CN204462415U - A kind of device utilizing hydrostatic pressure to measure acceleration of gravity - Google Patents

Abstract

The utility model discloses a device for measuring gravitational acceleration by hydrostatic pressure, which comprises a container, a pipe and a device for measuring gas pressure. Liquid is contained in the container, one end of the pipe is closed and the other end is open, and air is contained in the container. The opening of the tube is inserted vertically downward into the liquid contained in the container, so that the height difference between the liquid level in the container and the liquid level in the tube is h; the device for measuring gas pressure is used for The pressure p of the air in the tube is measured, from which the gravitational acceleration can be calculated according to the following formula: pp ₀ =ρgh, where p ₀ is the atmospheric pressure, g is the gravitational acceleration, and ρ is the density of the liquid. The device for measuring the gravitational acceleration of the utility model has the advantages of simple structure, convenient operation, high measurement precision and vivid measurement demonstration.

Description

A device for measuring the acceleration of gravity by using hydrostatic pressure

technical field

The utility model relates to the technical field of gravitational acceleration measurement, in particular to a device for measuring gravitational acceleration by hydrostatic pressure.

Background technique

Test gravity acceleration in the prior art and generally use simple pendulum test, device comprises thin wire, metal ball with hole, iron clip, iron frame platform and stopwatch; , pass the thin wire through the hole on the metal ball to make a pendulum, fix the pendulum on the iron stand through the iron clip, place the iron stand on the edge of the table so that the iron clip protrudes from the table, and let the pendulum hang down freely ; Use a vernier caliper to measure the diameter of the ball and record it as d; use a meter ruler to measure the distance from the suspension point of the metal ball to the upper end of the ball and record it as 1; offset the metal ball by 5 to 8 degrees from the vertical line in the vertical plane Swing freely, and use a stopwatch to record the time T that the metal ball completes 30 to 50 full vibrations; find the average time t=T/c used by the metal ball for each full vibration; where c is the metal ball within T time. The number of full vibrations made by the ball; the acceleration of gravity is obtained according to the formula g=4π ² L/t ² , where L=d/2+1.

When using the device in the prior art to test the acceleration of gravity, one person needs to watch the watch and one person records the number of times of the full vibration of the pendulum. It takes a lot of repeated operations to make a successful measurement, so it takes a relatively long time to measure the acceleration of gravity using the acceleration of gravity measuring device in the prior art.

Utility model content

(1) Technical problems to be solved

What the utility model aims to solve are the shortcomings of the existing device for measuring the acceleration of gravity, such as complicated operation, poor accuracy and long time consumption.

(2) Technical solution

The device for measuring the acceleration of gravity of the utility model measures the hydrostatic pressure, converts it into a voltage signal by the pressure sensor, and calculates the accurate acceleration of gravity.

(3) Beneficial effects

The device for measuring the acceleration of gravity of the utility model has the advantages of simple structure, convenient operation, high measurement precision, and vivid measurement demonstration.

Description of drawings

Fig. 1 is the structural representation of an embodiment of the device for measuring the acceleration of gravity of the present utility model;

Fig. 2 is the structural representation of another embodiment of the device for measuring the acceleration of gravity of the present utility model;

Fig. 3 is a chart of data measured by the device for measuring the acceleration of gravity of the present invention.

Detailed ways

In order to solve the above technical problems, the utility model proposes a new device for measuring the acceleration of gravity, which includes a container, a pipe, a pressure sensor and an air heat capacity ratio tester. The container contains liquid. One end of the tube is closed, and the other end is open, and air is contained therein. And, the opening of the tube is inserted vertically downward into the liquid contained in the container. The pressure sensor is fixed inside the closed end of the pipe, and the pressure sensor is connected to the air heat capacity ratio tester through the closed end of the pipe through a connecting line, and the air heat capacity ratio tester passes through the air heat capacity ratio tester. The pressure sensor measures a voltage converted from the pressure of the air in the tube.

In order to make the purpose, technical solutions and advantages of the utility model clearer, the utility model will be further described in detail below in combination with specific embodiments and with reference to the accompanying drawings.

Fig. 1 is a structural schematic diagram of an embodiment of the device for measuring the acceleration of gravity of the present invention. In this embodiment, a certain amount of water 6 is contained in a glass tank 1 . A glass tube 2 closed at one end is placed upside down in water, and a certain amount of air is contained in the glass tube 2 . Due to the pressure of the water, water will enter the glass tube, so that the liquid level in the glass tube 2 is kept at a certain height. A pressure sensor 3 is fixed inside the closed end of the glass tube 2 . The pressure sensor 3 is used to detect the pressure of the air in the glass tube 2 . Moreover, the pressure sensor 3 is connected to the air heat capacity ratio tester 5 located outside the glass cylinder 1 through an electrical connection wire 4 . The pressure in the glass tube measured by the pressure sensor 3 is transmitted to the air heat capacity ratio tester 5 through an electric signal. The air heat capacity ratio tester is used to convert the signal from the pressure sensor into the reading of the meter.

