KR20170010946A - Gas Detecting Apparatus Having Explosion-proof Infrared Sensor using Air Sampling - Google Patents

Abstract

The present invention relates to an explosion-proof air intake type infrared sensor type gas sensing device for detecting leakage of toxic gas in a factory or the like.
In the present invention, a sampling mechanism for controlling the suction of air for measurement and the discharge of air after measurement, an infrared sensor module for measuring a hydrocarbon-based combustible gas component in the inhaled air, a measurement value coming from the infrared sensor module , A control unit for outputting a measurement result, a terminal unit for communicating with outside and inputting and outputting information according to the control of the control unit, and a space for installing the sampling mechanism unit, the control unit and the terminal unit therein, An explosion-proof air intake type infrared sensor type gas sensing device including a housing having an explosion-proof function is disclosed.
According to the present invention, it is possible to apply the present invention to various environments including explosion-proof areas by the inhalation-type explosion-proof gas sensing technology, and to provide a fast and accurate gas measurement function by the gas sensing technology of the inhalation optical system .

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a gas detection apparatus,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air suction type gas sensing device, and more particularly, to an explosion proof air suction type gas sensing device to which an infrared sensor method is applied to increase the safety of combustible gas measurement and minimize malfunction.

Modern society uses fossil fuels such as petroleum, natural gas (LNG) and liquefied petroleum gas (LPG) as energy sources of the main industrial sites. Natural gas and liquefied petroleum gas are used for fuel of automobile, And is widely used as a power source for various industrial fields. Various combustible gases including natural gas and liquefied petroleum gas commonly have hydrocarbons and are composed of a combination of carbon and hydrogen. Methane, ethane, propane, and butane gas are classified into these combustible gas categories . In recent years, the number of factories and industrial sites handling such flammable gases has been increasing, and the risk of leakage due to the handling of flammable gases has also increased greatly. In case of leakage of flammable gas, explosion and fire can cause enormous damages. Therefore, in the industrial field where the gas is produced and managed, a gas detector capable of detecting the leakage of gas at an early stage is installed, .

In general, if the combustible gas is leaked abnormally, rapid detection and measurement values should be communicated to the user. However, the catalytic bead type gas sensor, which is mainly used in existing combustible gas sensors, has disadvantages such as slow reaction rate, low accuracy, and short life due to poisoning phenomenon depending on the usage environment. Most of the industrial gas sensing devices are of the diffusion type, and when the gas leaks into the atmosphere, it is configured to detect the convection gas due to the specific gravity of the gas and the leakage pressure.

The conventional apparatus has a simple and inexpensive device structure, but it has a disadvantage that it has an influence on the sensing speed depending on the installation position, and can not be used in a high temperature, high humidity and high pressure environment.

In an industrial plant using a combustible gas, there is a restriction that an ignition source spark caused by an electronic circuit spark in a gas sensor may be generated, and a sensor having an explosion-proof function for preventing the combustion spark inside thereof from spreading to the outside.

Recently, in order to maximize the efficiency and safety of industrial plant control, recent gas detectors require various digital communication methods that improve the conventional analog communication method.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems and provide a gas sensing apparatus having an explosion-proof gas sensing structure having an air inhaling function, not an atmospheric diffusion type. It is another object of the present invention to provide an explosion-proof air-infra-red infrared sensor type gas sensing apparatus using optical gas detection systems other than non-optical systems such as contact combustion systems and having various industrial standard interfaces so as to manage gas values measured remotely.

According to an aspect of the present invention, an explosion-proof air intake type infrared sensor type gas sensing apparatus includes a sampling mechanism for controlling intake of air for measurement and air exhaust after measurement, A control unit for processing measurement values coming from the infrared sensor module and outputting measurement results, a terminal unit for communicating with the outside and inputting and outputting information according to the control of the control unit, And a housing having a space capable of installing the sampling mechanism, the infrared sensor module, the control unit, and the terminal unit therein, and having an explosion-proof function.

The sampling mechanism of the explosion-proof air-intake type infrared sensor type gas sensing device measures a flow rate of the air to be sucked, a suction port for sucking air for the measurement, an exhaust port for discharging the air after the measurement, A flow sensor, and a sampling line for inducing internal circulation of the air and allowing the air, which has entered the inlet, to be discharged through the infrared sensor module, the flow sensor, and the exhaust port to the exhaust port.

The controller may control the operation of the pump by comparing the flow rate of the air measured by the flow rate sensor with the set target flow rate.

The infrared sensor module of the explosion-proof air-intake type infrared sensor type gas sensing device comprises an infrared ray generating element for generating infrared rays, an optical hole through which the generated infrared ray passes, a reference sensor for detecting the infrared ray passing through the optical hole, An interface for transmitting data measured by the reference sensor and the detection sensor to the controller, and a sapphire glass for completely separating and sealing the infrared sensor, the reference sensor and the detection sensor.

