A calibration cover

Abstract

This utility model relates to the field of metrological verification technology for gas detection alarms, specifically a calibration cover for calibrating gas detection alarms. The calibration cover includes a diffuser and an inlet assembly connected sequentially in the flow direction of the standard gas. The diffuser also has an outlet, a notch, and a groove. The outlet is located at the end of the diffuser away from the inlet assembly, and the notch is located at the outlet. The groove is located on the inner wall of the diffuser and extends along the inner wall towards the flow direction of the standard gas, extending to the outlet and communicating with at least part of the notch. This utility model, by providing a groove on the inner wall of the diffuser and a notch on the outlet, allows the standard gas to flow out through the groove and / or the notch. This ensures that the calibration cover can guarantee unobstructed exhaust of the standard gas when calibrating gas detection alarms of different sizes, preventing an increase in the concentration of the standard gas inside the calibration cover, which could then affect the determination of the calibration results.

Description

Technical Field

[0001] This utility model relates to the field of gas detection alarm metrological verification technology, and in particular to a calibration cover. Background Technology

[0002] Currently, there are many types of gas detection alarms, including combustible gas detectors, carbon monoxide detectors, hydrogen sulfide detectors, and combined gas detectors. They are widely used in power plants, chemical plants, and mines, playing a crucial role in ensuring production safety. To ensure the accuracy of the measured values, these gas detection alarms must be calibrated and verified regularly. According to the technical requirements of JJG693-2011 "Verification Procedure for Combustible Gas Detectors," diffusion-type combustible gas detectors must be equipped with a dedicated calibration hood. A standard gas of a specific concentration is introduced through the calibration hood close to the alarm. The concentration displayed by the gas detector is compared with the concentration of the standard gas to determine whether the gas detector is qualified. Therefore, ensuring that the concentration of the standard gas remains constant during the introduction of the gas detector is crucial in the detection process.

[0003] However, different manufacturers produce detectors for different gases with varying sizes and shapes. Therefore, the size and shape of the calibration hoods used for calibration and verification also differ. Verification personnel need to prepare multiple types of calibration hoods when calibrating detectors for different gases, resulting in a heavy workload and a high risk of errors. To address this, universal calibration hoods have emerged on the market that can be used for detectors of various sizes and shapes. These universal calibration hoods calibrate the detector by housing the detector's probe within the hood. However, when using these universal calibration hoods, two problems may arise: firstly, the exhaust end of the hood may come into contact with the detector; secondly, the probe may come into contact with the universal calibration hood itself. Both situations can lead to poor exhaust, increased concentration of the standard gas, and affect the interpretation of the calibration results. In addition, some detection alarms are installed at a high position. During the calibration, the calibration cover is usually assembled on the telescopic rod. The telescopic rod is used to raise the calibration cover to the height of the detection alarm for calibration. When the calibration personnel hold the telescopic rod, it is easy for it to shake and forcefully squeeze the calibration cover against the detection alarm. The calibration cover is more likely to experience the aforementioned problem of poor airflow. Utility Model Content

[0004] To address the aforementioned problems in the prior art, this utility model provides a calibration cover that solves at least one of the following problems when existing calibration covers are used to calibrate gas detection alarms: poor exhaust and poor versatility.

[0005] To achieve the above objectives, this utility model provides a calibration cover for calibrating a gas detection alarm. The calibration cover includes a diffuser and an air inlet assembly. In the flow direction of the standard gas, the air inlet assembly and the diffuser are connected in sequence. The diffuser is also provided with an outlet, a notch, and a groove. The outlet is located at the end of the diffuser away from the air inlet assembly, and the notch is located at the outlet. The groove is located on the inner wall of the diffuser and extends along the inner wall of the diffuser toward the flow direction of the standard gas. The groove extends to the outlet and communicates with at least a portion of the notch.

[0006] Furthermore, the outer wall of the diffuser is provided with reinforcing ribs, which are distributed correspondingly to the grooves.

[0007] Furthermore, the diffuser also includes a protrusion protruding outward from the outer circumference of the air outlet end, the protrusion being arranged in a ring shape and surrounding the outer circumference of the air outlet end.

[0008] Furthermore, the groove is provided in three parts, and the three grooves are evenly distributed on the inner sidewall of the diffuser.

[0009] Furthermore, the diffuser is arranged in a trumpet shape.

