Test equipment and test method for measuring influence of moisture on measurement result of open-circuit type gas detector

Abstract

The invention discloses test equipment for measuring the influence of moisture on the measurement result of an open-circuit type gas detector and a test method thereof.The test equipment comprises a water vapor generator, a transmission pipeline, a water vapor experiment module, a support, a transmitting device and a receiving device, one end of the transmission pipeline is connected with the water vapor generator, and the other end of the transmission pipeline is connected with the water vapor experiment module; one side of the water vapor experiment module is provided with a transmitting device, and the other side is provided with a receiving device; the water vapor experiment module is arranged at the top end of the bracket. The method for measuring the influence of the moisture in the gas on the measurement result of the open-circuit type gas detector is scientific, reasonable and feasible, rapid and simple in measurement and easy to operate, and is worthy of being applied to tests for confirming the influence of agglomerate fog, air moisture and the like on the measurement result of the open-circuit type gas detector in field conditions; the invention further relates to research on a measuring method for measuring the accuracy of the value measured by the open-circuit type gas detector in future.

Description

Technical Field

[0001] The invention relates to the technical field of gas monitoring, and in particular to a test device and a test method for measuring the influence of moisture on the measurement result of an open-circuit gas detector. Background Art

[0002] In the petroleum and petrochemical production site, flammable gas may be generated or leaked, and there is a risk of fire and explosion. The use of flammable gas detection alarm can monitor the leaked gas in time and issue an alarm to ensure safe production. For a long time, flammable gas detection at home and abroad has been mainly point-based, adopting the working mode of on-site detection. The detection technologies used include catalytic combustion, semiconductor, NDIR (non-dispersive infrared), etc. In practical applications, there are generally problems such as small detection range, short life, long response time, and high maintenance cost. With the advancement of technology and the gradual increase in the requirements for safety warning of major hazardous sources such as tank areas, some companies involved in the production and storage of hazardous chemicals have installed a certain number of open-circuit flammable gas detection alarms as a supplement in addition to conventional point gas detectors in hazardous areas to improve the reliability of hazardous gas leakage detection and shorten the alarm response time, which greatly improves the limitations of traditional detection technology in application and the various problems it brings. A large number of leakage incidents at home and abroad show that the open-circuit flammable gas detection alarm is set at the boundary of the hazardous source, which complements the point type and can significantly improve the reliability of leakage warning.

[0003] The working principle of the ELDS open-circuit combustible gas detection alarm is quite different from that of traditional alarms. It uses lasers in a specific band to transmit to the receiver end. The gas being measured will absorb the narrow-band laser radiation to produce a harmonic fingerprint. This harmonic fingerprint is unique to the gas being measured, and its harmonic amplitude is proportional to the total amount of gas in the laser beam. The gas concentration at the transmitting and receiving ends of the instrument is measured to obtain the gas integrated concentration. What is measured is the integral of the gas concentration on the monitoring path, or the average concentration of the gas along the line.

[0004] However, due to the characteristics of the measurement method, this method will be affected by the ambient air conditions and thus affect the measurement results. In particular, petroleum and petrochemical facilities and sites are mostly built in places far away from urban areas, especially in mountainous areas, which often produce high humidity environmental conditions such as fog in the morning and evening.

[0005] In view of the above problems, the present invention provides a test device and a test method for measuring the influence of moisture on the measurement results of an open-circuit gas detector in order to improve the reliability of leakage warning. Summary of the invention

[0006] The invention provides a test device and a test method for measuring the influence of moisture on the measurement result of an open-circuit gas detector, which can improve the reliability of leakage warning.

[0007] The purpose of the present invention is to provide a test device for measuring the influence of moisture on the measurement results of an open-circuit gas detector, comprising a water vapor generator, a transmission pipeline, a water vapor test chamber, a bracket, a transmitting device and a receiving device. One end of the transmission pipeline is connected to the water vapor generator, and the other end is connected to the water vapor test chamber. A transmitting device is provided on one side of the water vapor test chamber, and a receiving device is provided on the other side. The water vapor test chamber is arranged at the top of the bracket.

