FIELD OF THE INVENTION

The present invention relates to methods and apparatuses for temperature measurement. It is particularly, but not exclusively, related to methods and apparatuses which measure the temperature of products in a production line setting.

BACKGROUND OF THE INVENTION

Food production companies constantly need to improve productivity and reduce waste and labour/staff. They also need to take care to monitor temperatures throughout their production processes and at critical control points (“CCP”). This includes the temperatures of packaged foods that need be measured before storage or despatch.

At present, the most common technique is invasive probing by thermocouple, thermistor, or resistive temperature detectors (RTDs). These methods require a skilled operator with a probe that can pierce or break into/through the packaging. It is then necessary to wait for the probe to stabilise with the core temperature of the product, which can take typically from three to five minutes depending upon the product being tested. The displayed temperature is then recorded by writing it down. This important measurement can vary considerably from operator to operator which can lead to varying results from the same product tested by different operators. There also no record or proof of the actual value from the instrument used that is written down by the operator.

Products tested in this manner must be discarded after probing. Such a technique is therefore necessarily a sampling technique where the chosen samples are wasted. The temperature measured by probing therefore also only applies to a small volume of material around the probe, and the probing is subject to significant operator-dependent variability. In the case of frozen products it is very difficult, and in some cases not possible, to safely and accurately penetrate and measure the product.

Infra-red temperature sensors are occasionally used and are non-invasive. However, the results from such sensors are not particularly reliable as they require the sensor to be pointed at a clean and non-shiny area. This then only penetrates a few microns below the surface and gives variable results, particularly for packaged frozen products where the outer temperature of the packaging is unlikely to be representative of the temperature of the product itself.

Therefore, the food industry in particular, requires a non-invasive, non-destructive temperature measuring technique for process monitoring, product safety and quality control. Typical requirements are to check that a food product has been cooked, or at least partly cooked, to a specified minimum temperature, or cooled to below a specified temperature, e.g., for storage or distribution.

However, these problems are not limited to the food industry and there is a general desire in many sectors for automated temperature measurement apparatuses and methods, particularly those which can operate in a production line setting without interrupting the flow of the production line.

U.S. Pat. No. 6,964,514 describes an apparatus for measuring the temperature of an object such as a food object. The apparatus includes a coupling device for coupling radiation emanating from the objection to a radiation temperature measuring radiometer and a device for switching measurement circuitry between measuring the radiation temperature of a first reference temperature and the radiation temperature of the object. The apparatus make use of microwave radiometry to measure the temperature of the object.

Microwave radiometric temperature measurements are inherently non-invasive and non-destructive. This provides significant advantages in relation to the measurement of samples from a production line.

U.S. Pat. No. 7,059,765 describes an apparatus for measuring the temperature of an object using an electromagnetic antenna cavity operating in a combination of induction field and travelling wave modes or standing-wave modes.

Although U.S. Pat. Nos. 6,964,514 and 7,059,765 both mention the possibility of using the apparatus disclosed therein in a production line, no further detail of such an implementation is discussed. The present inventors have attempted such an implementation and discovered that there are numerous problems, such that simply implementing the apparatus described in that document in a production line is not possible. Without limitation, these problems include the ability to form a completely sealed cavity in a production line setting to ensure coupling of the radiation from the sample to the radiometer. As the radiation levels being measured and on which the temperature calculation is performed are very small, typically in the range of picowatts (10−12W), even minor imperfections in the sealing of the cavity can significantly affect the accuracy of the resultant temperature readings.

The present invention aims to provide methods and apparatuses which permit the automated and preferably non-invasive measurement of the temperature of products in an inline fashion in a production line setting.

A further preferred object of the present invention is to provide a method and apparatus which reduces or removes the need for human intervention in the measurement process and can store and record temperatures electronically.

A further preferred object of the present invention is to provide a method and apparatus that can automatically remove products that do not meet certain temperature criteria from the production line.

A further object of the present invention is to provide a method and apparatus for inline temperature measurement which can be auto-calibrated.

SUMMARY OF THE INVENTION

At their broadest, aspects of the present invention provide methods and apparatuses for measuring the temperature of an object in which the object is conveyed to a measurement position and the measurement process carried out automatically.

In particular aspects of the present invention, methods and apparatuses are provided in which a sealed cavity is formed around the object at the measurement position for radiometric measurement to be carried out.

