JP2003270104A - Metering pump for gas detecting tube - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a measuring error caused by erroneous counting of a suction frequency, by counting the suction frequency automatically to prevent an error in the suction frequency, in measurement of a gas concentration or the like using a metering pump for a gas detecting tube. <P>SOLUTION: In this pump stored with the detecting tube for measuring a specified gas to suck a fixed volume of air into the detecting tube, a pressure sensor and a display part are arranged in the pump to count the suction frequency by reaching to a specified value of pressure in an inside of the pump, the count is displayed to count the suction frequency automatically, and the erroneous counting of the suction frequency is thereby prevented to prevent the error in the measurement caused by the error in the suction frequency, so as to solve the purpose of the present invention. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metering pump for a gas detecting tube, which can automatically count the number of times of suction.

[0002]

2. Description of the Related Art When measuring the concentration of a specific gas,
A detection tube containing a detection agent that reacts with the specific gas is arranged in a metering pump, and a certain amount of ambient air is sucked by the metering pump to measure the gas concentration.

A suction amount is determined for each gas,
Therefore, the metering pump is generally adapted to suck a fixed amount of air. If the suction amount of the metering pump is 100 cc, the suction amount is 100 cc for the gas a, but 1000 cc for the gas b.
The measurement of the gas a is completed by one suction, but the measurement of the gas b is completed by performing the measurement 10 times.

Conventionally, when measuring the gas concentration, the gas b
As described above, in the case of measuring a gas that requires the work of suctioning a plurality of times, the measurer performed the measurement while counting the number of suctions.

[0005]

However, in the gas concentration measurement, the suction pressure remains for a certain period of time in the inside of the metering pump and the detection tube after the first suction, and during that time, Since the measurement cannot be accurately performed if the second suction is performed, it is necessary to wait without re-suction during the time when the suction pressure remains.

When the suction pressure remains for a long time, it may be about 4 minutes. Therefore, when the suction frequency is high, the waiting time and There is a problem that the time is repeated and becomes long, and while these operations are repeated, the count is erroneous and an error occurs in the measurement.

Therefore, the number of suctions is automatically counted,
There is a problem to be solved by preventing an error in the number of times of suction to prevent an error in measurement due to an error in the number of times of suction.

[0008]

As a concrete means for solving the above-mentioned problems of the conventional example, the present invention is a pump for accommodating a detection tube for measuring a specific gas and for sucking a fixed amount of air into the detection tube. The pump is provided with a pressure sensor and a display unit, and when the pressure inside the pump reaches a specified value, the number of suctions is counted and the count is displayed. Is provided.

In the present invention, the display is a digital display; when the pressure inside the pump is substantially the same as the outside pressure, suction can be performed; the pressure inside the pump is almost the same as the outside pressure. It is included as an additional requirement that a means for notifying that they have become the same is provided.

A metering pump for a gas detecting tube according to the present invention comprises:
By arranging a pressure sensor and a display unit and changing the numerical value of the counter when the pressure inside the pump reaches a specified value, the number of suctions is automatically counted, and by displaying and visually recognizing it, It is possible to prevent an error in the suction frequency and prevent a measurement error due to an incorrect suction frequency.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Next, the present invention will be described in detail based on specific embodiments. A sectional view of a metering pump 1 for a gas detector tube is shown in FIG. The metering pump 1 is composed of a casing 2 having a cylindrical shape, and a check valve 3 is provided at one end of the casing 2 and a gas introduction hole 4 is provided.
A guide cylinder 7 is provided which is in communication with the gas introduction hole 4 via the check valve 3 and in which the housing portion 6 of the detection tube 5 is provided.

At the other end of the guide cylinder 7 provided in the metering pump 1, a support cylinder 9 for supporting the shaft 8 in a state where the shaft 8 is inserted is provided. A piston 10 is provided at one end of the shaft 8 housed in the casing 2, and the piston 10 can be moved along with the movement of the shaft 8 by inserting and removing the shaft 8. At the other end,
A lever 11 is provided so that it can be easily gripped by hand.

The shaft 8 is designed to be movable by a certain distance. The moving distance of the shaft 8 and the piston 1
Since the amount of air that can be sucked is determined by the area of 0, a constant amount of air can always be sucked.

The piston 10 is provided with an air passage 12 at a predetermined portion, and the air passage 12 is provided with a check valve 13, which is an air chamber 14a divided by the piston 10 inside the casing 2. , 14b are communicated with each other by the air passage 12 via the check valve 13.

Therefore, when the shaft 8 is inserted, that is, when the air chamber 14a becomes narrow, air is not discharged from the gas introduction hole 4 to the outside of the metering pump 1 because of the check valve 3. However, since the air flows into the air chamber 14b through the air passage 12 and the check valve 13, the pressure inside the casing 2 is stable.

However, when the shaft 8 is pulled out, that is, when the air chamber 14a is widened, the pressure in the air chamber 14b is stable because the air is discharged from the minute gap portion 15 between the shaft 8 and the support cylinder 9. However, since the check valve 13 does not allow air to flow into the air chamber 14a from the air chamber 14b and the pressure in the air chamber 14a becomes low, the check valve 3 is used to feed the gas from the gas introduction hole 4 to the metering pump 1. To suck in the air around it.