[0010] Furthermore, the air intake assembly includes a connecting part and an air intake pipe, and the air intake pipe, the connecting part, and the diffuser are connected in sequence in the flow direction of the standard gas.

[0011] Furthermore, the intake pipe is provided with a gas channel, the connecting part is provided with a gas cavity, the diffuser includes a diffusion space, and the gas channel, the gas cavity and the diffusion space are sequentially connected.

[0012] Furthermore, the intake pipe has an external thread on its outer side wall near the connection part, and the calibration cover can be connected to other equipment through the external thread.

[0013] Furthermore, the connecting part is cylindrical in design, and the air intake pipe is connected to the middle of the connecting part.

[0014] Furthermore, the gas cavity is provided with a guide member that covers the gas channel, and the guide member is provided with a plurality of guide holes.

[0015] The beneficial effects of this utility model are as follows: By providing a groove on the inner wall of the diffuser, when a gas detector with a size smaller than the diameter of the outlet end extends into the diffuser and abuts against the inner wall of the diffuser, the standard gas can flow out through the groove; by providing a notch on the diffuser, when a gas detector with a size larger than the diameter of the outlet end abuts against the outlet end, the standard gas can flow out through the notch. By providing the groove and the notch, the calibration cover can ensure smooth exhaust of the standard gas when calibrating gas detectors of different sizes, avoiding an increase in the concentration of the standard gas in the calibration cover, which would affect the judgment of the calibration results. At the same time, it also improves the versatility and practicality of the calibration cover. Attached Figure Description

[0016] Figure 1 This is a three-dimensional schematic diagram of the calibration cover provided by this utility model.

[0017] Figure 2 This is a three-dimensional schematic diagram from another perspective of the calibration cover provided by this utility model.

[0018] Figure 3 This is a top view of the calibration cover provided by this utility model.

[0019] Figure 4 This is a cross-sectional view of the calibration cover provided by this utility model.

[0020] Figure 5 for Figure 1 A magnified view of part A in the middle.

[0021] Figure 6 This is a perspective view of the calibration cover of the second embodiment provided by this utility model.

[0022] Reference numerals: Calibration cover 100, diffuser 1, groove 11, air outlet 12, boss 13, notch 14, reinforcing rib 15, diffuser space 16; air inlet assembly 2, connecting part 21, air chamber 211, air inlet pipe 22, gas channel 221, external thread 222, guide 212, guide hole 213. Detailed Implementation

[0023] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0024] Please see Figure 1 and Figure 2As shown, this utility model discloses a calibration cover 100 for calibrating a gas detection alarm. The calibration cover 100 covers at least part of the gas detection alarm. Standard gas is delivered to the gas detection alarm through the calibration cover 100. The gas detection alarm is calibrated by comparing the concentration of the standard gas with the concentration detected by the gas detection alarm.

[0025] Please see Figure 1 , Figure 3 and Figure 4 As shown, the calibration cover 100 includes a diffuser 1 and an air inlet assembly 2. The air inlet assembly 2 and the diffuser 1 are connected sequentially in the flow direction of the standard gas. The diffuser 1 also has an outlet end 12, a notch 14, and a groove 11. The outlet end 12 is located at the end of the diffuser 1 away from the air inlet assembly 2. The notch 14 is formed at the outlet end 12. The groove 11 is located on the inner wall of the diffuser 1 and extends along the inner wall of the diffuser 1 towards the flow direction of the standard gas. The groove 11 extends to the outlet end 12 and communicates with at least a portion of the notch 14. The diffuser 1 is funnel-shaped, and the groove 11 is formed by recessing inward from the inner wall surface of the diffuser 1. The angle between the extending direction of the diffuser 1 and the plane containing the outlet end 12 is 30-60°, preferably 45°. The groove 11 is semi-circular with a radius of 4-8 mm, preferably 6 mm.

[0026] By providing a groove 11 extending along the flow direction of the standard gas on the inner wall of the diffuser 1, when a gas detector or gas detector probe with a size smaller than the diameter of the outlet 12 is inserted into the diffuser 1 and comes into contact with the inner wall of the horn-shaped diffuser 1, the standard gas can flow out through the groove 11, thus avoiding the formation of a closed space between the diffuser 1 and the gas detector, which would cause the standard gas to accumulate in the closed space and increase the concentration of the standard gas, thereby affecting the determination of the test results.

