WO2013135463A1

WO2013135463A1 - Method for contactless temperature measurement for detecting heat or cold bridges and temperature measuring device

Info

Publication number: WO2013135463A1
Application number: PCT/EP2013/053276
Authority: WO
Inventors: Michael Frank; Mike Uhlig; Patrick Meyer
Original assignee: Robert Bosch Gmbh
Priority date: 2012-03-14
Filing date: 2013-02-19
Publication date: 2013-09-19
Also published as: DE102012203996A1; EP2825869A1; CN104254770A

Abstract

The invention relates to a method for contactless temperature measurement, particularly a method for heat or cold bridge detection, in which a surface temperature measured in a contactless manner is compared with a reference value in order to detect a temperature deviation, particularly the risk of a heat or cold bridge. It is proposed that the reference value is measured by means of a second temperature sensor, particularly an ambient temperature sensor. The invention further relates to a measuring device, particularly an infrared temperature measuring device for performing said method.

Description

description

title

METHOD FOR CONTACTLESS TEMPERATURE MEASUREMENT FOR DETECTING HEAT OR BZW. COLD BRIDGES AND TEMPERATURE GAUGES

The invention relates to a method for non-contact temperature measurement, in particular a method for detecting heat or cold bridges and a temperature measuring device for carrying out the method.

State of the art

Non-contact temperature measuring devices have been known for some time. A class of these devices is formed by the so-called infrared temperature measuring devices. Such measuring devices, also called radiation thermometers or pyrometers, detect the heat radiation emitted by an object whose intensity and position of the emission maximum depend on its temperature.

From DE 20 2005 015 397 Ul such a hand-held radiation thermometer is known.

The invention has for its object to provide a method for non-contact temperature measurement, in particular a method for the detection of heat or cold bridges, which ensures ease of use and accurate measurement.

Moreover, it is an object of the present invention to provide a corresponding measuring device. Disclosure of the invention

The invention solves the underlying problem by means of a method having the features of claim 1. Subclaims give preferred embodiments again.

In addition, we the object of the invention by a measuring device according to claim 9 or 10 solved.

In the method according to the invention for non-contact temperature measurement, which is in particular a method for heat or cold bridge detection, a contactlessly measured surface temperature is compared with a reference value in order to detect a temperature deviation and in particular the risk of a heat or cold bridge. According to the invention, the reference value is measured by means of a second temperature sensor, in particular an ambient temperature sensor.

A thermal bridge - or sometimes referred to as a cold bridge - is an area in building components that transfers heat faster to the outside than through the other components. In the area of thermal bridges, the room-side surface temperature of components sinks more in cold outside temperatures than in the "normal areas" of the room. When the temperature falls below the dew point temperature, condensate (condensed water) drops out. On thermal bridges is thus in particular the risk of mold growth. This occurs not only with condensation water, but already at a - due to the surface temperature - relative humidity of about 80% on the component surface. Due to the internal heat transfer resistance of the wall, this may already be the case with a relative humidity of 70% of the room air. Thermal bridges lead to higher transmission heat demand and thus to higher heating requirements / heating costs.

In contrast to known thermal bridge detectors, which must set a reference value before the actual measurement, the ambient temperature is used as the reference value in the method according to the invention. This advantageously dispenses with the setting of the reference value and the associated error susceptibility due to incorrectly selected reference values.

In addition, can be dispensed with additional work or process steps. The HMI (Human Machine Interface) of a corresponding measuring device can be greatly simplified, the ease of use can be significantly increased.

However, the extra housing for the ambient temperature sensor is integrated in the housing contour of the measuring housing of the device, so that no protruding corners or knew in a case or shock of the meter due to their exposed position can be damaged.

Advantageously, the extra housing of the ambient temperature sensor is surrounded on at least three sides, in particular on four sides, by the device housing of the measuring device.

According to the invention, means are provided in the measuring device, which ensure that the extra housing is thermally decoupled from the housing of the device.

Thus, for thermal decoupling, the extra housing for the additional ambient temperature sensor can be connected via small webs or legs to the main housing of the measuring device.

The webs for attaching the extra housing in the device housing can be integrally connected to the extra housing.

Alternatively, the webs for attaching the extra housing in the device housing are integrally connected to the device housing.

It is also advantageous if the material of the extra housing is formed differently from the material of the device housing. Thus, the extra housing may be formed, for example, as a metal housing. It is also advantageous that the extra housing of the ambient temperature sensor to design largely open to allow the highest possible thermal contact of the ambient air with the sensor. Possible aspects, advantages and embodiments of the invention have been described above with reference to individual embodiments of the invention. The description, the associated figures and the claims contain numerous features in combination. A person skilled in the art will consider these features, in particular also the features of different exemplary embodiments, individually and combine them into meaningful further combinations.