At this time, when the detection tube 5 is housed in the housing portion 6, the surrounding air is sucked through the detection tube 5 by a certain amount, so that the suction takes a predetermined time. ,
The specified constant pressure immediately after the start of suction is gradually changed so as to become equal to the external pressure. At that time, the suctioned air comes into contact with the detection agent housed inside the detection tube 5. Then, it becomes possible to measure the gas concentration.

Further, inside the guide cylinder 7, the pressure sensor 1
6, a microcomputer 18, a notification device 19, a digital display device 20, a display changeover switch 21 arranged on the printed circuit board 17, and a battery 22 as a power source for these devices. The pressure sensor 16 uses the sensor unit 23 as the air chamber 14a.
The pressure inside the air chamber 14a can be observed because it is arranged so as to project.

The printed circuit board 17 is arranged substantially in parallel with the gas introduction hole 4 in FIG. 1, but the invention is not limited to this.
Is formed to have a shape substantially the same as the inner shape of the gas introduction hole, and a hole portion larger than the gas introduction hole 4 is formed in the central portion thereof.
It may be arranged around.

The printed circuit board 17 is arranged in front of the metering pump 1 in FIG. 1, but the invention is not limited to this. For example, the printed board 17 may be arranged in the central part or the rear part of the metering pump 1. May be.

FIG. 2 shows a flow chart of the metering pump for gas detection tube of the present invention. When the power switch 24 is turned on, power is supplied from the battery 22a to the microcomputer 18a via the voltage control 25, whereby the digital display 20a is turned on to indicate that the power is turned on.

The microcomputer 18a has a function of counting the number of times of suction, and the count immediately after the power switch 24 is turned on is, for example, "0".
The digital display 20a has a microcomputer 18
The count is displayed as a counter for displaying the count of the number of suctions of a.

The display of this digital display 20a is
In addition to the number of times of suction, the display changeover switch 21a can switch to, for example, suction pressure, suction volume, or air leakage amount (leak amount).

The pressure sensor 16a constantly observes the pressure in the air chamber 14a, and the information obtained by the pressure sensor 16a is converted into a digital signal by the A / D converter 26 and input to the microcomputer 18a. It

As described above, when the shaft 8 is moved in the extracting direction by a prescribed fixed distance, the air chamber 14 is moved.
The pressure of a suddenly changes and reaches the maximum pressure value immediately after the start of suction.
It is transmitted to the microcomputer 18a via the converter 26,
The digital display 20a displays, for example, a blinking display to indicate that suction is being performed, and caution is given not to perform the next suction operation.

The pressure inside the air chamber 14a is controlled by the gas introduction hole 4
By sucking ambient air through the check valve 3 and the check valve 3, the pressure gradually approaches the pressure outside the metering pump 1 with the passage of time, and when the suction pressure reaches the specified value, the microcomputer 18a The alarm 19a emits an alarm sound, the count of the number of times of suction is incremented by "1", the blinking display of the digital display 20a is terminated and the display is turned on, and the alarm sound is emitted from the alarm 19a. To notify that the suction is completed.

When the number of times of suction is two, it is confirmed that the blinking display of the digital display 20a is finished and the alarm sound is emitted, and the shaft 8 is again moved by a predetermined distance. Move in the direction of extraction and suction. Then, as described above, the microcomputer 18a increments the count of the number of times of suction to "+1" when the pressure inside the air chamber 14a reaches the specified value of the suction pressure, and displays "2" on the digital display 20a. . When the number of times of suction is plural, these operations are repeated for the specified number of times to measure the gas concentration.

In this way, since the number of times of suction can be visually confirmed with certainty by the digital display, for example, during a waiting time when the display of the digital display 20a is in a blinking state, a pause or the like can be used to talk or the like. Even if it does, the number of times of suction will not be erroneously measured.

FIG. 3 shows a record of changes in the suction pressure over time when the number of suctions is five. When the shaft 8 is moved in a direction for extracting a predetermined fixed distance,
The pressure inside the air chamber 14a reaches the initial pressure point 27 that indicates the maximum pressure immediately after the start of suction, and the pressure inside the air chamber 14a gradually decreases from the initial pressure point 27 with the passage of time, and is substantially the same as the external pressure. The end pressure point 28 is reached.

The pressure for counting the number of times of suction is
As described above, it is preferable to count when the external pressure is substantially the same as the external pressure, but the present invention is not limited to this. For example, a prescribed pressure is set in advance and the shaft 8
May be moved to reach the prescribed pressure set above, and counting may be performed.

In this way, by monitoring the pressure in the air chamber 14a and automatically counting the number of suctions,
It is possible to prevent an error in the number of times of suction and prevent an error in measurement due to an error in the number of times of suction, and when the pressure in the air chamber 14a reaches the prescribed constant pressure, by issuing an alarm sound from the alarm device 19a, It is also possible to prevent measurement errors due to insufficient suction.

