WO1999058940A1 - Radiation thermometer - Google Patents
Radiation thermometer Download PDFInfo
- Publication number
- WO1999058940A1 WO1999058940A1 PCT/JP1998/002045 JP9802045W WO9958940A1 WO 1999058940 A1 WO1999058940 A1 WO 1999058940A1 JP 9802045 W JP9802045 W JP 9802045W WO 9958940 A1 WO9958940 A1 WO 9958940A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- thermopile
- heating
- radiation thermometer
- output
- temperature
- Prior art date
Links
- 230000005855 radiation Effects 0.000 title claims abstract description 110
- 238000009529 body temperature measurement Methods 0.000 claims abstract description 55
- 238000010438 heat treatment Methods 0.000 claims description 206
- 238000005259 measurement Methods 0.000 claims description 66
- 238000001514 detection method Methods 0.000 claims description 29
- 230000007423 decrease Effects 0.000 abstract description 4
- 210000003454 tympanic membrane Anatomy 0.000 description 15
- 238000010586 diagram Methods 0.000 description 12
- 230000036760 body temperature Effects 0.000 description 10
- 238000000034 method Methods 0.000 description 8
- 239000004973 liquid crystal related substance Substances 0.000 description 5
- 239000002184 metal Substances 0.000 description 4
- 210000000613 ear canal Anatomy 0.000 description 2
- 210000000214 mouth Anatomy 0.000 description 2
- 206010049976 Impatience Diseases 0.000 description 1
- 210000001099 axilla Anatomy 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000003780 insertion Methods 0.000 description 1
- 230000037431 insertion Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 230000010349 pulsation Effects 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- 238000004904 shortening Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
- G01J5/00—Radiation pyrometry, e.g. infrared or optical thermometry
- G01J5/70—Passive compensation of pyrometer measurements, e.g. using ambient temperature sensing or sensing of temperature within housing
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
- G01J5/00—Radiation pyrometry, e.g. infrared or optical thermometry
- G01J5/10—Radiation pyrometry, e.g. infrared or optical thermometry using electric radiation detectors
- G01J5/12—Radiation pyrometry, e.g. infrared or optical thermometry using electric radiation detectors using thermoelectric elements, e.g. thermocouples
- G01J5/14—Electrical features thereof
- G01J5/16—Arrangements with respect to the cold junction; Compensating influence of ambient temperature or other variables
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
- G01J5/00—Radiation pyrometry, e.g. infrared or optical thermometry
- G01J5/02—Constructional details
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
- G01J5/00—Radiation pyrometry, e.g. infrared or optical thermometry
- G01J5/02—Constructional details
- G01J5/0295—Nulling devices or absolute detection
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
- G01J5/00—Radiation pyrometry, e.g. infrared or optical thermometry
- G01J5/02—Constructional details
- G01J5/04—Casings
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
- G01J5/00—Radiation pyrometry, e.g. infrared or optical thermometry
- G01J5/02—Constructional details
- G01J5/04—Casings
- G01J5/049—Casings for tympanic thermometers
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
- G01J5/00—Radiation pyrometry, e.g. infrared or optical thermometry
- G01J5/02—Constructional details
- G01J5/06—Arrangements for eliminating effects of disturbing radiation; Arrangements for compensating changes in sensitivity
- G01J5/061—Arrangements for eliminating effects of disturbing radiation; Arrangements for compensating changes in sensitivity by controlling the temperature of the apparatus or parts thereof, e.g. using cooling means or thermostats
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
- G01J5/00—Radiation pyrometry, e.g. infrared or optical thermometry
- G01J5/02—Constructional details
- G01J5/06—Arrangements for eliminating effects of disturbing radiation; Arrangements for compensating changes in sensitivity
- G01J5/064—Ambient temperature sensor; Housing temperature sensor; Constructional details thereof
Definitions
- the present invention relates to a radiation thermometer, and more particularly, to a radiation thermometer that detects infrared rays radiated from a measurement target with a thermopile and measures the temperature of the measurement target in a non-contact manner.
- thermometer has been used to detect infrared rays emitted from an object to be measured and to measure the temperature of the object without contact.
- thermometers emit less radiation from the eardrum and surrounding tissues than contact-type thermometers such as the sublingual thermometer that measures the temperature of the oral cavity for the reasons of hygiene and convenience, and the axillary thermometer that measures the temperature of the armpit.
- the demand for non-contact thermometers that measure body temperature by detecting infrared radiation is increasing.
- the tympanic membrane Since the tympanic membrane is located deep in the human body and is less susceptible to the external environment, it can measure body temperature more accurately than other parts of the human body such as the oral cavity and axilla. One.
