CN2789764Y - Self-calibrating gas test alarm device - Google Patents

Abstract

The utility model relates to a self-calibrating gas detection and alarm device, which relates to a gas detection and alarm device. The utility model solves the problem that the existing gas detection and alarm device with the gas sensor as the sensitive part needs to be calibrated frequently and regularly, thus causing inconvenience to use. The self-calibrating gas detection alarm includes a single-chip microcomputer, the signal input end of the single-chip microcomputer is connected with a detection gas sensor, the signal output end of the single-chip microcomputer is connected with a gas display and alarm circuit; the signal input end of the single-chip microcomputer is also connected with a self-calibration gas sensor. In the utility model, by adding a self-calibration circuit, the gas detection alarm can avoid repeated artificial calibration, and the stability of the gas detection alarm can be increased by more than 20 times. The self-calibration can avoid frequent manual calibration of the gas detection alarm in the actual use process, making the gas detection alarm more convenient to use.

Description

Self-calibrating gas detection alarm

technical field

The utility model relates to a gas detection and alarm device, in particular to a self-calibrating gas detection and alarm device.

Background technique

Existing gas detection alarms use gas sensors as sensitive components for collecting gas concentration signals. In the actual working process of the gas sensor for early warning in the coal mine, the environment is relatively harsh. In some places, the concentration of CH4 is high, and there are some gas impurities. The gas sensor reacts with the measured gas for a long time and repeatedly. After that, it will be insensitive to the gas to be measured, thus forming a "dead zone" (the area where the sensitive film is not sensitive to the gas to be measured), causing the signal output of the gas sensor to drift, which will inevitably result in failure to make a test at the required concentration. Accurate alarm response, resulting in false positives and missed negatives. In order to make this kind of sensor with dead zone reach the critical state of alarm, a larger concentration of the measured gas is required than in the normal state, and the longer the sensor is used, this situation will become more obvious. The hidden dangers of applying dangerous gas detection and alarm in work are self-evident; therefore, the existing gas detection and alarm devices need to calibrate the sensor frequently and regularly with standard gas samples, which brings inconvenience to the use of gas detection and alarm devices .

Contents of the invention

The utility model solves the problem that the existing gas detection and alarm devices with gas sensors as sensitive parts need to be calibrated frequently and regularly, thus bringing inconvenience to use, and provides a self-calibrating gas detection and alarm device, which only provides the The hardware structure of the gas detection alarm is for the purpose.

The utility model is realized by adopting the following technical scheme: a self-calibrating gas detection alarm, including a single-chip microcomputer, the signal input end of the single-chip microcomputer is connected with a detection gas sensor, and the signal output end of the single-chip microcomputer is connected with a gas display and alarm circuit; A self-calibrating gas sensor is also connected to the input.

Taking the single-chip microcomputer as the core, the gas sensor collects the gas concentration signal and sends it to the single-chip microcomputer. The single-chip microcomputer analyzes and judges the gas concentration signal collected with the support of corresponding software. When the gas concentration exceeds a certain set value, the single-chip microcomputer controls The corresponding display alarm circuit carries out the display alarm of excessive gas. This is the known structure and working process of the existing conventional gas detection alarm. For those skilled in the field of electricity or computers, the specific connection between the gas sensor and the single-chip microcomputer, the specific composition of the display alarm circuit, and the specific connection between the display alarm circuit and the single-chip microcomputer are well known and easy to implement, and the display alarm circuit Many different known circuit structures can be used. Therefore, the utility model does not make any specific connection between the gas sensor and the single-chip microcomputer, the specific composition of the display alarm circuit, and the specific connection between the display alarm circuit and the single-chip microcomputer in the claims. It is described in detail, but a specific circuit principle diagram is given in the accompanying drawings of the description, and it is described in detail in the specific implementation manner.

Compared with the existing gas detection alarm, the utility model has a prominent substantive feature that a self-calibrating gas sensor is connected to the signal input end of the single-chip microcomputer. The single-chip microcomputer controls the self-calibration gas sensor with the support of the corresponding software, so that it is not powered on and does not work at ordinary times. Working with electricity, the signal acquired by the self-calibration sensor is used as the benchmark for calibrating the detection gas sensor, that is, the single-chip microcomputer, with the support of the corresponding software, uses the signal value acquired by the detection sensor as the signal value acquired by the self-calibration gas sensor. The reference is converted and calibrated, so as to realize the self-calibration of the gas detection alarm. Since the self-calibrating gas sensor will not react with the measured gas when it is not energized at ordinary times (it is only energized intermittently during calibration), it can maintain high sensitivity for a long time, and it is feasible to use it as a reference. The self-calibration can avoid frequent manual calibration of the gas detection alarm in the actual use process, making the gas detection alarm more convenient to use.

