A probe for nondestructive detection of water vapor content in a sealed cavity

Abstract

A nondestructive detection probe for water vapor content in a sealed cavity belongs to the technical field of humidity sensors, and includes a detector housing, a refrigeration device, and a condensation detector. The refrigeration device and the condensation detector are arranged inside the detector housing. The input ends of the refrigeration device, the condensation detector, and the optical fiber are all embedded in an aluminum block and flush with its surface. The output end of the condensation detector is connected to the input end of the optical fiber. The aluminum block is embedded in the detector housing and flush with its surface. The output end of the refrigeration device is connected to a fiber optic sensor. The output end of the optical fiber is connected to the fiber optic sensor. The fiber optic sensor is connected to a host. The present invention can save working hours and avoid risks through a method for detecting water vapor content in a sealed cavity, quickly give a quantitative value of humidity in the sealed cavity, improve the detection efficiency of the whole machine, and realize reliable detection of a small amount of moisture in the sealed cavity without disassembly.

Description

Technical Field

[0001] The invention belongs to the technical field of humidity sensors, and in particular relates to a probe for nondestructive detection of water vapor content in a sealed cavity. Background Art

[0002] Humidity detectors are widely used in all walks of life. The cavity of extravehicular optical equipment may experience water ingress due to seal failure due to rotational joint movement, seal aging, and temperature differences between day and night. In most cases, the small amount of water that enters the cavity exists in the form of water vapor. When the temperature drops at night, it will condense on the optical surface, causing the optical properties of the equipment to deteriorate. It will condense on the circuit part to cause metal corrosion, low insulation, leakage, etc., which will have an adverse effect on the normal operation of the equipment. This requires the use of a humidity detector to detect humidity in devices that are often in humid environments.

[0003] The traditional method of detecting the water vapor content in the sealed cavity requires disassembly of the cavity, which will damage the seal during the disassembly process. In addition to completing the disassembly and assembly process at the equipment installation site, it is also necessary to replace the seals and perform complex operations such as drying, nitrogen filling, and leak detection in the cavity. Under limited on-site conditions, this operation is time-consuming, labor-intensive, and has certain risks. Summary of the invention

[0004] In order to solve the above-mentioned problems, the present invention proposes: a nondestructive detection probe for water vapor content in a sealed cavity, comprising a detector housing, a refrigeration device and a condensation detector, the refrigeration device and the condensation detector are arranged inside the detector housing, the refrigeration device, the condensation detector and the input end of the optical fiber are all embedded in an aluminum block and flush with its surface, the output end of the condensation detector is connected to the input end of the optical fiber, the aluminum block is embedded in the detector housing and flush with its surface, the output end of the refrigeration device is connected to the optical fiber sensor, the output end of the optical fiber is connected to the optical fiber sensor, and the optical fiber sensor is connected to the host.

[0005] Furthermore, the refrigeration device includes a first-stage refrigeration plate of a semiconductor refrigeration tower, a second-stage refrigeration plate of a semiconductor refrigeration tower, a third-stage refrigeration plate of a semiconductor refrigeration tower and an axial flow fan. The aluminum block is connected to the first-stage refrigeration plate of the semiconductor refrigeration tower, the second-stage refrigeration plate of the semiconductor refrigeration tower, the third-stage refrigeration plate of the semiconductor refrigeration tower and the axial flow fan in sequence, and the axial flow fan is connected to the host through an optical fiber sensor.

[0006] Furthermore, the output end of the refrigeration device is connected to the optical fiber sensor through a cable.

[0007] Furthermore, the condensation detector is a laser emitter, and the laser emitter is connected to the optical fiber sensor via an optical fiber.

[0008] Furthermore, the electric cable and the optical fiber form a cable, and the refrigeration device and the laser transmitter are connected to the optical fiber sensor through the cable.

[0009] Furthermore, the optical fiber sensor is connected to the re232 interface via a cable.

[0010] Furthermore, the re232 interface is connected to a host.

[0011] The beneficial effects of the present invention are as follows: some devices are closed inside. If the outer shell is opened, changes in pressure, temperature and humidity may cause problems in the device. The device of the present invention can detect humidity facing the closed cavity. Compared with the prior art, there is no need to open the inside of the device to affect the internal environment, thus ensuring the high efficiency and accuracy of the detection;

[0012] The present invention can save man-hours, avoid risks, quickly give a quantitative value of humidity in the sealed cavity, and improve the detection efficiency of the whole machine through the method for detecting water vapor content in the sealed cavity. It realizes reliable detection of a small amount of water in the sealed cavity without disassembly, and is designed according to the device's external dimensions. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the three-dimensional structure of the probe for nondestructive detection of water vapor content in a sealed cavity of the present invention;

[0014] Figure 2 It is a schematic diagram of the internal structure of the probe for nondestructive detection of water vapor content in a sealed cavity of the present invention;

[0015] Figure 3 This is a flow chart of the method for detecting water vapor content in a sealed cavity of the present invention.