And the infrared ray generating element can generate infrared rays including a wavelength of 5.6 micrometer in a 2 micrometer (micro meter). The reference sensor may include a first optical filter for selectively passing only light in a wavelength band centering on 4.0um which is not absorbed by hydrocarbon-based flammable gas, and the detection sensor may be absorbed by a hydrocarbon- The second optical filter may selectively pass only the light in the wavelength band centered on the second optical filter.

The sapphire glass of the infrared sensor module is positioned at both ends of the optical hole so that the infrared ray generating element, the reference sensor and the detection sensor are completely separated and sealed.

The terminal unit of the explosion-proof air-intake type infrared sensor type gas sensing device supports at least one of a power unit for receiving power supply, an RS485 communication unit for sharing the measurement result with an external system, and a current output unit for outputting a current An alarm output unit for outputting an alarm generated by the device under the control of the control unit, a key input unit for inputting a user, and a display unit for displaying a setting screen and a measurement result according to the control of the control unit .

The current output section of the terminal section may output a current value in proportion to the measurement result. This current value is expressed by the equation "

In addition, the current output unit may include an alarm for notifying that the explosion-proof air-intake type infrared sensor type gas sensing device is abnormal, and the maximum output value may be a maximum value of the range set by the control unit. A current of 0 mA or 2 mA can be outputted as a signal and a current value of 20 mA to 22 mA can be outputted to indicate that the measurement result is larger than the preset maximum value.

The alarm output section of the terminal section may include three alarm signals. In addition, a jumper or switch for determining the output mode of the alarm signal is further provided, and the alarm signal can be outputted in the form of NC (Normal Close) signal or NO (Normal Open) signal by connection of the jumper or switch have

The key input unit of the terminal unit includes a function key for switching or setting a mode in entering a function setting mode or a function setting mode, an Up key and a Down key used for moving between items configured in each mode, Lt; RTI ID = 0.0 > RST < / RTI >

Further, the key input unit of the terminal unit may be configured to use a non-contact type magnetic switches as an input unit to input a key when a magnetic bar is positioned outside the housing at a predetermined position on the transparent window.

The display unit of the terminal unit includes a light source for indicating whether a power supply is normally supplied, a light source for displaying a fault when a self-diagnosis is detected, and a light source for displaying an alarm when the alarm is being set A light source for alarms, a gas concentration value measured in an infrared sensor module, an FND (Flexible Numeric Display) indicated by numbers and icons set in the function setting mode, a light source for displaying the current air flow rate in the form of a graph bar , A light source indicating that the calibration is in progress, a light source to be displayed upon entering the function setting mode, a light source to be displayed when the RS485 communication is connected, a light source to be displayed when the maintenance mode is executed, .

 According to another aspect of the present invention, there is provided a method for generating an alarm in an explosion-proof air-intake type infrared sensor gas sensing apparatus having an explosion-proof structure and measuring gas concentration by sensing gas, The alarm generating method includes an alarm reference value setting step of setting a reference value for generating an alarm, a condition for generating an alarm when the alarm reference value is equal to or higher than the alarm reference value (an upward condition), and a condition for generating an alarm A hysteresis value setting step for preventing the occurrence / release of the alarm from being repeated by repeating the gas concentration being larger or smaller than the alarm reference value; And a delay time setting step for preventing a momentary malfunction due to the influence When the alarm direction is an upward condition, an alarm is generated when the gas concentration is equal to or more than (the alarm reference value + the hysteresis value) longer than the delay time, and when the alarm direction is a downward condition, (The alarm reference value - the hysteresis value), the alarm may be generated.

 According to another aspect of the present invention, there is provided a method for measuring gas in an explosion-proof air-intake type infrared sensor type gas sensing apparatus having an explosion-proof structure, Actively aspirating air for measurement to meet a set target flow rate using a gas flow meter, measuring the gas component in the inhaled air, indicating the gas component being measured, and after the measurement, And discharging the air.

According to the present invention, it is possible to apply the present invention to various environments including explosion-hazardous areas by the inhalation-type explosion-proof gas sensing technology, and to provide a quick and accurate gas measurement function by the gas sensing technology of the inhalation optical system .

1 is a block diagram schematically showing the overall configuration of an explosion-proof air-intake type infrared sensor type gas sensing apparatus according to an embodiment of the present invention.
2 is a view schematically showing a configuration of an infrared sensor module according to an embodiment of the present invention.
3A and 3B are views showing a structure of an explosion-proof housing according to an embodiment of the present invention.
4 is a view showing a power unit, a current output unit, an RS485 communication unit, and an alarm output unit of a terminal unit according to an embodiment of the present invention.
5 is an exemplary view showing a display unit of an explosion-proof air intake type infrared sensor type gas sensing apparatus according to an embodiment of the present invention.
6 is an exemplary diagram showing a device control flow of a control unit according to an embodiment of the present invention.
7 is a flowchart illustrating a method of setting an alarm generation condition in a controller according to an embodiment of the present invention.
8 is a flowchart showing a gas measurement method according to an embodiment of the present invention.

In the following description, well-known functions or constructions are not described in detail to avoid unnecessarily obscuring the subject matter of the present invention.

Although the present invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, But should be understood to include all modifications, equivalents, and alternatives.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description with reference to the accompanying drawings, the same or corresponding components will be denoted by the same reference numerals, and redundant description thereof will be omitted.

