JPH10185732A - Gas-pressure measuring apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a gas-pressure measuring apparatus which can be attached easily and which prevents a gas leak during a measurement by a method wherein a stopper member which can be attached airtightly to an opening part, for gas pressure measurement, at a conduit is provided and a pressure sensor is installed at the stopper member in such a way that its sensor face is exposed to a gas atmosphere. SOLUTION: A ring-shaped seal member 23 which is formed of an elastic member such as a rubber or the like is fitted to the root of a screw part 22, and a gas leak is prevented completely when a pressure sensor part 2 is attached to a socket. A pressure sensor 24 which is composed of a semiconductor is buried and installed in a state that its sensor face is exposed to the air, and its detection signal is sent to a control part via a connecting cable 3 and a connector 31. Thereby, the pressure sensor 24 and a measuring apparatus body 1 are connected electrically by the connecting cable 31 and the like, a gas-pressure measuring apparatus is attached easily, there is no fear of a gas leak during a measurement, and the periodic maintenance such as the inspection, the replacement or the like of a rubber tube is not required.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas pressure measuring device for measuring a gas pressure, particularly a gas pressure in a conduit for city gas or the like.

[0002]

_2. Description of the Related Art In order to prevent extinction and the like, city gas companies provide gas supply destinations such as homes with a specified gas pressure (specified by each company, about 150 to 220 mmH ₂ O, and further referred to as “mmH " ₂ O" indicates a unit of measurement of gas pressure that can raise a water column to a height of mm.) In order to confirm whether gas is supplied or not, a gas pipe at a place specified by a prescribed government agency is used. It is obliged to measure the gas pressure inside and notify the relevant government office,
In addition, gas pressures are measured at locations that are voluntarily selected by each business operator to enhance safety even at locations other than those specified by the designated government offices.

Conventionally, a gas pressure measuring device for this purpose has been measured using, for example, a chart type pressure gauge. The chart type pressure gauge slowly rotates a disc-shaped chart paper with a concentric memory with a rotating mechanism powered by a mainspring, and moves the recording pen in the radial direction by a displacement mechanism that displaces according to gas pressure. By moving, the change over time of the gas pressure is recorded on the chart paper. This displacement mechanism has, for example, a simple configuration in which gas in a conduit is introduced through a rubber tube into a bellows-shaped closed container formed of an elastic member, and the recording pen is expanded and contracted in accordance with the gas pressure. To record the gas pressure.

[0004] By the way, it is desirable to measure the gas pressure in the gas conduit at a position as close as possible to the supply destination from the above-mentioned purpose of preventing the disappearance at the supply destination. For this reason, the measurement is usually performed using water collectors installed at various places in the gas conduit. This drainer is
It is provided for the purpose of, for example, preventing the gas conduit from being clogged by water generated by condensation of water vapor in the gas.

FIG. 6 is a partially cutaway view showing the structure of the water drainer. As shown in FIG.
A concave portion 203 is provided in the middle of the gas conduit 201 and stores water generated by dew condensation at a lower portion of a cylindrical member 202 having a diameter slightly larger than the conduit 201.
A standpipe 204 extending to near the surface of the ground is attached to the upper part of 2.

[0006] A socket 205 is attached to the upper part of the standing pipe 204. A screw groove is formed inside the opening of the socket 205, and a plug 206 is screwed into this portion to prevent gas leakage. Standpipe 204
A metal cylindrical member 207 is buried near the surface of the vertical hole where the buried hole is buried so that the hole does not collapse, and a cover is made at its upper opening by a protector 208 so that an unexpected accident does not occur. Has become.

When a worker removes water from a conduit,
Open the protector 208 on the ground surface, remove the plug 206, insert the pipe into the upright
The water that has accumulated in the pump is being pumped out. The following method was used to measure the gas pressure with the above-mentioned chart type pressure gauge using such a water removal device 200.

