Penetrating temperature sensor with insulating cup

Description

[0001] The present invention relates to the field of temperature measurement, in particular in a cold environment.

[0002] The present invention particularly relates to a penetration temperature sensor.

[0003] Measuring the temperature of a surface or body with an accuracy of one degree can be difficult in a cold environment, such as a cold room. The temperature can often be below 10°C. This cold environment tends to cause measurement errors of several degrees depending on the type of measuring element used. Temperature measurements in a cold environment can therefore be unreliable, particularly when using thermocouples associated with a portable reader.

[0004] This reliability is essential for certain applications such as temperature control of foodstuffs, such as meat. The consequences of an erroneous measurement can be regulatory, health and economic due to the refusal of goods that can occur if a defined temperature threshold is exceeded.

[0005] A rise in temperature of a few degrees leads to significant microbial growth and greater health risks for consumers. Reliable measurement is therefore necessary to control food quality.

[0006] Furthermore, a measurement error due to the use of an unsuitable temperature sensor can result in the customer rejecting an entire load of food. Indeed, if the temperature reading upon receipt of refrigerated products is 2 or 3°C too high, the food may be rejected.

[0007] There are different temperature measurement technologies, including without or with contact with the surface or body to be measured.

[0008] Non-contact measurement includes infrared thermometers that use infrared thermal radiation emitted by the body to be measured. It has been observed that infrared thermometers have a measurement error in cold environments between 2 and 4°C. These measurement errors are mainly due to thermal radiation and convective exchanges from the air circulating around the measuring surface. Thus, these infrared thermometers are not suitable for use in cold environments, particularly on refrigerated foods. Another drawback of this type of measuring device is that the surface area of the portion of the surface whose radiation is measured depends on the distance between the thermometer and the surface.Knowing that the measured temperature corresponds to the temperature of this portion of the surface, the measured temperature can vary significantly if the body measured is heterogeneous, such as an animal carcass containing muscle, fat and fascia.

[0009] Contact measurement includes contact thermometers. This type of thermometer includes a sensor with flexible strips placed in contact with the surface to be measured. It is necessary to be able to hold the sensor against the surface to be measured with a certain amount of pressure throughout the measurement. Maintaining the position of the thermometer and the pressure against the surface can be difficult and variable over time, leading to measurement variations. The inclination of the thermometer also tends to cause measurement variations. On surfaces of different types, such as an animal carcass, different temperature values can also be obtained due to the variation in resistivity between the different components of the surface. Thus, it has been observed that contact thermometers have a measurement error in cold environments that can exceed 2°C.

[0010] It should also be noted that infrared and contact thermometers only allow measurements to be taken on the surface of a body, not at depth. However, some applications require temperature measurements to be taken at a predefined depth of the body. This is particularly the case for taking the temperature of animal carcasses, for which a temperature measurement must be taken at an effective depth of 0.5 cm.

[0011] Contact measurement also includes penetration thermometers comprising a prod to be inserted inside the body to be measured, as disclosed for example in document FR 3 003 945 A1. However, existing penetration thermometers do not allow for accurate and reliable surface temperature measurement. There is in fact no way of knowing how deep the prod is inserted, which leads to a variation in the measurements.

[0012] There is therefore a need for a temperature measuring device which does not have the aforementioned drawbacks when taking temperature in a cold environment.

[0013] More particularly, there is a need for a measuring device that allows accurate and reliable temperature measurement, while allowing temperature measurement at a predefined depth of the body to be measured.

[0014] For this purpose, the invention proposes a penetration temperature sensor comprising a housing forming an annular abutment surface intended to be arranged in contact with a body to be measured, said abutment surface defining an abutment plane, said sensor also comprising a measuring prod intended to penetrate the body to be measured, said prod being fixed to the housing such that a penetration portion of the prod extends out of the housing, perpendicular to the abutment plane, the abutment surface extending around the prod, the housing forming an open insulation cavity extending around and along the measuring prod, an open end of the insulation cavity being delimited by the abutment surface.

[0015] The arrangement of the prod and the housing makes it possible to thermally and electrically insulate the measuring element arranged inside the prod, which makes it possible to reduce temperature variations due, on the one hand, to the temperature difference between the ambient air and the measuring surface and, on the other hand, to external thermal radiation which strikes the measuring surface and the temperature sensor.

[0016] In addition, the stop surface allows support to be formed on the surface to be measured in order to maintain and stabilize the temperature sensor on this surface during measurement.