1 is a block diagram schematically showing the overall configuration of an explosion-proof air-intake type infrared sensor type gas sensing apparatus according to an embodiment of the present invention.

1, an explosion-proof air intake type infrared sensor type gas sensing apparatus according to an embodiment of the present invention includes a sampling mechanism and a sensor unit 110, an explosion-proof housing 120, a control unit 130, and a terminal unit 140 ).

The sampling mechanism and the sensor unit 110 can perform the function of sucking air for gas sensing and measurement and discharging air after measurement. The amount of air sucked / discharged into the infrared sensor module 115 must always be constantly supplied in order to minimize the malfunction of the gas measurement. In order to constantly suck outside air, a pump 119 for suctioning air and a flow sensor 117 for measuring the suction amount may be provided in the sensing device, and the sucked air is supplied to the outside through the infrared sensor module 115 The sampling mechanism and the sensor unit 110 for controlling the inflow air may include a mechanism (not shown) and a pump 119 for air intake / circulation / exhaust, a flow sensor 117, . ≪ / RTI >

The mechanism section may be constituted by a suction port 111 for sucking in air, an exhaust port 113 for exhausting, and a sampling line 112 for inducing internal circulation.

The suction port 111 is where the air for measurement is sucked, and the sucked air can be transferred to the infrared sensor module 115 for measurement. The air outlet 113 can exhaust the air discharged after the measurement by the infrared sensor module 115 to the outside. The sampling line 112 induces the circulation of the air so that the air introduced into the inlet 111 passes through the infrared sensor module 115 and then is discharged to the outside through the exhaust port via the flow sensor 117 and the pump 119 Can be done.

The pump 119 may be a diaphragm type pump, and actively suck air from the outside by a pump operation. The flow sensor 117 detects the flow rate of the incoming air in real time, and when there is a difference from the preset flow rate, the controller 130 controls the pump 119 so that a constant amount of air can be always introduced. When there is a difference between the flow rate and the predetermined target flow rate, the pump 119 can be controlled to always allow a certain amount of air to flow.

The infrared sensor module 115 of the present invention is configured in a non-dispersive infrared (NDIR) system that utilizes the property of absorbing the infrared specific band wavelength of hydrocarbon-based flammable gases to measure the concentration of the combustible gas.

2 is a view schematically showing a configuration of an infrared sensor module according to an embodiment of the present invention.

2, the infrared sensor module 115 includes an infrared generating element 210 for generating infrared rays, an optical cavity 230 through which the generated infrared rays pass, a reference for detecting infrared rays passing through the optical hole, A sensor 240 and a detection sensor 250, an interface unit 260 for transmitting a detection result to the control unit, and a shielding film 220.

The infrared ray generating element 210 can generate a medium infrared ray including a wavelength of 5.6 micrometer at 2 micrometers (10-6 meters).

The optical hole 230 serves to guide the intermediate infrared ray generated by the infrared ray generating element 210 to the reference sensor 240 and the detection sensor 250. At this time, the sucked air passes through the optical hole. If a combustible gas is present in the sucked air, a certain wavelength band of infrared rays is absorbed by the combustible gas, and infrared rays are transmitted to the reference sensor 240 and the detection sensor 250 Can arrive.

The reference sensor 240 includes an optical filter that selectively passes only light in a wavelength band centered on 4.0 um that is not absorbed by the hydrocarbon-based combustible gas, and detects only the wavelength of 4.0 um.

The detection sensor 250 includes an optical filter that selectively passes only light in a wavelength band centering on 3.3um absorbed by a hydrocarbon-based combustible gas, and detects only the wavelength of the 3.3um band.

The reason why the reference sensor 240 and the detection sensor 250 are provided is to prevent a deviation or a measurement malfunction due to an environmental change.

At both ends of the optical hole, a shielding film 220 is provided so that the infrared ray generating element 210, the reference sensor 240, and the detection sensor 250 are completely separated from each other and sealed. Or the above-mentioned film may be placed in the middle portion of the optical aperture. This shielding film 220 may be sapphire glass.

FIGS. 3A and 3B are views showing the structure of the explosion-proof housing 120 according to an embodiment of the present invention.

Referring to FIGS. 3A and 3B, the explosion-proof housing 120 has a pressure-proof structure and includes a housing body 121 and a housing body 121 having a space in which a sampling mechanism, a sensor unit, an electronic circuit, And a housing cover 123 which rotates and is coupled to an upper end portion of the housing in a screw-tight manner to seal the inside thereof.

The housing body 121 may have two holes for an intake port 111 capable of sucking outside air and an exhaust port 113 for exhausting and one hole 330 for connecting an external cable.

The housing cover 123 is provided with a viewing window 340 formed of tempered glass at its center so that the user can check various states of the display portion 146 even when the inside is completely sealed and explosion-proofed.

In addition, the explosion-proof housing 120 may be provided with two fastening holes 310 in the housing body 121 so that the explosion-proof housing 120 can be mounted on the wall.