A first aspect of the present invention provides an apparatus for measuring the temperature of an object, the apparatus including: a conveyance system; and a temperature measurement unit having: a first member and a second member which are movable relative to each other between at least a first position in which the first and second members cooperate to form an internal space which is substantially internally reflective of radiofrequency radiation and a second position in which the object can be introduced into said internal space; and a radiometer arranged so that it is coupled to said internal space; wherein the conveyance system is arranged to convey the object to a measurement position in said internal space whilst the first and second members are in the second position, for a measurement of the radiation emitted from the object to be performed by the radiometer when the first and second members are in the first position and to convey the object away from said measurement position once the measurement has been performed and said first and second members have returned to the second position.

In some embodiments, the first member is a container with an opening in one wall and the second member is a plate which is arranged to completely cover that opening.

In certain embodiments there are a plurality of said plates which are joined to form a continuous loop and form part of the conveyance system. This enables the second members to form part of the conveyance system and removes the requirement for the object to be moved onto a separate support for the measurement to take place. The plates can be pivoted relative to each other to permit the forming of the loop. The pivots may be about an axis substantially perpendicular to the direction of travel but in the same plane as the direction of conveyance to form a caterpillar-type track combination which rotates around driven rollers in a substantially vertical loop. Alternatively the pivots may be about an axis substantially perpendicular to the plane of the conveyance of the objects to form a scale-type track which rotates in a substantially horizontal loop.

In other embodiments, the measurement unit is configured to move with the conveyance system whilst in the first position so that the movement of objects on the conveyance system is not interrupted. The measurement unit can then return to a position earlier on the conveyance system to carry out the next measurement.

In other embodiments the plate is attached to one end of an arm, the arm being pivotable about an axis passing through a point distant from the plate so that the plate can be moved between a plurality of positions, at least one of those positions being the measurement position. This configuration requires only a single plate and the object can be loaded onto the plate in one position, rotated to the measurement position, and then rotated to a further position where it is offloaded back onto the conveyance system.

In such embodiments, there may be a plurality of said plates, each attached to an arm, the arms all being pivotable about the same point. For example, there may be three plates, thus permitting one object to be loaded on to a plate in one position whilst another object is being measured and a further object is being unloaded. The arms may be fixed relative to each other, or may be independently controlled.

In a development of these embodiments, the arm may also pivot about a second axis to change the orientation of the plate and cause an object on the plate to slide off under the action of gravity. This allows an easy process for unloading the plates as mechanical force is not required.

The apparatus may further include at least one separator which is substantially transparent to radiofrequency radiation, wherein the object rests on the separator at least when it is in the measurement position. The separator can separate the object from the plate or other part of the measurement unit when the measurement is being conducted. This can improve the coupling of the radiation from the object to the radiometer.

The separator may be recessed into the plate such that the upper surfaces of the plate and the separator are substantially level. This configuration can make the loading and unloading of the objects onto and off the separator easier as there is no level difference between separator and the surrounding plate and so the objects can be pushed or slid onto and off the separator.

In other embodiments, the first member is a container with an opening in one wall and the second member is a door attached to the first member which is arranged to seal that opening.

Preferably, in such embodiments, the conveyance system includes a section located within the internal space which supports the object in the measurement position during the measurement and is separate from the other parts of the conveyance system to allow the door to close. This allows the object to be conveyed until it is wholly within the internal space and supported there whilst the door closes to seal the internal space. After the measurement, the object can then be conveyed out of the internal space by the section and the remainder of the conveyance system.

Preferably the section of the conveyance system is substantially transparent to radiofrequency radiation and therefore does not impact on the measurement of the radiation emanating from the object.

In certain arrangements, the temperature measurement unit further includes a second door. The object can then enter the internal space via the first door and exit via the second. This enables the temperature measurement unit to effectively be positioned along a continuous conveyance system, so that objects can enter, be measured and move on as a further object is introduced into the unit. This improves the efficiency of the measurement and also means that all parts of the conveyance system surrounding the unit need only operate in a single direction.

Preferably the measurement unit further includes a seal between the first and second members, the seal forming a substantially complete barrier to radiofrequency radiation when the first and second members are in the first position.

In certain embodiments the seal is a compressible gasket. Preferably in such embodiments, the first and second members are brought together and a positive overpressure is applied to maintain them together. This pressure compresses the gasket to ensure a complete seal around the full perimeter of the connection between the members.

In other embodiments the seal may be a labyrinthine seal comprising a plurality of first projections on the first member and a plurality of second projections on the second member such that the first and second projections intermesh in the first position. With this seal, even if there is not complete matching between the first and second projections, the path from the interior of the cavity to the exterior is so long and tortuous that no radiation escapes.

