JP2023035217A - Clamp-on temperature sensor - Google Patents

Abstract

An object of the present invention is to maintain stable and high temperature measurement accuracy even if it is retrofitted.
A temperature measuring resistor (216) having a temperature measuring part (202a) that measures the temperature of a portion that contacts a pipe, and a temperature measuring resistor housing (220) that surrounds the temperature measuring resistor (216). , an insulating part that insulates the temperature measuring resistor housing (220) and the temperature measuring resistor (216), mounting members (206, 208) that detachably fix the temperature measuring resistor housing (220) to the pipe, A metal couplant (222) different from the metal of the temperature measuring part is placed between the temperature measuring part (202a) of the temperature measuring resistor and the pipe, and the adhesion between the metal couplant (222) and the pipe is increased, and a tightening portion (212) for tightening the mounting members (206, 208) against the pipe.
[Selection drawing] Fig. 6

Description

TECHNICAL FIELD The present invention relates to a temperature sensor, and more particularly to a clamp-on temperature sensor that is detachably mounted on a pipe after retrofitting.

The present inventors came up with the idea of the present invention in the process of developing optimized ultrasonic flow rate detection devices, including ultrasonic flow rate switches, concentration sensors, and temperature sensors, for the management of fluids in factories. be.

For convenience of explanation, the ultrasonic flow switch will be described first. ON/OFF signal is output at sites where it is sufficient to detect whether or not the fluid is flowing in the pipe at a flow rate above a certain value, in other words, at a site where the accurate flow rate value of the fluid flowing through the pipe is not required. An ultrasonic flow switch is used (Patent Document 1). US Pat. No. 6,200,000 also discloses a clamp-on ultrasonic flow switch. A clamp-on ultrasonic flow switch is retrofitted with a unit incorporating the elements contained therein at a suitable location on the outer circumference of the pipe. A clamp-on ultrasonic flow switch is attachable to and detachable from the tubing.

Patent Document 1 discloses, as a typical example of a clamp-on ultrasonic flow switch, an integrated clamp having a structure in which a pair of first and second ultrasonic elements included in the ultrasonic flow switch are held by one element holding part. An on ultrasonic flow switch is disclosed. That is, in the integrated clamp-on ultrasonic flow switch disclosed in Patent Document 1, in a state in which the first and second ultrasonic elements are relatively positioned by one element holding portion, is waterproofed and integrally retained in the The integrated clamp-on ultrasonic flow switch makes it easier for the user to install the ultrasonic flow switch. In other words, the user does not have to perform troublesome work of installing the first and second ultrasonic elements on the pipe while positioning them relative to each other. Patent document 2 discloses in detail the functional circuit blocks included in the clamp-on ultrasonic flow switch.

Next, the present inventors studied the ideal form of the temperature sensor in the ultrasonic flow rate detection device including the ultrasonic flow rate switch, the concentration sensor, and the temperature sensor. In particular, in an ultrasonic flow rate detector that employs a clamp-on ultrasonic flow rate switch, an ideal form of a temperature sensor to be incorporated in this ultrasonic flow rate detector was investigated.

JP 2016-217734 A JP 2019-15549 A

As a method of installing the temperature sensor, it is first conceivable to install the temperature sensor so that the temperature detection part, that is, the temperature measurement part, is inserted into the liquid to be measured in the pipe. This is relatively easy to do when installing a new pipe, but when installing the temperature measuring unit in an existing pipe, it is not desirable because it involves work such as cutting the pipe.

A clamp-on ultrasonic flow switch has the advantage that it can be detachably retrofitted to a desired location in existing piping. In order to make the most of this advantage, it is desired that the temperature sensor can be retrofitted to the existing piping as well as the clamp-on ultrasonic flow switch. As a retrofitting method, for example, a thermocouple is installed on the outer peripheral surface of the pipe and fixed with an adhesive tape, or the thermocouple is fixed using solder or the like. Existing piping is affected by the surrounding environment and is contaminated, for example, oil is attached to the outer peripheral surface of the piping. If this is limited to the temporary installation of thermocouples, there may be no operational problems. However, in the current situation where various installation methods that enable long-term and stable operation related to clamp-on ultrasonic flow switches have been proposed, It is necessary to develop a clamp-on temperature sensor installation method that allows

SUMMARY OF THE INVENTION It is an object of the present invention to provide a clamp-on temperature sensor that can stably maintain a high degree of temperature measurement accuracy even if it is retrofitted.