According to the JIS standard, the air chamber 14a
The air leak amount (leak amount) is regulated within 3%. However, since the metering pump for gas detection pipe of the present invention constantly observes the pressure of the air chamber 14a by the pressure sensor 16a, it is digital. It can be easily confirmed by displaying it on the display 20a.

The leak amount is measured by a digital display 2
The display 0a is displayed by the display changeover switch 21a to indicate the amount of leak, and the detection tube 5 in an unused state in which air is not introduced is housed in the housing portion 6 and the housing portion 6 is sealed, and the shaft 8 is kept at a constant distance. The microcomputer 18a observes the information from the pressure sensor 16a by moving only the suction volume, that is, the suction volume, that is, the volume at the time of designing the air chamber 14a is 100%.
Is compared with the value observed by the microcomputer 18a from the information from the pressure sensor 16a. For example, if the numerical value when the specified time has elapsed is within 3%, the alarm 19a When a short alarm sound is emitted and exceeds 3%, a long alarm sound is emitted from the alarm device 19a and the numerical values are displayed on the digital display device 20a.

The operating portion 29 of the metering pump 1 is shown in FIG.
The operation unit 29 includes, for example, the digital display 20.
The display screen 20b of a, the power switch 24a, and the display changeover switch 21b are arranged, and the opening hole 30 for the alarm device is provided.
Is provided, and a notification sound is emitted from the opening 30.

The display on the display screen 20b can be switched by the display changeover switch 21b, and as described above, for example, the number of times of suction, the suction pressure, the suction volume, and the leak amount can be switched and displayed.

When the suction pressure is displayed by the display changeover switch 21b, the microcomputer 18a processes the information from the pressure sensor 16a which defines the large pressure as 0 kPa, and the numerical value calculated by the above processing is " It is displayed on the display screen 20b by adding a symbol "-".

When the display changeover switch 21b is used to display the suction volume, the pressure sensor 1 based on suction is used.
The information from 6a is processed by the microcomputer 18a, the information previously stored in the microcomputer 18a is compared with the information from the pressure sensor 16a, and the previously stored numerical value is displayed on the display screen 20b.

As for the number of display digits of the display screen 20b for displaying these, at least three or more digits may be displayed.

As a means for counting the number of times of suction, the shaft 8 may be moved to a prescribed position for counting, but as described above, the air chamber 14
Since the leak amount and the like can be observed by observing and counting the internal pressure such as a, it is preferable to dispose the pressure sensor 16 and count with the change of the pressure.

[0040]

As described above, the metering pump for a gas detecting pipe according to the present invention is a pump which accommodates a detecting pipe for measuring a specific gas and sucks a fixed amount of air into the detecting pipe. The pump is provided with a pressure sensor and a display unit, the number of times of suction is counted when the pressure inside the pump reaches a specified value, and the number of times of suction is automatically counted by displaying the count, and the count is performed. By displaying and making it visible, it is possible to prevent an error in the number of times of suction, prevent an error in measurement due to an error in the number of times of suction, and measure the amount of leak, etc. Play.

[Brief description of drawings]

FIG. 1 is a cross-sectional view schematically showing a metering pump for a gas detection tube according to the present invention.

FIG. 2 is a flowchart of the metering pump for the gas detecting tube.

FIG. 3 is a view showing a change in suction pressure during suction of the metering pump for a gas detection tube, which is recorded and shown over time.

FIG. 4 is a plan view of an operation unit of the metering pump for the gas detecting tube.

[Explanation of symbols]

1 metering pump; 2 casing; 3 check valve;
4 Gas introduction hole 5 Detection tube; 6 Housing section; 7 Guide tube; 8 Shaft; 9 Support tube 10 Piston; 11 Lever; 12 Air passage;
13 Check valves 14a, 14b Air chamber; 15 Micro gap part; 1
6, 16a Pressure sensor 17 Printed circuit board; 18, 18a Microcomputer; 1
9, 19a Notification device 20, 20a, 20b Digital display device 21, 21a, 21b Display changeover switch 22, 22a Battery; 23 Sensor unit 24, 24a Power switch; 25 Voltage control 26 A / D converter; 27 Initial pressure point; 28
End pressure point 29 Operation part; 30 Opening hole

Claims (5)

[Claims] 1. A detection tube for measuring a specific gas is accommodated,
A pump for sucking a certain amount of air into the detection pipe, wherein the pump is provided with a pressure sensor and a display unit, and the suction frequency is counted when the pressure inside the pump reaches a specified value, and the count is A metering pump for gas detection tubes characterized by displaying. 2. The metering pump for a gas detecting tube according to claim 1, wherein the display is a digital display. 3. The metering pump for a gas detecting pipe according to claim 1, wherein suction is possible when the pressure inside the pump is substantially the same as the outside pressure. 4. The metering pump for a gas detecting pipe according to claim 1, wherein when the internal pressure of the pump is not substantially the same as the external pressure, the display section blinks to display it. 5. The metering pump for a gas detecting pipe according to claim 1, further comprising means for notifying that the pressure inside the pump has become substantially the same as the outside pressure.