In certain embodiments the conveyance system further includes a main conveyance; a sample conveyance and a first selection mechanism for selecting objects on the main conveyance and moving them to the sample conveyance and wherein the sample conveyance conveys the selected objects to the measurement position. This configuration allows the sampling of products from a larger production line so that the speed of the production line is not affected by the measurement process.

Preferably the apparatus further includes a controller, wherein the controller is arranged to receive a measurement of the radiation from an object from the radiometer and calculate the temperature of the object from that measurement.

The conveyance system may further include a second selection mechanism, wherein the controller is further arranged to compare the calculated temperature of the object against a predetermined criterion and control the second selection mechanism to remove an object from the conveyance system if its calculated temperature does not meet the criterion.

The conveyance system may further include a main conveyance; a sample conveyance and a first selection mechanism for selecting objects on the main conveyance and moving them to the sample conveyance and wherein the sample conveyance conveys the selected objects to the measurement position and returns the object to the main conveyance if the calculated temperature of the object meets the criterion.

Thus the controller can select objects from the main conveyance for measurement. This selection can be periodic (e.g. every tenth object or similar), or may be random. The selection could also be driven by further testing of the objects before they reach the first selection mechanism, which might identify objects which are thought not to meet the criterion for other reasons.

The controller can then test the selected objects and either reject them by removing them from the conveyance system, or returning them to the main conveyance.

In the case where the measurement unit forms part of the main conveyance, the controller may just control a reject mechanism which removes objects which do not meet the criterion.

The apparatus may further include an agitator positioned on the conveyance prior to the temperature measurement unit. The agitator may be arranged to agitate the objects prior to them being conveyed to the measurement position. For containers having liquid contents, this agitation can help to ensure that the temperature of the object as a whole is uniform. The agitator may be, for example, a table or other support onto which the object can be placed and which is then vibrated.

In certain embodiments, the apparatus further includes a temperature probe and a reference sample, wherein: the conveyance system is arranged to convey the reference sample to a second measurement position where its temperature is measured by the temperature probe, and to subsequently convey the reference sample to the measurement position where a measurement of the radiation emitted from the object is performed by the radiometer, and the controller is arranged to calibrate the calculations of temperature of objects based on the temperature of the reference sample measured by the temperature probe and the radiation detected from the reference sample by the radiometer.

In this way, the apparatus can be auto-calibrating by checking the accuracy of the calculations being made by the controller based on the temperature calculated for the reference sample whose temperature has been measured independently prior to the measurement by the radiometer.

Preferably the apparatus is arranged to measure the temperature and radiation emission of the reference sample on a repeated basis to maintain the calibration of the calculations.

The apparatus of the present aspect may include any combination of some, all or none of the above described preferred and optional features.

The apparatus of the present aspect may operate by carrying out a method according to the second aspect of this invention described below, but need not do so.

A second aspect of the present invention provides a method of measuring the temperature of an object on a conveyance system, the method including the steps of: locating the object on the conveyance system; conveying the object to a measurement position using the conveyance system; forming, around the object, a cavity which is substantially internally reflective of radiofrequency radiation; measuring the radiation emitted from the object; determining the temperature of the object from the measured radiation; and conveying the object from the measurement position using the conveyance system.

In some embodiments, the cavity is formed by bringing together a container with an opening in one wall and a plate which is arranged to completely cover that opening.

In certain embodiments there are a plurality of said plates which are joined to form a continuous loop and form part of the conveyance system. This enables the plates to form part of the conveyance system and removes the requirement for the object to be moved onto a separate support for the measurement to take place. The plates can be pivoted relative to each other to permit the forming of the loop. The pivots may be about an axis substantially perpendicular to the direction of travel but in the same plane as the direction of conveyance to form a caterpillar-type track combination which rotates around driven rollers in a substantially vertical loop. Alternatively the pivots may be about an axis substantially perpendicular to the plane of the conveyance of the objects to form a scale-type track which rotates in a substantially horizontal loop.

In other embodiments, the measuring step is performed by moving the cavity with the conveyance system so that the movement of objects on the conveyance system is not interrupted. The components forming the cavity can then return to a position earlier on the conveyance system to carry out the next measurement.

In other embodiments the plate is attached to one end of an arm and the step of conveying the object to the measurement position includes rotating said arm and said plate. This configuration requires only a single plate and the object can be loaded onto the plate in one position, rotated to the measurement position, and then rotated to a further position where it is offloaded back onto the conveyance system.