As mentioned above, the concept of the present invention was conceived during the development process for optimizing ultrasonic flow rate detection devices including ultrasonic flow rate switches, concentration sensors, and temperature sensors. aimed at the development of The clamp-on temperature sensor according to the present invention is not limited to application to an ultrasonic flow rate detection device, but can be widely and generally implemented in society as a retrofitted clamp-on temperature sensor with advanced temperature measurement capability. Needless to say.

According to the present invention, the above technical problems are solved by:
A temperature measuring resistor having a temperature measuring part that measures the temperature of the part that contacts the pipe,
a housing surrounding the temperature measuring resistor;
an insulating part that insulates the housing and the temperature measuring resistor;
a mounting member for detachably fixing the housing to a pipe;
A metal couplant different from the metal of the temperature measuring part and a pipe between the temperature measuring part of the temperature measuring resistor and the pipe;
This is achieved by providing a clamp-on temperature sensor having a tightening portion that enhances adhesion between the metal couplant and the pipe and tightens the mounting member against the pipe.

According to the present invention, a metal couplant is interposed between the temperature measuring part and the pipe, and the mounting member is tightened so as to press the temperature measuring part against the pipe. By increasing the adhesion between the temperature measuring part and the pipe, it is possible to reduce the error in the detected temperature. A typical example of a metal couplant is tin or a tin alloy. Tin or a tin alloy can achieve the effect of ensuring adhesion even at room temperature. By using a metal couplant such as tin or a tin alloy, the clamp-on temperature sensor can be attached to and detached from the pipe.

The effects of the present invention and other objects of the present invention will become clear from the detailed description of the embodiments below.

1 is an overall configuration diagram of an ultrasonic flow rate detection device to which a refractive index type concentration sensor of an embodiment is preferably applied; FIG. FIG. 2 is a diagram for explaining the configuration of a clamp-on ultrasonic flow rate switch included in the ultrasonic flow rate detection device shown in FIG. 1; 1 is a perspective view of a belt-type clamp-on temperature sensor attached to piping; FIG. FIG. 4 is a front view related to FIG. 3; FIG. 4 is a side view related to FIG. 3; 6 is a cross-sectional view taken along line VI-VI of FIG. 5; FIG. 1 is a perspective view of a box-type clamp-on temperature sensor attached to piping; FIG. FIG. 8 is a front view related to FIG. 7; FIG. 8 is a side view related to FIG. 7; FIG. 10 is a cross-sectional view taken along line XX of FIG. 9; FIG. 10 is a perspective view for explaining the overall configuration in which a relay amplifier is installed adjacent to and physically separated from the belt-type clamp-on temperature sensor using a fixture (belt) for the belt-type clamp-on temperature sensor; FIG. 12 is a side view related to FIG. 11; A perspective view for explaining the overall configuration in which a box-type clamp-on temperature sensor fixture (U-shaped housing) is used to install a relay amplifier adjacent to and physically separated from the box-type clamp-on temperature sensor. is. FIG. 14 is a side view related to FIG. 13; 1 is an overall block diagram of an ultrasonic flow rate detection device to which a refractive index concentration sensor of an embodiment is preferably applied; FIG.

Before describing the refractive index type concentration sensor of the embodiment, an ultrasonic flow rate detection device optimized for the management of coolant in machine tools will be described. An ultrasonic flow rate detector is composed of an ultrasonic flow rate switch, a concentration sensor, and a temperature sensor. The ultrasonic flow switch employs an integrated clamp-on ultrasonic flow switch with display capability.

Referring to FIG. 1, reference numeral 2 indicates a coolant storage tank. The coolant storage tank 2 stores a water-soluble cutting fluid diluted with water, that is, a coolant. The coolant in the coolant storage tank 2 is supplied through a metal pipe 4 to a machine tool (not shown).