- Non-contact type thermometers generally use a pyroelectric sensor or a thermopile sensor as a non-contact type temperature sensor for detecting infrared rays radiated from an object to be measured.
- a pyroelectric sensor is a sensor that detects, as an output, a change in the surface charge of a pyroelectric body due to a temperature change at a hook that absorbs infrared energy radiated from an object to be measured.
- Impatience In order to output only when the temperature of the pyroelectric body changes, the electric sensor outputs the continuous output by intermittently cutting off the incident infrared rays by shoving.
- a thermopile sensor is a sensor in which thermocouples are deposited using integrated circuit technology, and a continuous output for the temperature difference between the hot junction and the cold junction is obtained by a large number of directly connected thermocouples.
- thermometer using a thermopile will be described as an example of a conventional radiation thermometer as a non-contact temperature sensor for detecting infrared rays radiated from an object to be measured.
- thermometer As a conventional non-contact thermometer using a thermopile, there is, for example, a radiation thermometer disclosed in Japanese Patent Application Laid-Open No. 3-27331. Such a radiation thermometer will be described based on the block diagram of FIG.
- thermopile 21 provided in the radiation thermometer outputs a voltage corresponding to the amount of infrared radiation from the eardrum 30.
- the amplifier 22 connected to the output terminal of the thermopile 21 amplifies the weak output voltage of the thermopile 21 to a predetermined magnitude.
- the differential power amplifier 23 connected to the amplifier 22 applies an output to the heater 24 in proportion to the difference between the output of the amplifier 22 and a reference voltage (for example, set to 0 V).
- the heat sink 25 is stored together with the heat sink 24 and the heat pile 21 in a block 26 made of a material having good heat conductivity.
- the temperature calculation circuit 27 calculates the temperature of the block 26, that is, the temperature of the thermopile 21 from the resistance of the thermistor 25 and displays the temperature by the display means 28.
- thermopile 21 the output of the thermopile 21 is V
- T the temperature of the object to be measured
- thermopile 21 the temperature of the thermopile 21 is ⁇ .
- V of the thermopile 21 is given by Stefan-Boltzmann's law.
- V k (T 4 — T. 4 ) k is a constant (1)
- thermopile 21 is controlled by the output of the thermopile 21. Therefore, the output V of the thermopile 21 becomes 0.
- thermopile 21 when the feedback control is performed so that the output V of the thermopile 21 becomes zero.
- the temperature T of the object to be measured can be known by detecting the temperature T at the same time.
- the radiation thermometer disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 3-2731 121 is not affected by the sensitivity of the thermopile 21 or the amplifier circuit, and therefore has the advantage that measurement errors can be reduced.
- the radiation thermometer disclosed in Japanese Unexamined Patent Publication No. 3-27331 uses a control means for performing feedback control so that the output V of the thermopile 21 becomes zero.
- the feedback control is a closed loop control, that is, a heat quantity corresponding to the output of the thermopile 21 heats the thermopile 21 via the heater 24 to adjust the temperature of the thermopile 21.
- the heating amount of the heater 24 changes every moment according to the result of the feedback, and the output V of the thermopile 21 decreases toward 0. I have.
- the amount of heating becomes small as shown in the heating amount-time graph of FIG. It takes a certain time from the start of heating to achieve the state where the output V is 0.
- the amount of infrared light incident on the thermopile 21 changes due to a change in the insertion angle of the thermopile 21 inserted into the ear canal when measuring the temperature of the eardrum, and the influence of the temperature of the ear canal.
- the output of the thermopile 21 changes as the amount of infrared light incident on the thermopile 21 changes during measurement of the eardrum temperature. Therefore, the amount of heat applied to the thermopile 21 is successively adjusted by the differential power amplifier 23. Particularly, when the output of the thermopile 21 is close to 0, the frequency of fine adjustment increases. Become.
- the feedback control circuit usually has a propagation delay factor.
- a transmission delay coefficient cannot be treated as a fixed constant when the heating state changes every moment due to feedback control. Therefore, a coefficient for correcting the propagation delay cannot be set, and the above-mentioned change in the output of the thermopile 21 is controlled while maintaining a large propagation delay coefficient. It cannot follow changes in the output of the thermopile 21.
- This propagation delay causes the feedback finger Since a mismatch occurs between the command value and the control result, the heating adjustment of the thermopile 21 is frequently performed, and is finely controlled. Such fine adjustment causes a pulsation phenomenon in the vicinity of zero of the output of the thermopile 21 in combination with a change in the amount of infrared light incident on the thermopile 21. It takes a long time to correct such a pulsating phenomenon and to achieve a state where the output of the thermopile 21 is 0 as shown in the output one-hour graph of FIG.
- the time t! Required for feedback control is required to improve the measurement accuracy, which is a conventional problem. Had to be set long beforehand.
