CN204228690U - A kind of gas sensor calibration Multi-way switching device - Google Patents

Abstract

The utility model discloses a kind of gas sensor calibration Multi-way switching device, comprise some the gas circuits for being communicated with variable concentrations standard source of the gas, every bar gas circuit is provided with a change-over switch, the outlet side of each bar gas circuit is connected with at least one verification passage, on each verification passage, string is provided with verification switch and at least one gas sensor to be measured, and the end of each verification passage is used for being communicated with gas exhaust duct.Gas sensor calibration Multi-way switching device of the present utility model, provide the measurement gas circuit of the gas of many variable concentrations, and different gas circuits is switched by change-over switch, well solve application methane transducer and demarcate and checkout procedure complexity, the problems such as troublesome poeration.This apparatus cost is with low cost, greatly reduces survey crew work difficulty, easy to use, and has very high promotional value.

Description

A multi-channel switching device for gas sensor calibration

technical field

The utility model relates to a multi-channel switching device for calibrating a gas sensor.

Background technique

At present, coal mine safety production is the top priority of the coal mine industry. The most important thing for coal mine safety production is the drainage and early warning of methane and carbon monoxide gas. As a measuring instrument for methane and CO gas, it is also an indispensable measuring tool in various mining areas. There are many gas measuring instruments on the market. However, the calibration and verification of this measuring instrument is a major problem that plagues the development of the industry at present.

The measurement range of general methane gas measuring instruments is: 0-100%. According to the coal industry standard, the gas calibration and verification of methane sensors requires at least 6 points, and each calibration and verification point requires a stable time of at least 20 minutes. The replacement of methane gas with different concentrations also needs to be replaced by nitrogen gas, which takes a long time. It takes nearly 3 hours to calibrate an instrument, and it needs manual persistence, which greatly reduces the work efficiency, and the calibration instrument needs to be replaced constantly. Cylinders, poor safety and handling.

At present, many manufacturers in the industry use manual gas cylinder replacement. Gases of different concentrations need to be replaced, and the pressure of the gas cylinder and the flow rate of methane gas need to be adjusted once for replacement. In the case of multiple instrument calibrations, there are insufficient gas cylinders, which greatly reduces production efficiency and company operating costs.

Utility model content

The purpose of the utility model is to provide a multi-channel switching device for gas sensor calibration to solve the problem of poor safety and operability caused by manual ventilation during gas sensor calibration and verification.

In order to achieve the above purpose, the technical solution adopted by the utility model is: a multi-channel switching device for gas sensor calibration, including several gas circuits for communicating with different concentration standard gas sources, each gas circuit is provided with a switch The gas outlet of each gas circuit is connected with at least one calibration channel, and each calibration channel is equipped with a calibration switch and at least one gas sensor to be tested in series. The end of each calibration channel is used to connect with the exhaust pipe. connected.

Control valves corresponding to the gas sensors to be tested are arranged in series on each calibration channel, and each gas sensor to be tested is arranged at intervals from the corresponding control valves.

A flowmeter is connected in series on each calibration channel.

The changeover switch, the check switch and the control valve are all explosion-proof electromagnetic valves.

Each verification channel is also connected with a replacement gas path for communicating with a replacement gas source to quickly adjust the gas concentration in the verification channel.

The multi-channel switching device for gas sensor calibration of the utility model provides a plurality of measuring gas paths for calibration gas with different concentrations, and switches different gas paths through the switching switch, which solves the problem of calibration and inspection of methane sensors. The process is complicated and the operation is troublesome. The device is low in cost, greatly reduces the work difficulty of surveyors, is convenient to use, and has high popularization value.

Each switch, calibration switch, and control valve are electromagnetic valves, and the industrial computer is used to automatically control the switch of the station, which greatly improves the efficiency and accuracy of the test; multiple calibration channels are connected in parallel and connected in series with the sensors in each channel. The combination method provides different station settings, which solves the problem of time-consuming series connection and calibration gas cost for parallel connection.

Description of drawings

Fig. 1 is the structural schematic diagram of the multi-channel switching device of the present invention.

Detailed ways

Below in conjunction with accompanying drawing and specific embodiment the utility model is further introduced.

As shown in Figure 1, it is the structural principle diagram of the embodiment of the multi-channel switching device for calibrating the gas sensor of the present invention. As can be seen from the figure, the device includes several gas circuits for communicating with different concentration standard gas sources, each gas circuit There is a switching switch, and at least one calibration channel is connected to the gas outlet of each gas circuit, and each calibration channel is equipped with a calibration switch and at least one gas sensor to be tested in series. The end of each calibration channel is used for connected to the exhaust pipe.

A flowmeter and control valves corresponding to the gas sensors to be tested are arranged in series on each calibration channel, and each gas sensor to be tested is arranged at intervals from the corresponding control valves.

Since this device is used for the calibration of gas sensors, some gases are flammable and explosive gases. Therefore, strict attention should be paid to the airtightness and explosion-proof performance of pipelines and switches. All use explosion-proof solenoid valves.