[0016] The accompanying drawings are marked as follows:

[0017] 1. Detector housing; 2. Laser transmitter; 3. Optical fiber; 4. Aluminum block; 5. Cable; 6. Optical fiber sensor; 7. RE232 interface; 8. First-stage cooling plate of semiconductor refrigeration tower; 9. Second-stage cooling plate of semiconductor refrigeration tower; 10. Third-stage cooling plate of semiconductor refrigeration tower; 11. Axial flow fan; 12. Cable. DETAILED DESCRIPTION

[0018] Example 1

[0019] In order to make the technical means adopted by the present invention and the purpose achieved easy to understand, the present invention is further explained in combination with a specific implementation method below. A non-destructive detection probe for water vapor content in a sealed cavity includes a detector housing 1, a refrigeration device and a condensation detector. The refrigeration device and the condensation detector are arranged inside the detector housing 1. The input ends of the refrigeration device, the condensation detector and the optical fiber 3 are all embedded in the aluminum block 4 and flush with its surface. The output end of the condensation detector is connected to the input end of the optical fiber 3. The aluminum block 4 is embedded in the detector housing 1 and flush with its surface. The output end of the refrigeration device is connected to the optical fiber sensor 6. The output end of the optical fiber 3 is connected to the optical fiber sensor 6, and the optical fiber sensor 6 is connected to the host.

[0020] Among them, the refrigeration device includes a semiconductor refrigeration tower first-stage refrigeration plate 8, a semiconductor refrigeration tower second-stage refrigeration plate 9, a semiconductor refrigeration tower third-stage refrigeration plate 10 and an axial flow fan 11. The aluminum block 4 is connected to the semiconductor refrigeration tower first-stage refrigeration plate 8, the semiconductor refrigeration tower second-stage refrigeration plate 9, the semiconductor refrigeration tower third-stage refrigeration plate 10, and the axial flow fan 11 in sequence, and the axial flow fan 11 is connected to the host through the optical fiber sensor 6.

[0021] The output end of the refrigeration device is connected to the optical fiber sensor 6 via a cable 12 .

[0022] The condensation detector is a laser emitter 2 , and the laser emitter 2 is connected to the optical fiber sensor 6 via an optical fiber 3 .

[0023] The cable 12 and the optical fiber 3 form a cable 5 , and the refrigeration device and the laser transmitter 2 are connected to the optical fiber sensor 6 via the cable 5 .

[0024] The optical fiber sensor 6 is connected to the re232 interface 7 via a cable 5 .

[0025] Wherein, the re232 interface 7 is connected to the host.

[0026] See also Figure 1 In the present invention, the aluminum block 4 is embedded from the inside of the detector housing 1 to the surface due to its superior thermal conductivity. The detector housing 1 is flush with the surface of the aluminum block 4. The laser emitter 2 and the optical fiber 3 are embedded from the inside of the aluminum block 4 to the surface. The laser emitter 2 and the optical fiber 3 are flush with the surface of the aluminum block 4 to ensure that there is no gap when the instrument is attached to the glass. The optical fiber 2 is connected to the optical fiber sensor 6 to transmit the optical signal to the optical fiber sensor 6. Whether water has entered the measuring device is determined by whether the optical fiber sensor has a signal.

[0027] See also Figure 2, the aluminum block 4 is connected with the first-stage refrigeration sheet 8 of the semiconductor refrigeration tower, the second-stage refrigeration sheet 9 of the semiconductor refrigeration tower, and the third-stage refrigeration sheet 10 of the semiconductor refrigeration tower. The third-stage refrigeration sheet 10 of the semiconductor refrigeration tower is fixed together with the axial flow fan 11. The first-stage refrigeration sheet 8 of the semiconductor refrigeration tower, the second-stage refrigeration sheet 9 of the semiconductor refrigeration tower, the third-stage refrigeration sheet 10 of the semiconductor refrigeration tower and the axial flow fan 11 are powered by the cable 12, and the cable is powered by 13V, 3A standard. The optical fiber 3 extends to the cable 5. The internal temperature of the device is changed by cooling the refrigeration sheet. The optical fiber 3 and the cable 12 constitute the cable 5, and the first-stage refrigeration sheet 8 of the semiconductor refrigeration tower, the second-stage refrigeration sheet 9 of the semiconductor refrigeration tower, the third-stage refrigeration sheet 10 of the semiconductor refrigeration tower and the axial flow fan 11 are powered by the re232 interface 7.