[0008] A test method for measuring the effect of moisture on the measurement results of an open-circuit gas detector, the test method comprising the following steps: Step 1: Filling the standard gas chamber: prepare standard gas with a concentration of about 20%, 50%, and 80% of the full scale, with a concentration of about 0.25 LEL·m, 0.50 LEL·m, and 0.77 LEL·m; Step 2: Debug the instrument: Align the optical path so that the light intensity at the receiving end of the instrument meets the normal working requirements and is in a stable working state; Step 3: Calibrate the instrument: Place the standard gas chamber filled with zero-point gas in the optical path of the instrument, make the lenses on both sides of the standard gas chamber perpendicular to the optical path, and the transmitted light beam is located at the center of the two lenses of the gas chamber. After the indication is stable, adjust the zero point of the instrument, and then place a standard gas chamber of about 80% of the full scale in the optical path of the instrument. After the indication is stable, adjust the indication of the instrument to be consistent with the gas integrated concentration value of the standard gas chamber. Step 4, error measurement: Place standard gas chambers with gas concentrations of approximately 20%, 50%, and 80% of the full scale in the optical path of the instrument, so that the lenses on both sides of the standard gas chamber are perpendicular to the optical path, and the transmitted light beam is located at the center of the two lenses of the gas chamber. After the indication is stable, record the instrument indication and the length of the standard gas chamber. Repeat the measurement 3 times and take the average value as the instrument measurement result. Step 5. Measurement of moisture impact: Place the developed moisture interference equipment at different positions in the optical path, and measure the impact of moisture interfering gases of different concentrations and different lengths on the measurement results.

[0009] The present invention has the following advantages: the present invention measures the influence of moisture on the measurement results of an open-circuit gas detector. The method is scientific, reasonable and feasible. The measurement is quick and simple, and easy to operate. It is worthy of application in experiments to confirm the influence of moisture on the measurement results of an open-circuit gas detector, as well as in future measurements of the accuracy of the values ​​measured by an open-circuit gas detector. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a schematic diagram of the structure of the present invention.

[0011] In the figure: 1. Water vapor generator; 2. Transmission pipeline; 3. Water vapor experimental chamber; 4. Bracket; 5. Transmitter; 6. Receiving device. DETAILED DESCRIPTION

[0012] The present invention provides a test device for measuring the influence of moisture on the measurement result of an open-circuit gas detector, comprising a water vapor generator 1, a transmission pipeline 2, a water vapor test chamber 3, a bracket 4, a transmitting device 5 and a receiving device 6, one end of the transmission pipeline 2 is connected to the water vapor generator 1, and the other end is connected to the water vapor test chamber 3, one side of the water vapor test chamber 3 is provided with the transmitting device 5, and the other side is provided with the receiving device 6, and the water vapor test chamber 3 is arranged at the top of the bracket 4.

[0013] A test method for measuring the effect of moisture on the measurement results of an open-circuit gas detector, the test method comprising the following steps: Step 1: Filling the standard gas chamber: prepare standard gas with a concentration of about 20%, 50%, and 80% of the full scale, with a concentration of about 0.25 LEL•m, 0.50 LEL•m, and 0.77 LEL•m; Step 2: Debug the instrument: Align the optical path so that the light intensity at the receiving end of the instrument reaches the normal working requirements and is in a stable working state; Step 3: Calibrate the instrument: Place the standard gas chamber filled with zero-point gas in the optical path of the instrument, make the lenses on both sides of the standard gas chamber perpendicular to the optical path, and the transmitted light beam is located at the center of the two lenses of the gas chamber. After the indication is stable, adjust the zero point of the instrument, and then place a standard gas chamber of about 80% of the full scale in the optical path of the instrument. After the indication is stable, adjust the indication of the instrument to be consistent with the gas integrated concentration value of the standard gas chamber. Step 4, error measurement: Place standard gas chambers with gas concentrations of approximately 20%, 50%, and 80% of the full scale in the optical path of the instrument, so that the lenses on both sides of the standard gas chamber are perpendicular to the optical path, and the transmitted light beam is located at the center of the two lenses of the gas chamber. After the indication is stable, record the instrument indication and the length of the standard gas chamber. Repeat the measurement 3 times and take the average value as the instrument measurement result. Step 5. Measurement of moisture impact: Place the developed moisture interference equipment at different positions in the optical path, and measure the impact of moisture interfering gases of different concentrations and different lengths on the measurement results.