First, the plug 206 is removed from the socket 205, and as shown in FIG. 7, a nipple-attached plug 209 provided with a nipple 210 for leading the gas inside the conduit to the outside is sealed with a sealing tape (not shown). Screwed into the socket 205. On the other hand, the chart type pressure gauge 211
If it cannot be stored in the cylindrical member 207 covered by the protector 208, it is placed on the ground. A nipple 21 for gas introduction is provided on a protruding portion on the lower surface of the chart type pressure gauge 211.
The nipple 210 of the plug with nipple 209 and the nipple 21 of the chart type pressure gauge 211 are attached.
2 are connected by fitting the ends of the rubber tubes 213 respectively. As a result, the gas in the conduit is guided into the inside of the chart type pressure gauge 211, and the change with time of the gas pressure is recorded on a disk-shaped chart paper according to the above-described principle.

[0009]

However, in such a conventional gas pressure measuring method, if the connection operation by the rubber tube 213 is not performed quickly, a large amount of gas may be released into the atmosphere, and the measurement may not be performed. At times, it was necessary to pay sufficient attention to prevent gas leakage. In particular, the rubber tube 213 is used to prevent gas leakage during measurement.
Must be inserted sufficiently deep into the nipples 210 and 212 and the nipple-attached plug 209 must be securely fastened to the socket 205. Also, if the rubber tube itself becomes old, cracks may occur and gas leakage may occur therefrom. Care must also be taken in terms of maintenance, such as periodic replacement.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide a gas pressure measuring apparatus which is easy to mount and does not cause gas leakage during measurement.

[0011]

To achieve the above object, a gas pressure measuring device according to the present invention is a gas pressure measuring device for electrically measuring a gas pressure in a conduit using a pressure sensor, A plug member that can be hermetically attached to the gas pressure measurement opening of the conduit is provided, and the pressure sensor is provided on the plug member such that its sensor surface is exposed to the gas atmosphere. I do.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a gas pressure measuring device according to the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing the appearance of the gas pressure measuring device. As shown in FIG. 1, the gas pressure measuring device includes a measuring device main body 1 housed in a disk-shaped container, and a pressure sensor unit 2 connected to the measuring device main body 1 by a connection cable 3.

A liquid crystal display panel 1 is provided on the upper surface of the measuring device main body 1.
1 and an input unit 12 are provided. FIG. 2 is a plan view of the measuring device main body 1, and the diameter thereof is
Is smaller than the diameter of the cylindrical member 207 (about 80 mm), the liquid crystal display panel 11 can display eight characters, and the input unit 12 has a power key 12 from the left.
1, measurement key 122, end key 123, setting key 124
Is arranged. The display on the liquid crystal display panel 11 in FIG. 2 indicates that the gas pressure detected at 18:25 is 22
Indicating that 5mmH a ₂ O.

As shown in FIG. 1, a battery case 13 is vertically attached to the periphery of the bottom surface of the measuring device main body 1, and the lid member 14 is opened to open two AA size dry batteries. Are stored in series to supply power to the internal control unit 100 (FIG. 3). On the other hand, the pressure sensor section 2 includes a base section 21 and a screw section 22 formed below the base section 21. The socket 22 of the water drainer 200 is
A screw groove is formed with the same diameter and the same pitch as the plug 206 screwed into the plug 05, and is screwed into the socket 205 in an airtight manner. An annular seal member 23 made of an elastic member such as rubber is fitted into the root of the screw portion 22 to completely prevent gas leakage when the pressure sensor portion 2 is attached to the socket 205.

A well-known pressure sensor 24 made of a semiconductor is embedded in the screw portion 22 with its sensor surface exposed to the atmosphere, and its detection signal is controlled via the connection cable 3 and the connector 31. Sent to the unit 100.
At the time of gas pressure measurement, the screw part 22 of the pressure sensor part 2 is used.
Is tightened and fixed to the socket 205 instead of the plug 206 of the water drainer 200, and the control unit 100 measures the minimum gas pressure in the conduit based on the detection value detected by the pressure sensor 24.