[0017] According to one embodiment of the temperature sensor, the stop surface is delimited by an inner edge and an outer edge such that the distance separating the inner and outer edges is greater than or equal to 5 mm and less than or equal to 15 mm.

[0018] According to one embodiment of the temperature sensor, the length of the penetration portion is greater than or equal to 5 mm and less than or equal to 12 mm, the length of the prod portion being defined as the distance between a free end of the measuring prod and the intersection between the stop plane and the measuring prod.

[0019] According to one embodiment of the temperature sensor, the housing is made of an electrically and thermally insulating material.

[0020] According to one embodiment of the temperature sensor, the housing forms an annular gripping portion arranged opposite the housing relative to the measuring needle, the annular portion defining an annular center placed on the longitudinal extension axis of the measuring needle.

[0021] According to one embodiment of the temperature sensor, the annular gripping portion forms a support surface extending perpendicular to the longitudinal extension axis of the measuring pin.

[0022] According to one embodiment of the temperature sensor, the latter further comprises a resistive temperature measuring element arranged in the measuring needle. Brief description of the drawings

[0023] The accompanying drawings illustrate the invention: [ Fig. 1 ] schematically represents a perspective view of a penetration temperature sensor including in particular a measuring prod. [ Fig. 2 ] schematically represents a sectional view of the temperature sensor of the figure 1 in position for measuring the temperature of a body, the temperature sensor needle being inserted inside the body. Fig. 3 ] schematically represents a perspective view of the temperature sensor of the figure 1 when taken in hand by a user to carry out a measurement according to the figure 2 . Description of embodiment(s)

[0024] The inventive concept is described more fully below with reference to the accompanying drawings, in which embodiments of the inventive concept are shown. In the drawings, the size and relative sizes of the elements may be exaggerated for the sake of clarity. Like numerals refer to like elements throughout the drawings.

[0025] A reference throughout the specification to "an embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment is included in at least one embodiment of the present invention. Thus, the occurrence of the phrase "in an embodiment" at various locations throughout the specification does not necessarily refer to the same embodiment. Furthermore, the term "comprising" does not exclude other elements or steps.

[0026] The present invention is illustrated with the aid of figures which show an example of a penetration temperature sensor according to the invention. “Penetration” means that a portion of the temperature sensor is configured to perforate and penetrate a body to be measured in order to take a measurement. This penetration is carried out by means of a prod.

[0027] In reference to the figures 1 to 3, a penetration temperature sensor 10 is proposed comprising a housing 12 and a measuring prod 14 carried by the housing 12. The housing 12 thus forms a support for the measuring prod 14 for taking a measurement. The temperature sensor 10 is preferably configured to be held with one hand, or even with a single finger, which makes it portable. Taking a measurement is thus easy and easily repeatable.

[0028] The housing 12 comprises a measuring portion 15 carrying the measuring pin 14 and a gripping portion 17 connected to the measuring portion 15.

[0029] The measuring prod 14 is configured to penetrate inside a body 20 to be measured. For this purpose, the measuring prod 14 comprises a distal end 16 in the form of a point capable of perforating a surface. The free end 16 is in particular configured to perforate soft or fibrous materials, in particular animal tissues such as muscle, fat or fascia. It is also possible to penetrate the measuring prod 14 into fish flesh, a fruit or even a vegetable.

[0030] The measuring prod 14 also comprises a proximal end 18 attached to the housing 12. In particular, the measuring prod 14 is attached to the measuring portion 15 of the housing 12.

[0031] The temperature sensor 10 may further comprise a resistive element (not visible) for measuring temperature arranged in the measuring pin 14. The measuring pin 14 is for example a hollow body forming an internal cavity for receiving the resistive element. When the measuring pin 14 is inserted inside the body 20 to be measured, the temperature of this body 20 is transmitted to the measuring pin 14 and then to the resistive element. The variation in resistance of the resistive element makes it possible to determine the temperature of the body to be measured. Indeed, the resistance of the resistive element varies as a function of the temperature at this resistive element.

[0032] The resistive element of the temperature sensor 10 is a platinum resistor or a thermistor and is arranged inside the measuring needle 14. Thermometers using a resistive element make it possible to measure the temperature of a body without requiring a reference temperature, unlike thermocouples. This latter type of thermometer requires a reference temperature to operate, which makes them unsuitable for the portable nature of the temperature sensor 10 used in a cold environment. The cold environment of the room where the measurement takes place is in fact likely to distort the measurement of the reference temperature.

[0033] The resistive element is connected to a processing unit that can determine a temperature based on the resistance of the resistive element. The processing unit can also be connected to a temperature display unit. The connection between the processing and display units can be wired or wireless.

