Chapter 256: What about sodium carbonate?

Shangwen was lying on the mat, really couldn't sleep, no matter what the various postures were, he just couldn't sleep.

Not being able to sleep is a very uncomfortable thing. Shang Wen got up to drink. Want to keep sleeping. But forget it. Stay up all night with your energy. this era. There is no coffee, the only refreshing thing is tea.

But drink water. The tea is bitter.

Shangwen sat down and quietly sorted out his thoughts. First of all, the place to sit. this era. Everyone is sitting on a mat, and even the chairs and stools have not yet appeared. Sitting is actually kneeling. This is really a big test for people's willpower. Shangwen struggled to discuss the affairs of the court every time. Especially when it comes to huge war plans, Shangwen always stands up and speaks first, because sitting is kneeling. I can't stand my knees. However, Shang Wen believes that such a long-term kneeling. I don’t know if there are any diseases like arthritis.

Thinking of this, Shang Wen realized that his previous inventions were too much concentrated in heavy industry, or they were biased towards highly technical things, and seriously ignored some of the lives around him. For example, these furniture around. Shang Wen is not an invention at all. If it weren't for Yingyu's accidental proposal today. Shangwen has almost forgotten that life can be better.

Too much attention to one thing often overlooks many things.

Thought of this. Shangwen's interest suddenly came. Furniture, sofas, chairs, stools. Modern style coffee table, office desk. It would be best if you could add a boss chair. Shang Wen took out a wad of paper and began to draw graphics. There are now more modern wood processing machines. These things are not difficult to process. sofa. There is no sponge yet. Can only make old-fashioned spring sofa.

A chair with springs or thick foam, etc., with armrests on both sides. This is the basic overview of the sofa. With the sofa, it can be used in other places, not just at home. There are also carriages for outings. It’s okay on a carriage. Thanks to the four-wheeled carriage. The load capacity has not only doubled, but more importantly, manned and loaded. All have been greatly improved. If you add a sofa, the passengers may be more comfortable. Add transparent glass. It has the style of a modern car.

In addition, there are many things, chairs. Boss chair, and desk. These need to be processed.

Shang Wen spent an hour sketching the drawings, and then took a lot of drawings to the airship workshop. There is the most concentrated place for carpenters.

The drawings are given to the carpenters, and the rest is their own business. And Shang Wen still has a lot of time.

Shang Wen turned his attention to other aspects. Since you are in the airship workshop, you have to design something related to the airship.

The inability of airships to measure altitude has always been an important factor that bothers flying. Especially speed and altitude. Speed ​​requires PTS. Airspeed tube is also called Pitot tube, total pressure tube, total-static pressure tube. It is a device that senses the total pressure (also called total pressure) and static pressure of the airflow, and transmits the measured pressure data to the air data computer and flight instruments. This kind of aeronautical device is mainly used to measure flight speed, but also has many other functions. The current technology is still unable to develop such an advanced PTS.

It is composed of two concentric circular tubes, the inner tube is a total pressure tube, and the outer tube is a static pressure tube. The principle of the airspeed tube to measure the speed of an aircraft is this Cessna airspeed tube

When the plane flies forward, the airflow rushes into the airspeed tube, and the sensor at the end of the tube will feel the impact force of the airflow, that is, dynamic pressure. The faster the plane flies, the greater the dynamic pressure. If you compare the static pressure and the dynamic pressure when the air is at rest, you can know how fast the air is rushing in, that is, how fast the airplane flies. The tool for comparing the two pressures is a hollow circular box with corrugated surfaces made of two thin metal sheets, called a bellows. The box is sealed, but there is a tube connected to the PTS. If the airplane is fast, the dynamic pressure will increase, the pressure in the bellows will increase, and the bellows will bulge. A device composed of small levers and gears can measure the deformation of the bellows and display it with a pointer. This is the simplest airplane airspeed indicator.

The speed measured by the airspeed tube is not the actual speed of the aircraft relative to the ground, but only the speed relative to the atmosphere, so it is called airspeed. If there is wind, the speed of the aircraft relative to the ground (called ground speed) should also be added to the wind speed (flying downwind) or minus wind speed (flying upwind). In addition, the principle of PTT velocity measurement uses dynamic pressure, which is related to atmospheric density. For the same relative air velocity, if the atmospheric density is low, the dynamic pressure will be small, and the deformation of the bellows in the airspeed indicator will result in the same airspeed. At high altitude, the indicated value is higher than at low altitude. speed\". Modern airspeed indicators have two pointers, one is thinner and the other is wider. The wide pointer indicates \"gauge speed\", and the thin one indicates the airspeed equivalent to ground atmospheric pressure after various corrections, which is called \"real speed\".

In order to prevent the small holes in the front end of the PTS from freezing and blocking during flight, the PTS on the aircraft generally have an electric heating device.

The bellows becomes the key. The other is an instrument that measures and indicates the vertical distance of the aircraft from a selected horizontal datum, called an altimeter.

The altimeter installed on the cockpit dashboard of the aircraft usually includes a barometric altimeter and a radio altimeter. The barometric altimeter is actually a barometer, which indirectly measures the flight altitude by measuring the atmospheric pressure at the altitude of the aircraft. The radio altimeter is actually a range-finding radar that uses the ground (water surface) as the detection target, and the height it indicates is the true height.

Ultra-modern altimeters cannot be made either. But there is another thing. That is the barometer.

It is an instrument for measuring atmospheric pressure based on Torricelli's experimental principles. The types of barometers include mercury barometers and aneroid barometers. Its purpose is: it can predict the change of the weather. When the air pressure is high, the weather is clear; when the air pressure drops, there will be wind and rain. Measurable height. Every 12 meters higher, the mercury column is lowered by about 1 mm, so the height of the mountain and the height of the aircraft flying in the air can be measured.

It can also predict the change of the weather. When the air pressure is high, the weather is clear; when the air pressure drops, there will be wind and rain.

A device that uses a Torri tube to measure atmospheric pressure. The mercury tank at the bottom of the glass tube is replaced by a bladder, and is attached with an ivory needle that can be adjusted to indicate the mercury surface. It is called a "Forting-type mercury barometer". A metal sheath is added to the outside of the glass tube. A scale for measuring the height of the mercury column is engraved on the tube. An ivory needle is installed on the top of the mercury tank, the needle point is just at the zero point of the scale outside the tube, and a leather bag is used as the bottom of the mercury tank. When in use, lightly turn the spiral under the leather bag so that the mercury surface in the groove is exactly in contact with the ivory needle tip (that is, it is on a horizontal line with the zero point of the scale), and then the height of the mercury column is read from the scale on the tube. This altitude indication is the size of the local atmospheric pressure at that time. In addition, there are barometers for observation stations that do not need to be adjusted for ivory needles, barometers for measuring low pressure in mountains, and barometers for navigation that are not sensitive to the shaking of ships.

The height of the mercury column supported by different atmospheric pressures is different. According to P=p (mercury density) hg, the calculated pressure is equal to the atmospheric pressure. Of course, this calculated and manufactured barometer is calculated and marked on the barometer, which is aligned with the mercury surface. The scale of, you can know the size of the air pressure!

However, the problem ultimately points to a problem. Processing of glass tubes. And a lot of raw materials.

A very complicated logical reasoning. The barometer needs glass. Glass needs sodium carbonate. What about sodium carbonate?