Brief description of the figures

In the following the invention will be described in more detail with reference to the attached figures. Embodiments of the invention and sub-aspects contained therein will be described with reference to the accompanying drawings. The figures are only schematic and not to scale. Like or similar reference numerals in the figures indicate the same or similar elements.

Show it:

1 is a schematic representation of the sequence of the method according to the invention,

2 is a perspective view of a measuring device for carrying out the method according to the invention,

3 is a detail view of the measuring device according to Figure 2,

4 shows a housing of the ambient temperature sensor of the measuring device according to the invention in a single representation. Description of an embodiment

The temperature measuring device according to the invention (see FIG. 2) has inter alia a mode for the detection of heat or cold bridges. 1 shows a flowchart of some method steps of the method according to the invention for detecting heat or cold bridge detection.

In contrast to known thermal bridge detectors, which must set a reference value before the actual measurement, the ambient temperature is used as the reference value in the method according to the invention. This dispenses with the setting of the reference value and the associated error susceptibility.

After a trigger, for example the measuring button of a measuring device, is actuated, the measuring process of the non-contact temperature measurement is initiated. For this purpose, a light signal, for example one or more laser spots, is directed at the position of a surface to be measured.

It is also possible that the targeted measuring range is displayed on a display of the measuring device. For this purpose, the measuring device according to the invention can advantageously be equipped with a camera, in particular a digital camera, in order to record the measuring range of the contactless temperature measurement. In this camera image, which can be displayed on a display of the meter, then the - for example, computationally determined - accurate location of the temperature measurement can be displayed.

In the method according to the invention, a surface temperature is measured without contact via an IR sensor.

Furthermore, a reference value is measured. The reference value is used at

For this purpose, he is the ambient temperature

According to the invention, an additional temperature sensor is used.

If the reference value exceeds a predetermined limit (at

example, 12 ° C), a corresponding warning, for example a red LED, or a flashing display to the user.

If, during a measurement, large deviations or fluctuations in the reference value are measured or occur, an ent

speaking warning, for example by means of a red LED, or a flashing display to the user to be transmitted.

Surface temperature and ambient temperature can be measured simultaneously or sequentially. In particular, the surface temperature can be measured before or after the ambient temperature.

The measured surface temperature can be output, for example communicated to a user via a display and compared with the ambient temperature.

The ambient temperature can also be output as a numeric value.

The measured temperature values are transmitted to a computing unit, which from the measured values a temperature difference

determined.

The temperature deviation

is the difference, in particular the amount of the difference of the reference temperature (here according to the invention the ambient temperature) and the measured surface temperature. The deviation can be displayed as numerical values in the display and / or indicated by a colored display.

If this temperature difference is smaller than or equal to a predefinable or predetermined limit value G ₁ , a coded color signal, for example "green", is output in order to signal to a user that the danger of a thermal or cold bridge does not exist.

Although this temperature difference is greater than the predeterminable or predetermined first limit value G ₁ but less than or equal to a second predeterminable or predetermined limit value G ₂ , a different color coded signal, for example For example, a value of 3.5 °, for example, a value of 4 for the second limit value G ₂ , could be used as the first limit value G ₁ for signaling to a user that the danger of a thermal or cold bridge could exist , 5 ° These limits are to be considered as examples only and do not limit the general public.

If the temperature difference is also greater than the predefinable or predetermined second limit value G ₂ , a color which is in turn coded differently can be output, for example, "red" in order to signal to a user that the surface temperature deviates significantly from the ambient temperature and thus a heat or Cold bridge exists.

It is also possible to continuously measure the surface temperature and the reference temperature in order to scan a surface for heat or cold bridges. For example, during scanning, the trigger is held down and the marking laser spot can be slowly and continuously guided across the area to be measured. Temperature deviations between reference and measured value are shown as follows:

Temperature deviations between the reference and surface measured values can be represented, for example, as follows:

Color indicator red

Surface temperature within the measuring surface deviates significantly from the ambient temperature - there is a thermal bridge

Color indicator yellow

Surface temperature within the measuring area in the boundary area - there is a risk of a thermal bridge

Color display green

Low temperature difference - there is no thermal bridge Of course, other color coding can be used. To output the coded color signals, for example, different colored LEDs or even the backlight of a display can be used.

Temperature deviations can also be displayed additionally or solely numerically on a display and / or moreover be acoustically signaled to a user.

The method according to the invention makes it possible to eliminate additional process or work steps and, in particular, to avoid erroneous measurements by means of a predetermined reference value.

In order to set the ambient temperature as a reference value, the measuring device according to the invention for carrying out the method described above is provided with an additional ambient temperature sensor.

FIG. 1 shows the measuring device 10 according to the invention in an overview.