- priority was given to measuring the temperature of the measurement target instantaneously or in a very short time, which is a feature of the non-contact thermometer, a decrease in measurement accuracy was inevitable.
- control means for performing feedback control so that the output V of the thermopile 21 becomes 0 requires a feedback control circuit including the amplifier 22 and the differential power amplifier 23 as described above.
- the increase in the number of required parts has caused the cost to rise.
- the present invention which is provided to solve the above-described problems, relates to a radiation thermometer that detects infrared rays emitted from a measurement target by a thermopile and measures the temperature of the measurement target.
- This is a radiation thermometer having a detection device for detecting a temperature.
- thermometer By having a detector for detecting the presence or absence of the output of the thermopile, the temperature of the thermopile at the time when the output of the thermopile is 0 can be detected. -No need for temperature control means for feedback control of the mopile temperature. Therefore, according to the radiation thermometer according to the present invention, the measurement accuracy can be improved, and the measurement time can be shortened. Also, an inexpensive radiation thermometer with a small number of parts can be provided.
- the detection device for detecting the presence or absence of the output of the thermopile may be a detection device having a voltage comparator.
- thermopile By using a detection device having a voltage comparator, the temperature of the thermopile at the time when the output of the thermopile is 0 can be detected by an inexpensive circuit.
- the invention of the present application provided to solve the above-mentioned problem is to detect the presence or absence of the output of the thermopile in a radiation thermometer that detects infrared radiation emitted from the measurement target by a thermopile and measures the temperature of the measurement target.
- a radiation thermometer comprising a detection device and a heating device for heating the thermopile.
- thermopile By having a detection device that detects the presence or absence of the output of the thermopile and a heating device that heats the thermopile, the thermopile is heated independently of the output of the thermopile so that the output of the thermopile becomes 0 Since the temperature of the thermopile can be detected, there is no need for a temperature control means for controlling the thermopile temperature feedback. Therefore, according to the radiation thermometer according to the present invention, the measurement accuracy can be improved and the measurement time can be shortened. In addition, an inexpensive radiation thermometer with a small number of parts can be provided.
- the detection device for detecting the presence or absence of the output of the thermopile may be a detection device having a voltage comparator.
- thermopile By using a detection device having a voltage comparator, it is possible to detect the temperature of the thermopile when the output of the thermopile is 0 with an inexpensive circuit.
- the heating device for heating the thermopile may be a heating device for heating the thermopile with the heating amount per unit time being substantially constant.
- thermopile By heating the thermopile with the heating amount per unit time being substantially constant, the thermopile can be heated without feedback control. Therefore, the output of the thermopile can be reduced to 0 in a short time.
- the heating device for heating the thermopile is open-loop controlled during temperature measurement.
- the heating device can be controlled by control.
- the circuit including the heating device can be a simple circuit with a small number of components .
- the heating device for heating the thermopile may be a heating device for heating the thermopile to a set temperature before the start of temperature measurement.
- thermopile during temperature measurement can be efficiently heated in a short time. That is, considering the case where the present invention is a non-contact type thermometer as one embodiment, if the set temperature is set to a temperature near the body temperature, for example, 32 ° C. before the start of the temperature measurement, the temperature is the temperature to be measured. Heating a thermopile to body temperature (around 36 ° C) can be done in a shorter time than heating a thermopile from normal room temperature (eg, 20 ° C).
- the present invention provided to solve the above-mentioned problem is directed to a radiation thermometer that detects infrared radiation emitted from a measurement target by a thermopile and measures the temperature of the measurement target.
- a radiation thermometer characterized by having a radiation thermometer characterized by having a detection device for detecting an inverted output when the light is inverted to a region.
- thermopile By having a detection device that detects the inverted output when the output of the thermopile is inverted from the positive area to the negative area, the output when the output of the thermopile is inverted from plus to minus, that is, the output of the thermopile is 0 Since the temperature of the thermopile at the time can be detected, there is no need for a temperature adjusting means for feedback-controlling the temperature of the thermopile. Therefore, according to the radiation thermometer according to the present invention, the measurement accuracy can be improved, and the measurement time can be reduced. In addition, an inexpensive radiation thermometer with a small number of parts can be provided.
- the detecting device for detecting the inverted output when the output of the thermopile is inverted from the positive region to the negative region may be a detecting device having a voltage comparator.
- thermometer that detects infrared radiation emitted from a measurement target by a thermopile and measures the temperature of the measurement target.
- a radiation thermometer comprising: a detection device for detecting an inverted output when inverted to a region; and a heating device for heating a thermopile.
