JPS5813723Y2 - Temperature detector with leak detection circuit - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a temperature detector having a function of detecting leakage of a protection tube.

Temperature measuring elements such as resistance temperature detectors, thermocouples, and semiconductors for temperature measurement are generally housed in protective tubes and are often protected from direct contact with the temperature-measuring body.

In this case, a hole may develop in the protective tube due to erosion, or an imperfect seal at the terminal may allow external corrosive fluids (rainwater, etc.) to enter, deteriorating the insulation and causing errors in the measured temperature. In the end, something happens that destroys the thermometer.

Since temperature measurement is a precise measurement of the resistance value of a resistance temperature detector and a measurement of a minute voltage of a thermocouple, deterioration of insulation has a fatal effect on temperature measurement.

To prevent this, for example, as shown in FIG.
A so-called double sealing method is used in which the protective tube is covered with an insulating coating 2 and further protected with a protective tube 3.

However, even with this method, if the protective tube 3 ruptures and corrosive fluid enters, the thermometer will be protected by the insulating seal for a while, but the internal insulating seal will eventually erode, resulting in a slightly longer life. It's just that.

Therefore, it would be advantageous in terms of safety if detection could be made at the stage of destruction of the protective tube 3.

However, if the thermometer and its wiring are completely sealed, there is no way to electrically detect damage to the protection tube.
To check for damage, the temperature detector is removed and visual inspection or airtightness tests are periodically performed, but this is a very complicated process.

Therefore, 1 = ! with temperature detector installed! It is desired to remotely detect damage to the protection tube electrically.

SUMMARY OF THE INVENTION An object of the present invention is to provide a temperature detector with a leakage detection circuit for detecting destruction of an external protection device.

The structure for achieving the above object is characterized in that a leakage detection circuit consisting of two conductive wires is provided between the inner seal and the outer seal of the Il holder.

Embodiments of the present invention will be described below with reference to the drawings.

Referring to FIG. 1, the first embodiment of the present invention is 11]
The temperature resistor 1 is sealed with an internal seal, that is, an insulating coating 2, and the outside thereof is further sealed with an external seal, that is, a protective tube 3.
At the same time, a leakage detection circuit consisting of two mutually insulated fc conductors 4 and 5 is placed in the space between the insulation sheath 2 and the protection tube 30, and the upper part of the protection tube 3 is sealed with an airtight wall 6. It is composed of

The tips γ and 8 of the lead wires 4 and 5 of the leakage detection circuit are stripped of their insulation and are placed with a slight distance apart but not in contact with each other.

For example, two conductive wires may each be housed in an insulating seal 9Vc similar to the insulating coating 2, and the lower end of the seal 9 may be left open, or an insulating partition wall may simply be placed between the conductive wires 4 and 5. .

11 Terminal of hot body 1 9. ff and terminals 10. of conductors 4 and 5.
11 is provided on the upper part of the airtight wall 6, and is further surrounded by a terminal box 12Vc which is an extension of the protection tube 3.

This temperature sensor is fixed to a support flange 13, for example, and its tip is immersed in a fluid 14.

In this state, for example, if a hole is formed in the protective tube 3 due to erosion or if the airtight wall 6 is damaged and a fluid other than air, such as rainwater, leaks in, or if the resistance between the conductors 4 and 5 is air. Therefore, if the resistance between the conductors 4 and 5 is reduced by 1lJffl through the terminal 10.11, such intrusion of fluid can be detected electrically and remotely, that is, by the temperature sensor installed at 11. It is possible.

Referring to FIG. 2, a second embodiment of the present invention is shown.

In this second embodiment, a flexible tube 20 is used in place of the protective tube 30 of the first embodiment.

This should be used when the temperature sensor is long.

The flexible tube 20 is suspended from the lower end of the terminal box 12 fixed to the flange 13.

The resistance temperature detector 1 button and the conductive wire 4.5 are insulated from each other and housed in the inner insulating seal 21, and all these members are removed from the airtight wall 6, which also serves as a hanging mechanism, through a flexible tube by an appropriate method. It is suspended inside 20.

The ends γ and 8 of the conductive wires 4 and 5 pass through the bottom of the insulating seal 21 and extend into the space between the insulating seal 21 and the flexible tube 20, and their tips are respectively Although the insulator is removed, they are spaced apart from each other so as not to touch each other.

When using such a long temperature sensing resistor 1, the resistor 1 expands due to its own weight, which changes the resistance value and causes measurement errors.

Therefore, as shown in Figure 2, the resistor is 1, 1/, 1't
, 1″t, and each connection point is fixed to the conductor wires 4 and 5 to protect the load.

The upper airtight wall 6 and the hanging mechanism may be used together or may be provided separately.

Examples of hanging methods include the para-kink method of simply compressing the wire, the method of hanging the wiring section on a hook, and the method of compressing the wire by bending it as shown in Fig. 3.

The wiring may be separated or grouped together, and each wire may be insulated and sealed individually, or each line may be insulated and sealed.

Of course, it is also possible to suspend it using other cables.

Since the wiring from the terminals 9.9' and 10.11 can be made arbitrarily long, damage to the protective tube 3 or the flexible tube 20 can be detected remotely.

The effects of using this temperature sensor are as follows.

(I) Regular inspections are necessary to maintain the double protection function, but according to the present invention, it is only necessary to measure the resistance between the terminals, so inspections can be performed by remote measurement by wiring appropriately. become.

(2) The measuring object, that is, the temperature measuring element, can be any type and number of resistors, thermocouples, semiconductors, etc.

Furthermore, the type and arrangement of the protection tubes are also free.

(3) Can be used as a hanging tool for temperature measuring devices such as conductors.

In addition, the temperature sensor of the present invention has the following advantages.

(I) Erosion of protection pipes or rainwater infiltration can be detected remotely and continuously.

(2) It can be used regardless of the number or type of temperature measuring element.

(3) Any arrangement of the thermometer (horizontal, vertical, bent)
It can also be used in

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view of a first embodiment of the temperature sensor of the present invention. FIG. 2 is a schematic cross-sectional view of a second embodiment of the present invention. FIG. 3 is a schematic diagram showing one example of how to hang a temperature measuring element or a conducting wire. DESCRIPTION OF SYMBOLS 1...Resistance temperature sensor, 2...Insulating seal, 3...Protection tube, 4.5...Conducting wire, 6...Airtight wall, 1.8...
・Tip of conductor, 9.9', 10.11...Terminal, 1
2...Terminal box, 13...Flange, 14...Fluid, 20...Flexible tube.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) Double-seal temperature detection consisting of an internal seal that fluid-tightly insulates and protects the temperature measuring element inside, and an external seal that further fluid-tightly accommodates and insulates them. In the container, two conductive wires are insulated from each other, and the tips of each of the conductive wires are separated from the insulation and placed at a slight distance so that they do not touch each other, and the inner shield and the outer seal are separated. A temperature detector comprising a leakage detection circuit configured to be disposed at the lower part of the space between the temperature detectors. e) A temperature sensor according to claim 1, characterized in that the external seal is a flexible tube. (3) The temperature sensor is characterized in that the conductive wire is used as a hanging tool for the temperature measuring element. A temperature sensor according to claim (1) of the utility model registration claim.