The measuring device 10 according to the invention has a device housing 12 with a measuring head 14 and a grip area 16. A measuring switch 20 is formed on the grip area 10, with which a temperature measurement can be started.

Simultaneously with or upstream of the actual temperature measurement, an optically visible signal, for example a laser marking, can be emitted, which indicates to a user which region of a surface which is being targeted would be measured with respect to its temperature. For this purpose, the measuring device according to the invention has an optical marking unit 22, which is aligned with the field of view of the thermal detector.

The optical marking unit 22 may alternatively or additionally comprise a camera, in particular a digital camera. This makes it possible that the targeted measuring range can be displayed on a display of the measuring device. The camera, in particular a digital camera, records the extended measuring range of the surface temperature measurement. In this camera image, which can be displayed on a display of the meter, then the example As an example, the exact location of the temperature measurement can be displayed, in order to visualize to a user at which point exactly the surface temperature is measured.

In the measuring head 14, inter alia, an infrared sensor, not further shown in FIG. 2, is arranged, which detects the I R radiation emitted by a measuring object and focused by way of a lens element 24.

Which wavelength range is optimal for the desired measurement depends in principle on the material to be measured and its temperature. For temperatures around room temperature, wavelengths in the mid-infrared (MIR) are possible.

The lens 24 or a window introduced into the device instead of the lens may consist of glass, in particular a quartz glass. For the middle I R range, it may be useful to form the lenses or windows, if appropriate also from crystals such as germanium, CaF 2, ZnS, ZnSe, KRS 5 or also polyethylene (PE) or polypropylene (PP).

The collected I R radiation is detected and from this the surface temperature of the measurement object is determined. For this purpose, the measuring device according to the invention has a computing and evaluation unit in order to convert the detection signal into a temperature value.

The temperature value determined in this way can be displayed from an output unit, in particular a display 18, which is arranged on the side of the device housing 12 facing away from the measuring direction.

According to the invention, the measuring device has an additional temperature sensor for determining the ambient temperature. The temperature sensor is arranged in a separate extra housing 26, which is largely thermally separated from the device housing.

Core of the invention is the reduced interaction between the ambient temperature sensor and the disturbance variable (thermal mass), with good protection of the sensor against external influences, such as a fall or push. For this purpose, the invention dispenses with an exposed housing part for the ambient temperature sensor.

This also means the use of a low thermal mass for the printed circuit board (PCB) on which the ambient temperature sensor is applied. For example, a printed circuit board is used whose geometrical dimensions exceed only slightly the geometrical dimensions of the sensor.

Furthermore, the circuit board for the environmental sensor incl. Sensor is best mechanically and thermally decoupled from the main body of the meter. This is achieved by the PCB (PCB) incl. Sensor is placed in an extra housing 26 for the ambient temperature sensor, which in turn is best decoupled from the main housing 12 thermally by the number of points of contact between the two housings and their overlapping surfaces is performed as low as possible.

The extra housing 26 for the ambient temperature sensor is integrated into the housing contour of the measuring housing 12 of the device, so that no protruding corners or knew could be damaged in a case or shock of the meter due to their exposed position.

FIG. 3 shows a detail of the arrangement of the ambient temperature housing 26 in the measuring head 14 of the measuring device according to the invention.

According to the invention means 28 are provided in the measuring device, which ensure that the extra housing 26 is thermally decoupled from the housing 12 of the device.

Thus, for thermal decoupling, the extra housing 26 for the additional ambient temperature sensor can only be connected to the main housing 12 of the measuring instrument via small webs or legs 28.

The webs 28 for attaching the extra housing 26 in the device housing 12 can - as shown in Figure 4 - are integrally connected to the extra housing 26. Alternatively, the webs or legs could be used to attach the extender ra housing 26 in the device housing 12 are integrally connected to the device housing 12.

Advantageously, the extra housing 26 of the ambient temperature sensor is surrounded at least three, in particular four sides of the device housing 12 and adapts in particular to the contour of the measuring head of the measuring device according to the invention.

The extra housing 26 is largely open in order to realize a direct exchange with the ambient air. The extra housing 26 is largely open in particular on its outwardly facing surface or has only a protective grid or strip structure.

Advantageously, it is also possible that the material of the extra housing 26 is formed differently from the material of the device housing 12. Thus, the extra-housing 26 may be formed as a metal housing.

For reproducing measurement results, the measuring device according to the invention has at least one output unit 18, in particular a display, on which, for example, the measured temperature values or differences can be displayed.

In addition, the device 10 may also have additional LEDs capable of outputting encoded color signals. These LEDs are also advantageously arranged in the region of the display 18.