- thermopile irrespective of the thermopile output by having a detector that detects the inverted output when the output of the thermopile is inverted from the positive area to the negative area, and a heating device that heats the thermopile
- the temperature of the thermopile at the time when the output of the thermopile is 0 can be detected, so that there is no need for a temperature adjusting means for feedback controlling the temperature of the thermopile. Therefore, according to the radiation thermometer according to the present invention, the measurement accuracy can be improved and the measurement time can be shortened. In addition, an inexpensive radiation thermometer with a small number of parts can be provided.
- the detection device for detecting the presence or absence of the output of the thermopile may be a detection device having a voltage comparator.
- thermopile By using a detection device having a voltage comparator, it is possible to detect the temperature of the thermopile when the output of the thermopile is 0 with an inexpensive circuit.
- the output inversion position can be set to have a hysteresis characteristic.
- thermopile By providing a hysteresis characteristic at the output inversion position, the output of the thermopile is
- a stable inverted output can be obtained even when transiently unstable near 0. Therefore, a pulsating phenomenon that occurs when the output of the thermopile is close to zero can be prevented, so that the measurement accuracy can be further improved.
- the heating device for heating the thermopile may be a heating device for heating the thermopile with the heating amount per unit time being substantially constant.
- thermopile By heating the thermopile with the heating amount per unit time being substantially constant, the thermopile can be heated without feedback control. Therefore, the output of the thermopile can be reduced to 0 in a short time.
- the heating device for heating the thermopile may be a heating device controlled by open loop control during temperature measurement.
- a heating device that is controlled by open-loop control during temperature measurement feedback control that complicates the circuit is not required, so the circuit including the heating device can be a simple circuit with a small number of components .
- the heating device for heating the thermopile may be a heating device for heating the thermopile to a set temperature before the start of temperature measurement.
- thermopile during temperature measurement can be efficiently heated in a short time. That is, considering the case where the present invention is a non-contact type thermometer as one embodiment, if the set temperature is set to a temperature near the body temperature, for example, 32 ° C. before the start of the temperature measurement, the temperature is the temperature to be measured. Heating a thermopile to body temperature (around 36 ° C) can be done in a shorter time than heating a thermopile from normal room temperature (eg, 20 ° C).
- thermometer for heating a thermopile in a radiation thermometer that detects infrared radiation emitted from a measurement target by a thermopile and measures the temperature of the measurement target
- a radiation thermometer comprising: arithmetic means for detecting a thermopile output with respect to a set threshold value in a positive region of a thermopile output and a set threshold value in a negative region to obtain a temperature to be measured.
- thermopile By having heating means for heating the thermopile, and calculating means for detecting the output of the thermopile with respect to the set threshold value in the positive area of the thermopile output and the set threshold value in the negative area to obtain the temperature of the measurement object
- the thermopile is heated independently of the thermopile output, and the thermopile output is indirect from the thermopile output with respect to the set threshold in the positive region and the set threshold in the negative region of the thermopile output. Since the temperature of the thermopile can be detected when the value of the thermopile is 0, there is no need for a temperature adjusting means for feedback-controlling the temperature of the thermopile. Therefore, according to the radiation thermometer according to the present invention, the measurement accuracy can be improved and the measurement time can be shortened. In addition, an inexpensive radiation thermometer with a small number of parts can be provided ⁇
- a pair having the same absolute value of the set threshold value in the positive region and the negative region is set as a pair, and a plurality of pairs having different set threshold values are set.
- the target temperature can be measured with high accuracy by a simple calculating means. That is, if the absolute values of the set thresholds in the positive region and the negative region are made equal, a simple arithmetic means for correcting a measurement error caused by a difference in the measurement environment such as the ambient temperature and the measurement temperature with respect to the thermopile is sufficient.
- a simple arithmetic means for correcting a measurement error caused by a difference in the measurement environment such as the ambient temperature and the measurement temperature with respect to the thermopile is sufficient.
- the heating means for heating the thermopile may be a heating device for heating the thermopile with the heating amount per unit time being substantially constant. By heating the thermopile with the heating amount per unit time almost constant, the thermopile can be heated without feedback control. Therefore, the output of the thermomodile can be reduced to 0 in a short time.
- the heating means for heating the thermopile may be a heating device controlled by open loop control during temperature measurement.
- the circuit including the heating device can be a simple circuit with a small number of components .
- the heating means for heating the thermopile may be a heating device for heating the thermopile to a set temperature before the start of temperature measurement.
- thermopile during temperature measurement can be efficiently heated in a short time. That is, considering the case where the present invention is a non-contact type thermometer as one embodiment, if the set temperature is set to a temperature near the body temperature, for example, 32 ° C. before the start of the temperature measurement, the temperature is the temperature to be measured. Heating the thermopile to body temperature (around 36 ° C) can be done in a shorter time than heating the thermopile from normal room temperature (eg, 20 ° C).
