JP2000214122A - Pinhole detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a detector which is excellent in simplicity and mobility and which can be carried by a method wherein a first electrode which is connected electrically to a wall is installed and a second electrode which is impregnated with a conductive liquid and which comprises a coating used to apply the liquid to the surface of a coating layer is installed. SOLUTION: A first electrode body 3 which is connected to a first connecting terminal 6 via a coupling or the like is connected electrically, by a proper means such as, e.g. a clip or the like, to the exposed part of a reinforcing bar buried inside a wall body W at a concrete liquid storage tank A or to the conductive part D of an object, to be inspected, such as an anchor or the like which is buried deep in advance for measurement. In addition, a second electrode 4 is connected to a second connecting terminal 7, and a coating 10 is formed at the tip of the second electrode 4 via a lead wire. The coating 10 scans the surface of a film layer C so as to detect a pinhole which is generated in the film layer C. When the pinhole is detected, an electric resistance is different according to the structure, the material and the environment of a treatment tank as an object to be inspected. As a result, it is preferable to adjust the resistance for every liquid storage tank as an object.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pinhole detector for detecting pinholes in a coating layer for waterproofing and protecting a conductive wall such as concrete.

[0002]

2. Description of the Related Art Large storage tanks for storing various liquids such as beverages, chemicals, and sewage, and storage tanks such as large containers are made of iron or iron from the viewpoint of strength and cost. The wall is made of concrete and waterproof and anticorrosion treatment is given by a coating layer using a paint, a lining sheet or the like. As such a liquid storage tank, for example, a tank in which the inner surface of a tank body made of a concrete wall is covered with a coating layer formed by attaching a polyethylene sheet or the like is often used.

[0003] A pinhole detector used for inspecting the waterproofing and anticorrosion treatment of such a storage tank after the completion of construction or after the use of the storage tank has a state in which the storage tank is usually installed underground and the ceiling is closed. However, since the opening is generally small, a large-sized device or the like impairs the efficiency of inspection and requires safety of inspection. In addition, in the inspection of the pinhole in the liquid storage tank, it is necessary to specify the location of the pinhole together with the presence or absence of the pinhole for repair.
Mobility is required.

On the other hand, to detect pinholes, an electric spark type detection method and a vacuum box type detection method are known.
The former is inspected by applying a high voltage of several thousand volts or more to the electrode of the metal brush to detect the spark discharge in a pinhole passing through the inside and outside of the coating layer, and the latter is a container for sealing the inspection area of the coating layer. This method detects bubbles generated from pinholes by filling the inside with soapy water and evacuating the container.

Further, Japanese Patent Publication No. 58-56829 proposes a pinhole detection method for an enamel bathtub. In this publication, a phenolphthalein-containing salt solution is immersed in felt on a DC power supply (60 to 80 V) side. It discloses an electrolysis method for detecting by red reaction of caustic soda generated by electrolysis through a pinhole, a neon detection tube method for lighting a neon detection tube by a pinhole using a DC power supply, and the like.

[0006]

However, the electric spark type detection method involves a danger of handling due to the use of a high voltage, cannot be employed in a tank using a flammable solvent, and has a vacuum box type detection method. The method requires a power source for driving a pump for evacuation, and the electrolysis method and the neon detector tube method also lack the simplicity and mobility described above.

SUMMARY OF THE INVENTION An object of the present invention is to provide a pinhole detector which is excellent in simplicity and mobility, can be carried around, and can improve inspection efficiency.

[0008]

In order to achieve the above object, a pinhole detector according to claim 1 is provided with a waterproof material made of a non-conductive material covering the inner wall surface of a wall made of a conductive material. What is claimed is: 1. A pinhole detector for inspecting a pinhole of a coating layer, comprising: a first connection terminal portion, a second connection terminal portion, and electricity between the first connection terminal portion and the second connection terminal portion. A tester main body having a detection unit capable of detecting a change in resistance or current, a first electrode body electrically connected to the first connection terminal unit and electrically connected to the wall, and the second connection terminal And a second electrode body having an application portion that conducts to the portion and impregnates the conductive liquid and adheres the liquid to the surface of the coating layer.

The invention according to claim 2 is characterized in that the application section is made of felt, fiber cloth, sponge, or brush, and the invention of claim 3 is that the application section is made of brush, and The tester main body is characterized in that the maximum measured value of the electric resistance of the detection unit is 1 MΩ, and that the power supply includes a power on / off display, a pinhole detection display, and a continuity test display.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a pinhole detector 1 according to the present invention.
Is shown together with its use state, and the pinhole detector 1 is a wall W of a concrete storage tank A in this example.
It is used to inspect the pinholes of the waterproof coating layer C made of a non-conductive material that covers the inner wall surface of the device.