A clamp-on ultrasonic flow switch 6 is detachably fixed to the piping 4 as a retrofit. The clamp-on ultrasonic flow rate switch 6 is connected to a concentration sensor 8 having a detecting portion 8a inserted in the coolant storage tank 2, for example. Concentration sensor 8 preferably includes an indicator light 8b. The clamp-on ultrasonic flow switch 6 is also connected to a temperature sensor 10 installed at, for example, a connecting portion of the pipe 4 . The clamp-on ultrasonic flow rate switch 6 has a display portion which will be described later, and these elements constitute the ultrasonic flow rate detection device 12 .

FIG. 2 is a diagram for explaining a specific example of the clamp-on ultrasonic flow switch 6. As shown in FIG. The clamp-on ultrasonic flow switch 6 is composed of three members: a mounting base member 60 , a measuring head member 62 and a switch indicator 64 . The mounting base member 60 can be installed at an appropriate location on the pipe 4 as a retrofit and detachable. The measuring head member 62 includes first and second ultrasonic elements (see Patent Document 1) that constitute a flow rate detecting section, and is detachably attached to the mounting base member 60 described above. Then, the mounting base member 60 keeps the measuring head member 62 in pressure contact with the pipe 4 .

A switch indicator 64 is assembled to the measuring head member 62 . 2, (I) is a front view of the switch indicator 64, and (II) is a rear view of the switch indicator 64. FIG. The concentration sensor 8 and the temperature sensor 10 are connected to the switch indicator 64 . The detected values detected by the concentration sensor 8 and the temperature sensor 10 are displayed on the display portion 64a of the switch display 64 as actual numerical values detected without processing such as calculation. In addition to the switch indicator 64 having a first indicator light 64b, the measuring head member 62 is also provided with a second indicator light 62b.

The clamp-on ultrasonic flow switch 6 most preferably comprises an integrated clamp-on ultrasonic flow switch. In the measuring head member 62, it is preferable that the first ultrasonic element and the second ultrasonic element are integrally held by one element holding portion (Patent Document 1).

Regarding the clamp-on temperature sensor 10 described above with reference to FIG. 1, two types of temperature sensors are provided. One is belt type and the other is box type. The clamp-on temperature sensor 10 exemplarily illustrated in FIG. 1 is of the latter box type. 7 to 10, 13 and 14 are diagrams related to the box type. When it is necessary to distinguish between the belt type and the box type, the belt type clamp-on temperature sensor is labeled 10A, while the box type clamp-on temperature sensor is labeled 10B. 3 to 6, 11 and 12 are diagrams relating to the belt type. The belt-type temperature sensor 10A is designed to be applied to the pipe 4 having a medium or larger diameter. The box-type temperature sensor 10B is designed to be applied to the pipe 4 with a small diameter.

3 to 6, the belt-type clamp-on temperature sensor 10A includes a metal plate seat 204 forming a seat of a temperature sensor body 202 and a metal plate seat 204 extending from one end and the other end of the metal plate seat 204, preferably made of metal. It has a pair of fabricated belt portions 206, 208, one belt portion 206 having a plurality of longitudinally aligned transverse slits 210 (FIG. 3) formed therein. The diameter that the pair of belt portions 206 , 208 can encircle, ie, the substantial length dimension of the pair of belt portions 206 , 208 can be adjusted by operating screw 212 .

Referring to FIG. 6, a temperature measuring resistor housing 220 surrounding a temperature measuring resistor 216 is arranged between a metal plate seat 204 and a metal pipe 4, and a pair of belt portions 206, 206 and 206 are connected by operating a screw 212. By reducing the substantial length dimension of 208 , temperature measuring resistor housing 220 can be tightened against metal pipe 4 . As a result, the temperature measuring resistance housing 220 can be pressed against the metal pipe 4 to fix the belt-type clamp-on temperature sensor 10A to the metal pipe 4 . This pressing force, ie, tightening force, can be adjusted by screw 212 .