[0028] The refrigeration working principle of the present invention is: the method for detecting the water vapor content in the sealed cavity is based on the principle of water vapor condensation. By cooling outside the optical window, a certain concentration of water vapor in the cavity reaches the dew point, and condensation is generated on the inner surface of the optical window. The time and temperature of condensation generation are measured, and the water vapor content humidity of the gas in the cavity can be obtained through the humidity-temperature conversion relationship. The probe adopts a three-stage semiconductor refrigeration technology. The hot end of the semiconductor refrigeration tower first-stage refrigeration plate 8, the semiconductor refrigeration tower second-stage refrigeration plate 9, and the semiconductor refrigeration tower third-stage refrigeration plate 10 is dissipated by the axial flow fan 11, and the cold end is in contact with the optical window of the device through a coupling agent. The current passing through the semiconductor refrigeration tower is generated by the optical fiber sensor 6 installed at the cold end through a feedback amplification loop, and the cold end temperature can be controlled by adjusting the amplification amount. When working, the cold end temperature can reach -40°C in a short time.

[0029] The optical working principle of the present invention is: if a condensation detector is installed on the cold end side, it is composed of a laser transmitter 2 and a fiber optic sensor 6. The laser emits modulated laser into the device through the optical window of the device, and the laser spot is located on the inner surface of the optical window at the center of the projection of the cold end metal contact surface. The reasonably designed inclination angle prevents the laser beam from being totally reflected when passing through the external atmosphere-optical window-internal gas optical path, that is, part of the laser passes through the optical window into the device. The fiber optic sensor 6 points to the spot position on the inner surface of the optical window to avoid the reflection interference of each optical surface. When there is no condensation, most of the light enters the device and is absorbed, and only a small amount of light is reflected back to the spot position. When condensation exists, most of the light is diffusely reflected at the condensation position on the inner surface of the optical window, and a switch signal is generated after being received by the fiber optic sensor, thereby detecting water ingress into the device.

[0030] Example 2

[0031] A method for detecting water vapor content in a sealed cavity, such as Figure 3 As shown, the following steps are included:

[0032] S1, start the probe for cooling;

[0033] S2. Determine whether the device under test contains water by observing whether condensation occurs on the optical window;

[0034] S3, starting the condensation detector of the probe to detect condensation;

[0035] S4. Calculate the humidity by measuring the time and temperature of condensation.

[0036] Wherein, in the step S1, the probe is attached to the optical window of the device under test, and a refrigeration device of the probe is started to perform refrigeration.

[0037] Wherein, in the step S2, condensation occurs on the optical window, and the device to be tested contains water.

[0038] Wherein, in the step S2, if there is no condensation on the optical window, then the device under test does not contain water.

[0039] Wherein, in step S3, when there is no condensation, most of the light from the condensation detector enters the interior of the device and is absorbed, and only a small amount of light is reflected back to the light spot position.

[0040] Among them, in step S3, when condensation exists, most of the light from the condensation detector is diffusely reflected at the condensation position on the inner surface of the optical window, and the optical fiber sensor generates a switching signal after receiving the signal to detect water ingress into the equipment.

[0041] Wherein, in the step S4, the water vapor content of the gas in the cavity, that is, the humidity, is obtained through the humidity-temperature conversion relationship.

[0042] Example 3

[0043] The object of the present invention is to provide a humidity detector facing a closed cavity to solve the problems raised in the above background technology.

[0044] The technical solution adopted by the present invention is: a humidity detector facing a closed cavity, including a detector housing 1, a laser transmitter 2, an optical fiber 3, an aluminum block 4, a cable 5, an optical fiber sensor 6, a re232 interface 7, a primary cooling sheet 8, a secondary cooling sheet 9, a tertiary cooling sheet 10, a fan 11, and a cable 12. The aluminum block 4 is embedded from the inside of the detector housing 1 to the surface, and the detector housing 1 is flush with the aluminum block 4.

[0045] As a preferred solution of a humidity sensor described in the present invention, the detector housing 1 is composed of an aluminum block 4, a laser emitter 2, an optical cable 3, a cable 12, a primary cooling sheet 8, a secondary cooling sheet 9, a tertiary cooling sheet 10, and a fan 11. The laser emitter 2 and the optical fiber 3 are embedded in the aluminum block 4, the aluminum block 4 is connected with the primary cooling sheet 8, the secondary cooling sheet 9, and the tertiary cooling sheet 10, the tertiary cooling sheet 10 is fixed with the fan 11, and the primary cooling sheet 8, the secondary cooling sheet 9, the tertiary cooling sheet 10 and the fan are powered by a cable 12, and the cable is powered by 13V, 3A standard.

[0046] As a preferred solution of the humidity sensor described in the present invention, the laser emitter 2 and the optical fiber 3 are embedded from the inside of the aluminum block 4 to the surface, the laser emitter 2 and the optical fiber 3 are flush with the aluminum block 4, and the optical fiber 3 extends into the cable 5.

[0047] As a preferred solution of the humidity sensor described in the present invention, the optical fiber 2 is connected to the optical sensor 6 to transmit the optical signal to the optical sensor 6.