The terminal unit 140 displays a measurement result under the control of the controller 130 or transmits measurement results to an external system. The terminal 140 includes a power supply unit 141 for receiving power supply, a current output unit 142 for sharing the measurement result with an external system, an RS485 communication unit 143, A key input unit 145 for allowing a user to input a set value for measurement, and a display unit 146 for displaying a measurement result according to the control of the control unit 130 .

4 is a view showing a power supply unit 141, a current output unit 142, an RS485 communication unit 143, and an alarm output unit 144 of the terminal unit 140 according to an embodiment of the present invention.

Referring to FIG. 4, the power supply unit 141 has two terminals. In order to operate the device according to the present invention, a direct current power of 18V to 31V can be applied, and a voltage of 24V can be generally applied

The current output unit 142 can output a current of 0 to 22 mA using two terminals. The output terminal of the current output section 142 can output a current of 22 mA at the maximum. The control unit 130 can set a range of the gas concentration to be measured by the infrared sensor module. Based on this, the current output unit 142 can output a current of 4 mA to indicate that no gas is measured, and a current of 20 mA to indicate that the maximum value of the set range has been measured , The current between 4 mA and 20 mA can be output proportional to the measured gas concentration for the gas concentration measured within the set range. More specifically, the current value according to Equation (1) can be outputted in proportion to the measurement result (the concentration of the measured gas) from the infrared sensor module.

In Equation (1), the set maximum value means the maximum value of the gas concentration range set by the controller 130.

In the case of less than 3 mA from 0 mA, it can operate with an alarm signal indicating that there is an abnormality in the apparatus according to the present invention. A current of 20 mA or more can be used to indicate that the measured value is greater than the set maximum.

The control unit 130 can perform digital communication with an external system using the RS485 communication unit 143. [ At this time, measurement results can be shared with external system using MODBUS protocol.

The alarm output unit 144 may include a plurality of alarm output terminals for outputting alarms generated in the explosion-proof air intake type infrared sensor type gas sensing apparatus of the present invention. FIG. 4 illustrates an example in which the alarm output unit 144 includes three alarm output terminals.

Each alarm terminal can be output in the form of NO (Normal Open) and NC (Normal Close). NO, the OUT terminals 410 to 412 and the COM terminals 420 to 422 of the alarm signals of FIG. 4 are separated from each other in the normal state in which no alarm occurs. When an alarm occurs, the OUT terminals 410 to 412 and the COM terminals 420 to 422 come into contact with each other. In the case of NC, the OUT terminals 410 to 412 and the COM terminals 420 to 422 are attached when no alarm occurs, and when the alarm occurs, the OUT terminals 410 to 412 and the COM terminal (420 to 422) are dropped.

A jumper or switches 430 to 432 are used for each of the alarm output terminals AL2, AL1 and TRB to determine whether the alarm output terminals A1, A2 and TRB operate as NO or NC . 4, if the O and G of the jumper or switches 430 to 432 are connected to each other, an NO-type alarm signal can be output. If C and G are connected, an NC-type alarm A signal can be output.

5 is an exemplary diagram showing a display unit 146 of an explosion-proof air-intake type infrared sensor type gas sensing apparatus according to an embodiment of the present invention.

Referring to FIG. 5, the display unit 146 includes a PWR LED 511 for turning on the LED when the power is normally supplied, a gas sensor for detecting a fault in the self- A TRB LED 512 for displaying the alarm 1, an AL1 LED 513 for displaying when the alarm 1 is set by the control unit 130 or when the set alarm 1 is detected, the alarm 130 is set by the control unit 130, 2, an FND (Flexible Numeric Display) 520 for displaying the gas concentration value measured by the infrared sensor module and the number and icon set in the function setting mode, an AL2 LED 514 for displaying the current air flow rate FLOW LED (540) to display in the form of a graph bar, CAL LED (531) to indicate that calibration is in progress, MAINT LED (532) to display when entering the function setting mode in measurement mode, RS485 communication A COMM LED (533) for displaying, a check mode A TEST LED 534 displayed when a maintenance mode is executed, and a unit display unit 550 indicating a gas measurement unit.

The key input unit 145 includes keys for enabling the user to set a function in the function setting mode in connection with the operation of the explosion-proof air intake type infrared sensor type gas sensing apparatus.

The key input unit 145 includes a function key 321 for entering and setting modes in the function setting mode and a function setting mode, an Up key 323 and a Down key 323 for moving between the items configured in the respective modes, And an RST key 327 for returning to the measurement mode in the function setting mode. The detailed operation of each of the above keys can be referred to the function description part of the following control part. The key of the key input unit 145 can not be operated by using a general key existing in the housing which is completely sealed and explosion-proofed. Therefore, by using the non-contact type magnetic switches as the input means of the keys, key input is possible only when the magnetic stick is placed at a predetermined position on the viewing window 340 outside the housing.

The control unit 130 sets the function of the apparatus and processes the measurement signal from the infrared sensor module 115 and outputs the processed result to the current output unit 142, the RS485 communication unit 143, or the alarm output unit 144, To the outside or to output it to the display unit 146. [ Also, the controller 130 can store the measured gas and operation events in real time using the internal memory, and can output the result to the terminal 140 in real time.