In such embodiments there may be a plurality of said plates, each attached to an arm, such that the steps of conveying, forming, measuring and conveying can be performed simultaneously for a plurality of objects. For example, there may be three plates, thus permitting one object to be loaded on to a plate in one position whilst another object is being measured and a further object is being unloaded. The arms may be fixed relative to each other, or may be independently controlled.

In a development of these embodiments, the method may further include the step of sliding the object off the plate by tilting the plate. This allows an easy process for unloading the plates as mechanical force is not required.

The step of locating the object on the plate may locate the object on a separator which is substantially transparent to radiofrequency radiation. The separator can separate the object from the plate or other part of the measurement unit when the measurement is being conducted. This can improve the coupling of the radiation from the object to the radiometer.

In other embodiments the cavity is formed by closing a door to seal an opening in one wall of a container.

Preferably, in such embodiments, the step of conveying the object to the measurement position includes transferring the object to a section of the conveyance system which is located within the internal space and is separate from the other parts of the conveyance system to allow the door to close. This allows the object to be conveyed until it is wholly within the internal space and supported there whilst the door closes to seal the internal space. After the measurement, the object can then be conveyed out of the internal space by the section and the remainder of the conveyance system.

Preferably the section of the conveyance system is substantially transparent to radiofrequency radiation and therefore does not impact on the measurement of the radiation emanating from the object.

In certain arrangements, there is a further door which seals a further opening in the container and the step of conveying the object from the measurement position includes passing the object through the further door. The object can then enter the internal space via the first door and exit via the second. This enables the temperature measurement unit to effectively be positioned along a continuous conveyance system, so that objects can enter, be measured and move on as a further object is introduced into the unit. This improves the efficiency of the measurement and also means that all parts of the conveyance system surrounding the unit need only operate in a single direction.

In certain embodiments the method further includes the step of comparing the determined temperature of the object against a predetermined criterion and removing an object from the conveyance system if its determined temperature does not meet the criterion.

The conveyance system may further include a main conveyance; a sample conveyance and the method may further include the step of selecting objects on the main conveyance and moving them to the sample conveyance and wherein the sample conveyance conveys the selected objects to the measurement position. This allows the sampling of products from a larger production line so that the speed of the production line is not affected by the measurement process.

The method may further include the step of comparing the determined temperature of the object against a predetermined criterion and removing an object from the conveyance system if its determined temperature does not meet the criterion or returning the object to the main conveyance if its determined temperature meets the criterion.

Thus the method can select objects from the main conveyance for measurement. This selection can be periodic (e.g. every tenth object or similar), or may be random. The selection could also be driven by further testing of the objects before they reach the first selection mechanism, which might identify objects which are thought not to meet the criterion for other reasons.

The selected objects can then be tested and either reject them by removing them from the conveyance system, or returning them to the main conveyance.

In the case where the measurement unit forms part of the main conveyance, the step of removing may remove objects which do not meet the criterion from the main conveyance.

The method may further include agitating the object prior to measuring the radiation. For containers having liquid contents, this agitation can help to ensure that the temperature of the object as a whole is uniform.

In certain embodiments the method further includes the step of calibrating the determination of temperatures from the measured radiation, the step of calibrating including the sub-steps of: conveying a reference sample to a second measurement position; measuring the temperature of the reference sample using a temperature probe; conveying the reference sample to the measurement position; measuring the radiation emitted from the object; and calibrate the determinations of temperatures of objects based on the temperature of the reference sample measured by the temperature probe and the radiation measured from the reference sample. This may be repeated for multi-point calibration steps using several reference samples at varying temperatures.

In this way, the method can auto-calibrate by checking the accuracy of the temperature determinations being made based on the temperature determined for the reference sample (s) whose temperature has been measured independently prior to the measurement by the radiometric process.

The step of calibrating is preferably performed on a repeated basis to maintain the calibration of the calculations.

The method of this aspect may include any combination of some, all or none of the above described preferred and optional features.

The method of the above aspects are preferably implemented by an apparatus according to the first aspect of this invention, as described above, but need not be.

A third aspect of the present invention provides an apparatus for measuring the temperature of an object, the apparatus including: a conveyance system; and a temperature measurement unit having: controller and at least one arm whose motion is controlled by the controller; and a probe attached to said arm and having a temperature sensor, wherein the conveyance system is arranged to convey the object to a measurement position proximate said arm and the controller is arranged to automatically control the motion of the arm so as to cause the probe to penetrate the object, such that a temperature measurement of the object can be taken from the temperature sensor.