The pinhole detector 1 includes a tester body 2
, A first electrode body 3, and a second electrode body 4, and the tester body 2 includes a housing 5, a first connection terminal portion 6 through which the first electrode body 3 is conducted, A second connection terminal portion 7 to which the second electrode body 4 conducts, a meter portion M, and an operation display portion S on which various switches, lamps, buzzers and the like can be provided are arranged, and further as shown in FIG. The detection unit 9 is housed. Further, in this example, a power supply cord 12 is provided.

The cord 12 is connected to, for example, a household AC 100 V power supply and is used as a low DC voltage by a built-in transformer rectifier, and is shown as a battery BT in FIG. It should be noted that a power storage device allowing operation for a predetermined time can be built in, a commercially available battery can be used as a spare, and the cord 12 and the power storage device can be omitted because they can be operated only by a battery. You can also.

The first electrode body 3 connected to the first connection terminal portion 6 via a joint or the like is an exposed portion of a reinforcing bar buried inside the wall W of the concrete storage tank A, or For measurement, it is electrically connected to a conductive portion D of an object to be inspected such as an anchor which is deeply embedded in advance by an appropriate means such as a clip.

A second electrode body 4 is connected to the second connection terminal part 7, and the second electrode body 4 is provided with a coating part 10 at the tip thereof via a lead wire. This coating unit 10
Scans the surface of the coating layer C and finds pinholes formed in the coating layer C. In the case shown in FIG. 3, the base cylinder portion 16 and a conductive liquid such as an appropriate Brush portion 17 formed in a brush shape that can contain water mixed with a conductive liquid
And a current-carrying portion 19 that passes through the inside of the base cylinder portion 16 and is fixed therein, and also exposes the leading end of the lead wire to conduct the inside of the brush portion 17. The tip of the lead wire may be a rod. As a result, the energizing section 19
The conductive liquid impregnated in the brush part 16 comes into contact with the brush part 16 by capillary action. In addition, a liquid containing felt, fiber cloth, sponge, or the like can be used as the brush portion 17.

As shown in FIG. 4, the coating portion 10 can pass the lead wire through the outside of the base tube portion 16 and fix only the tip portion to the base tube portion 16. Reference numeral 17 denotes a knife-like shape made of a continuous-cell sponge.

The first electrode body 3 and the first connection terminal part 6 and the second electrode body 4 and the second connection terminal part 7 can be connected to the first and second connection terminals 7 via the connection fitting 20. The electrode bodies 3 and 4 may be formed by providing the inside of the housing 5 and drawing out the lead wires of the first and second electrode bodies 6 and 7 from the housing 5.

When the brush portion 17 is impregnated with conductive water or the like and applied to the inner surface of the coating layer C and scanned, if there is a pinhole in the coating layer C, it penetrates the pinhole and passes through the pinhole. Thus, the first electrode body 3 is electrically connected to the first electrode body 3.

FIG. 5 shows an example of the detecting section 9. In the figure, a resistor R1 is connected to the first connection terminal portion 6.
Is connected to the base B of the transistor TR1. The transistor TR1 is connected to the transistor TR1.
2. A positive feedback circuit is formed in cooperation with the resistor R2 and the capacitor CD. Therefore, when the first and second electrode bodies 3 and 4 are turned on with the power supply on / off switch SW closed, the base voltage of the resistor R1 is changed to the transistor TR1.
To make the transistor TR1 conductive,
The positive feedback circuit oscillates at a time constant determined by the resistor R2 and the capacitor CD, and an alarm is issued by, for example, an alarm SK1 which is a speaker, so that conduction, that is, the presence of a pinhole can be notified. A lamp may be used as an alarm, but the use of a buzzer makes inspection in daylight convenient.

In this example, BT is a 3V battery, SK1 is an 8Ω speaker, and TR2 and TR1 are transistors 2SA.
733, 2SC945, and the resistors R2 and R1 are each 16K
Ω, 270 KΩ, and CD are set to about 0.047 μF. Various known means for detecting conduction can be adopted as the detection unit 9.