6 is an exemplary diagram showing a device control flow of the control unit 130 according to an embodiment of the present invention.

The control unit 130 enters the start mode 610 to turn on the PWR LED 511 in the display unit 146 to indicate that the power is inputted and exchanges information with the infrared sensor module 115, It is possible to prepare a measurement by warming-up the sensor, and enter the measurement mode 620 when the preparation is completed.

The control unit 130 may display the gas concentration received from the infrared sensor module 115 in the measurement mode 620 on the FND 520 and acquire the current flow rate from the flow rate sensor 117 and output the flow rate to the Flow LED 540. [ In the form of a graph bar. If the gas concentration value inputted from the infrared sensor module 115 is 10% or more of the set maximum value, the control unit 130 may blink the character "OUER " in the FND 520 at 0.5 second intervals. When the gas concentration value inputted from the infrared sensor module 115 is equal to or higher than a value set as an alarm and the state continues to be less than the set alarm delay time, the controller 130 controls the AL1 LED 513 and the AL2 LED 514, , The corresponding LED is flickered at intervals of 0.5 second, and if the delay time is longer than the alarm delay time, the corresponding LED is continuously turned on. In response to the alarm latch type setting by the user, when the alarm latch type setting is ON, the controller 130 does not release the alarm LED state even if the gas concentration falls below the alarm set value, The value can also be expressed as a measured or measurable maximum and can only be released with the RST key 327. If the alarm latch type setting is OFF, the controller 130 can control the AL1 LED 513 or the AL2 LED 514 to operate automatically according to the gas concentration.

If an error occurs in the infrared sensor module in the measurement mode 620, the control unit may display an error related character in the FND 520 and may display the TRB LED 512, and may turn on the TRB LED 512. The related characters displayed on the FND 520 are shown in Table 1 below.

Related text occurrence condition E-10 When the infrared sensor module is not installed or is defective E-11 When there is no communication between the control unit and the infrared sensor module E-12 When there is no sensor in the sensing part in the infrared sensor module E-13 When the EPROM of the infrared sensor module is defective E-19 When sensor zero is low (UNDER) E-20 When the flow sensor does not work E-21 When the flow rate of the flow sensor is low E-22 When the flow rate of the flow sensor is high E-31 When the control unit's EEPROM is not recognized W-01 When the validity period has passed W-02 When the manufacturing date of the sensor is not inputted

The control unit 130 controls the function setting mode 630 when the function key 321 is pressed for more than 2 seconds in the measurement mode 620. At this time, the controller 130 performs a password check step 631 to confirm whether the user is a legitimate user, and enters an L1 selecting step 633 if the user is a legitimate user.

Table 2 is an exemplary diagram showing functions selectable at each selection step of the function setting mode 630 according to an embodiment of the present invention.

Referring to Table 2, in an L1 selection step 633, the controller 130 sets CONF (CONFIGURATION MODE), PRGM (PROGRAM MODE), PRGM (PROGRAM MODE), and the like, each time the Up key 323 or the Down key 325 is pressed. (CALIBRATION MODE), ALAM (ALARM MODE), TIME (TIME MODE), S-DT (SENSOR DATA MODE) TEST TEST MODE FLOW MODE MAINTENANCE MODE ADJUST MODE And the user presses the function key 321, the control unit 130 can enter the lower L2 selecting step 635 of the mode currently displayed on the FND 520. In this case, The items appearing in the L2 selection step 633 may be different for each mode selected in the L 1 selection step 633. As an example, if ALAM is selected as the alarm-related setting mode of Table 2 and the user presses the function key 321, the controller 130 sets the alarm-related setting mode to LACH, EN-Z, AL-1, 1H / 1L, , AL-2, 2H / 2L, 2H00 / 2L00, AL2T, A2RL, and END. Table 2 shows the setting function of each item. In one embodiment, when the user selects the ALAM and presses the function key 321, the control unit 13 enters the alarm setting mode and displays the LACH on the FND 520. If the user presses the function key 321 of the key input unit 145 at this time, the user enters the alarm latch type setting mode which is the L3 selection step 637 and the Up key 323 or the Down key 325 of the key input unit 145 The control unit 130 displays the next item (EN-Z in the present embodiment) on the FND 520. When the user presses the function key 321, do. In the above manner, all items related to the alarm setting mode can be set using the Fuction key, the Up key 323, and the Down key 325 of the key input unit 145. Finally, the END is set to the FND 520 When the user presses the function key 321, the setting and the change are completed, and the process returns to the L1 selection 633 to proceed with the setting of the other item. The control unit 130 receives the key input from the user and can set all items related to the device. The function when the alarm latch type is ON and the function when the alarm latch type is OFF have been described above.

When the RST key 327 is input in the function setting mode, the controller 130 can directly enter the measurement mode 620. [

FIG. 7 is a flowchart illustrating a method of setting an alarm generation condition in the controller 130 according to an embodiment of the present invention.