- the present invention provided to solve the above-mentioned problem is directed to a temperature measuring method for measuring the temperature of an object to be measured by detecting infrared rays radiated from the object to be measured by a thermopile.
- Mopile output is positive and negative
- This is a temperature measuring method characterized by detecting a temperature of a measurement target by detecting a temperature of a thermopile when a set threshold value set in each output range is reached.
- thermopile By detecting the temperature of the measurement object by detecting the temperature of the thermopile when the output of the thermopile reaches the set threshold set in the positive range and the negative range and the output range of the thermopile in the process of heating the thermopile, The thermopile is heated irrespective of the thermopile output, and the thermopile output is indirectly output from the thermopile output with respect to the set threshold in the positive region and the set threshold in the negative region of the thermopile output. Since the temperature of the thermopile at the time of 0 can be detected, there is no need for a temperature adjusting means for feedback-controlling the temperature of the thermopile. Therefore, according to the temperature measurement method according to the present invention, it is possible to improve the measurement accuracy and shorten the measurement time.
- the target temperature can be measured with high accuracy by a simple calculating means.
- a simple calculation means is sufficient for correcting the measurement error caused by the difference in the measurement environment such as the ambient temperature and the measurement temperature for the thermopile.
- the heating means for heating the thermopile may be a heating device for heating the thermopile with the heating amount per unit time being substantially constant. By heating the thermopile with the heating amount per unit time being substantially constant, the thermopile can be heated without feedback control. Therefore, the output of the thermomodile can be reduced to 0 in a short time.
- the heating means for heating the thermopile may be a heating device controlled by open loop control during temperature measurement.
- the circuit including the heating device can be a simple circuit with a small number of components.
- the heating means for heating the thermopile may be a heating device for heating the thermopile to a set temperature before the start of temperature measurement.
- thermopile during temperature measurement can be efficiently heated in a short time. That is, considering the case where the present invention is a non-contact type thermometer as one embodiment, if the set temperature is set to a temperature near the body temperature, for example, 32 ° C. before the start of the temperature measurement, the temperature is the temperature to be measured. Heating the thermopile to body temperature (around 36 ° C) can be done in a shorter time than heating the thermopile from normal room temperature (eg, 20 ° C).
- FIG. 1 is a block diagram showing a temperature measuring circuit of a radiation thermometer according to one embodiment of the present invention.
- FIG. 2 is a diagram showing a relationship between a thermopile output time and a heating amount-time in the radiation thermometer according to one embodiment of the present invention.
- FIG. 3 is a block diagram showing a temperature measuring circuit of a radiation thermometer according to another embodiment of the present invention.
- FIG. 4 is a diagram showing the relationship between one hour of thermopile output and one hour of comparator output in a radiation thermometer according to another embodiment of the present invention.
- FIG. 5 is a block diagram showing a temperature measuring circuit of a radiation thermometer according to another embodiment of the present invention.
- FIG. 6 is a diagram showing the relationship between one hour of thermopile output and one hour of heating in a radiation thermometer according to another embodiment of the present invention.
- FIG. 7 is a block diagram showing a temperature measuring circuit of a conventional radiation thermometer.
- FIG. 8 shows the output of the thermopile-time and heating amount-time in the conventional radiation thermometer.
- FIG. 4 is a diagram showing a relationship between symbols.
- FIG. 1 is a block diagram showing a temperature measuring circuit of a radiation thermometer according to one embodiment of the present invention.
- the thermopile 1 provided in the radiation thermometer outputs a voltage depending on the amount of infrared radiation radiated from the eardrum and the temperature of the thermopile 1. That is, the thermopile 1 outputs a voltage corresponding to the difference between the temperature of the measurement target and the temperature of the thermopile 1, and such an output is output as a positive voltage when the temperature of the measurement target is higher than the temperature of the thermopile 1. If the temperature of the object to be measured is lower than the temperature of the thermopile 1, it is output as a negative voltage. In addition, the temperature and
- thermopile 1 If the temperatures of mopile 1 are equal, the output of thermopile 1 will be 0.
- the operational amplifier 2 connected to the thermopile 1 amplifies the small voltage output from the thermopile 1 to a predetermined magnitude.
- the comparator (voltage comparator) IC 3 connected to the operational amplifier 2 detects whether or not the output of the thermopile 1 amplified by the operational amplifier 2 is present. In other words, the comparator IC 3 sends a signal indicating whether the output of the thermopile 1 is 0 or not to the microphone opening combination 7 regardless of the magnitude of the output of the thermopile 1 and the sign.
- the detection device having the comparator IC 3 is used as an example of the detection device that detects the presence or absence of the output of the thermopile 1.