[0034] The processing member can be arranged inside or outside the housing 12. Thus, the housing 12 can contain the entire temperature measurement chain, namely the resistive element and the processing member, or else be connected to a processing member outside the housing 12. A portion of the prod 14 can be arranged inside the housing 12 so that the resistive element can be totally or partly arranged inside the housing 12.

[0035] The display member may be arranged inside or outside the housing 12. Thus, the housing 12 may comprise a display portion allowing a user to view the display member or may be connected to a display member outside the housing 12. The connection between the display member and the processing member may be wired or wireless. The display member may be a computer communicating with the measurement sensor 10.

[0036] The processing and display members are preferably housed inside the measuring portion 15 of the housing 12 when they are integrated inside the housing 12.

[0037] When the processing member and / or the display member are arranged outside the housing 12, the temperature sensor 10 may comprise a connector arranged between the gripping 17 and measuring 15 portions. This connector allows a wired connection between the members present inside the housing 12 and those arranged outside it.

[0038] The housing 12, in particular the measuring portion 15, forms a stop surface 22 intended to be arranged in contact with the body 20 to be measured. Thus, a temperature measurement of the body 20 comprises the penetration of the body 20 by the measuring prod 14 then the contacting of the stop surface 22 on the body 20 as illustrated in figure 2 .

[0039] The abutment surface 22 defines a stop plane P. In other words, the abutment surface 22 is included within the abutment plane P so as to form a flat stop. The abutment plane P is a theoretical mean plane defined by the abutment surface 22. This flat arrangement of the abutment surface 22 makes it possible to stabilize the position and orientation of the housing 12 on the body 20 during a measurement.

[0040] The abutment surface 22 may comprise a plurality of reliefs, hollow or projecting, while being included in said abutment plane P. For example, the abutment surface 22 may comprise grooves or micro-points. These reliefs may make it possible to improve the maintenance in position and orientation of the housing 12 relative to the body 20.

[0041] The measuring pin 14 is attached to the housing 12 such that a penetration portion of the measuring pin 14 extends out of the housing 12, in particular out of the abutment surface 22. In other words, the measuring pin 14 protrudes out of the housing 12, in particular out of the abutment surface 22.

[0042] The penetration portion of the measuring prod 14 is therefore defined by the stop plane P. In fact, the penetration portion extends between the distal end 16 of the measuring prod 14 and the section of the measuring prod 14 included in the stop plane P.

[0043] The measuring pin 14 extends perpendicular to the stop plane P. Thus, the measuring pin 14 extends along an extension axis A perpendicular to the plane P.

[0044] The stop surface 22 preferably extends around the measuring pin 14, i.e. around the extension axis A. Positioning the measuring pin inside the stop surface 22 makes it possible to further improve the maintenance of the orientation and position of the housing 12 relative to the body 20.

[0045] The abutment surface 22 is preferably annular. Thus, an insulation cavity 24 is formed inside the housing 12 and delimited by the abutment surface 22. The insulation cavity 24 is open to the outside of the housing 12. When the abutment surface 22 is arranged against the body 20, the insulation cavity 24 is closed by the body 20. This insulation cavity 24 extends around the measuring prod 14. Thus, the insulation cavity 24 makes it possible to form around the measuring prod 14 a volume of air thermally and electrically insulating the measuring prod 14, and therefore the resistive element. This insulation makes it possible to reduce the influence of the temperature difference between the ambient air and the surface of the body 20 to be measured and of external thermal radiation.

[0046] The measuring portion 15 thus forms an insulating cup surrounding the measuring pin 14 and insulating it by means of a physical wall belonging to the housing and the volume of air present in the insulating cavity 24.

[0047] The housing 12 is preferably made of an electrically and thermally insulating material so as to reinforce this thermal and electrical insulation. The housing 12 is for example made of a plastic material.

[0048] The abutment surface 22 is configured to prevent the housing 12 from being pushed into the body 20. Thus, the geometry and dimensions of the abutment surface 12 are configured to prevent the housing 12 from being pushed into the body 20.

[0049] The abutment surface is delimited by an inner edge 26 and an outer edge 28. The distance separating the inner 26 and outer 28 edges is preferably greater than or equal to 5 mm and less than or equal to 15 mm. This range of distance separating the inner 26 and outer 28 edges allows the abutment surface 22 to be wide enough to guarantee good stability of the housing 12 on the body and, at the same time, not to be too wide to be able to adapt to irregular surfaces. Indeed, the body 20 can be locally irregular with a curved surface or comprising reliefs. To obtain sufficient penetration of the measuring pin 14, it is therefore preferable to have a abutment surface 22 which is not too large.