Alternatively, instead of the LEDs, a different color backlight of the display can be used to transmit different temperature information to a user. The measuring device 10 according to the invention can have different measuring modes, of which the method according to the invention is only one. For example, in a measuring mode 1, the measuring device according to the invention can measure the surface temperature of walls and objects, for example radiators, with a measuring accuracy of, for example, ± 1 degree. As a result, for example, be asked if radiators work properly. The exact values can be read quickly and easily on the illuminated display.

In a measuring mode 2, the measuring device according to the invention can measure the room and surface temperature, set the values in relation, interpret the data and detect thermal bridges in this way. The result can be displayed by LED. The exact measured values can be read off the display.

In a measuring mode 3, the thermodetector can also measure the humidity in addition to the room and surface temperature. On the basis of these three values, it is then also possible to define or detect mold-prone areas in one. If there is an acute danger of mold, the device can warn with a red LED or, for example, acoustically. Even in this measurement mode, the exact measurement results can be read in a display.

The device measures the room temperature, the surface temperature of walls and objects or the relative humidity according to the selected measuring mode.

Claims

claims

1 . Method for non-contact temperature measurement, in particular a method for heat or cold bridge detection, in which a measured by means of an I R sensor contactless surface temperature with a

Temperature reference value is compared to a Temperaturabwei

in particular the danger of a heat or cold bridge to detect, characterized in that the temperature reference value with

A second temperature sensor, in particular an ambient temperature sensor, is measured.

2. A method for non-contact temperature measurement according to claim 1, d, characterized in that as a temperature reference value, the Umg

Application temperature T _Um g is used.

3. A method for non-contact temperature measurement, in particular a method for heat or cold bridge detection according to the preamble of claim 1, comprising at least the following steps:

Measuring the ambient temperature by means of an ambient

temperature sensor,

Measuring a surface temperature

by means of a surface temperature sensor different from the ambient temperature sensor, calculating the temperature difference

between ambient temperature and surface temperature

Output of a temperature information signal (A, B, C) as a function of the measured temperature difference

4. The method according to claim 3, characterized in that the measured temperature difference

by means of a display unit (18) is output as a numerical value.

5. The method according to claim 3 or 4, characterized in that, depending on the size of the measured temperature difference

a coded color signal is output.

6. The method according to any one of claims 3 to 5, characterized in that in the event that the amount of the measured temperature difference smaller

or equal to, as a first predetermined or specifiable limit G ₁ , a first color signal, in particular a green color signal is output.

7. The method according to any one of claims 3 to 6, characterized in that in the event that the amount of the measured temperature difference

is greater than a first predetermined or predeterminable limit G ₁ but is less than or equal to, as a second predetermined or specifiable limit G _2, a second color signal, in particular a yellow color signal is output.

8. The method according to any one of claims 3 to 7, characterized in that in the event that the amount of the measured temperature difference

is greater than a second predetermined or predetermined limit G _2, a third color signal, in particular a red color signal is output.

9. Measuring device, in particular infrared temperature measuring device (10) for carrying out the method according to one of claims 1 to 8.

10. A measuring device for non-contact temperature measurement, in particular a hand-held device for heat or cold bridge detection, with a device housing (12), as well as in the device housing (12) arranged infrared sensor, characterized in that an additional ambient temperature sensor is provided which is configured and / or is arranged to measure a temperature _{reference value} (T _Ref ).

11. The device according to claim 9 or 10, characterized in that the ambient temperature sensor is thermally decoupled from the housing (12) for non-contact temperature measurement.

12. The device according to at least one of claims 9 to 11, characterized in that the ambient temperature sensor in an extra housing

(26) of the measuring device (10) is positioned.

13. The apparatus according to claim 12, characterized in that means (28) are provided, which ensure that the extra housing (26) from the housing (12) of the measuring device (10) is thermally decoupled.

14. The apparatus of claim 12 or 13, characterized in that the extra housing (26) with the device housing (12) via at least two webs

(28) is connected.

15. The apparatus according to claim 14, characterized in that the webs (28) are integrally connected to the extra housing (26).

16. The apparatus according to claim 12, characterized in that the webs are integrally connected to the device housing (12).

17. The device according to at least one of claims 12 to 16, characterized in that the material of the extra housing (26) is formed differently from the material of the device housing (12).

18. The device according to at least one of claims 12 to 17, characterized in that the extra housing (26) is a metal housing.

19. The device according to at least one of claims 12 to 18, characterized in that the extra housing (26) is designed to be substantially open.

20. The device according to at least one of claims 12 to 19, characterized in that the extra housing (26) on the device housing (12), in particular on the measuring head (15) of the device housing, is arranged.

21. The device according to at least one of claims 12 to 20, characterized in that the extra housing (26) on at least three sides, in particular on four sides, of the device housing (12) is surrounded.