A temperature-measuring couplant 222 is interposed between the temperature-measuring resistor 216 and the pipe 4 (FIGS. 4 and 6). The temperature-measuring couplant 222 is preferably made of metal in order to secure the detachability of the belt-type clamp-on temperature sensor 10A from the pipe 4 . The temperature-measuring couplant 222 is made of a material different from the metal used in the temperature-measuring part 202a, such as platinum (Pt). A specific example of temperature measuring couplant 222 is tin (Sn) or a tin alloy. When the screw 212 is operated to press the temperature measuring portion 202a against the pipe 4 with the pair of belt portions 206 and 208, the temperature measuring couplant 222 is deformed and the adhesion between the temperature measuring portion 202a and the pipe 4 is reduced. can be enhanced. For example, even if there is minute unevenness on the outer circumference of the pipe, it is possible to follow the unevenness and enhance the thermal coupling. In other words, the temperature detection error can be reduced by the close contact with the deformation of the temperature measuring couplant 222 between the temperature measuring part 202a and the pipe 4. FIG.

As a condition of the temperature-measuring couplant 222, the Vickers hardness is preferably 30 or less. Aluminum of about 45 and copper of about 50 are not preferable, and even lead-free solder, solder, gold, silver, or alloys thereof of about 20 satisfy this condition. Even hard tin is around 10, which satisfies this condition.

The material of the temperature-measuring couplant 222 must be excellent in terms of thermal conductivity and long-term reliability. Resin and rubber are not preferable because of their large creep at high temperatures, and metal is preferable.

Even if the temperature-measuring couplant 222 is plastically deformed without being elastically deformed, it is plastically deformed in accordance with the outer shape of the pipe, forming an arc shape. Even if the temperature-measuring couplant 222 is plastically deformed when it is attached or detached after installation, it can be attached and detached freely because it is firmly fixed to the piping by a belt or the like when it is re-installed on the piping. Can be attached to piping.

The box type clamp-on temperature sensor 10B will be described with reference to FIGS. 7 to 10. FIG. Box-type clamp-on temperature sensor 10B has a metal housing 230 . The metal housing 230 has a U-shape in front view with one end closed and the other end open. In the box-type clamp-on temperature sensor 10B, similarly to the belt-type clamp-on temperature sensor 10A, a heat-dissipating filler ( (not shown) are thermally coupled and insulated. The resistance temperature sensor housing 220 is insulated with a heat insulating material 218 and is not affected by the environmental temperature.

8 and 10, the pipe 4 is inserted into the U-shaped housing 230 and sandwiched between the closed end of the U-shaped housing 230 and the temperature measuring resistance housing 220. are placed in the same position. By operating a pair of left and right bolts 242 , the temperature measuring resistance housing 220 can be pressed against the pipe 4 to fix the box-type clamp-on temperature sensor 10 B to the pipe 4 . This pressing force, that is, tightening force can be adjusted by a pair of left and right bolts 242 .

The temperature-measuring couplant 222 described above is interposed between the temperature-measuring resistor 236 and the pipe 4 (FIGS. 8 and 10). When the right and left bolts 242 are operated to press the temperature measuring resistor housing 220 including the temperature measuring resistor 236 of the temperature sensor main body 234 against the pipe 4, the temperature measuring part 234a and the pipe are deformed with the deformation of the temperature measuring couplant 222. 4 can be enhanced. In other words, the temperature detection error can be reduced by the close contact with the deformation of the temperature measuring couplant 222 between the temperature measuring part 234a and the pipe 4. FIG.

The belt-type clamp-on temperature sensor 10A and the box-type clamp-on temperature sensor 10B include a common relay amplifier 250. FIG. 11 and 12 illustrate relay amplifier 250 incorporated in belt-type clamp-on temperature sensor 10A. 13 and 14 illustrate the relay amplifier 250 incorporated in the box-type clamp-on temperature sensor 10B.

11 and 12, relay amplifier 250 is installed on belt portion 208 that fixes temperature sensor main body 202 of belt-type clamp-on temperature sensor 10A to pipe 4. Referring to FIGS. 11 and 12, the relay amplifier 250 has an elongated shape. becomes consistent with Interfaces are formed on one end surface and the other end surface of the relay amplifier 250 in the longitudinal direction.