Before the test, whether the tester operates normally is checked by moistening the coating unit 10 and bringing it into contact with the first electrode body 3 to check the continuity by using a tester 23 which indicates the self-conduction of the circuit. . Further, in this example, the alarm S of the detection unit 9 is used.
In addition to K1, an alarm SK2 such as a lamp and a buzzer is provided in the base cylinder portion 16 of the application section 10. By arranging the pinholes in the coating section 10 in this manner, pinhole locations can be easily specified. A lamp and a buzzer can be used together as the alarms SK1 and SK2.

The maximum value of the resistor R1 for detecting the electrical continuity of the tester main body 2 is preferably about 1 MΩ in terms of detection accuracy. The operation display section S of the housing 5 of the tester main body 2 includes the pinhole notification device SK1, the power on / off switch SW, the self-circuit changeover switch 22, the notification device 23 for displaying the self-conduction of the circuit,
A buzzer on / off switch 25 and the like are provided.

At the time of inspection, the on / off switch SW is turned on and the detection circuit changeover switch 22 for continuity test before measurement is switched, so that the first electrode body 3 and the second electrode body 4 are brought into direct contact with each other, and Check that the circuit is normal. When it is normal, the self-circuit inspection alarm 23
Lights up.

Further, when the self-circuit changeover switch 22 is turned to the water leakage detection display side, a water leakage sheet or the like is provided as a water leakage detection display circuit for detecting conduction of the inspection object. When a buzzer sounds when electrical conduction is detected, the buzzer on / off switch 25 is turned on. According to the requirement, a buzzer can be sounded together with the display lamp. These circuits are omitted in FIG.

In one embodiment, a pinhole detector using a resistance of 1 MΩ is used. In the application section 10, a conductive rod is contact-fixed to a paintbrush-like brush and connected to the tester body 2 with a lead wire of 50 cm. . When the first connection terminal portion 6 was brought into contact with an anchor provided on a concrete wall as a so-called earth electrode with a lead wire 10 m, conduction of a resistance of 100 KΩ was displayed.

Since the electrical resistance varies depending on the structure, material, or environment of the processing tank to be inspected, it is preferable to adjust the resistance R1 for each target storage tank. However, if the materials are almost the same, it is possible to detect the presence or absence of electrical continuity even in a slightly different environment.

Therefore, in the case of inspecting substantially the same inspection object, it is preferable to simplify the conducting circuit to make it lightweight and convenient in form. Here, the maximum weight of the portable device is 1 kg, and in the case of 500 g or more, it is better to provide an assisting device to be fastened to the body of the measurer with a shoulder strap or a belt. , More preferably 300 g or less or 100 × 150 m
m or less. That is, the configuration can be made in consideration of functions and convenience. Note that the pinhole detector of the present invention can also be configured using a commercially available tester.

[0027]

As described above, the pinhole detector of the present invention is excellent in simplicity and mobility, can be carried around, and can improve the inspection efficiency.

[Brief description of the drawings]

FIG. 1 is a perspective view illustrating an embodiment of a pinhole detector of the present invention together with a state of use.

FIG. 2 is an enlarged front view showing an example of a tester main body.

FIG. 3 is a front view illustrating an example of a coating unit.

FIG. 4 is a front view showing another example of a coating unit.

FIG. 5 is a diagram illustrating a circuit of an inspection unit;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pinhole detector 2 Tester main body 3 1st connection terminal part 4 1st connection terminal part 5 Housing 6 1st electrode body 7 2nd electrode body 9 Detecting part 10 Coating part 12 Code 16 Base cylinder part 17 Brush Unit 19 Energizing unit 20 Power ON / OFF switch SK1 Alarm

Claims (3)

[Claims] 1. A pinhole detector for inspecting a pinhole of a waterproof coating layer made of a non-conductive material which covers an inner wall surface of a wall made of a conductive material, comprising: a first connection terminal portion; A tester main body having a second connection terminal portion, and a detection portion capable of detecting a change in electric resistance or current between the first connection terminal portion and the second connection terminal portion; the first connection terminal portion And a first electrode body electrically connected to the wall body and electrically connected to the second connection terminal, and impregnated with a conductive liquid and adhering the liquid to the surface of the coating layer. A pinhole detector comprising: a second electrode body having an application section. 2. The pinhole detector according to claim 1, wherein said coating section is made of felt, fiber cloth, sponge, or brush. 3. The tester according to claim 2, wherein the application section is made of brush, and the tester main body measures a maximum measured value of electric resistance of the detection section by 1M.
3. The pinhole detector according to claim 1, further comprising a power on / off indicator, a pinhole detection indicator, and a continuity test indicator.