[0027] By setting the diffuser 1 in a horn shape, the diffuser 1 can be used to calibrate gas detectors of different shapes and sizes, thereby improving the versatility and practicality of the calibration cover 100.

[0028] Combination Figure 5As shown, the notch 14 is recessed from the end face of the outlet end 12 toward the diffuser 1. By providing the notch 14 on the outlet end 12, when a gas detector or gas detector probe with a size larger than the diameter of the outlet end 12 cannot be inserted into the diffuser 1, causing the outlet end 12 of the diffuser 1 to be in complete contact with the gas detector or gas detector probe, the standard gas in the diffuser 1 can flow out through the notch 14, preventing the concentration of the standard gas in the diffuser 1 from increasing, thereby ensuring the accuracy of the calibration; at the same time, when the gas detector or gas detector probe is provided with other structures, some of the structures can also be accommodated in the notch 14, improving the applicability of the diffuser shroud 100.

[0029] In this embodiment, there are three grooves 11, and the grooves 11 are semi-circular or similar to semi-circular. The three grooves 11 are evenly distributed on the inner wall of the diffuser 1. Specifically, the three grooves 11 are radially distributed on the inner wall of the diffuser 1. Of course, in other embodiments, the number of grooves 11 can be set to one, two, four, five, or other numbers according to the actual situation. They can also be non-uniformly distributed. The shape of the grooves 11 can also be designed as arc or triangle, etc., as long as it can enable the standard gas to flow out through the grooves 11 when the gas detection alarm abuts against the inner wall of the calibration cover 100. There is no limitation here.

[0030] In this embodiment, there are three notches 14 corresponding to the grooves 11. Of course, in other embodiments, the number of notches 14 can be greater than the number of grooves 11, that is, some notches 14 do not correspond to the grooves 11. As long as it can achieve the purpose of preventing the standard gas in the diffuser 1 from flowing out through the notches 14 when the gas outlet 12 of the diffuser 1 is fully in contact with the gas detection alarm, the concentration of the standard gas in the diffuser 1 will not increase. There is no limitation here.

[0031] The air outlet 12 is located at the end with the larger flared opening, i.e., the outer edge of the diffuser 1. The end face of the air outlet 12 is rounded to avoid scratching other equipment or operators. The air outlet 12 is circular with a diameter of 60-100mm, preferably 80mm.

[0032] Please see Figure 2 and Figure 3 As shown, the diffuser 1 also includes a boss 13 protruding outward from the outer circumference of the air outlet 12. The boss 13 is arranged in a ring shape and surrounds the outer circumference of the air outlet 12. This arrangement makes the edge of the diffuser 1 aesthetically pleasing and strengthens the air outlet 12, preventing the air outlet 12 from deforming and being damaged under external force.

[0033] A reinforcing rib 15 is also provided on the outer wall of the diffuser 1, and the reinforcing rib 15 is distributed correspondingly to the groove 11. Specifically, the reinforcing rib 15 protrudes from the outer wall surface of the diffuser 1 in a direction away from the diffuser 1. This arrangement improves the strength of the diffuser 1, making it less prone to deformation or damage. There are three reinforcing ribs 15 corresponding to the groove 11. Of course, in other embodiments, the number of reinforcing ribs 15 can be more or less depending on the actual situation, and there is no limitation here.

[0034] Please see Figure 2 and Figure 4 As shown, the air intake assembly 2 of the calibration cover 100 includes a connecting portion 21 and an air intake pipe 22. In the flow direction of the standard gas, the air intake pipe 22, the connecting portion 21, and the diffuser 1 are sequentially connected to the connecting portion 21. The air intake pipe 22 extends from the connecting portion 21 in a direction away from the diffuser 1. Specifically, the air intake pipe 22 is located at the middle of the connecting portion 21. Specifically, the calibration cover 100 is integrally formed by die stamping, that is, the air intake assembly 2 of the connecting portion 21 and the diffuser 1 are integrally formed. Of course, in other embodiments, the calibration cover 100 can also be formed by 3D printing.