In the utility model, by adding a self-calibration circuit, the gas detection alarm can avoid repeated manual calibration, and the stability of the gas detection alarm (that is, the drift time of the gas sensor) can be increased by more than 20 times.

Description of drawings

Fig. 1 is the circuit schematic diagram of the self-calibrating gas detection alarm described in the utility model;

In Fig. 1, the same line ends are connected.

Detailed ways

Self-calibrating gas detection alarm, including single-chip microcomputer A1, the signal input end of the single-chip microcomputer is connected with a detection gas sensor, the signal output end of the single-chip microcomputer is connected with a gas display and alarm circuit; the signal input end of the single-chip microcomputer is also connected with a self-calibration gas sensor .

Single-chip A1 selects ATM128 model. The detection gas sensor and the self-calibration sensor are selected from LXK-3, which are respectively connected to the circuit through the interfaces S3 and S2; the output terminals of the detection gas sensor and the self-calibration sensor are respectively connected to the signal amplifier chips A2 and A3 (AD623 is selected), and the signal The output terminals SAOUT and SBOUT of the amplifier chips A2 and A3 are respectively connected to the corresponding signal input terminals of the single chip microcomputer A1; the detection gas sensor and the self-calibration sensor are equipped with drive circuits composed of constant voltage drive chips M8 and M2 (select MAX1818) , the drive circuit is a known circuit necessary for the normal operation of the gas sensor. The input terminals AS and BS of the constant voltage drive chips M8 and M2 are respectively connected to the corresponding control terminals of the single-chip microcomputer, and the single-chip microcomputer controls the constant voltage drive chip through the corresponding control terminals. M8, M2, and then control the working state of the detection gas sensor and the self-calibration sensor.

The alarm circuit connected to the signal output terminal BELL of the single-chip microcomputer includes a constant voltage driver chip M4 (MAX1818 is selected), and the output terminal of the constant voltage driver chip M4 is connected with a buzzer B1.

The display circuit connected to the signal output terminal of the single-chip microcomputer includes three constant-voltage driver chips M1, M2, and M3 (MAX1916 is selected), and its input terminals LINGHT1, LINGHT2, and LINGHT3 are respectively connected to the corresponding output terminals of the single-chip microcomputer. Each constant-voltage driver chip The output ends of M1, M2, and M3 are respectively connected with three light-emitting diodes L1, L2, L3, L4, L5, L6, L7, L8, and L9, and the light-emitting diodes connected to the output ends of each constant voltage driver chip are of different colors, such as The LEDs L1, L2, and L3 at the output end of the constant voltage driver chip M1 are red, the LEDs L4, L5, and L6 at the output end of the constant voltage driver chip M2 are yellow, and the LEDs L7, L8, and L9 at the output end of the constant voltage driver chip M3 are green . According to different gas concentration levels, the single-chip microcomputer makes different constant voltage drive chips in the display circuit conduction, and emits different colors of light, which is very intuitive to display.

The circuit structure of the self-calibrating gas detection alarm has the advantages of small size, low power consumption, high sensitivity, easy mass production, low cost, etc., especially its circuit structure has a high degree of integration and is very small in size. Therefore, the self-calibrating gas detection alarm can be fixed in the housing of the miner's lamp. When the gas concentration is lower than a certain value (such as 1%), the single-chip microcomputer controls a constant voltage driving chip in the display circuit to work, and now the light-emitting diode can be used as lighting. When the gas concentration is higher than a certain value (such as 1%), another constant voltage driver chip will glow red when it is working, and it will be displayed intuitively. At the same time, the alarm circuit will sound an alarm. When the gas concentration is higher, the third constant voltage driver chip will The green light is on when working, and the limit alarm is displayed.

Claims (3)

1, a kind of self calibration gas detecting alarm comprises single-chip microcomputer (A1), and the signal input part of single-chip microcomputer is connected with the probe gas dependent sensor, and the signal output part of single-chip microcomputer is connected with gas demonstration, warning circuit; It is characterized by: the signal input part at single-chip microcomputer also is connected with the self calibration gas sensor.

2, self calibration gas detecting alarm as claimed in claim 1, it is characterized by: the display circuit that links to each other with the signal output part of single-chip microcomputer comprises three constant voltage driving chips (M1, M2, M3), the output terminal of each constant voltage driving chip (M1, M2, M3) is connected with three light emitting diodes (L1, L2, L3 respectively, L4, L5, L6, L7, L8, L9), and the light emitting diode that each constant voltage driving chip output connects is a different colours.

3, self calibration gas detecting alarm as claimed in claim 1 or 2 is characterized by: this self calibration gas detecting alarm is fixed in the mine lamp housing.