The relay amplifier 250 has a temperature conversion section 251 that converts the electrical signals obtained by the resistance temperature detectors 216 and 236 into temperature signals, and an amplifier display section 250a that displays the temperature. The relay amplifier 250 has an amplifier display lamp 251 next to the amplifier display section 250a. The amplifier indicator lamp 251 has green and red LEDs, and lights up, goes out, or flashes according to the state of the temperature sensor 10 . As shown in FIG. 12, the relay amplifier 250 is provided with an operation key 255, which is an up/down button, and a determination button 256. The display unit 250a is selected by the operation key 255 and the determination button 256, and threshold adjustment and setting are performed. be able to. Here, the setting that can be performed by the relay amplifier 250 is closer to the measurement of the temperature sensor 10 than the setting that can be performed by button operation of the switch indicator 64 . This is because the temperature measurement value, the threshold value, and the ON/OFF output are indicated by the indicator or the indicator lamp based on the setting performed by the relay amplifier 250 .

The settings that can be made with the relay amplifier 250 are language switching (Japanese, English, simplified Chinese, German), output switching (NPN/PNP), unit switching (°C, Fahrenheit), output contents (ON・OFF signal/two analog signals).

In the relay amplifier 250, an example of the display section 250a during normal operation is a display screen as shown in FIG. 14(b). On the right side is the current temperature of 27.9°C, on the left side is the upper limit setting value, and below is the lower limit setting value. It should be noted that it is possible to perform either normally-on in which an ON determination is output within the set values of the upper and lower limits, or normally-off in which an OFF determination is output.

During normal operation, the operation keys 255 can be used to move the cursor to the upper limit setting value and the lower limit setting value, the decision button 256 can be pressed for a short time to select, and the upper and lower setting values can be set using the operation keys 255 .

During normal operation, the detailed settings can be changed by pressing the operation key 255 for a long time. It is possible to switch normally on/off, and switch the averaging time (for example, 10, 20, 60, 300 seconds, etc.) for averaging and outputting the temperature for a predetermined time. In addition, the setting can be changed in a deep setting hierarchy as an item for which detailed setting is possible, which is a setting for more experienced users.

The detailed settings that can be changed include hysteresis, offset, ambient temperature correction, language switching, display upside down, screen brightness, key lock, password lock, and indicator light lighting mode. You can also check the current settings.

The modes of the amplifier indicator lamp 251 are green when the judgment is ON, red when the judgment is OFF, green when the judgment is ON, and go out (no light) when the judgment is OFF, and when the judgment is ON. It is possible to switch between turning off the light (not lighting anything), lighting red when the judgment is OFF, and turning off the light both when the judgment is ON and when the judgment is OFF. The amplifier indicator light 251 also serves as an error indicator light. When disconnection or overcurrent is detected in the signal line on the flow switch 6 side, the indicator light flashes red and the warning light turns off. It can also have a role.

The temperature sensor main body 202 is connected to one end face of the relay amplifier 250 by the first cable 252, the analog signal is supplied from the temperature sensor main body 202 to the relay amplifier 250, and the temperature is displayed on the display section 250a. The other end surface of the relay amplifier 250 has an interface for outputting to the outside via a second cable 254, and a temperature signal is output to the switch indicator 64 (clamp-on flow switch 6). The switch indicator 64 of the clamp-on flow switch 6 includes a multiprocessing display function, and the history of temperature information supplied to the switch indicator 64 of the clamp-on flow switch 6 through the relay amplifier 250 is managed by the switch indicator 64. .

Here, the entire system according to FIG. 1 will be described with reference to FIG. The temperature sensors 10A and 10B themselves only have temperature measuring resistors 216 and 236, and are connected to a relay amplifier 250 by four metal wires, that is, signal wires. A current is passed through the resistance temperature detectors 216 and 236, and the voltage is detected to derive the temperature from the resistance value. ing. Therefore, the temperature sensors 10A and 10B do not include electronic components such as ICs. It only transmits the resistance value to the relay amplifier 250 .

The relay amplifier 250 has a temperature conversion section 251 that converts the voltage difference obtained from the temperature sensor 10 into temperature, and the temperature can be displayed on the display section 250 a of the relay amplifier 250 . The digital signal temperature-converted by the temperature converter is sent to the clamp-on flow switch 6, and the flow rate of the flow switch 6 and the temperature are displayed on the switch indicator 64. FIG.

