JP2002312870A - Portable gas detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a portable gas detector for searching the position of gas leakage in emergency of gas leakage. SOLUTION: With respect to a portable gas detector 1, a gas entrance 4, an alarm part 3, and a display part 7 are provided on a case 2, and a gas sensor 5 which detects the concentration of gas introduced from the gas entrance 4, an ultrasonic microphone 8 having directivity, and a signal processing circuit 6 which processes an electric signal detected by the gas sensor 5 to not only output an alarm from the alarm part 3 in the case of the gas concentration higher than a prescribed value but also process an electric signal detected by the ultrasonic microphone 8 to output the result to the display part 7 are arranged in the case 2. The concentration of gas introduced from the gas entrance 4 is detected by the gas sensor 5, and an alarm is outputted from the alarm part 3 by the signal processing circuit 6 when the gas concentration exceeds the prescribed value. When emergency of gas leakage occurs to output the alarm, the direction of the case 2 is changed to change the turning direction of the ultrasonic microphone 8 having directivity, and then an ultrasonic wave radiated from the leakage position is detected as the electric signal by the ultrasonic microphone 8, and this electric signal is processed by the signal processing circuit 6 and is outputted to the display part 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a portable gas detector for detecting gas leaking from various facilities such as a gas piping system and a sealed gas container which are installed in many plants and factories. The present invention relates to a device capable of detecting a leakage position.

In equipment such as plants and factories handling toxic and combustible gases, workers carry portable gas detectors that detect gas concentrations and output alarms so that they can evacuate in the event of gas leakage. I have to.

[0003]

2. Description of the Related Art A conventional portable gas detector is provided with a gas sensor for detecting the concentration of gas introduced from the gas inlet in a case having a gas inlet and an alarm unit, and an electric signal detected by the gas sensor. And a signal processing circuit for outputting an alarm from the alarm unit when the gas concentration is higher than a predetermined value.

[0004]

The worker carries the portable gas detector to evacuate in the event of a gas leak in which an alarm is output. However, the worker is supposed to evacuate because the position of the leak is unknown. On the contrary, there is a case where it approaches the leakage position, and there is a risk of causing fatal injury. Accordingly, it is an object of the present invention to provide a portable gas detector capable of detecting a leak position in the event of a gas leak.

[0005]

Means for Solving the Problems The technical means of the present invention taken to solve the above-mentioned technical problem is to provide a case having a gas inlet and an alarm section, the concentration of the gas introduced from the gas inlet. And a signal processing circuit that processes an electric signal detected by the gas sensor and outputs an alarm from the alarm unit when the gas concentration is equal to or higher than a predetermined value. A display unit is provided, and an ultrasonic microphone having directivity is arranged in the case, and an electric signal detected by the ultrasonic microphone is processed by the signal processing circuit and output to the display unit. The feature is a portable gas detector.

[0006]

According to the above-mentioned technical means of the present invention, the direction of the ultrasonic microphone having directivity is changed by changing the direction of the case in the event of gas leakage when an alarm is output. Thereby, when the directional direction of the ultrasonic microphone approaches the direction of the leakage position, the ultrasonic waves radiated from the leakage position are detected as electric signals by the ultrasonic microphone, and the electric signals are processed by the signal processing circuit. Output to the display unit. When the pointing direction of the ultrasonic microphone coincides with the leak position, the output value of the display unit becomes maximum, so that the leak position can be detected based on the pointing direction of the ultrasonic microphone at this time.

[0007]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is an external front view of a portable gas detector of the present invention, and FIG. 2 is a block diagram of an electric circuit of the portable gas detector of the present invention. Case 2 of portable gas detector 1
Is so large that the cross section can be gripped by one hand having a substantially square shape. Case 2 has an alarm unit 3 such as a buzzer or lamp on the front.
And a gas sensor 4 that has a gas inlet 4 at the top and detects the gas concentration of the gas introduced from the gas inlet 4 therein, and processes an electric signal detected by the gas sensor 5 to reduce the gas concentration. A signal processing circuit 6 for outputting an alarm from the alarm unit 3 when a predetermined value or more is provided. The case 2 is provided with a display unit 7 having a liquid crystal panel structure on the front and an ultrasonic microphone 8 having directivity beside the gas inlet 4 on the upper side. The signal processing circuit 6 processes the electric signal detected by the ultrasonic microphone 8 and outputs the processed signal to the display unit 7.

The gas sensor 5 is a sensor that outputs a detection signal corresponding to the gas concentration. For example, a hot-wire type semiconductor gas sensor is used, but another type of gas sensor such as an electrochemical gas sensor may be used. The signal processing circuit 6 includes the amplifying unit 1
0, A / D converter 11 and CPU (central processing unit) 12
, Amplifying section 13, filter section 14, detecting section 15, and rectifying section 1.
6 The gas sensor 5 is connected to the alarm unit 3 through the amplification unit 10, the A / D conversion unit 11, and the CPU 12, and the ultrasonic microphone 8 is connected to the display unit 7 through the amplification unit 13, the filter unit 14, the detection unit 15, the rectification unit 16, and the CPU 12. connect.

The concentration of the gas introduced from the gas inlet 4 is detected by the gas sensor 5, and an alarm is output from the alarm unit 3 by the signal processing circuit 6 when the gas concentration is equal to or higher than a predetermined value. By changing the direction of the case 2 to change the direction of the ultrasonic microphone 8 having directivity in the event of a gas leak when this alarm is output, the direction of the ultrasonic microphone 8 is changed to the direction of the leak position. When approaching, an ultrasonic wave emitted from the leak position is detected as an electric signal by the ultrasonic microphone 8, and the electric signal is processed by the signal processing circuit 6 and output to the display unit 7. When the pointing direction of the ultrasonic microphone 8 coincides with the leak position, the output value of the display unit 7 becomes maximum. Therefore, the leak position can be detected based on the pointing direction of the ultrasonic microphone 8 at this time.

[0010]

The present invention has the following specific effects. As described above, according to the present invention, a leak position can be detected in the event of a gas leak in which an alarm is output, so that an excellent effect of being able to evacuate in a direction away from the leak position is produced.

[Brief description of the drawings]

FIG. 1 is an external front view showing an embodiment of a portable gas detector of the present invention.

FIG. 2 is a block diagram showing an electric circuit of the portable gas detector of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Portable gas detector 2 Case 3 Alarm part 4 Gas inlet 5 Gas sensor 6 Signal processing circuit 7 Display part 8 Ultrasonic microphone

Claims (1)

[Claims] In a case having a gas inlet and an alarm unit,
A gas sensor for detecting the concentration of gas introduced from the gas inlet, and a signal processing circuit for processing an electric signal detected by the gas sensor and outputting an alarm from the alarm unit when the gas concentration is equal to or higher than a predetermined value are provided. In the portable gas detector, a display unit is provided in the case, an ultrasonic microphone having directivity is provided in the case, and an electric signal detected by the ultrasonic microphone is processed by the signal processing circuit. A portable gas detector, wherein the gas is processed and output to the display unit.