It can be seen from the above that the air heat capacity ratio tester 5 and the pressure sensor 3 are used to measure the voltage corresponding to the gas pressure in the glass tube. In this embodiment, the air heat capacity ratio tester 5 adopts FD-NCD-II type and diffused silicon pressure sensor.

The formula provided by the FD-NCD-II air heat capacity ratio tester instruction is as follows:

$\mathrm{<span\; class="notranslate">\; p</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; p</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; u</span>}}{\mathrm{<span\; class="notranslate">\; 2000</span>}}<span\; class="notranslate">\; \&times;</span>{\mathrm{<span\; class="notranslate">\; 10</span>}}^{\mathrm{<span\; class="notranslate">\; 5</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$

Wherein p (unit: Pa) is the air pressure in the glass tube 2, U (unit: mV) is the voltage value measured by the air heat capacity ratio tester (the pressure inside the glass tube is obtained by converting the pressure sensor).

According to the principle of pressure, if the standard atmospheric pressure is p ₀ (generally the conventional value can be used, if in order to improve the accuracy, the actual value can be measured in advance by a barometer, etc.), the height difference from the liquid level in the glass cylinder to the liquid level in the glass tube is h (the height difference can also be obtained by subtracting the depth h ₁ of the water entering the glass from the depth h ₂ of the glass tube inserted into the water), and the density of water is ρ. According to the principle of pressure, it can be obtained

pp ₀ =ρgh (2)

The acceleration of gravity can be calculated by formula (1) and formula (2)

$\mathrm{<span\; class="notranslate">\; g</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 50</span>}\mathrm{<span\; class="notranslate">\; u</span>}}{\mathrm{<span\; class="notranslate">\; \&rho;h</span>}}$

By changing the depth of the glass tube inserted into the water, multiple values of U and h can be obtained, and the slope of the U-h line is the value of the acceleration of gravity. Figure 3 shows the U-h line for this example.

In the present invention, the glass cylinder and the glass tube can also adopt other materials, but they are preferably transparent or translucent materials, so as to clearly show the height position of the liquid level. In addition, height scales can be set on the glass cylinder and glass tube for easy reading of the liquid level.

In another embodiment of the present invention, the acceleration of gravity measurement device can also include a height gauge 7, as shown in Figure 3, it can also be erected in the glass cylinder 1 and be fixed, thus, can read more clearly The height of the liquid level in the glass cylinder and glass tube. The height gauge can be of various known sizes, such as steel ruler, plastic ruler and the like.

The air heat capacity ratio tester 5 and the pressure sensor 3 in the embodiment can also be replaced by other devices for measuring gas pressure. Moreover, the liquid water in the embodiment can also be replaced by other liquid substances, but it is preferably a non-toxic, harmless liquid with low volatility and small density change.

Compared with the prior art of directly measuring the acceleration, the utility model converts the measurement of the acceleration of gravity into the measurement of the gas pressure through the principle of pressure, which is beneficial to increase the difficulty of the structure of the measuring device, thereby improving the accuracy of the measurement. Simultaneously, the measuring method of the utility model is simple and effective, and can improve the measuring effect. Simultaneously, the measurement process of the utility model is vivid and vivid, and can be applied to experimental equipment in teaching and scientific research, so as to improve the vividness and quality of teaching.

The specific embodiments described above have further described the purpose, technical solutions and beneficial effects of the utility model in detail. It should be understood that the above descriptions are only specific embodiments of the utility model and are not intended to limit the utility model. For new models, any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present utility model shall be included in the protection scope of the present utility model.

Claims (5)

1. utilize hydrostatic pressure to measure a device for acceleration of gravity, comprise a container and a pipe, it is characterized in that, also comprise the equipment of a measurement gas pressure, wherein

A kind of liquid is accommodated in described container;

One end of described pipe is closed, and other end opening, wherein accommodates air, and the opening of described pipe vertically inserts in the liquid held in described container down, makes the difference in height of liquid level in the liquid level in described container and described pipe be h;

The equipment of described measurement gas pressure is for measuring the pressure p of the air in described pipe;

The equipment of described measurement gas pressure comprises heat capacity of air than tester and pressure transducer;

Described pressure transducer is connected than tester with described heat capacity of air by the blind end of connecting line through described pipe;

Described pressure transducer is for detecting the pressure of the air in described pipe;

Described heat capacity of air is used for than tester the reading signal from pressure transducer being converted to instrument.

2. utilize hydrostatic pressure to measure the device of acceleration of gravity as claimed in claim 1, it is characterized in that, the material of described container and/or described pipe is transparent or semitransparent material.

3. utilize hydrostatic pressure to measure the device of acceleration of gravity as claimed in claim 1, it is characterized in that, described liquid is water.

4. utilize hydrostatic pressure to measure the device of acceleration of gravity as claimed in claim 1, it is characterized in that, rational height scale on described container and/or pipe.

5. utilize hydrostatic pressure to measure the device of acceleration of gravity as claimed in claim 1, it is characterized in that, also comprise a height gauge, it is erect in the above-described container and is fixed.