Level1 Level2 Level3 Default


CONF
(CONFIGURATION MODE)
ADD (Address) OFF, 1 to 64 (Address when using 485 Modbus communication) OFF PSWD (Password) 0 ~ 99 (password setting) 00 C-TM
(Calibration Time) OFF, 1 ~ 12 (Set the gas detector calibration period month) OFF SKIP (Skip) OFF, 1 to 20
(Actuation of the measured gas value suppression ratio, 20% of full range) 03% U-01 (Version) Firmware version notation - END - -
PRGM
(PROGRAM MODE)
UNIT PPM, PPB,% VOL,% LEL (Setting the measurement unit) % LEL DP-S
(Decimal Point) 1000, 100 . 0, 10 . 00, 1 . 000 (Set the number of measured values) 100 H-SL (High Scale) 1 to 9999 (Measurement Full Range (High Scale) setting) 100 END - -


CALB
(CALIBRATION MODE)
ZERO NO, YES NO 0 Zero Current measurement value - WAIT (Wait) - - GOOD (Good) Good, Fail - 0 Zero calibration value after calibration - SPAN NO, YES NO 50 Set standard gas value for SPAN calibration 50% / F.R. 45 Current measurement value WAIT (Wait) GOOD (Good) Good when Calibration succeeded, Fail when Failure - 50 Measured value after span calibration - END - -




ALAM
(ALARM
MODE)
LACH (Latching) ON, OFF OFF EN-Z (Energizer) ON, OFF OFF AL-1 (Alarm 1) 1 to 90% of Full Range 20% / F.R. 1H / 1L (Alarm operation direction) H: rising alarm / L: falling alarm 1H 1H00 / 1L00 (Dead band) 0 ~ 10% / Full Range 1H00 AL1T (Alarm1 time) 0 to 30 sec (Alarm delay time) One A1RL (Alarm1 Relay) ON, OFF (Relay use setting) ON AL-2 (Alarm 2) 1 to 100% of Full Range 40% / F.S. 2H / 2L (Alarm operation direction) H: rising alarm / L: falling alarm 2H 2H00 / 2L00 (Dead band) 0 ~ 10% / Full Range 2H00 AL2T (Alarm2 time) 0 to 30 sec (Alarm delay time) One A2RL (Alarm2 Relay) ON, OFF (Relay use setting) ON END - -

TIME
(TIME MODE)
CLOC (Clock) Check Current Time Mode 2012 year 10-16 Month / day 12:30 Hour / minute END - - CLTM (Calibration time) Checking Calibration Date Mode 2012 year 10-16 Month / day 12:30 Hour / minute END - -







S-DT
(SENSOR DATA
MODE)


GAS HC default PROP CO CO2 LOW HIGH N2O MDET Sensor Detection ADC value - MREF Sensor Reference ADC value - RATO The ratio of the zero value to the measured value (Ratio) M-T Sensor Temperature Data value ZDET Zero Detection Data value - ZREF Zero Reference Data value - Z-T Temperature at Zero SDET Span Detection Data value - SREF Span Reference Data value - S-T Temperature at Span - AZ-D Auto Zero Detection Data value - AZ-R Auto Zero Reference Data value - AZ-T Temperature at Auto Zero - END - -

TEST
(TEST MODE) FND FND display status check mode TRLY Relay ON / OFF during test OFF T-MA ON / OFF of mA output during test OFF TGAS Gas concentration simulation test FOUT Check the flow sensor output TEMP Check current sensor temperature END -

FLOW
(FLOW MODE) AUTO (Auto) YES (automatic), no (manual) (Flow control method setting) NO F-LE (Flow level) OFF ~ 2000 ml / min Flow Level Setting 1000ml / min Flow delay time (F-TM) 15 ~ 60sec (Flow error delay time setting) 30sec END -

MT
(MAINTENANCE MODE) AOO (mA Output Offset) -1.00 to + 1.00, mA Analog Output Offset Setting 0 CSEN (Cross sensitivity) 1.00 to 5.00 (Relative sensitivity value setting) 100 MUAL (Maintenance Value) 0 ~ Full Range (Set value to output when checking (EMS))
Check Mode (EMS: Emergency Maintenance System) 0 ZBAN (Zero band) ON, OFF (Zero band suppression control setting) OFF TZRO (Temp. Zero) ON, OFF (Temp. Zero control setting) ON TCMP (Temp. Compensation) ON, OFF (Temp. Compensation control setting) ON AUZO (Auto zero) ON, OFF (Auto zero control setting) ON BASE (Base Zero) ON, OFF (Base zero control setting) ON BSPN (Base Span) ON, OFF (Base span control setting) ON RFZO (Reference Zero) ON, OFF (Reference zero control setting) OFF ENGM (Engineering Mode) ON, OFF (Enable / Disable Engineering Mode) OFF UNDR (Under) ON, OFF (Under function enable / disable setting) OFF Output delay time (ODT) OFF, 1 ~ 60sec (Setting of measurement data delay time) OFF Output delay value (ODU) OFF, 1 ~ 20% / F.S (Output signal delay value range setting) OFF E-TO
(Emergency mode - time out) ON, OFF (Enable / disable time out) OFF FTMA (Faultma Output) 0mA, 2mA 2mA END -



ADJ
(ADJUST MODE)
FCAL (Flow Calibration) NO, YES NO 0 Pressure Sensor value when Pump is not operated - 500 Value for SPAN calibration. 500cc / min 450 Current measurement value MA-C
(mA Output Calibration) mA Output Output Calibration
NO, YES NO 0A04 4mA output calibration mode 0A20 20mA output calibration mode END -

The explosion-proof air intake type infrared sensor type gas sensing apparatus according to an embodiment of the present invention can set a condition for generating two alarms, and two alarms can be set according to the flowchart of FIG. 7, respectively.