- Thermistor 4 houses the thermopile 1 inside and is attached to a metal can package 5 with excellent thermal conductivity.
- the thermometer 4 is a temperature measuring element for measuring the temperature of the thermopile 1 via the metal can package 5.A change in the resistance value in the thermometer 4 due to a change in the temperature of the thermometer 4 is converted into a voltage. And output.
- the operational amplifier 6 connected to the summit 4 amplifies the output of the summit 4.
- the micro-computer 7 has an A / D converter built in, and the micro-computer 7 performs arithmetic processing based on the output signal from the comparator 3 and the output signal from the monitor 4 to display the liquid crystal temperature. Sends the temperature value output of the object to be measured to the device 8.
- the liquid crystal temperature display 8 digitally displays the temperature of the measurement target.
- Light 9 is wrapped around metal can package 5 to heat thermopile 1.
- the drive IC 10 transmits the heating command signal from the micro combination 7 to the evening 9.
- a heating device having a heater 9 is used as an example of a heating device for heating the thermopile 1. The following describes how the temperature of the measurement object is measured by the temperature measurement circuit described above.
- thermopile 1 before the temperature measurement is started, the micropile 1 is heated from the microcombination 7 to the heating 9 so that the temperature of the thermopile 1 becomes a preset temperature, for example, about 32 ° C. A command signal is sent. Therefore, at the start of temperature measurement, the temperature of thermopile 1 has risen to the set temperature.
- thermopile 1 When a command to start temperature measurement is transmitted from the outside to the microcomputer 7, a heating command signal for heating the thermopile 1 with the heating amount per unit time being almost constant is sent from the microcomputer 7 via the drive IC 10. He is sent at 9pm. During temperature measurement, the thermopile 1 is heated by the open loop control, that is, without changing the heating amount of the heater 9.
- thermopile 1 When the temperature measurement is started, the thermopile 1 is rapidly heated, and the output of the thermopile 1 rapidly decreases as shown in the thermopile output one hour graph in FIG. When heating proceeds and the temperature of the thermopile 1 becomes equal to the temperature of the eardrum to be measured, the output of the thermopile 1 becomes 0. Since the output signal of the thermopile 1 is sent to the microcomputer 7 by the comparator IC 3, the temperature of the thermopile 1 at the time when the output of the thermopile 1 becomes 0 becomes the temperature of the thermopile 1. The microcomputer 7 performs arithmetic processing based on the output from the CPU, thereby detecting the temperature of the eardrum to be measured. The detected temperature of the eardrum is recognized by being displayed on the liquid crystal temperature display.
- thermopile 1 The heating of the thermopile 1 by the heater 9, the comparator Isseki IC 3 that the output of the mono- thermopile 1 is 0 after micro Combi Yu evening 7 detects, microcontroller at time t 2 of FIG. 2 The operation ends when the heating stop signal from Pyu-Yu 7 is transmitted to He-Yu 9.
- the radiation thermometer uses a detection device having the comparator IC 3 as a detection device for detecting the presence or absence of the output of the thermopile 1, so that an inexpensive circuit can be obtained. Therefore, the temperature of the thermopile 1 at the time when the output of the thermopile 1 is 0 can be detected, so that there is no need for a temperature adjusting means for feedback-controlling the temperature of the thermopile 1. Therefore, the radiation temperature according to the present embodiment According to the meter, the measurement accuracy can be improved and the measurement time can be shortened. In addition, an inexpensive radiation thermometer with a small number of parts can be provided.
- thermopile 1 heats the thermopile 1 with the heating amount per unit time being substantially constant during the temperature measurement, as shown in the heating amount one hour graph in FIG.
- the thermopile 1 can be rapidly heated without feedback control. Therefore, the output of the thermopile 1 can be made 0 in a short time as shown in the thermopile output-time graph of FIG.
- the radiation thermometer uses a heating device controlled by open-loop control during temperature measurement, which eliminates the need for feedback control that complicates the circuit.
- the circuit including can be a simple circuit with a small number of components.
- the radiation thermometer according to the present embodiment can heat the thermopile 1 during the temperature measurement efficiently in a short time by heating the thermopile 1 to the set temperature before the start of the temperature measurement.
- FIG. 3 is a block diagram showing a temperature measuring circuit of a radiation thermometer according to another embodiment of the present invention.
- the comparator (voltage comparator) IC 3 has a function of detecting an inverted output when the output of the thermopile 1 amplified by the operational amplifier 2 is inverted from the positive region to the negative region by heating the heater 9. Fulfill. That is, the comparator IC 3 sends a signal to the microcomputer 7 that the output area of the thermopile 1 has been inverted. In the present embodiment, the output reversal position of the comparator IC 3 is set to a position where the output of the sample 1 changes from the positive region to the negative region.