FIG. 3 is a block diagram showing the configuration of the control unit 100, and the power supply is not shown for convenience.
As shown in the figure, the control unit 100 includes an A / D converter 101
, CPU 102, clock IC 103, RAM 104
Consists of The value detected by the pressure sensor 24 is A / D
The signal is converted into a digital signal by the converter 101 and
02 is input.

A sampling interval (hereinafter, referred to as a "sampling interval") is set in advance in a memory inside the CPU 102 by an operation from the input unit 12, and the first sampling is performed in response to a measurement start instruction from a measurer. Then, a value (sampling value) obtained by converting the detected value into a gas pressure and a measurement time are stored in the RAM 104. afterwards,
Sampling is performed at the set sampling intervals based on the time of the clock IC 103, and only when the sampled value is smaller than the sampled value stored in the RAM 104, the sampled value and the measured time are written to the RAM 104 to update the stored contents. I do.

The above-described comparison operation is repeated at each sampling interval, and when there is an instruction to end the measurement by operating the input unit 12, the content stored in the RAM 104 at that time is displayed on the liquid crystal display panel 11. Next, the operation of gas pressure measurement in such a gas pressure measurement device will be described based on the flowchart of FIG.
explain in detail.

First, the operator operates the power key 1 of the input unit 12.
Press 21 (FIG. 2) to turn on the power and perform zero adjustment (steps S1, S2). This zero adjustment is performed by opening the pressure sensor 24 to the atmosphere, and pressing the power key 121 while pressing the setting key 124. When the pressure sensor detects the atmospheric pressure, the gas pressure becomes zero.
mmH ₂ O is automatically set.

At the same time as this setting, the mode is switched to the span adjustment mode, and the span is adjusted (step S3). In this span adjustment, the pressure sensor unit 2 is attached to the socket 205 of the water removal device 200, and the gas pressure displayed on the liquid crystal display panel 11 becomes equal to the accurate gas pressure measured in advance by the pressure calibrator. Is adjusted as follows. That is, when the span adjustment mode is set, the display value increases when the measurement key 122 is pressed, and the display value decreases when the end key 123 is pressed. This display value is equal to the value indicated by the pressure calibrator. When the setting key 124 is depressed, the ratio of the gas pressure change to the change in the detection value of the pressure sensor 24 is set correctly.

Thereafter, other contents are set (step S4). This means that every time the setting key 124 is pressed, the display screen of the liquid crystal display panel 11 changes the sampling interval,
Switch to a screen such as the time, and in each display screen, press the measurement key 122 and the end key 123 as described above to change the corresponding numerical value to a desired value, and finally press the setting key 124 to CPU 10
2 is set in the internal memory.

The "zero adjustment", "span adjustment", and "other settings" in steps S2 to S4 do not necessarily need to be performed at the measurement site, but may be performed periodically or before going to the measurement site. Is also good. After setting the above contents, the measurement is started by pressing the measurement key 122 with the pressure sensor unit 2 attached to the socket 205, the detection value of the pressure sensor 24 is sampled, and the detection value is used as a gas. Pressure and convert the value and time to R
The sampling is performed at the set sampling interval (Steps S5 and S5).
6, S7). Then, for each sampling, the sampling value is compared with the stored sampling value, and if the current sampling value is smaller than the previous sampling value,
The storage value is updated by writing the sampling value and the measurement time in the RAM 104 (“Y” in step S8, step S9), otherwise, the storage content is left as it is (“N” in step S8). .

The operation of comparing the sampled values is continued until the measurer presses the end key 123 to instruct the end of the measurement (step S10). When there is an instruction to finish measurement, R
The sampling value stored in the AM 104, that is, the minimum gas pressure value from the start to the end of the measurement and the measurement time are displayed on the liquid crystal display panel 11 (step S11). When the button is pressed, the power is turned off (step S12), and a series of measurement operations ends.

Thus, the minimum gas pressure can be measured with the minimum operation, and the measurer only needs to go to the measurement site at the start and end of the measurement, so that the danger of measurement and the time burden are extremely reduced. You. In addition, since the digital measuring device is used, the reliability of the measured value is greatly improved, and the device main body can be formed compact. As shown in FIG.
The measuring device main body 1 can be housed inside the cylindrical member 207 of the water drainer 200 and can be covered with a protector 208 from above, so that there is no possibility of obstructing traffic during the measurement as in the related art.

