter of water column (4°C) mm w.c. column (4°C) inch w.c. head of water (4°C) foot of water (4°C) inch of water (60°F) foot of water (60°F) technical atmosphere physical atmosphere decibar of wall per square meter barium pieza (barium) Planck pressure meter of sea water foot of sea water (at 15°C) meter of water column (4°C)

Thermal efficiency and fuel economy

More about pressure

General information

In physics, pressure is defined as the force acting per unit area of a surface. If two identical forces act on one large and one smaller surface, then the pressure on the smaller surface will be greater. Agree, it is much worse if the owner of studs steps on your foot than the mistress of sneakers. For example, if you press the blade of a sharp knife on a tomato or carrot, the vegetable will be cut in half. The surface area of the blade in contact with the vegetable is small, so the pressure is high enough to cut through the vegetable. If you press with the same force on a tomato or carrot with a blunt knife, then most likely the vegetable will not be cut, since the surface area of \u200b\u200bthe knife is now larger, which means the pressure is less.

In the SI system, pressure is measured in pascals, or newtons per square meter.

Relative pressure

Sometimes pressure is measured as the difference between absolute and atmospheric pressure. This pressure is called relative or gauge pressure and it is measured, for example, when checking the pressure in car tires. Measuring instruments often, although not always, indicate relative pressure.

Atmosphere pressure

Atmospheric pressure is the air pressure in this place. It usually refers to the pressure of a column of air per unit surface area. A change in atmospheric pressure affects the weather and air temperature. People and animals suffer from severe pressure drops. Low blood pressure causes problems in people and animals of varying severity, from mental and physical discomfort to fatal diseases. For this reason, aircraft cabins are maintained at a pressure above atmospheric pressure at a given altitude because the atmospheric pressure at cruising altitude is too low.

Atmospheric pressure decreases with altitude. People and animals living high in the mountains, such as the Himalayas, adapt to such conditions. Travelers, on the other hand, should take the necessary precautions so as not to get sick due to the fact that the body is not accustomed to such low pressure. Climbers, for example, can get altitude sickness associated with a lack of oxygen in the blood and oxygen starvation of the body. This disease is especially dangerous if you stay in the mountains for a long time. Exacerbation of altitude sickness leads to serious complications, such as acute mountain sickness, high-altitude pulmonary edema, high-altitude cerebral edema, and the most acute form of mountain sickness. The danger of altitude and mountain sickness begins at an altitude of 2400 meters above sea level. To avoid altitude sickness, doctors advise not using depressants such as alcohol and sleeping pills, drinking plenty of fluids, and ascending to altitude gradually, for example by walking rather than by transport. It's also good to eat plenty of carbohydrates and get plenty of rest, especially if the climb is fast. These measures will allow the body to get used to the lack of oxygen caused by low atmospheric pressure. If you follow these recommendations, then the body will be able to produce more red blood cells to transport oxygen to the brain and internal organs. To do this, the body will increase the pulse and respiratory rate.

First aid in such cases is provided immediately. It is important to move the patient to a lower altitude where atmospheric pressure is higher, preferably lower than 2400 meters above sea level. Drugs and portable hyperbaric chambers are also used. These are lightweight, portable chambers that can be pressurized with a foot pump. A patient with mountain sickness is placed in a chamber in which pressure is maintained corresponding to a lower altitude above sea level. This camera is used only for providing the first medical care, after which the patient must be lowered.

Some athletes use low blood pressure to improve circulation. Usually, for this, training takes place under normal conditions, and these athletes sleep in a low-pressure environment. Thus, their body gets used to high altitude conditions and begins to produce more red blood cells, which in turn increases the amount of oxygen in the blood, and allows them to achieve better results in sports. For this, special tents are produced, the pressure in which is regulated. Some athletes even change the pressure throughout the bedroom, but sealing the bedroom is an expensive process.

suits

Pilots and cosmonauts have to work in a low pressure environment, so they work in spacesuits that allow them to compensate for low pressure. environment. Space suits completely protect a person from the environment. They are used in space. Altitude compensation suits are used by pilots on high altitudes- they help the pilot breathe and counteract low barometric pressure.

hydrostatic pressure

Hydrostatic pressure is the pressure of a fluid caused by gravity. This phenomenon plays a huge role not only in engineering and physics, but also in medicine. For example, blood pressure is the hydrostatic pressure of blood against the walls of blood vessels. Blood pressure is the pressure in the arteries. It is represented by two values: systolic, or the highest pressure, and diastolic, or the lowest pressure during the heartbeat. Devices for measuring blood pressure are called sphygmomanometers or tonometers. The unit of blood pressure is millimeters of mercury.