Referring to FIG. 7, in order to set an alarm generation condition, the controller 130 sets an alarm reference value (S710) and sets an alarm direction (S720). The alarm direction is a setting indicating whether to generate an alarm when the alarm reference value is greater than or equal to the set alarm reference value, or to generate an alarm when the alarm reference value is less than the alarm reference value. As an example, when an alarm is generated when the concentration of toxic gas is 1000 parts per million (parts per million) or more, the alarm reference value may be set to 1000 ppm and the alarm direction may be set upward.

Next, the control unit 130 may set a hysteresis value (S730). If the gas concentration reaches or falls below the alarm reference value, or if the gas concentration becomes larger or smaller than the alarm reference value, the alarm can be repeatedly operated / released repeatedly. To eliminate this phenomenon, a hysteresis value can be set. When the alarm direction is upward, the alarm is generated when the alarm reference value is equal to or greater than the hysteresis value, and the alarm is released when the alarm reference value is less than the hysteresis value. When the alarm direction is downward, the alarm occurs when the alarm reference value is less than the hysteresis value, and the alarm is released when the alarm reference value is more than the hysteresis value. For example, if the alarm reference value is 1000 ppm, the hysteresis value is 100 ppm, and the alarm direction is upward, the alarm is generated when the gas concentration is 1100 ppm or more, and the alarm is released when the gas concentration is 900 ppm or less.

Next, the control unit 130 may set the delay time (S740). An alarm is not generated if the alarm condition is satisfied within the set delay time even if the alarm condition is reached, And generates an alarm only when the alarm condition is continuously reached beyond the set delay time. In one embodiment, if the delay time is set to 5 seconds, the alarm is generated only when the alarm condition is set for 5 seconds or longer. Otherwise, if the alarm condition is satisfied within 5 seconds, the alarm is not generated .

8 is a flowchart showing a gas measurement method according to an embodiment of the present invention.

Referring to FIG. 8, in the explosion-proof air-intake type infrared sensor type gas sensing apparatus having an explosion-proof structure, the method for measuring the gas may actively suck air for measurement (S810) to meet the set target flow rate. The amount of air to be inhaled must be constant for an accurate measurement of the gas composition. For this, the air can be actively sucked in accordance with the target flow rate set in the apparatus by using the flow sensor 117 and the pump 119. The gas component present in the inhaled air can be measured (S820) using an infrared sensor module. Then, the air sucked after the measurement is discharged (S840), and the measurement result can be displayed on the display (S830).

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims and their equivalents. Only. The scope of the present invention is defined by the appended claims rather than the detailed description and all changes or modifications derived from the meaning and scope of the claims and their equivalents are to be construed as being included within the scope of the present invention do.

Claims (19)

A sampling mechanism for controlling the suction of air for measurement and the discharge of air after measurement;
An infrared sensor module for measuring a gas component in the sucked air;
A control unit for processing measurement values coming from the infrared sensor module and outputting measurement results;
A terminal unit for communicating with outside and receiving and outputting information under the control of the control unit; And
And a housing having a space capable of installing the sampling mechanism unit, the infrared sensor module, the control unit, and the terminal unit therein,
Explosion-proof air intake type infrared sensor type gas sensing device. The apparatus according to claim 1,
A suction port through which air for measurement is sucked;
An exhaust port for exhausting the air after the measurement;
A pump for sucking the air;
A flow rate sensor for measuring a flow rate of the sucked air; And
And a sampling line for guiding internal circulation of the air to allow the air that has entered the suction port to be discharged to the exhaust port via the infrared sensor module, the flow rate sensor, and the pump.
Explosion-proof air intake type infrared sensor type gas sensing device. 3. The apparatus of claim 2,
And controlling the operation of the pump by comparing the flow rate measured by the flow rate sensor with a set target flow rate,
Explosion-proof air intake type infrared sensor type gas sensing device. The infrared sensor module according to claim 1,
An infrared ray generating element for generating an infrared ray;
An optical aperture through which the generated infrared light passes;
A reference sensor and a detection sensor for detecting the infrared ray passing through the optical aperture;
An interface unit for transmitting data measured by the reference sensor and the detection sensor to the control unit; And
And a sapphire glass for completely separating and sealing the infrared ray generating element, the reference sensor and the detection sensor.
Explosion-proof air intake type infrared sensor type gas sensing device. The infrared ray generating device according to claim 4,
Generating infrared rays containing a wavelength of 5.6 [micro] m at 2 [micro] m (micro meter)
Explosion-proof air intake type infrared sensor type gas sensing device. 5. The method of claim 4,
Wherein the reference sensor comprises a first optical filter for selectively passing only light in a wavelength band centered at 4.0 um which is not absorbed by hydrocarbon-based flammable gases,
Wherein the detection sensor comprises a second optical filter for selectively passing only light in a wavelength band centered at 3.3 um absorbed by a hydrocarbon-based combustible gas,
Explosion-proof air intake type infrared sensor type gas sensing device. 5. The sapphire glass according to claim 4,
Wherein the infrared sensor is located at both ends of the optical hole so that the infrared ray generating element, the reference sensor,
Explosion-proof air intake type infrared sensor type gas sensing device. The terminal according to claim 1,
A power supply for receiving a power supply;
A communication unit for supporting at least one of an RS485 communication unit for sharing the measurement result with an external system and a current output unit for outputting a current indicating a measurement result;
An alarm output unit for outputting alarms generated by the device under the control of the control unit;
A key input unit for user input; And
And a display unit for displaying a setting screen and a measurement result under the control of the control unit.
Explosion-proof air intake type infrared sensor type gas sensing device. 9. The semiconductor memory device according to claim 8,
And outputting a current value proportional to the measurement result,
Explosion-proof air intake type infrared sensor type gas sensing device. 10. The method according to claim 9,
"