The apparatus of this aspect can provide automated temperature measurement of objects in a production line setting. This reduces the variability associated with manual testing. In particular the apparatus can ensure accurate and repeatable positioning of the probe within the object being measured, and ensure that the probe remains in the object for long enough for an accurate measurement of the temperature to be obtained.

Preferably the controller controls the motion of the arm so as to cause the probe to penetrate the object to a predetermined depth. This can ensure the accurate and repeatable positioning of the temperature sensor within the object when the temperature measurement is taken.

The apparatus may further include a position sensor which provides information on the position of the temperature sensor to the controller. This position sensor may be a specific sensor, such as a laser ranging device positioned on the arm which determines its position relative to the object, from which the position of the temperature sensor can be derived. Alternatively or additionally the position sensor can work based on the movement of the arm from its known base or starting position.

Preferably the controller acquires information about the object and the predetermined depth is calculated so as to cause the temperature sensor to be positioned approximately in the geometric centre of the object or a part of the object. For many objects, the operator is interested in knowing the core temperature of the object (which is least likely to be affected by the surrounding environment). However, for certain objects, the temperature of other parts of the object will be of interest, for example to determine that the outer regions of the object have not cooled (or warmed up) more than acceptable during the passage of the object along a production line.

Preferably the controller controls the motion of the arm so as to cause the probe to remain in the object until a stabilised temperature measurement is made.

Generally, the temperature is considered stabilised when a consistent reading is obtained for a predetermined period of time (for example 1 to 3 seconds). This avoids spikes or spurious readings resulting from cold/hot spots in the product, such as an ice crystal. Although the apparatus will generally record the entire output of the sensor from the point of entry of into the object, it is the stable maximum or minimum temperature which is of most interest and on which the accept/reject decision is made.

The amount of time which constitutes a stable temperature measurement can be adjusted/programmed by the user, but can also be set for each type of object and stored and retrieved from a database depending on the product being processed.

Preferably the apparatus further includes a scanner which obtains information about the product from the object whilst it is being conveyed to the measurement position or when it is at the measurement position. Where the information is obtained from text or a code (such as a barcode) on the object itself, the apparatus may have multiple scanners arranged around the conveyance system to ensure that at least one such scanner is able to read the information. Alternatively or additionally, the objects may carry identification (such as an RFID device) which enable the scanner to obtain information about the product.

By identifying the type of product, further information about the product can be retrieved from a database. This further information may include the size and shape of the object. The further information may also include acceptable temperature ranges for the object which can be used for the basis of an accept/reject decision.

Alternatively or additionally the apparatus may have one or more measurement devices (e.g. laser ranging devices) which allow the dimensions of the object to be determined.

Preferably the apparatus further includes guide elements arranged on the conveyance to cause the object to arrive at the measurement position and/or to stop the object at the measurement position. Such guide elements can ensure accurate positioning of the probe within the object and may be adjustable to work with products of different shapes and sizes.

Alternatively or additionally, the apparatus may have a plurality of probes and temperature sensors arranged in an array. The array of probes can be brought into contact with the object by movement of the arm. Some of the probes in the array may contact the object, whilst others may not, but the array can ensure that at least some contact and penetrate the object to measure its temperature, regardless of the positioning or orientation of the object relative to the apparatus.

The probe or probes may be elastically-biased towards the object so that, whilst it can penetrate the object, if it encounters a solid item (whether inside the object or outside), it is able to recoil against the biasing rather than attempt to move further.

The apparatus of the present aspect may include any or all of the optional or preferred features of the above described first aspect which do not relate to the specifics of the radiometric sensing of that apparatus.

The apparatus of the present aspect may include any combination of some, all or none of the above described preferred and optional features.

The apparatus of the present aspect may operate by carrying out a method according to the second aspect of this invention described below, but need not do so.

A fourth aspect of the present invention provides a method of measuring the temperature of an object, on a conveyance system, the method including the steps of: locating the object on the conveyance system; conveying the object to a measurement position using the conveyance system; when the object arrives at the measurement position, automatically causing a probe having a temperature sensor to penetrate the object and taking a temperature measurement of the object using the temperature sensor.

The method of this aspect can provide automated temperature measurement of objects in a production line setting. This reduces the variability associated with manual testing. In particular the apparatus can ensure accurate positioning of the probe within the object being measured, and ensure that the probe remains in the object for long enough for an accurate measurement of the temperature to be obtained.