The Pythagorean mug is an entertaining vessel that uses hydrostatic pressure, specifically the siphon principle. According to legend, Pythagoras invented this cup to control the amount of wine he drank. According to other sources, this cup was supposed to control the amount of water drunk during a drought. Inside the mug is a curved U-shaped tube hidden under the dome. One end of the tube is longer, and ends with a hole in the stem of the mug. The other, shorter end is connected by a hole to the inner bottom of the mug so that the water in the cup fills the tube. The principle of operation of the mug is similar to the operation of a modern toilet tank. If the liquid level rises above the level of the tube, the liquid overflows into the other half of the tube and flows out due to the hydrostatic pressure. If the level, on the contrary, is lower, then the mug can be safely used.

pressure in geology

Pressure is an important concept in geology. Without pressure, it is impossible to form gemstones, both natural and artificial. High pressure and high temperature are also necessary for the formation of oil from the remains of plants and animals. Unlike gems, which are mostly found in rocks, oil forms at the bottom of rivers, lakes, or seas. Over time, more and more sand accumulates over these remnants. The weight of water and sand presses on the remains of animals and plant organisms. Over time, this organic material sinks deeper and deeper into the earth, reaching several kilometers below the earth's surface. The temperature increases by 25°C for every kilometer below the earth's surface, so at a depth of several kilometers the temperature reaches 50-80°C. Depending on the temperature and temperature difference in the formation medium, natural gas may be formed instead of oil.

natural gems

Gem formation is not always the same, but pressure is one of the main constituent parts this process. For example, diamonds are formed in the Earth's mantle, under conditions of high pressure and high temperature. During volcanic eruptions, diamonds move to the upper layers of the Earth's surface due to magma. Some diamonds come to Earth from meteorites, and scientists believe they were formed on Earth-like planets.

Synthetic gems

The production of synthetic gemstones began in the 1950s and has been gaining popularity in recent years. Some buyers prefer natural gemstones, but artificial gemstones are becoming more and more popular due to the low price and lack of problems associated with natural gemstone mining. Thus, many buyers choose synthetic gemstones because their extraction and sale is not associated with the violation of human rights, child labor and the financing of wars and armed conflicts.

One of the technologies for growing diamonds in the laboratory is the method of growing crystals at high pressure and high temperature. In special devices, carbon is heated to 1000 ° C and subjected to a pressure of about 5 gigapascals. Typically, a small diamond is used as the seed crystal, and graphite is used for the carbon base. A new diamond grows from it. This is the most common method of growing diamonds, especially as gemstones, due to its low cost. The properties of diamonds grown in this way are the same or better than those of natural stones. The quality of synthetic diamonds depends on the method of their cultivation. Compared to natural diamonds, which are most often transparent, most artificial diamonds are colored.

Due to their hardness, diamonds are widely used in manufacturing. In addition, their high thermal conductivity, optical properties and resistance to alkalis and acids are highly valued. Cutting tools are often coated with diamond dust, which is also used in abrasives and materials. Most of the diamonds in production are of artificial origin due to the low price and because the demand for such diamonds exceeds the ability to mine them in nature.

Some companies offer services to create memorial diamonds from the ashes of the deceased. To do this, after cremation, the ashes are cleaned until carbon is obtained, and then a diamond is grown on its basis. Manufacturers advertise these diamonds as a memory of the departed, and their services are popular, especially in countries with a high percentage of wealthy citizens, such as the United States and Japan.

Crystal growth method at high pressure and high temperature

The high pressure, high temperature crystal growth method is mainly used to synthesize diamonds, but more recently, this method has been used to improve natural diamonds or change their color. Different presses are used to artificially grow diamonds. The most expensive to maintain and the most difficult of these is the cubic press. It is mainly used to enhance or change the color of natural diamonds. Diamonds grow in the press at a rate of approximately 0.5 carats per day.