By setting the relay amplifier 250, the ambient temperature of the temperature sensor 10 can be corrected. This corrects the temperature value taking into account the influence of the ambient temperature. The resistance temperature detector 216 is covered with a housing made of a heat-insulating sponge 218 to prevent heat from being transferred to the resistance temperature detector from the surroundings other than the surface of the resistance temperature detector that is in contact with the piping. However, since the type of piping is affected by the ambient temperature, correction is made according to the piping 4 to be applied. Correction parameters are prepared in advance according to the material of the pipe, such as iron, SUS, etc., which are assumed in advance, and stored in the relay amplifier. Temperature correction is performed using correction parameters for the measured temperature. This can reduce the influence of the ambient temperature. It is also possible not to compensate for the ambient temperature by user selection. For example, there may be cases where there is insulation in the piping and there is no need to compensate for ambient temperature.

Referring to FIG. 15, refractive index type concentration sensor 8 has one signal cable with the outside. As shown in FIG. 1, the clamp-on ultrasonic flow switch 6 is connected to the refractive index concentration sensor 8 via a branch connector. It is connected from the ultrasonic flow rate switch 6 by one cable including a power line and a communication line. The signal line is divided into a power line and a communication IF section inside the refractive index concentration sensor, and the power line supplies power to each circuit element in the refractive index concentration sensor. The communication IF is for two-way communication from the flow rate switch 6 to the concentration sensor 8 and from the concentration sensor 8 to the flow rate switch 6 . The LED substrate (LED light source) 102 is controlled by the controller CB(m) to irradiate the prism with light, the light reflected by the liquid is received by the CMOS substrate 106, and converted into a refractive index depending on the light receiving position. A monitor PD 130 is provided in the vicinity of the LED light source 102 on the LED substrate to monitor the light emission amount of the LED. The current supplied to the LED light source 102 is adjusted according to the amount of light emitted by the LED light source 102, and controlled so that the amount of light emitted is constant. The indicator lamp 8b changes its lighting state depending on the light-receiving state and refractive index of the CMOS substrate 106. FIG. A temperature measurement circuit 40 including a thermometer is provided on the liquid surface side of the refractive index concentration sensor 8 . The temperature obtained by the thermometer of the temperature measurement circuit 40 may indicate the temperature of the fluid. Further, since the refractive index of the liquid changes with temperature, the obtained concentration may be corrected using the liquid temperature in order to correct this temperature dependence.

13 and 14, the relay amplifier 250 is installed on the outer surface of a U-shaped housing 230 that fixes the box-type clamp-on temperature sensor 10B to the pipe 4. As shown in FIG. As can be seen from FIGS. 13 and 14 , when the relay amplifier 250 is removably fixed to the U-shaped housing 230 , the longitudinal direction of the relay amplifier 250 is aligned with the longitudinal direction of the pipe 4 .

In the belt-type clamp-on temperature sensor 10A, the relay amplifier 250 is detachably installed using the belt 208 that constitutes the fixture, while being physically separated from the temperature sensor main body 202 that is in contact with the pipe 4, which is the heat source. can do. In the box-type clamp-on temperature sensor 10B as well, it is physically separated from the temperature sensor main body 234 in contact with the pipe 4, which is the heat source, by using, for example, the outer surface of the U-shaped housing 230 that constitutes the fixture. , the relay amplifier 250 can be detachably installed.

As shown in FIG. 2, the switch indicator 64 is connected to a concentration sensor and a temperature sensor. By using two temperature sensors and a flow rate sensor to measure upstream and downstream temperatures and measuring the flow rate of the fluid, it is also possible to calculate the amount of heat and display it on the display.

