Remote transmission type gas density meter

Abstract

The utility model belongs to the technical field of gas density measurement, and particularly relates to a remote transmission type gas density meter. Comprising a shell, a bourdon tube, a movement, a pointer and a bimetal compensating plate, the angle sensor sleeves the rotating shaft end of the pointer and is used for detecting the deflection angle of the pointer; the remote transmission circuit board is arranged in a remote transmission signal box, and the remote transmission signal box is arranged outside the shell; wherein a signal amplification and filter circuit, a signal acquisition circuit, a main control chip circuit and a wireless communication module are integrated on the remote transmission circuit board; and the input end of the signal amplifying and filtering circuit is connected with the signal output end of the angle sensor. According to the utility model, the deflection angle of the pointer is obtained by designing the angle sensor, and angle data is converted into a density numerical value through the main control chip, and then the density numerical value is remotely transmitted to a remote terminal background, so that the functions of remotely monitoring and reading the density numerical value are realized.

Description

Technical Field

[0001] This utility model belongs to the field of gas density measurement technology, and specifically relates to a remote transmission type gas density meter. Background Technology

[0002] Existing gas density meters or gas density relays typically consist of a Bourdon tube assembly, a mechanism, a pointer, and a bimetallic compensator. The Bourdon tube assembly acts as the pressure-sensing element, and the bimetallic compensator acts as the temperature compensation element. The displacement generated by the pressure-sensing element is converted and amplified into angular displacement by gears in the mechanism, and the corresponding density value is displayed on the dial by the pointer. Existing remote-transmission density meters mainly collect pressure and temperature data using temperature and pressure sensors. After processing and converting this data into density data by a microcontroller, the data is transmitted remotely to a backend system.

[0003] However, due to the different sensitivities of the temperature compensation element and the temperature sensor to temperature changes, a measurement deviation will occur between the temperature compensation element currently displayed on the instrument and the density value measured by the sensor, making it impossible to provide accurate remote transmission data. Utility Model Content

[0004] The purpose of this invention is to provide a remote-reading gas density meter. This invention obtains the deflection angle of the pointer by designing an angle sensor, and after the main control chip converts the angle data into a density value, it transmits the data to a remote terminal backend to realize the function of remote monitoring and reading of density values.

[0005] To solve the above-mentioned technical problems, this utility model provides a remote-reading gas density meter, comprising: a housing, a Bourdon tube, a movement, a pointer, and a bimetallic compensating plate; and further comprising:

[0006] An angle sensor, fitted onto the pivot end of the pointer, is used to detect the deflection angle of the pointer;

[0007] The remote transmission circuit board is installed inside the remote transmission signal box, which is installed outside the housing.

[0008] The remote transmission circuit board integrates a signal amplification and filtering circuit, a signal acquisition circuit, a main control chip circuit, and a wireless communication module. The input terminal of the signal amplification and filtering circuit is connected to the signal output terminal of the angle sensor. The output terminal of the signal amplification and filtering circuit is connected in sequence to the signal acquisition circuit and the main control chip circuit. The main control chip circuit is connected to the wireless communication module, and the wireless communication module is wirelessly connected to an external remote terminal.

[0009] Preferably, the signal amplification and filtering circuit consists of a programmable gain amplifier, a fourth-order Butterworth low-pass filter, and an ADuM3151 digital isolation chip connected in sequence.

[0010] Preferably, the signal acquisition circuit uses an AD7124 analog-to-digital converter chip.

[0011] Preferably, the main control chip circuit uses an STM32 main control chip.

[0012] Preferably, the wireless communication module is a Zigbee communication module, a LoRaWAN communication module, an NB-IoT communication module, or a 5G communication module.

[0013] Preferred options also include:

[0014] An airbag chamber is connected to the inner cavity of the shell, and a reference airbag is suspended in the airbag chamber. The reference airbag is filled with a reference gas for use as a density reference.

[0015] An elastic element is provided, through which the reference airbag is connected to the spring tube.

[0016] Preferably, it also includes a gauge connector, which is connected to the inner cavity of the housing.

[0017] Compared with the prior art, this utility model has the following advantages:

[0018] 1. This utility model detects the pointer deflection angle by setting an angle sensor and outputs a corresponding signal. After being processed by the main control chip on the remote transmission circuit board, the density value data corresponding to the angle is finally sent to the remote terminal through the wireless communication module, realizing the function of remote monitoring and reading of density values.