Do you find it difficult to translate units of measurement from one language to another? Colleagues are ready to help you. Post a question to TCTerms and within a few minutes you will receive an answer.

At the bottom of the ocean, where the water pressure reaches 100 megapascals, deep-sea fish live. The organism of these living beings has been adapted to the extreme conditions of life since time immemorial. Does air act on land like water on the bottom of the expanses of the sea? How does it manifest itself, how can its impact be measured? How many atmospheres is 1 bar?

Mercury, water, wine...

The earth is surrounded by a layer of air, consisting of a mixture of gases. This air layer is called the atmosphere. Objects on Earth are subject to atmospheric influence.

E. Toricelli (1608 - 1647) was the first to come up with a method for measuring it.

3 years after the mercury barometer was made, the great B. Pascal designed a water barometer. The scientist repeated the experiment, replacing mercury with water. But this seemed to him not enough. He continued to experiment with oil, wine and ... who knows how many liquids leaked during the research!

There are many units of pressure measurement:

Pa - pascal (and its derivatives: MPa (megapascal), kPa (kilopascal)
atmosphere
millimeters of mercury
inches of mercury
millimeters of water column
inches of water
kilogram of force per cm 2 (kgf / cm 2)
meters of water column

Relationship between different units of measure

Using the table, you can compare different values \u200b\u200band find out how 1 bar will be measured in atmospheres, or find out how many kPa are 1 kgf / cm 2.

Instantly convert pressure units and express atmospheres in mmHg. Art. you can follow the link.

The list shows the most common transitions:

bar = 100 kPa
bar = 1 tech. atm (at)
bar = 750 mmHg pillar
bar = 0.1 MPa
bar \u003d 1.0197 kgf / cm 2

A bar is one of the quantities by which pressure can be measured. It has nothing to do with a barrel, that is, a unit of oil volume. Unless only the first three sonorous letters unite them.

Let's compare the values:

1 pa = 0.00001 bar
kilopascal = 0.01 bar
pascal = 9.869210 -6 atm
kpa = 9.869210 -3 atm
megapascal = 9.8692 atm
kilogram force / cm 2 \u003d 0.98 bar
atm = 101325 Pa

Explanation: at - technical atmosphere, atm - physical. The physical atmosphere is characterized by exposure to gas at 760 mmHg. and a temperature of 0 0 C. The term "technical atmosphere" is appropriate for normal specifications, characterized by a pressure of 735.6 mm Hg. at t=15 0 C.

If you need to translate bars into atmospheres, feel free to click here - without any problems, everything is very clear.

Let's summarize

A few words need to be said about the "foreigners" in our table - the "psi" and "psf" measurements.

Pounds scuare feet (psf) are pounds per square foot; they, as well as "psi" (pounds scuare inches) - pounds per square inch, can measure pressure when described in English sources. So, for example, one kgf / cm2 is approximately equal to 14 psi.

And this video illustrates with a specific example how to convert one unit to another within the SI system:

Having delved into the topic, you will soon learn how to translate not only MPa into kilogram s / cm 2, but also to perform reverse translation, i.e. convert kilogram s/cm 2 to MPa.

Pascal (Pa, Pa)

Pascal (Pa, Pa) - a unit of pressure in international system units of measurement (SI system). The unit is named after the French physicist and mathematician Blaise Pascal.

Pascal is equal to the pressure caused by a force equal to one newton (N), evenly distributed over a surface normal to it with an area of \u200b\u200bone square meter:

1 pascal (Pa) ≡ 1 N/m²

Multiple units are formed using standard SI prefixes:

1 MPa (1 megapascal) = 1000 kPa (1000 kilopascals)

Atmosphere (physical, technical)

Atmosphere is a non-systemic unit of pressure, approximately equal to atmospheric pressure on the Earth's surface at the level of the World Ocean.

There are two approximately equal units with the following name:

Physical, normal or standard atmosphere (atm, atm) - exactly equal to 101,325 Pa or 760 millimeters of mercury.

Technical atmosphere (at, at, kgf/cm²)- equal to the pressure produced by a force of 1 kgf, directed perpendicularly and evenly distributed over a flat surface of 1 cm² (98,066.5 Pa).