4 piping through which the liquid to be measured flows 10 temperature sensor 202a temperature measuring part 216 temperature measuring resistor 220 temperature measuring resistor housing 206, 208 belt part 212 screw (tightening part)
222 metal couplants

Claims (16)

a temperature measuring resistor having a temperature measuring part that measures the temperature of the part that contacts the metal pipe;
a temperature-measuring resistance housing surrounding the temperature-measuring resistance;
an insulating part that insulates the temperature measuring resistor housing and the temperature measuring resistor;
a mounting member for detachably fixing the temperature measuring resistance housing to a pipe;
A metal couplant having adhesion to the pipe, unlike the metal of the temperature measuring part, between the temperature measuring part of the temperature measuring resistor and the pipe;
A clamp-on temperature sensor, comprising: a clamping portion that attaches the metal couplant to the metal pipe in a state of being pressed, and clamps the mounting member to the metal pipe. A clamp-on temperature sensor as recited in claim 1, wherein said mounting member comprises a belt surrounding a pipe. 2. The clamp-on temperature sensor according to claim 1, wherein said mounting member comprises a U-shaped housing surrounding a pipe and said temperature measuring resistor housing containing said temperature measuring resistor. Clamp-on temperature sensor according to any one of claims 1 to 3, characterized in that the metal couplant is tin or a tin alloy. The clamp-on temperature sensor according to any one of claims 1 to 4, wherein the tightening portion is tightened to the pipe by fixing the mounting member to the pipe. The clamp-on temperature sensor according to any one of claims 1 to 5,
The clamp-on temperature sensor comprises a temperature sensor head and an amplifier,
The temperature sensor head is
The temperature measuring resistor, the insulating part, the metal couplant, and the housing,
The amplifier
an interface unit that receives an electrical signal obtained by the temperature sensor of the temperature sensor head;
a temperature conversion unit that converts the electrical signal into a temperature signal;
a display unit for displaying the temperature-converted temperature signal;
and an output unit for outputting the temperature signal to the outside. A clamp-on temperature sensor comprising a temperature sensor head and an amplifier,
The temperature sensor head is
A temperature measuring resistor having a temperature measuring part that measures the temperature of the part that contacts the pipe,
a housing surrounding the temperature measuring resistor;
an insulating part that insulates the housing and the temperature measuring resistor;
a mounting member for detachably fixing the housing to the pipe,
The amplifier
an interface unit that receives an electrical signal obtained by the temperature sensor of the temperature sensor head;
a temperature conversion unit that converts the electrical signal into a temperature signal;
a display unit for displaying the temperature-converted temperature signal;
and an output unit for outputting the temperature signal to the outside. The mounting member is composed of a belt that surrounds the pipe,
8. The clamp-on temperature sensor of claim 7, wherein the belt is used to detachably secure the amplifier while physically separated from the resistance temperature detector. The mounting member is composed of a U-shaped housing that surrounds the pipe and a temperature measuring resistance housing that includes the temperature measuring resistor,
8. The clamp-on temperature sensor according to claim 7, wherein said amplifier is detachably fixed in a state of being physically separated from said temperature sensing resistor using a side surface of said housing. A clamp-on temperature sensor according to any one of claims 7 to 9, wherein the current to the resistance temperature detector is supplied by an amplifier and the temperature sensor head has no electronic components. There is one communication cable between the temperature sensor head and the amplifier,
a metal wire that supplies current from the amplifier to the temperature sensing resistor of the temperature sensor head;
a metal wire for measuring the potential difference across the temperature sensor head of the temperature sensor head;
The clamp-on temperature sensor according to any one of claims 7 to 10, having Claims 7 to 11, further comprising a relay amplifier having an indicator lamp, wherein the indicator lamp of the relay amplifier is lit, extinguished, or blinked in accordance with the result of comparison between the temperature signal and the set value input by the user. A clamp-on temperature sensor according to any one of Claims 1 to 3. 13. The clamp-on temperature sensor according to claim 12, wherein said relay amplifier has an operation unit for receiving user input in a housing, and can change a set value for said temperature signal according to input by said operation unit. The relay amplifier has a correction value according to the material of the pipe to which the temperature sensor head is attached,
14. The clamp-on temperature sensor according to claim 12, wherein a temperature signal is output or displayed based on the temperature signal converted by said temperature converter and said correction value. 15. The clamp-on temperature sensor according to claim 14, wherein said correction value uses a pre-stored correction value based on the user's selection of pipe material. The clamp-on temperature sensor according to any one of claims 1 to 6, wherein the metal couplant is a metal having a Vickers hardness of 30 or less.

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