Preferably the step of penetrating causes the probe to penetrate the object to a predetermined depth. This can ensure the accurate positioning of the temperature sensor within the object when the temperature measurement is taken.

The method may further include the step of determining the position of the temperature sensor during the step of penetrating. This may involve direct sensing of the position of the probe and/or arm relative to the object (such as determining the position of the arm relative to the object, from which the position of the temperature sensor can be derived). Alternatively or additionally the position may be determined based on the movement of the arm from its known base or starting position.

Preferably the method further includes the steps of: acquiring information about the object; and determining the predetermined depth from said information such that the predetermined depth causes the temperature sensor to be positioned approximately in the geometric centre of the object or a part of the object. For many objects, the operator is interested in knowing the core temperature of the object (which is least likely to be affected by the surrounding environment). However, for certain objects, the temperature of other parts of the object will be of interest, for example to determine that the outer regions of the object have not cooled (or warmed up) more than acceptable during the passage of the object along a production line. This would provide an accurate and repeatable temperature profile of a product.

Preferably the temperature measurement is monitored whilst the probe is in the object and the probe is withdrawn from the object when a stabilised temperature measurement has been taken. Thus the method can ensure that the probe is in the product for a sufficient time for the stabilised measurement to be achieved.

Generally, the temperature is considered stabilised when a consistent reading is obtained for a predetermined period of time (for example 1 to 3 seconds). This avoids spikes or spurious readings resulting from cold/hot spots in the product, such as an ice crystal. Although the method will generally record the temperature measurements from the point of entry of the probe into the object, it is the stable maximum or minimum temperature which is of most interest and on which the accept/reject decision is made.

The amount of time which constitutes a stable temperature measurement can be adjusted/programmed by the user, but can also be set for each type of object and stored and retrieved from a database depending on the object being processed.

Preferably the method further includes the step of acquiring information about the object. This may be through scanning the product whilst it is being conveyed to the measurement position or when it is at the measurement position.

The information typically includes information identifying the object. By identifying the type of product, further information about the object can be retrieved from a database. The further information may include the size and shape of the object. The further information may additionally or alternatively include acceptable temperature ranges for the object which can be used for the basis of an accept/reject decision. The further information may additionally or alternatively include the length of time which constitutes a stabilised temperature measurement for that object.

Alternatively or additionally the dimensions of the object may be determined as it passes along the conveyance system, or when it arrives at the measurement position. This may be done, for example, by laser measurement.

The method may further include the step of guiding the object to arrive at the measurement position in a particular orientation, or with a particular degree of precision. This can ensure accurate positioning of the probe within the object.

Alternatively or additionally, the apparatus may have a plurality of probes and temperature sensors arranged in an array. The method may include bringing the array of probes into contact with the object by movement of the arm. Some of the probes in the array may contact the object, whilst others may not, but the array can ensure that at least some contact and penetrate the object to measure its temperature, regardless of the positioning or orientation of the object relative to the apparatus.

The probe or probes may be elastically-biased towards the object so that, whilst it can penetrate the object, if it encounters a solid item (whether inside the object or outside), it is able to recoil against the biasing rather than attempt to move further.

The method of the present aspect may include any or all of the optional or preferred features of the above described second aspect which do not relate to the specifics of the radiometric sensing of that method.

The method of this aspect may include any combination of some, all or none of the above described preferred and optional features.

The method of the above aspects are preferably implemented by an apparatus according to the third aspect of this invention, as described above, but need not be.

A fifth aspect of the present invention applies the method of the above described fourth aspect, including some, all or none of the preferred and optional features of that aspect, to a handheld temperature probe. Whilst this method would not have the advantages of automation, it could allow closer control of the handheld probe, for example by sensing the position of the temperature sensor in the object and/or determining when a stabilised temperature measurement has been obtained. The method may include providing feedback (e.g. visual or audible signals) to the user of the handheld probe to indicate when the correct probe depth is reached and/or when a stabilised temperature measurement has been achieved. Even if the position or depth is not controlled the method could calculate the stabilised values as mentioned above which could be recorded in the instrument and relayed to the operator audibly and visually. The stored data could also be transferred to external computers by various means, such as Bluetooth, infrared, WiFi, USB etc.

A further aspect of the present invention is a handheld temperature probe for use in the method of the above fifth aspect and having features which enable the improved and/or semi-automated operation of that probe by an operator.

Further aspects of the present invention include computer software which, when run on a computer, carry out the steps of any of the above methods, including some, all or none of the preferred or optional features of those methods.