[0050] When the abutment surface 22 is a circular ring, the inner 26 and outer 28 edges form an inner circle and an outer circle respectively. The distance range mentioned above in this case corresponds to the difference in radius between these inner and outer circles.

[0051] The measuring prod 14 and the abutment surface 22 are preferably configured such that the length of the penetration portion of the measuring prod 14 is greater than or equal to 5 mm and less than or equal to 12 mm. The length of the penetration portion is defined as the distance between the distal end 16 and the intersection between the abutment plane P and the measuring prod 14. This distance is denoted D on the figure 2 .

[0052] The gripping portion 17 of the housing 12 is preferably annular so that a finger can be inserted therein. In other words, the housing 12 forms a hole 32 or a portion of a hole into which a finger can be inserted. Thus, the temperature sensor 10 is securely held in the user's hand. This makes it easier to control the position and orientation of the housing 12 during a measurement.

[0053] The annular shape of the gripping portion 17 may be truncated or open. The gripping portion 17 may thus be open so that the hole 32 is open to the outside of the housing 12. The gripping portion 17 may therefore be discontinuous around the hole 32.

[0054] The gripping portion 17 of the housing 12 is arranged opposite the housing 12 with respect to the measuring needle 14.

[0055] The gripping portion defines an annular center C which is preferably placed on the axis A of longitudinal extension of the measuring pin 14. This alignment allows the user having his finger inserted in the gripping portion 17 to apply a force directly in the axis of the measuring pin 14. This allows better control of the force applied by the user and therefore better stability during the measurement.

[0056] The annular center corresponds to a midpoint of the hole formed by the gripping portion 17. When the hole is circular, the annular center C is the center of the circle.

[0057] The gripping portion 17 also forms at least one bearing surface 30 extending perpendicularly to the extension axis A of the measuring prod 14. This bearing surface 30 allows the user to more easily apply the penetration force of the measuring prod 14 and the pressing of the housing 12 onto the body 20. This bearing surface 30 may be formed inside the hole formed by the gripping portion 17 and / or on a circumferential wall of the housing 12. Preferably, the housing comprises at least two bearing surfaces 30, a first inside the hole of the gripping portion 17 and a second on the circumferential surface of the housing 12. The user can thus respectively place a surface of his finger inserted inside the gripping portion on the first bearing surface and his thumb on the second bearing surface, such as illustrated on the figure 3. Control of the position, orientation and force applied by the temperature sensor 10 on the body is facilitated.

Claims

1. Penetration temperature sensor (10) comprising a housing (12) forming an annular stop surface (22) intended to be brought into contact with a body (20) to be measured, said stop surface (22) defining a stop plane (P), said sensor also comprising a measuring needle (14) intended to penetrate the body to be measured, said needle (14) being fastened to the housing (12) in such a way that a penetration portion of the needle extends out of the housing, perpendicular to the stop plane, the stop surface (22) extending about the needle (14), characterized in that the housing (12) forms an open insulating cavity (24) extending about and along the measuring needle, an open end of the insulating cavity being delimited by the stop surface (22).

2. Temperature sensor (10) according to Claim 1, wherein the stop surface (22) is delimited by an inner edge (26) and an outer edge (28) such that the distance between the inner and outer edges is greater than or equal to 5 mm and less than or equal to 15 mm.

3. Temperature sensor (10) according to Claim 1 or 2, wherein the length of the penetration portion is greater than or equal to 5 mm and less than or equal to 12 mm, the length of the needle portion (14) being defined as the distance (D) between a free end (16) of the measuring needle and the intersection between the stop plane (P) and the measuring needle (14).

4. Temperature sensor (10) according to any one of the preceding claims, wherein the housing (12) is made of an electrically and thermally insulating material.

5. Temperature sensor (10) according to any one of the preceding claims, wherein the housing (12) forms an annular gripping portion arranged on the opposite side of the housing with respect to the measuring needle (14), the annular portion defining an annular centre placed on the longitudinal extension axis of the measuring needle.

6. Temperature sensor (10) according to Claim 5, wherein the annular gripping portion forms a bearing surface (30) extending perpendicularly to the longitudinal extension axis (A) of the measuring needle.

7. Temperature sensor (10) according to any one of the preceding claims, further comprising a temperature-measuring resistive element arranged in the measuring needle (14).