Braun Aktiengesellschaft

Braun Gmbh

Manfred Kaiser

Bernhard Kraus

Frank Beerwerth

Klaus Heubach

Katja Honnefeller

Jochen Cimbal

Heinz Richter

Heinz B&uuml;ltges

Albrecht Jest&auml;dt

A method of calibrating a radiation thermometer including a radiation sensor that is characterized by a sensitivity (S) and a temperature-responsive resistor that serves as an ambient temperature sensor, the temperature-responsive resistor having at a specified reference temperature a reference resistance (R,). The method includes the steps of using a first radiation standard having a known temperature T,(,); while the ambient temperature sensor is at a first ambient temperature T,(,), using the radiation thermometer to read the temperature of the first radiation standard; while using the radiation thermometer to read the temperature of the first radiation standard, measuring a first output signal U(,) of the radiation sensor; using a second radiation standard having a known temperature T,(,); while the ambient temperature sensor is at said first ambient temperature T,(,), using the radiation thermometer to read the temperature of the second radiation standard; while using the radiation thermometer to read the temperature of the second radiation standard, measuring a second output signal U(,) of the radiation sensor; and calibrating the radiation sensor and the ambient temperature sensor by using T,(,), T,(,) and the values obtained for U(,) and U(,) and without using any value for T,(,) that is derived from measuring an output of the ambient sensor, wherein the step of calibrating involves calculating at least one of the reference resistance (R,) of the ambient temperature sensor, the ambient temperature (T,), and the sensitivity (S) of the radiation sensor.

Method of calibrating a radiation thermometer

The invention is directed to a method of evaluating the signal of an infrared thermometer for measuring human body temperature, in which the infrared thermometer includes a probe adapted to receive thereon a probe cover or protective film sufficiently transparent to infrared radiation, and in which on a measuring operation performed with the probe cover or protective film in &ldquo;installed&rdquo; condition the signal is evaluated, so that a measuring operation is performed also when the probe cover or protective film is not installed, with an appropriate allowance being made for the consequently more intensive infrared radiation by different signal evaluation.

Process for evaluating the signal of an infrared thermometer, and infrared thermometer

The invention is directed to a method of computing the radiation temperature of a body from the signals of a radiation and an ambient temperature sensor, and further to a radiation thermometer, in particular a clinical radiation thermometer. In the method of the present invention, computation of the temperature is not using the Stefan Boltzmann law, but rather, a polynomial is used, preferably a third-degree polynomial, which is adjusted to the radiation-optical properties of the thermometer in the relevant wavelength range. The reciprocal value of the sensitivity of the radiation sensor is preferably represented as a polynomial as well. In this manner, the computation of a fourth root or divisions which are otherwise customary are avoided, enabling the necessary computations to be also performed, for example, by a 4-bit microprocessor with great speed.

Radiation thermometer and method of computing the temperature

A method of calibrating a radiation thermometer including a radiation sensor and an ambient temperature sensor, the method including the steps of using a first radiation standard having a known temperature T.sub.S (1) and with the ambient temperature sensor at a first ambient temperature T.sub.U (1), using the radiation thermometer to read the temperature of the first radiation standard and while doing so, measuring a first output signal U(1) of the radiation sensor; using a second radiation standard having a known temperature T.sub.S (2) and with the ambient temperature sensor again at the first ambient temperature T.sub.U (1), using the radiation thermometer to read the temperature of the second radiation standard and while doing so, measuring a second output signal U(2) of the radiation sensor; and calibrating the radiation sensor and the ambient temperature sensor by using the values obtained for U(1) and U(2) and without using a value for T.sub.U (1) that is derived from measuring an output of the ambient sensor.

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Karben, Germany

Manfred Kaiser