The reason why the battery case 13 is vertically attached to the disc-shaped measuring device main body 1 is that when the battery case 13 is stored in the measuring device main body 1, the thickness of the disc-shaped portion of the measuring device main body 1 is increased. The thickness of the socket 20 is increased.
This is because the space around 5 is used effectively. Since the standing position of the battery case 13 is near the periphery of the bottom surface of the disc-shaped measuring device main body 1, the battery case 13 does not engage with the socket 205, and the position of the standing tube 204 is temporarily shifted from the center of the cylindrical member 207. However, if the battery case 13 is arranged in a wide space opposite to the shift direction, the battery case 13 can be easily installed.

In the above-described embodiment, in order to measure the minimum gas pressure, the sampled values are compared for each sampling, and only the lower gas pressure value is stored in the RAM 104, thereby extracting the minimum gas pressure. I did,
The same result can be obtained by storing all the sampling values and extracting the lowest one from among them at the end of the measurement. However, in the latter case, a larger storage capacity is required. Therefore, in terms of cost, it is preferable to store only necessary data in comparison with each sampling as in the above embodiment.

In the above embodiment, the detection value of the pressure sensor 24 is converted into a gas pressure value, and this is stored in the RAM 104 as a detection result. However, the A / D converted detection value is used as it is. May be stored and converted into a gas pressure value when the stored content is displayed on the liquid crystal display panel 11. Further, in the above embodiment, the water removal device 2
00, the gas pressure in the conduit was measured, but it is also possible to use, for example, a nipple of a gas cock at home as an opening for gas pressure measurement. In this case, a gas connector of a cassette type is used. What is necessary is just to incorporate a pressure sensor inside.

[0028]

As described above, according to the present invention, in a gas pressure measuring device for electrically measuring gas pressure with a pressure sensor, the pressure sensor is connected to a measurement port provided in a gas conduit in an airtight manner. Since the pressure sensor and the measuring device main body are only electrically connected with a connection cable or the like because they are provided on the attachable plug member, the measuring device main body is connected to the measuring device main body using a rubber tube, etc. There is no longer any need to conduct gas. This facilitates installation of the gas pressure measuring device, almost eliminates the risk of gas leakage during measurement, and eliminates troublesome maintenance such as periodic inspection and replacement of the rubber tube.

[Brief description of the drawings]

FIG. 1 is a perspective view showing the appearance of a gas pressure measuring device according to the present invention.

FIG. 2 is a top view of the gas pressure measuring device main body.

FIG. 3 is a block diagram showing a configuration of a control unit installed inside the gas pressure measuring device main body.

FIG. 4 is a flowchart showing an operation of measuring a minimum gas pressure.

FIG. 5 is a view showing a state in which the gas pressure measuring device is attached to a water removal device.

FIG. 6 is a diagram showing a configuration of a general water drainer arranged in the middle of a gas conduit.

FIG. 7 is a diagram showing a state when a conventional chart-type pressure gauge is installed in a water removal device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Measuring device main body 2 Pressure sensor part 3 Connection cable 11 Liquid crystal display panel 12 Input part 13 Battery case 22 Screw part 24 Pressure sensor 100 Control part 101 A / D converter 102 CPU 103 Clock IC 104 RAM 200 Drainer

 ──────────────────────────────────────────────────の Continuing from the front page (72) Inventor Nobuhisa Takamatsu 19-18 Sakuradacho, Atsuta-ku, Nagoya-shi Toho Gas Co., Ltd.

Claims (1)

[Claims] 1. A gas pressure measuring device for electrically measuring a gas pressure in a conduit using a pressure sensor, comprising a plug member which can be hermetically attached to a gas pressure measuring opening of the conduit, The gas pressure measuring device, wherein the pressure sensor is provided on the plug member such that the sensor surface is exposed to the gas atmosphere.