[0014] In this embodiment, the moisture interference device can adjust the amount of different moisture concentrations and the effective interference distance of different interfering gases. The instrument is easy to carry and move, which is convenient for conducting experiments on site and measuring the degree of influence of different moisture concentrations and interference distances on the measurement results.

[0015] In this embodiment, a test method and a calculation method for the influence of moisture on the measurement result of an open-circuit gas detector are studied. This method can prove the influence of moisture on the measurement result of an open-circuit gas detector.

[0016] In this embodiment, the transmitting device 5 generates an optical signal, which passes through the water vapor test chamber 3 and is received by the receiving device 6. During the experiment, the water vapor concentration is adjusted by the water vapor generator 1, and different concentrations of water vapor are used to test whether the signal strength of the receiving end 6 is consistent when the same intensity signal is generated at the generating end.

[0017] In this embodiment, the water vapor test chamber 3 is composed of three water vapor test chambers 3 of different lengths, 0.5 m, 1.0 m, and 1.5 m, to test the influence of water vapor of different lengths on the receiving intensity of the receiving end 6.

[0018] Although the specific implementation of the present invention is described in detail in conjunction with the drawings, it should not be understood as limiting the scope of protection of this patent. Within the scope described in the claims, various modifications and variations that can be made by those skilled in the art without creative work still fall within the scope of protection of this patent.

Claims

1. A test device for measuring the influence of moisture on the measurement results of an open-circuit gas detector, comprising a water vapor generator, a transmission pipeline, a water vapor test chamber, a bracket, a transmitting device and a receiving device, characterized in that: One end of the transmission pipeline is connected to the water vapor generator, and the other end is connected to the water vapor test cabin. One side of the water vapor test cabin is provided with a transmitting device, and the other side is provided with a receiving device. The water vapor test cabin is arranged at the top of the bracket.

2. A test method for measuring the effect of moisture on the measurement results of an open-circuit gas detector, the test method comprising the following steps: Step 1: Filling the standard gas chamber: prepare standard gas with a concentration of about 20%, 50%, and 80% of the full scale, with a concentration of about 0.25 LEL·m, 0.50 LEL·m, and 0.77 LEL·m; Step 2: Debug the instrument: Align the optical path so that the light intensity at the receiving end of the instrument meets the normal working requirements and is in a stable working state; Step 3: Calibrate the instrument: Place the standard gas chamber filled with zero-point gas in the optical path of the instrument, make the lenses on both sides of the standard gas chamber perpendicular to the optical path, and the transmitted light beam is located at the center of the two lenses of the gas chamber. After the indication is stable, adjust the zero point of the instrument, and then place a standard gas chamber of about 80% of the full scale in the optical path of the instrument. After the indication is stable, adjust the indication of the instrument to be consistent with the gas integrated concentration value of the standard gas chamber. Step 4, error measurement: Place standard gas chambers with gas concentrations of approximately 20%, 50%, and 80% of the full scale in the optical path of the instrument, so that the lenses on both sides of the standard gas chamber are perpendicular to the optical path, and the transmitted light beam is located at the center of the two lenses of the gas chamber. After the indication is stable, record the instrument indication and the length of the standard gas chamber. Repeat the measurement 3 times and take the average value as the instrument measurement result. Step 5. Measurement of moisture impact: Place the developed moisture interference equipment at different positions in the optical path, and measure the impact of moisture interfering gases of different concentrations and different lengths on the measurement results.

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