[0035] The groove 11 extends from the connection between the diffuser 1 and the connecting part 21 along the inner wall of the diffuser 1 to the outlet end 12. Correspondingly, the reinforcing rib 15 also extends from the connection 21 between the diffuser 1 and the connecting part 21 along the outer wall of the diffuser 1 to the outlet end 12. Specifically, the reinforcing rib 15 extends to the boss 13 and connects with the boss 13. Of course, in other embodiments, the length of the groove 11 can be set according to the actual situation. That is, the groove 11 can extend outward from near the middle of the inner wall of the diffuser 1, or the groove 11 can extend outward from the inner wall of the connecting part 21. There is no limitation here.

[0036] In the direction of standard gas flow, the length of the connecting part 21 is 30-50 mm, preferably 40 mm.

[0037] The connecting part 21 is cylindrical, and its cross-section along the standard gas flow direction is U-shaped. Specifically, the edge of the connecting part 21 away from the outlet end 12 is designed with an annular bevel. This design improves the appearance of the connecting part 21 and prevents the edge from scratching other equipment or operators.

[0038] The inlet pipe 22 has a gas channel 221, the connecting part 21 has a gas chamber 211, and the diffuser 1 includes a diffuser space 16. The gas channel 221, the gas chamber 211, and the diffuser space 16 are connected in sequence. When the inlet pipe 22 is connected to an external standard gas tank (not shown), the gas in the standard gas tank enters the gas chamber 211 through the gas channel 221, then enters the diffuser space 16 through the gas chamber 211, and flows out from the outlet end 12. Specifically, by setting the gas chamber 211 in the connecting part 21, the calibration cover 100 can create a space below the gas detector probe when in use. When the standard gas flows in through the gas channel 221, it will first fill the gas chamber 211, then rise evenly and enter the gas detector probe, thereby ensuring that the concentration of the standard gas remains constant throughout the calibration process.

[0039] The gas channel 221 is circular in design, and the diameter of the gas channel 221 is 4-8mm, preferably 6mm.

[0040] An external thread 222 is provided on the outer wall of the air intake pipe 22. Specifically, the external thread 222 is located on the side of the air intake pipe 22 near the connecting part 21, and the calibration cover 100 can be connected to other equipment through the external thread 222. Specifically, the calibration cover 100 can be threadedly connected to an external telescopic rod (not shown) through the external thread to calibrate gas detection alarms installed at higher positions.

[0041] The material of the standard cover 100 in this utility model can be ordinary plastic, rubber or metal, etc.

[0042] It should be noted that in this invention, the flow direction of the standard gas is from the inlet pipe 22 toward the outlet pipe 12.

[0043] In the above embodiments, the calibration hood 100 is preferably used in a propane gas detector alarm that is heavier than air. After the propane standard gas enters the gas chamber 211, it can be deposited in the gas chamber 211 and flow out evenly after filling the gas chamber 211, so that the standard gas maintains the standard concentration and thus avoids the error in the calibration.

[0044] In Embodiment 2 of this utility model, the calibration cover 100 can be used for both propane gas detectors (which are heavier than air) and methane gas detectors (which are lighter than air). Please refer to [link / reference]. Figure 6As shown, the other parts of the calibration cover 100 are the same as in Embodiment 1, except that the connecting part 21 further includes a guide member 212 that is housed in the air cavity 211 and connected to the cavity wall of the air cavity 211. The guide member 212 covers at least a portion of the air cavity 211, and is fixedly connected to the connecting part 21 and covers the gas passage 221 in the air inlet pipe 22. Specifically, the guide member 212 is provided with a plurality of guide holes 213 penetrating the guide member 212, and the plurality of guide holes 213 are evenly distributed in a ring on the guide member 212. With this configuration, the standard gas is sprayed onto the guide member 212 after passing through the gas channel 221, and flows outward through the guide hole 213 on the guide member 212, so that the standard gas can be evenly distributed in the gas chamber 211. Furthermore, regardless of whether the standard gas is a methane gas lighter than air or a propane gas heavier than air, it can be evenly distributed in the gas chamber 211 and then flow into the diffusion space 16, further ensuring the concentration of the standard gas in the calibration hood 100 and improving the accuracy of the calibration.

[0045] Of course, in embodiment 3 of this utility model, the calibration cover 100 may not have the connecting part 21. That is, the air inlet pipe 22 is directly connected to the horn-shaped diffuser 1, specifically connected to the small opening end of the horn shape. This can also achieve the effect of avoiding the increase of the concentration of standard gas in the diffuser 1 and the strong versatility of the calibration cover 100.