- a detection device having a comparator IC 3 is used as an example of a detection device that detects an inverted output when the output of the thermopile 1 is inverted from the positive region to the negative region. I have.
- the method for heating the thermopile 1 and the procedure for measuring the temperature of the object to be measured are almost the same. This is similar to the above-described embodiment. That is, when the temperature measurement is started, the thermopile 1 is rapidly heated as in the above-described embodiment, and the output of the thermopile 1 is rapidly reduced. When the heating proceeds and the temperature of the thermopile 1 becomes equal to the temperature of the eardrum to be measured, the output of the thermopile 1 is inverted from the positive region to the negative region.
- thermometer 1 Since the output inversion signal of the output of thermopile 1 is sent to microcomputer 7 by comparison IC 3, the temperature of thermopile 1 at the time when the output of thermopile 1 is inverted is output from the thermometer 1
- the temperature of the eardrum which is the measurement target, is detected by the microcomputer 7 performing arithmetic processing based on the data.
- the detected temperature of the eardrum is recognized by being displayed on the liquid crystal temperature display.
- the output inversion position of the comparator IC 3 is set to a position where the output of the thermopile 1 changes from the positive region to the negative region. It is also possible to set so as to have a hysteresis width as shown in FIG. That is, the output inversion position is set near 0 in the positive region and the negative region of the output of the thermopile 1 respectively. In this embodiment, the output at the time of the fourth time, as shown in FIG t 3 and 1 4 are reversed.
- Such a hysteresis width can be set as close as possible to the output 0 as much as possible by setting a constant of the shunt circuit using the comparator.
- the heating of the thermopile 1 proceeds, and a stable inverted output can be obtained even when the output becomes transiently unstable near 0. Therefore, a pulsating phenomenon that occurs near zero output can be prevented, so that the measurement accuracy can be further improved.
- FIG. 5 is a block diagram showing a temperature measuring circuit of a radiation thermometer according to another embodiment of the present invention.
- the output of the thermopile 1 and the output of the thermopile 4 are not directly connected to the microcomputer 7 through the switch circuit 11 without using the comparator IC 3. Is detected.
- the timing signal is sent from the microcombiner 7 to the switch circuit 11, so that the microcomputer 7 switches from the mode for processing the output signal of the thermopile 1 to the mode for processing the output signal of the thermistor 4. Switch to one.
- the arithmetic processing inside the micro-computer 7 is different from that of the above-described embodiment. That is, in the present embodiment, as shown in FIG. 6, the microcomputer 7 detects only the thresholds set in the positive region and the negative region of the output of the thermopile 1 respectively. The threshold is set near zero of the output of the thermopile 1, and the absolute values of the thresholds are set to be equal.
- thermometer measures the temperature of the measurement target.
- the method of heating the thermopile 1 is almost the same as in the above-described embodiment.
- thermopile 1 When a command to start temperature measurement is transmitted from the outside to the microcomputer 7 and temperature measurement is not started, the thermopile 1 is rapidly heated. Until the heating time 1 4 As shown in FIG. 6, that is carried out until a threshold output of the thermopile 1 is set to a negative region. In this way, the heating of the thermopile 1 proceeds, and the temperature of the thermopile 1 at the time when the output of the thermopile 1 reaches the above two thresholds is determined based on the output from the thermopile 4.
- Convenience store 7 performs the arithmetic processing.
- the temperature of the eardrum to be measured is detected by calculating the average value of the temperatures corresponding to the two thresholds.
- the detected temperature of the eardrum is recognized by being displayed on a liquid crystal temperature indicator. Note that a plurality of pairs of thresholds having the same absolute value can be set.
- the radiation thermometer detects the heating means for heating the thermopile 1 and the output of the thermopile 1 with respect to the set threshold in the positive region and the set threshold in the negative region of the output of the thermopile 1.
- the thermopile 1 temperature can be detected indirectly from the output of the thermopile 1 when the output of the thermopile 1 is 0 with respect to the set threshold value in the negative region. No need for temperature control means. Therefore, according to the radiation thermometer according to the present invention, the measurement accuracy can be improved and the measurement time can be reduced. it can.
- an inexpensive radiation thermometer with a small number of parts can be provided.
- the target temperature can be accurately calculated by a simple arithmetic unit. Can be measured. That is, if the absolute values of the set thresholds in the positive region and the negative region are made equal, a simple calculation means for correcting the measurement error caused by the difference in the measurement environment such as the ambient temperature and the measurement temperature with respect to the thermopile 1 is sufficient. Also, by setting a plurality of pairs having different set thresholds, the measurement temperature can be calculated from a plurality of data, so that the accuracy can be improved.
