Radiation thermometer comprising a heated measuring tip

[0001] Not Applicable.

[0002] Not Applicable.

[0003] Not Applicable.

[0004] The invention relates to a radiation thermometer comprising a heated measuring tip, especially an infrared thermometer for measuring temperature. Such thermometers are known to contain an infrared sensor, an ambient temperature sensor and an evaluating device which determines the temperature of a measurement object from the output signals of the sensors.

[0005] An infrared ear thermometer comprising a measuring tip which can be heated by a built-in heating element is known from WO 00/58703. If a heated measuring tip is inserted in an auditory canal, almost no more heat exchange takes place between the measuring tip and the auditory canal so that the measuring tip and the auditory canal are in thermal equilibrium during the temperature measurement. In this way, measurement errors which arise as a result of cooling of the ear canal if the measuring tip inserted in the ear canal is cooler than said canal, are avoided. The ear thermometer is provided with a control device for regulating the temperature of the measuring tip which also determines whether the measuring tip is located in the auditory canal and switches the heating element on or off when the measuring tip is inserted in the auditory canal or withdrawn therefrom.

[0006] An infrared thermometer is known from EP 1081475 whose measuring tip can be heated at its anterior end by a heatable infrared sensor arranged there.

[0007] Not Applicable.

[0008] Not Applicable.

[0009] The object of the invention is a radiation thermometer comprising a heatable measuring tip and a method of measurement for such a thermometer which allows the same simple operation as is known from thermometers without a heatable measuring tip.

[0010] A thermometer according to the invention is provided with a device for controlling the measuring sequence. In a preferred embodiment of a thermometer according to the invention the control device and the evaluating device are combined in a microcontroller or the like which also controls a display device. The measuring sequence is independent of whether the measuring tip is heated directly by a heating element or indirectly by a heatable infrared sensor.

[0011] The measuring sequence according to the invention is described in the following. The user will first turn on the thermometer. Turning on the thermometer results in the measuring tip of the thermometer being heated to a specific temperature, for example, to approximately 37° C. This temperature is achieved in a very short time, for example, a few seconds, in a thermometer having a structure known from WO 00/58703 or EP 1081475. The user can now insert the measuring tip of the thermometer into the ear and start the temperature measurement by actuating an actuating device, for example, by pressing a button.

[0012] The thermometer according to the invention may also contain a detecting device which establishes whether the measuring tip of the thermometer is inserted in the ear or not. In this case, the insertion of the measuring tip into the ear has the same result as actuation of the actuating device, i.e., after insertion the detection device will establish that the measuring tip is located in the ear and thereupon start the further measuring process without the user needing to actuate a separate actuating device.

[0013] With a battery-operated thermometer, it is especially advantageous if the thermometer automatically turns itself off, for example, after 1 minute in order to save current if the user has not yet actuated the actuating device by then.

[0014] After the user has actuated the actuating device, with an infrared thermometer according to the invention a measuring process takes place automatically in the following fashion: first, the heating of the measuring tip is discontinued. Preferably after a certain time has elapsed, for example 1 second, the temperature of the measurement object, i.e., especially the body temperature, is measured several times. This delay in the measuring sequence has the advantage that any temperature differences which may be present in the measuring tip or the infrared sensor can be equalized before the temperature measurements. The temperature of the measurement object to be displayed is then determined from the measured temperatures and, at the latest after a maximum measurement time has elapsed or after a maximum number of temperature measurements, is displayed on a display device. However, if the measured temperatures differ too much from one another or a minimum number of successively measured temperatures are not at least approximately the same or do not settle down to a specific value in the course of the measurement process or another suitable criterion for the validity of the measured temperatures is not satisfied, it is advantageous if an error message is output instead of a temperature, which recommends that the user repeats the temperature measuring process. The error message can be output after a minimum measuring time or a minimum number of temperature measurements if a valid temperature value can no longer be expected within the maximum measuring time or after the maximum number of temperature measurements. However, if the measured temperatures do not differ too much from one another or a minimum number of successively measured temperatures are at least approximately the same or settle down to a specific value in the course of the measurement process or another suitable criterion for the validity of the measured temperatures is satisfied, the temperature to be displayed is preferably displayed immediately, i.e. before the maximum measuring time has elapsed or before the maximum number of temperature measurements.

[0015] In a preferred embodiment of the thermometer according to the invention, during the current temperature measurements a signalling device is activated by the control device, for example, in the form of a flashing light-emitting diode and/or a series of beeps which indicates to the user that the measuring process is completed, for example, by the light-emitting diode being lit continuously and/or a long-drawn-out beep. In this way the user knows that the measuring process is not complete and he should not withdraw the thermometer from the ear.

[0016] An advantageous embodiment of the thermometer according to the invention also has a data storage device and the above-mentioned signalling device by which means the data stored in the data storage device can be output, for example, the measured temperatures, the displayed temperatures, the total number of measuring sequences carried out or the like. For this purpose the flashing of the light-emitting diode or the beeping is coded in a specific fashion so that this data can be recorded by an external reader, decoded, further processed and/or displayed.