[0019] 2. This utility model changes the stress on the elastic element by varying the buoyancy of the reference airbag, thereby further compensating for the deformation of the spring tube through the elastic element. By performing secondary compensation based on the compensation of the spring tube by the bimetallic compensation plate, the density of the gas can be measured more accurately. Attached Figure Description

[0020] Fig. 1 This is a front view of the structure of a remote-transmitting gas density meter according to this utility model.

[0021] Fig. 2 This is a side view of the structure of a remote-transmitting gas density meter according to this utility model.

[0022] Fig. 3 This is a circuit diagram of the remote transmission circuit board of this utility model.

[0023] Fig. 4This is a circuit block diagram of the signal amplification and filtering circuit of this utility model.

[0024] In the diagram: 1-Housing, 2-Angle sensor, 3-Remote transmission circuit board, 31-Signal amplification and filtering circuit, 311-Programmable gain amplifier, 312-4th order Butterworth low-pass filter, 313-ADuM3151 digital isolation chip, 32-Signal acquisition circuit, 33-Main control chip circuit, 34-Wireless communication module, 35-Remote terminal, 4-Remote transmission signal box, 5-Airbag chamber, 6-Reference airbag, 7-Meter connector. Detailed Implementation

[0025] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The advantages and features of the present invention will become clearer from the following description. It should be noted that the drawings are all in a very simplified form and use non-precise proportions, and are only used to facilitate and clarify the illustration of the embodiments of the present invention.

[0026] like Figs. 1-4 As shown, this utility model embodiment specifically provides a remote-reading gas density meter, including: a housing 1, a Bourdon tube, a movement, a pointer, and a bimetallic compensating plate; the specific connection structure and working principle of the aforementioned movement, pointer, Bourdon tube, and bimetallic compensating plate are technologies well known to those skilled in the art, and therefore will not be described in detail; it also includes:

[0027] Angle sensor 2 is sleeved on the rotating shaft end of the pointer. Here, the measuring rotating shaft end of angle sensor 2 is connected to the rotating shaft. The outer seat of angle sensor 2 can be detachably installed on the dial inside the density meter housing 1 to detect the deflection angle of the pointer.

[0028] The remote transmission circuit board 3 is installed inside the remote transmission signal box 4, which is installed outside the housing 1.

[0029] The remote transmission circuit board 3 integrates a signal amplification and filtering circuit 31, a signal acquisition circuit 32, a main control chip circuit 33, and a wireless communication module 34. The input end of the signal amplification and filtering circuit 31 is connected to the signal output end of the angle sensor 2. The output end of the signal amplification and filtering circuit 31 is connected to the signal acquisition circuit 32 and the main control chip circuit 33 in sequence. The main control chip circuit 33 is connected to the wireless communication module 34. The wireless communication module 34 is wirelessly connected to the external remote terminal 35.

[0030] The aforementioned angle sensor 2 detects the pointer deflection angle and outputs a corresponding signal. After a series of processing steps on the remote transmission circuit board 3, the density value data corresponding to the angle is finally sent to the remote terminal 35 through the wireless communication module 34, thereby realizing the remote transmission of density values.

[0031] The signal amplification and filtering circuit 31 consists of a programmable gain amplifier 311, a 4th-order Butterworth low-pass filter 312, and an ADuM3151 digital isolation chip 313 connected in sequence. The signal output from the angle sensor 2 is generally a weak electrical signal. First, the signal enters the programmable gain amplifier 311, which can adjust the gain according to actual needs, amplifying the weak signal to a suitable amplitude for subsequent processing. The amplified signal then passes through the 4th-order Butterworth low-pass filter 312, whose function is to filter out high-frequency noise interference. In real-world environments, the signal output from the angle sensor 2 may be affected by various high-frequency interference sources, such as electromagnetic interference. The 4th-order Butterworth low-pass filter 312 can effectively attenuate high-frequency signals above its cutoff frequency, retaining low-frequency signals, making the signal cleaner and beneficial for accurate subsequent data acquisition. After the signal amplification and filtering circuit 31, the signal passes through the ADuM3151 digital isolation chip 313. The main function of the digital isolation chip is to provide signal isolation, preventing interference from the preceding circuit from affecting the following circuit, and also protecting the following circuit from abnormal voltage surges that may occur in the preceding circuit. It can isolate and transmit the signal from a high-voltage, high-noise environment to a low-voltage, low-noise signal acquisition circuit 32 while ensuring signal integrity.

[0032] The signal acquisition circuit 32 uses the AD7124 analog-to-digital converter chip. The signal acquisition circuit 32 receives the signal after amplification, filtering and isolation. The AD7124 analog-to-digital converter chip converts the analog signal into a digital signal so that it can be recognized and processed by the main control chip circuit 33.