1 technical atmosphere = 1 kgf / cm² (“kilogram-force per square centimeter”). // 1 kgf = 9.80665 newtons (exactly) ≈ 10 N; 1 N ≈ 0.10197162 kgf ≈ 0.1 kgf

On the English language kilogram-force is denoted as kgf (kilogram-force) or kp (kilopond) - kilopond, from the Latin pondus, meaning weight.

Notice the difference: not pound (in English "pound"), but pondus.

In practice, they approximately accept: 1 MPa = 10 atmospheres, 1 atmosphere = 0.1 MPa.

Bar

Bar (from the Greek βάρος - gravity) is a non-systemic unit of pressure, approximately equal to one atmosphere. One bar is equal to 105 N/m² (or 0.1 MPa).

Relations between units of pressure

1 MPa \u003d 10 bar \u003d 10.19716 kgf / cm² \u003d 145.0377 PSI \u003d 9.869233 (phys. atm.) \u003d 7500.7 mm Hg

1 bar \u003d 0.1 MPa \u003d 1.019716 kgf / cm² \u003d 14.50377 PSI \u003d 0.986923 (phys. atm.) \u003d 750.07 mm Hg

1 atm (technical atmosphere) = 1 kgf/cm² (1 kp/cm², 1 kilopond/cm²) = 0.0980665 MPa = 0.98066 bar = 14.223

1 atm (physical atmosphere) \u003d 760 mm Hg \u003d 0.101325 MPa \u003d 1.01325 bar \u003d 1.0333 kgf / cm²

1 mm Hg = 133.32 Pa = 13.5951 mm water column

Volumes of liquids and gases / Volume

1 gl (US) = 3.785 liters

1 gl (Imperial) = 4.546 l

1 cu ft = 28.32 l = 0.0283 cubic meters

1 cu in = 16.387 cc

Flow rate / Flow

1 l/s = 60 l/min = 3.6 m3/h = 2.119 cfm

1 l/min = 0.0167 l/s = 0.06 m3/h = 0.0353 cfm

1 m3/hour = 16.667 l/min = 0.2777 l/s = 0.5885 cfm

1 cfm (cubic foot per minute) = 0.47195 l/s = 28.31685 l/min = 1.699011 cfm/hour

Flow capacity / Valve flow characteristics

Flow coefficient (factor) Kv

Flow Factor - Kv

The main parameter of the shut-off and regulating body is the flow coefficient Kv. The flow coefficient Kv indicates the volume of water in cubic meters per hour (cbm/h) at a temperature of 5-30ºC, passing through the valve with a head loss of 1 bar.

Flow coefficient Cv

Flow Coefficient - Cv

In inch countries, the Cv factor is used. It shows how much water in gallon/minute (gpm) at 60ºF passes through a valve for a 1 psi pressure drop across the valve.

Kinematic viscosity / Viscosity

1 ft = 12 in = 0.3048 m

1 in = 0.0833 ft = 0.0254 m = 25.4 mm

1 m = 3.28083 ft = 39.3699 in

Force units

1 N = 0.102 kgf = 0.2248 lbf

1 lbf = 0.454 kgf = 4.448 N

1 kgf \u003d 9.80665 N (exactly) ≈ 10 N; 1 N ≈ 0.10197162 kgf ≈ 0.1 kgf

In English, kilogram-force is denoted as kgf (kilogram-force) or kp (kilopond) - kilopond, from the Latin pondusmeaning weight. Please note: not pound (in English "pound"), but pondus.

Mass units / Mass

1 lb = 16 oz = 453.59 g

Moment of force (torque)/Torque

1 kgf. m = 9.81 N. m = 7.233 lbf ft (lbf * ft)

Power units / power

Some quantities:

Watt (W, W, 1 W = 1 J / s), horsepower (hp - Russian, hp or HP - English, CV - French, PS - German)

Unit Ratio:

In Russia and some other countries, 1 hp. (1 PS, 1 CV) = 75 kgf * m / s = 735.4988 W

US, UK and other countries 1 hp = 550 ft.lb/s = 745.6999 W

Temperature

Temperature Fahrenheit: