JP3063513U - Surface thermometer - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide an inexpensive radiation type surface thermometer that is not equipped with a light collector or a laser marker device, with good usability and good measurement accuracy. SOLUTION: The front end of a housing 6 provided with an infrared sensor 3 for measuring the intensity of thermal radiation energy from the surface of the device under test 1 is pressed against the surface of the device under test 1. At the same time as securing a constant measurement distance L between the measurement point on one surface and the infrared sensor 3,
A spacer 8 is provided to protrude from the sensing point within the sensing field of view W of the infrared sensor 3 so as to prevent a field deviation due to hand shake of the surface thermometer or the like.

Description

[Detailed description of the invention]

[0001]

[Technical field to which the invention belongs]

 The present invention relates to a surface thermometer that is widely used for actually measuring a cooking temperature, a freezing temperature, a refrigeration temperature of a food, a heating temperature of an industrial product, and the like.In particular, the surface temperature of an object to be measured is measured from the surface. The present invention relates to a surface thermometer that measures heat radiation of an object by an infrared sensor that converts the heat radiation into an electric signal.

[0002]

[Prior art]

 Surface thermometers include a contact type that measures the surface temperature by bringing a thermocouple or RTD into contact with the surface that is the measurement point of the device under test, and a measurement point that is located away from the surface of the device under test. There is a non-contact type that measures the surface temperature of an object.

[0003] As a non-contact type surface thermometer, there is a radiation thermometer that measures the intensity of thermal radiation energy from the surface of an object to be measured by an infrared sensor to obtain a surface temperature. As shown in FIG. 2, an optical system 2 having a condenser or a condensing mirror such as a lens or a concave mirror that efficiently collects heat radiation from the surface of the device under test 1, an aperture, an optical filter, and the like. In general, an infrared sensor 3 such as a thermopile for converting heat radiation to an electric signal and an electric system 4 for amplifying the electric signal of the sensor 3 and outputting the amplified signal to a temperature display device 5 are provided in a housing 6. It is.

There is also a radiation thermometer provided with a laser marker device that irradiates a laser beam onto a measurement point on the surface of an object to be measured and attaches a target mark to accurately direct an infrared sensor to the measurement point. .

[0005]

[Problems to be solved by the invention]

 By the way, a contact-type surface thermometer contacts a temperature sensor such as a thermocouple or a resistance thermometer with a measurement point on the surface of the object to be measured, so the heat capacity of the surface is small due to the contact of the temperature sensor. The object to be measured has a disadvantage that the temperature at the measurement point changes and an accurate surface temperature cannot be obtained.

Further, the thermal equilibrium between the object to be measured and the temperature sensor is essentially imperfect. In particular, when the measurement point receives wind, the thermal equilibrium cannot be obtained due to the influence.

[0007] On the other hand, a non-contact radiation thermometer is suitable for measuring the surface temperature of an object to be measured having a small heat capacity. And there was a problem that an accurate surface temperature could not be obtained.

[0008] The radiation thermometer includes a condenser such as a lens for condensing heat radiation from the surface of the object to be measured, and a laser marker for marking a measurement point on the surface of the object to be measured with a laser beam. The device enables accurate measurement of the surface temperature of the device under test from a distance, but the cost of the concentrator and laser marker device makes the radiation thermometer equipped with them expensive. It was very expensive.

Although there are inexpensive radiation thermometers that are not equipped with a light collector or a laser marker device, without a light collector, the viewing angle of the infrared sensor is widened, and the infrared sensor becomes less sensitive to the surface of the object to be measured. Since the measurement point gradually increases as the distance from the sensor increases, it is impossible to obtain a small measurement point unless the infrared sensor is brought close to the surface of the object to be measured. Each time, it is troublesome that the distance between the infrared sensor and the surface of the object to be measured must be finely adjusted so that the distance is a predetermined distance according to the size of the measurement point.

The measurement distance at which a small measurement point of a predetermined size can be obtained is calculated in advance by the manufacturer and is set to, for example, about 10 mm. However, it is difficult to accurately adjust the measurement distance by visual measurement. In particular, when the radiation thermometer shakes, it is not only difficult to adjust the measurement distance, but also there is a risk that the adjustment may be erroneously made and the measurement accuracy may be deteriorated.

Further, if there is no laser marker device for marking a target point at a measurement point, the infrared sensor cannot be accurately pointed at the measurement point, and the measurement point is out of the sensing field of view of the infrared sensor. There may be a gap.

Therefore, the present invention relates to an inexpensive radiation type surface thermometer which is not equipped with a concentrator or a laser marker device, in order to obtain a small measuring point of a predetermined size, in order to obtain a small measuring point of a predetermined size. In addition to eliminating the hassle of adjusting the measurement distance by eye measurement, the risk of incorrect adjustment of the measurement distance due to hand shake of the thermometer and the likelihood of misalignment of the visual field due to unintentional aiming at the measurement point is eliminated, significantly improving measurement accuracy. Improvement is a technical issue.

[0013]

[Means for Solving the Problems]

 In order to solve the above problems, the present invention provides a surface thermometer that measures the surface temperature of an object to be measured with an infrared sensor that converts heat radiation from the surface into an electric signal. A spacer is provided at the front end of the housing provided with the narrowing diaphragm to press the tip against the surface of the object to be measured to secure a constant measurement distance between the measurement point on the surface and the infrared sensor. The spacer is formed into a shape that does not fall within the sensing viewing angle of the infrared sensor narrowed by the diaphragm, and the tip of the spacer concentrically extends the sensing viewing range of the infrared sensor. It is characterized in that it is formed in a shape surrounded by.

In the surface thermometer according to the present invention, when the center of the tip of the spacer is pressed against the measurement point on the surface of the object to be measured, a certain measurement distance is secured between the measurement point and the infrared sensor. At the same time, the measurement point is necessarily captured in the sensing field of view of the infrared sensor.

[0015] Also, while aiming at the measurement point on the surface of the object to be measured with the tip of the spacer, the tip is pressed against the surface of the object to be measured, so that the measurement point falls within the sensing field of view of the infrared sensor. As well as being reliably captured, positional deviation due to hand shake of the surface thermometer and the like is prevented, and visual field deviation in which the measurement point is out of the sensing visual field range of the infrared sensor is also reliably prevented.

[0016]

[Embodiment of the invention]

 Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings. FIG. 1 is a cross-sectional view showing an example of the surface thermometer according to the present invention, FIG. 2 is a view showing examples of various spacers to be selectively used according to the use conditions of the surface thermometer, and FIG. 3 is a perspective view showing a modified example of the spacer. It is. Members common to those of the conventional surface thermometer shown in FIG. 4 are denoted by the same reference numerals, and detailed description of the common members will be omitted.

The surface thermometer shown in FIG. 1 has a front end at a front end of a housing 6 provided with an infrared sensor 3 and a diaphragm 7 for narrowing a sensing viewing angle of the sensor, and a front end at a surface of the object 1 to be measured. A spacer 8 is provided protruding from the measurement point on the surface and the infrared sensor 3 to secure a certain measurement distance L.

The infrared sensor 3 is composed of a thermopile or the like that radiates heat radiation from the surface of the device under test 1 to a central sensing portion and converts the temperature rise of the portion into an electromotive force. There is no optical system having a condenser such as the above, and only the stop 7 is provided. The aperture 7 is formed of, for example, a thin pipe that narrows the sensing viewing angle 111 ° of the thermopile serving as the infrared sensor 3 to 12 °.

The spacer 8 is made of a material having a low thermal conductivity, such as stainless steel, and does not fall within the sensing viewing angle θ of the infrared sensor 3 narrowed to 12 ° by the aperture 7, and is positioned between the surface of the DUT 1 and the infrared ray. The measuring optical path formed between the sensor 3 and the sensor 3 is formed into a pipe shape that can be shielded from the outside, and the tip portion is formed into a circular shape that concentrically surrounds the sensing field of view W of the infrared sensor 3. Have been.

The spacer 8 is detachably attached to the front end of the housing 6 by fitting or screwing the rear end of the spacer 8 into a spacer attachment portion 9 projecting to the front end side of the housing 6. It has become.

In the surface thermometer shown in FIG. 1, the tip of the spacer 8 protruding from the front end of the housing 6 is simply pressed against the measurement point on the surface of the object 1 to be measured. A constant measurement distance L can be automatically secured between the two.

By aiming at the measurement point on the surface of the object 1 at the tip of the spacer 8, the measurement point can be reliably captured in the sensing field of view W of the infrared sensor 3, and at the same time, the spacer By pressing the tip of 8 on the surface of the DUT 1, visual field deviation due to camera shake of the surface thermometer or the like is reliably prevented, so that the surface temperature at the measurement point can be accurately measured.

Even if the DUT 1 is an object having a small heat capacity, the temperature measurement time by the infrared sensor 3 such as a thermopile is about 1 to 2 seconds, and the spacer 8 has a low heat conductivity. Since it is formed of a material, there is little possibility that the measurement accuracy of the surface temperature is impaired by pressing the tip of the spacer 8.

If the spacer 8 is configured to be detachable from the front end of the housing 6, it is convenient to remove dust and dirt attached to the spacer 8, and at the same time, as shown in FIG. Various spacers can be used according to the conditions of use of the surface thermometer.

That is, when the measurement point on the surface of the DUT 1 is small, as shown in FIG. 2A, a spacer 8 made of a short pipe having a small inner diameter at the tip is used, and infrared rays at the tip of the spacer 8 are used. The sensing field of view W of the sensor 3 is reduced.

When the surface of the DUT 1 is relatively hot, the infrared sensor 3 is measured by using a spacer 8 made of a long pipe having a large inner diameter at the tip end as shown in FIG. Move away from the surface of object 1. As a result, the sensing field of view W of the infrared sensor 3 at the distal end of the spacer 8 is expanded, but the possibility that the infrared sensor 3 or the electric system 4 or the like breaks down due to the high temperature is reduced.

Further, when the DUT 1 is a soft object, as shown in FIG. 2C, the DUT 1 is provided with a spacer 8 having a flange 10 protruding in the circumferential direction at its tip. By increasing the contact area of the tip of the spacer with respect to the surface, the tip of the spacer 8 pressed against the surface of the DUT 1 is prevented from being buried in the surface or damaging the surface.

The spacer 8 is formed into a shape that does not fall within the sensing viewing angle θ of the infrared sensor 3, and furthermore, as shown in FIGS. 1 and 2, the distance between the surface of the object 1 and the infrared sensor 3. If the pipe is formed in a pipe shape that shields the measurement optical path formed between the pipes from outside, light disturbance due to heat radiation from the spacer 8, heat radiation from a high-temperature object other than the DUT 1, heat reflection, etc. In addition, it is possible to prevent heat from being removed from the surface serving as a measurement point of the DUT 1 by the wind, and the measurement error becomes extremely small.

Further, as shown in FIG. 2C, if a flange 10 is formed at the tip of the spacer 8, it does not hurt even if it is directly pressed against human skin, and there is no danger of damaging the skin. Therefore, it is also suitable as a thermometer for measuring the temperature of the body surface.

Next, the spacer 8 shown in FIG. 3 is formed in a frame shape in which one or several leg portions 12 support the tip portion formed of a circular ring 11.

Since the tip of the spacer 8 is formed in a ring shape such as a sight which makes it easy to aim at a measurement point on the surface of the DUT 1, the measurement point is set in the sensing field of view W of the infrared sensor 3. It is easy to catch and the displacement of the visual field can be reliably prevented.

The spacer 8 shown in FIG. 3 cannot shield the measurement optical path formed between the surface of the object 1 and the infrared sensor 3 from the outside. There is an advantage that when pressed against the surface of the sample, there is no danger that water vapor will be trapped inside the spacer 8 or that water drops will adhere to the measurement optical path.

If the ring 11 forming the distal end of the spacer 8 is made wide, the same effect as that obtained by forming the flange 10 at the distal end as shown in FIG. 2C can be obtained.

The infrared sensor 3 is not limited to a thermoelectric sensor such as a thermopile, but may be a photoelectric sensor such as PbS or PbSe.

[0035]

[Effect of the invention]

 According to the present invention, for an inexpensive radiation-type surface thermometer that does not have a condenser or a laser marker device, it is troublesome to visually adjust the measurement distance between the measurement point on the surface of the object to be measured and the infrared sensor. At the same time, the possibility that the measurement point deviates from the sensing field of view of the infrared sensor and the field of view shifts is also eliminated, so that there is an extremely excellent effect that the measurement accuracy is significantly improved.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an example of a surface thermometer according to the present invention.

FIG. 2 is a cross-sectional view illustrating an example of a spacer.

FIG. 3 is a perspective view showing an example of a spacer.

FIG. 4 is a sectional view showing a conventional surface thermometer.

[Explanation of symbols]

 1 ···· Measured object 3 ···· Infrared sensor 6 ····· Housing 7 ···· Aperture 8 ····· Spacer 10 ····· Flange 11 ··· ..Ring 12 ... Legs

Claims (6)

[Utility model registration claims] 1. A surface thermometer for measuring a surface temperature of an object to be measured by an infrared sensor for converting heat radiation from the surface into an electric signal, wherein the infrared sensor (3) and a diaphragm for narrowing a sensing viewing angle thereof. A front end of the housing (6) provided with (7) is pressed against the surface of the object (1) by measuring the distance between a measurement point on the surface and the infrared sensor (3). A spacer (8) for securing (L) is protruded, and the spacer (8) is formed into a shape that does not enter the sensing viewing angle (θ) of the infrared sensor (3) narrowed by the aperture (7). And a tip portion of the spacer (8) is formed in a shape concentrically surrounding the sensing field of view (W) of the infrared sensor (3). 2. The spacer (8) is formed in a pipe shape for shielding a measurement optical path formed between the surface of the object (1) to be measured and the infrared sensor (3) from the outside. The surface thermometer according to 1. 3. The surface thermometer according to claim 2, wherein a flange (10) projecting in a circumferential direction is formed at a tip of the spacer (8) formed in a pipe shape. 4. The surface thermometer according to claim 1, wherein the spacer (8) is formed in a frame shape in which one or more legs support a ring-shaped tip. 5. The surface thermometer according to claim 1, wherein the spacer is detachably attached to a front end of the housing. 6. The surface thermometer according to claim 1, wherein said spacer (8) is formed of a material having low thermal conductivity.