In addition, in order to quickly dilute the high-concentration gas in the calibration channel into low-concentration gas during switching, this embodiment not only provides a plurality of gas paths communicating with standard gas sources of different concentrations, but also sets up a The replacement gas source is connected to the replacement gas path for quickly adjusting the gas concentration in the calibration channel.

Let’s take the methane gas sensor as an example to illustrate: As shown in Figure 1, according to the coal industry standard, since the gas calibration and verification of the methane sensor requires at least 6 points, there are 6 methane calibration points with different concentrations in this embodiment. gas path and 1 replacement gas path, because the mixed gas in methane standard gas of different concentrations is generally nitrogen, then the replacement gas path is connected with pure nitrogen standard gas for replacement of methane gas with different concentrations, greatly improving work efficiency. An explosion-proof solenoid valve is used as a switch in each standard gas circuit.

In this embodiment, 3 inspection channels are selected for parallel connection, and each verification channel is connected in series with 2 methane sensors, so that the calibration and verification of 6 methane sensors (1A, 1B, 2A, 2B, 3A, 3B) can be performed at the same time. The hybrid connection mode of series and parallel connection is adopted, which not only saves methane calibration gas but also improves work efficiency.

In order to realize the test control of a single sensor, a control switch is provided for each sensor to be tested. Taking channel 1 as an example, valve 8 is the calibration switch of this channel, which is used to communicate with the calibration channel; FR is the float flowmeter of this channel; valve 11 is the control valve of sensor 1A, and its 1 port is connected with sensor 1A , 2 ports are used to communicate with the next serially connected sensor 1B, and 3 ports are used to communicate with the exhaust pipeline. This connection structure can meet the test of a single sensor; valve 14 is the control valve of sensor 1B, and its 1 port is connected to the sensor 1B is connected, and both ports 2 and 3 are connected to the outlet pipeline.

All the above-mentioned electromagnetic valves are connected with ports 1-2 when the power is on, and ports 1-3 are connected when the power is off, which ensures that the gas in the discharge pipeline can also be controlled when the power is off.

Explosion-proof solenoid valve 1-valve 7 in Figure 1 is used to adjust methane gas and nitrogen of different concentrations (valve 1 is used for the access of nitrogen standard gas, valve 2-valve 7 is used for the access of different concentrations of methane standard gas), through The measurement and control station controls the switching of different valves to realize the switching of different concentrations of methane standard gas. The monitoring host is a PC, which is used to set the process and complete the communication during calibration and verification. The rotameter is used to control the flow of methane gas in different channels, so that the methane sensor can measure stably and avoid measurement errors. The three channels are connected in parallel and are controlled by different valves. Each channel provides 2 stations, and a total of 6 test stations can be provided. The use of the channels and stations can be set through the host computer.

The working principle and process of the device are as follows: first turn on the power supply of the device (220V AC), then install the methane sensor to be tested on the corresponding station, and set the station of the sensor and the concentration of the gas to be tested on the PC Corresponding valves, and set the test process. Here, the principle of switching from low concentration to high concentration is generally adopted, which can ensure that when switching between the two concentrations, the concentration balance will be automatically achieved from low to high; when switching from high concentration to low concentration, the replacement gas can be introduced for a period of time , to ensure that the gas concentration in the channel is low enough before introducing low-concentration calibration gas.

Enter the measurement interface, follow the software prompts, set the standard gas cylinders connected (the flow rate of the gas controlled to each concentration is the required value); enter the automatic calibration process, the device will perform the calibration according to the set process Automatic switching of different concentrations of methane gas; after the test is completed, record the test results and shut down.

It should be noted that the utility model can not only realize the calibration of the methane gas sensor, but also can realize the inspection of other gas sensors such as CO and CO2. The principle is the same, and only the corresponding calibration gas can be replaced during the test.

The above embodiments are only used to help understand the core idea of the utility model, and cannot limit the utility model with this. For those skilled in the art, any modification or equivalent replacement of the utility model based on the idea of the utility model, any changes made in the specific implementation and scope of application shall be included in the utility model. within the scope of the new protection.

Claims (5)

1. a gas sensor calibration Multi-way switching device, it is characterized in that: comprise some the gas circuits for being communicated with variable concentrations standard source of the gas, every bar gas circuit is provided with a change-over switch, the outlet side of each bar gas circuit is connected with at least one verification passage, on each verification passage, string is provided with verification switch and at least one gas sensor to be measured, and the end of each verification passage is used for being communicated with gas exhaust duct.

2. gas sensor calibration Multi-way switching device according to claim 1, is characterized in that: on each verification passage, also string is provided with and gas sensor to be measured operation valve one to one, and each gas sensor to be measured and corresponding operation valve interval are arranged.

3. gas sensor calibration Multi-way switching device according to claim 1, is characterized in that: on each verification passage, all string is provided with a flowmeter.

4. gas sensor calibration Multi-way switching device according to claim 2, is characterized in that: described change-over switch and check valve and operation valve are explosion-proof solenoid valve.

5. the gas sensor calibration Multi-way switching device according to Claims 1 to 4 any one, is characterized in that: each verification passage is also connected with one for being communicated with displacement source of the gas the displacement gas circuit verifying gas concentration in passage with quick adjustment.