"And "
Wherein the set maximum value is a maximum value of a range set by the controller,
Explosion-proof air intake type infrared sensor type gas sensing device. 11. The semiconductor memory device according to claim 10,
Explosion-proof air intake type infrared sensor type It is an alarm signal to notify that there is an abnormality in the gas detection device. It outputs 0mA or 2mA current,
Explosion-proof air intake type infrared sensor type gas sensing device. 11. The semiconductor memory device according to claim 10,
And outputting a current value of 20 mA to 22 mA to indicate that the measurement result is larger than the set maximum value,
Explosion-proof air intake type infrared sensor type gas sensing device. 9. The apparatus according to claim 8,
It includes three alarm signals,
Explosion-proof air intake type infrared sensor type gas sensing device. 14. The apparatus according to claim 13,
Further comprising a jumper or switch for determining an output mode of the alarm signal,
And outputting the alarm signal in the form of an NC (Normal Close) signal or a NO (Normal Open) signal by connection of the jumper or switch.
Explosion-proof air intake type infrared sensor type gas sensing device. The apparatus of claim 8, wherein the key input unit comprises:
Function key for entering or setting mode in entering function setting mode;
An Up key and a Down key, which are used to move between the items configured in each mode; And
And an RST key for returning to the measurement mode in the function setting mode,
Explosion-proof air intake type infrared sensor type gas sensing device. The apparatus of claim 8, wherein the key input unit comprises:
The non-contact type magnetic switches are employed as input means, and when the magnetic bar is positioned at a predetermined position on the transparent window from the outside of the housing,
Explosion-proof air intake type infrared sensor type gas sensing device. The display device according to claim 8,
A light source for indicating whether or not the power supply is normally supplied;
A light source for displaying a fault when a self-diagnosis is detected;
Two alarm light sources for displaying an alarm when the alarm is being set or an alarm is set by the controller;
An FND (Flexible Numeric Display) indicating the gas concentration value measured in the sensor cartridge and the number and icon set in the function setting mode;
A light source for displaying current air flow in the form of a graph bar;
A light source indicating that the calibration is in progress;
A light source to be displayed upon entry into the function setting mode;
A light source to indicate when RS485 communication is connected;
A light source displayed when the maintenance mode is executed; And
And a unit display unit for displaying a gas measurement unit.
Explosion-proof air intake type infrared sensor type gas sensing device. A method for generating an alarm in an explosion-proof air-intake type infrared sensor type gas sensing apparatus having an explosion-proof structure and measuring gas concentration by sensing gas,
An alarm reference value setting step of setting a reference value for generating an alarm;
An alarm direction setting step of setting an alarm generating condition when the alarm reference value is equal to or greater than the alarm reference value and an alarm generating condition when the alarm reference value is equal to or less than the alarm reference value;
A hysteresis value setting step of preventing occurrence / release of an alarm by repeating the gas concentration being greater or smaller than the alarm reference value; And
And a delay time setting step for preventing a momentary malfunction due to external impact or noise,
When the alarm direction is an upward condition, generates an alarm when the gas concentration is longer than the delay time by more than (the alarm reference value + the hysteresis value)
When the alarm direction is downward, generates an alarm when the gas concentration is equal to or less than the alarm reference value (hysteresis value) or longer than the delay time,
How to generate an alarm. A method for measuring gas in an explosion-proof air-intake type infrared sensor type gas sensing apparatus having an explosion-proof structure and measuring gas concentration by sensing gas,
Actively sucking air for measurement to a target flow rate set using a pump;
Measuring a gas component in the inhaled air;
Displaying the gas component being measured; And
Discharging the sucked air after the measurement;
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