[0046] In summary, the calibration cover 100 of this invention, by providing a groove 11 on the inner wall of the diffuser 1, allows standard gas to flow out through the groove 11 when a gas detector with a size smaller than the diameter of the outlet 12 extends into the diffuser 1 and abuts against the inner wall of the diffuser 1; by providing a notch 14 on the diffuser 1, allows standard gas to flow out through the notch 14 when a gas detector with a size larger than the diameter of the outlet 12 abuts against the outlet 12. By providing the groove 11 and the notch 14, the calibration cover 100 ensures smooth exhaust of standard gas when calibrating gas detectors of different sizes, preventing the standard gas inside the calibration cover 100 from being lost. Increased concentration affects the determination of calibration results; by setting the diffuser 1 in a trumpet shape, the diffuser 1 can calibrate gas detectors of different shapes and sizes, improving the versatility and practicality of the calibration cover 100; by setting the boss 13 and reinforcing rib 15 on the diffuser 1, the strength of the calibration cover 100 is improved, preventing deformation of the calibration cover 100; by setting the external thread 222 on the air inlet pipe 22, the calibration cover 100 can be connected to an external telescopic rod, improving the practicality of the calibration cover 100; by setting the guide 212 on the connecting part 21, the calibration cover 100 can be used with methane gas detectors and propane gas detectors.

[0047] In the description of the embodiments of this utility model, it should be understood that the terms "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "center," "top," "bottom," "top," "bottom," "inner," "outer," "inner side," and "outer side," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. "Inner side" refers to the interior or enclosed area or space. "Outer perimeter" refers to the area surrounding a specific component or specific area.

[0048] In the description of embodiments of this utility model, the terms "first," "second," "third," and "fourth" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first," "second," "third," or "fourth" may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0049] In the description of the embodiments of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "assembly" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0050] In the description of the embodiments of this utility model, specific features, structures, materials or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0051] In the description of the embodiments of this utility model, it should be understood that "-" and "~" represent a range of two values, and this range includes the endpoints. For example, "AB" represents a range greater than or equal to A and less than or equal to B. "A~B" represents a range greater than or equal to A and less than or equal to B.

[0052] In the description of the embodiments of this utility model, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0053] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A calibration cover for calibrating a gas detection alarm, characterized in that: The calibration hood includes a diffuser and an air inlet assembly. In the flow direction of the standard gas, the air inlet assembly is sequentially connected to the diffuser. The diffuser is also provided with an outlet, a notch, and a groove. The outlet is located at the end of the diffuser away from the air inlet assembly, and the notch is located at the outlet. The groove is located on the inner wall of the diffuser and extends along the inner wall of the diffuser toward the flow direction of the standard gas. The groove extends to the outlet and communicates with at least a portion of the notch.

2. The calibration cover according to claim 1, characterized in that: The outer wall of the diffuser is also provided with reinforcing ribs, which are distributed correspondingly to the grooves.

3. The calibration cover according to claim 1, characterized in that: The diffuser also includes a protrusion that protrudes outward from the outer circumference of the air outlet end, the protrusion being arranged in a ring shape and surrounding the outer circumference of the air outlet end.

4. The calibration cover according to claim 1, characterized in that: The groove is provided in three parts, and the three grooves are evenly distributed on the inner sidewall of the diffuser.

5. The calibration cover according to claim 1, characterized in that: The diffuser is arranged in a trumpet shape.

6. The calibration cover according to claim 1, characterized in that: The air intake assembly includes a connecting part and an air intake pipe, and the air intake pipe, the connecting part and the diffuser are connected in sequence in the flow direction of the standard gas.

7. The calibration cover according to claim 6, characterized in that: The air intake pipe is provided with a gas channel, the connecting part is provided with a gas cavity, the diffuser part includes a diffusion space, and the gas channel, the gas cavity and the diffusion space are connected in sequence.

8. The calibration cover according to claim 6, characterized in that: The intake pipe has an external thread on its outer side wall near the connection part, and the calibration cover can be connected to other equipment through the external thread.

9. The calibration cover according to claim 6, characterized in that: The connecting part is cylindrical in shape, and the air intake pipe is connected to the middle of the connecting part.

10. The calibration cover according to claim 7, characterized in that: The gas cavity is provided with a guide component that covers the gas passage, and the guide component is provided with a plurality of guide holes.

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