[0033] The main control chip circuit 33 uses an STM32 main control chip. The main control chip circuit 33 receives digital signals from the signal acquisition circuit 32. The main control chip typically has functions such as data processing, storage, and control. It further processes the acquired angle data, such as data calibration and compensation. For example, it corrects the angle data according to pre-stored calibration parameters to improve measurement accuracy. Simultaneously, the main control chip also performs data packetization and other operations to prepare for subsequent wireless communication.

[0034] The wireless communication module 34 adopts a Zigbee communication module, a LoRaWAN communication module, an NB-IoT communication module, or a 5G communication module. The data processed by the main control chip is sent to the wireless communication module 34, which is responsible for transmitting the data wirelessly to the remote terminal 35 in the external central control room, facilitating centralized monitoring and management by staff.

[0035] It also includes: an airbag chamber 5, which is connected to the inner cavity of the housing 1, and a reference airbag 6 is suspended in the airbag chamber 5. The reference airbag 6 is filled with a reference gas and is used as a density reference. An elastic element is also included, and the reference airbag 6 is connected to the Bourdon tube via the elastic element. It also includes a dial indicator 7, which is connected to the inner cavity of the housing 1.

[0036] This invention uses a reference gas within a reference airbag 6 as a density reference. The density of the gas to be measured is determined by measuring the change in buoyancy within the reference airbag 6. The magnitude of the buoyancy is directly proportional to the gas density. By altering the force on the elastic element through the change in buoyancy on the reference airbag 6, the deformation of the Bourdon tube is further compensated by the elastic element. This secondary compensation, based on the compensation of the Bourdon tube by a bimetallic compensating plate, allows for more accurate measurement of gas density. While ordinary instruments rely on the characteristics of a bimetallic strip and temperature changes for temperature compensation, the reference instrument utilizes the pressure and temperature changes of the reference airbag 6 for temperature compensation, building upon the bimetallic strip compensation. Compared to bimetallic compensating plates, this method offers more stable characteristics and higher measurement accuracy and sensitivity.

[0037] The above description is only a description of the preferred embodiment of the present utility model and is not intended to limit the scope of the present utility model in any way. Any changes or modifications made by those skilled in the art based on the above disclosure shall fall within the protection scope of the claims.

Claims

1. A remote-reading gas density meter, comprising: The housing (1), Bourdon tube, movement, pointer, and bimetallic compensator; characterized in that it further includes: An angle sensor (2) is fitted onto the shaft end of the pointer and is used to detect the deflection angle of the pointer; The remote transmission circuit board (3) is installed inside the remote transmission signal box (4), which is installed outside the housing (1). The remote transmission circuit board (3) integrates a signal amplification and filtering circuit (31), a signal acquisition circuit (32), a main control chip circuit (33), and a wireless communication module (34). The input terminal of the signal amplification and filtering circuit (31) is connected to the signal output terminal of the angle sensor (2). The output terminal of the signal amplification and filtering circuit (31) is connected to the signal acquisition circuit (32) and the main control chip circuit (33) in sequence. The main control chip circuit (33) is connected to the wireless communication module (34). The wireless communication module (34) is wirelessly connected to an external remote terminal (35).

2. A remote-reading gas density meter as described in claim 1, characterized in that, The signal amplification and filtering circuit (31) consists of a programmable gain amplifier (311), a fourth-order Butterworth low-pass filter (312), and an ADuM3151 digital isolation chip (313) connected in sequence.

3. A remote-reading gas density meter as described in claim 1, characterized in that, The signal acquisition circuit (32) uses the AD7124 analog-to-digital converter chip.

4. A remote-reading gas density meter as described in claim 1, characterized in that, The main control chip circuit (33) adopts an STM32 main control chip.

5. A remote-reading gas density meter as described in claim 1, characterized in that, The wireless communication module (34) adopts a Zigbee communication module, a LoRaWAN communication module, an NB-IoT communication module or a 5G communication module.

6. A remote-reading gas density meter as described in claim 1, characterized in that, Also includes: An airbag chamber (5) is connected to the inner cavity of the shell (1), and a reference airbag (6) is suspended in the airbag chamber (5). The reference airbag (6) is filled with a reference gas for use as a density reference. The reference airbag (6) is connected to the spring tube via the elastic element.

7. A remote-reading gas density meter as described in claim 6, characterized in that, It also includes a meter connector (7), which is connected to the inner cavity of the housing (1).

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