[0048] As a preferred solution of the humidity sensor described in the present invention, the optical fiber 3 and the cable 12 form a cable 5, and the re232 interface 7 is used to power the first-stage cooling plate 8, the second-stage cooling plate 9, the third-stage cooling plate 10 and the fan 11.

[0049] See also Figure 1 In the present invention, the aluminum block 4 is embedded from the inside of the detector housing 1 to the surface due to its superior thermal conductivity. The detector housing 1 is flush with the surface of the aluminum block 4. The laser emitter 3 and the optical fiber 2 are embedded from the inside of the aluminum block 4 to the surface. The laser emitter 2 and the optical fiber 3 are flush with the surface of the aluminum block 4 to ensure that there is no gap when the instrument is attached to the glass. The optical fiber 3 is connected to the optical sensor 6 to transmit the optical signal to the optical sensor 6. Whether water has entered the measuring device is determined by whether the optical sensor has a signal.

[0050] See also Figure 2 The aluminum block 4 is connected with the primary cooling sheet 8, the secondary cooling sheet 9, and the tertiary cooling sheet 10. The tertiary cooling sheet 10 is fixed with the fan 11. The primary cooling sheet 8, the secondary cooling sheet 9, the tertiary cooling sheet 10, and the fan 11 are powered by the cable 12, and the cable is powered by 13V, 3A standard. The optical fiber 3 extends to the cable 5. The internal temperature of the device is changed by cooling the cooling sheet. The optical fiber 3 and the cable 12 constitute the cable 5, and the primary cooling sheet 8, the secondary cooling sheet 9, the tertiary cooling sheet 10, and the fan 11 are powered by the re232 interface 7.

[0051] The working principle of the present invention is: first, the device is connected to a power source. The refrigeration sheet cools, and the front of the instrument is attached to the glass of the device to be tested. The aluminum sheet 4 transfers heat to the glass, thereby reducing the temperature inside the device. If water enters the device to be tested, the temperature drop will cause condensation on the internal glass. At the same time, the laser transmitter 2 continues to output. When condensation occurs inside the device, the dew will scatter the laser, and then scatter the light into the optical fiber 3. The optical fiber 3 transmits the optical signal to the optical sensor 6. The optical sensor 6 responds to the signal, proving that water has entered the device.

[0052] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solutions and concepts of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A probe for nondestructive detection of water vapor content in a sealed cavity, characterized in that: The invention comprises a detector housing (1), a refrigeration device and a condensation detector. The refrigeration device and the condensation detector are arranged inside the detector housing (1). The input ends of the refrigeration device, the condensation detector and the optical fiber (3) are all embedded in an aluminum block (4) and flush with the surface thereof. The output end of the condensation detector is connected to the input end of the optical fiber (3). The aluminum block (4) is embedded in the detector housing (1) and flush with the surface thereof. The output end of the refrigeration device is connected to the optical fiber sensor (6). The output end of the optical fiber (3) is connected to the optical fiber sensor (6). The optical fiber sensor (6) is connected to a host computer.

2. The probe for nondestructive detection of water vapor content in a sealed cavity according to claim 1, characterized in that: The refrigeration device comprises a semiconductor refrigeration tower primary refrigeration sheet (8), a semiconductor refrigeration tower secondary refrigeration sheet (9), a semiconductor refrigeration tower tertiary refrigeration sheet (10) and an axial flow fan (11); the aluminum block (4) is connected to the semiconductor refrigeration tower primary refrigeration sheet (8), the semiconductor refrigeration tower secondary refrigeration sheet (9), the semiconductor refrigeration tower tertiary refrigeration sheet (10) and the axial flow fan (11) in sequence; and the axial flow fan (11) is connected to a host computer via an optical fiber sensor (6).

3. The probe for nondestructive detection of water vapor content in a sealed cavity according to claim 2, characterized in that: The output end of the refrigeration device is connected to the optical fiber sensor (6) via a cable (12).

4. The probe for nondestructive detection of water vapor content in a sealed cavity according to claim 3, characterized in that: The condensation detector is a laser emitter (2), and the laser emitter (2) is connected to the optical fiber sensor (6) via an optical fiber (3).

5. The probe for nondestructive detection of water vapor content in a sealed cavity according to claim 4, characterized in that: The cable (12) and the optical fiber (3) form a cable (5), and the refrigeration device and the laser transmitter (2) are connected to the optical fiber sensor (6) via the cable (5).

6. The probe for nondestructive detection of water vapor content in a sealed cavity according to claim 5, characterized in that: The optical fiber sensor (6) is connected to the RE232 interface (7) via a cable (5).

7. The probe for nondestructive detection of water vapor content in a sealed cavity according to claim 6, characterized in that: The re232 interface (7) is connected to the host.

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