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Spectroscopy & Molecular Physics (AREA)
- Measuring And Recording Apparatus For Diagnosis (AREA)
- Radiation Pyrometers (AREA)
Abstract
Description
Claims
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
AU72346/98A AU7234698A (en) | 1998-05-08 | 1998-05-08 | Radiation thermometer |
PCT/JP1998/002045 WO1999058940A1 (en) | 1998-05-08 | 1998-05-08 | Radiation thermometer |
JP55273299A JP3175775B2 (en) | 1998-05-08 | 1998-05-08 | Temperature measurement method of radiation thermometer and radiation thermometer |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
PCT/JP1998/002045 WO1999058940A1 (en) | 1998-05-08 | 1998-05-08 | Radiation thermometer |
Publications (1)
Publication Number | Publication Date |
---|---|
WO1999058940A1 true WO1999058940A1 (en) | 1999-11-18 |
Family
ID=14208169
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP1998/002045 WO1999058940A1 (en) | 1998-05-08 | 1998-05-08 | Radiation thermometer |
Country Status (3)
Country | Link |
---|---|
JP (1) | JP3175775B2 (en) |
AU (1) | AU7234698A (en) |
WO (1) | WO1999058940A1 (en) |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH03273121A (en) * | 1990-03-23 | 1991-12-04 | Citizen Watch Co Ltd | Radiation thermometer |
JPH0528617B2 (en) * | 1988-09-15 | 1993-04-26 | Temupu Suteitsuku Corp | |
JP2588792B2 (en) * | 1990-09-21 | 1997-03-12 | 山武ハネウエル株式会社 | Method and apparatus for calculating thermal sensation |
-
1998
- 1998-05-08 WO PCT/JP1998/002045 patent/WO1999058940A1/en active Application Filing
- 1998-05-08 JP JP55273299A patent/JP3175775B2/en not_active Expired - Fee Related
- 1998-05-08 AU AU72346/98A patent/AU7234698A/en not_active Abandoned
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH0528617B2 (en) * | 1988-09-15 | 1993-04-26 | Temupu Suteitsuku Corp | |
JPH03273121A (en) * | 1990-03-23 | 1991-12-04 | Citizen Watch Co Ltd | Radiation thermometer |
JP2588792B2 (en) * | 1990-09-21 | 1997-03-12 | 山武ハネウエル株式会社 | Method and apparatus for calculating thermal sensation |
Also Published As
Publication number | Publication date |
---|---|
JP3175775B2 (en) | 2001-06-11 |
AU7234698A (en) | 1999-11-29 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
EP0391128B1 (en) | Infrared thermometry system and method | |
US6155712A (en) | Radiation clinical thermometer | |
US6839651B2 (en) | Probe tip thermal isolation and fast prediction algorithm | |
US20090154519A1 (en) | Thermometer calibration | |
WO1999015866A1 (en) | Radiation thermometer and method for adjusting the same | |
JP2006250883A (en) | Ear clinical thermometer | |
JPH0228524A (en) | Radiation clinical thermometer | |
JP3873528B2 (en) | Radiation thermometer | |
JPH05115443A (en) | System to perform determination and correction of temperature by biomedical thermometer | |
JPH0666639A (en) | Infrared thermometer | |
JP4771193B2 (en) | Ear thermometer temperature correction device | |
JP3040444B2 (en) | Thermometer | |
JP4580562B2 (en) | Non-contact temperature sensor and infrared thermometer using the same | |
WO1999058940A1 (en) | Radiation thermometer | |
JPH03273121A (en) | Radiation thermometer | |
JPH06142063A (en) | Radiation clinical thermometer | |
JP3338456B2 (en) | Radiation thermometer and method of measuring temperature of radiation thermometer | |
JP4621363B2 (en) | Infrared thermometer | |
WO2000004353A1 (en) | Radiation thermometer | |
JPH03251729A (en) | Thermometric device | |
JPH0536056B2 (en) | ||
JP2005334254A (en) | Eardrum thermometer | |
JPH09126896A (en) | Method for compensating temperature of thermopile | |
JP2001218742A (en) | Infrared ray clinical thermometer | |
JP2003106905A (en) | Electronic clinical thermometer |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AK | Designated states |
Kind code of ref document: A1 Designated state(s): AL AM AT AU AZ BA BB BG BR BY CA CH CN CU CZ DE DK EE ES FI GB GE GH GM GW HU ID IL IS JP KE KG KR KZ LC LK LR LS LT LU LV MD MG MK MN MW MX NO NZ PL PT RO RU SD SE SG SI SK SL TJ TM TR TT UA UG US UZ VN YU ZW |
|
AL | Designated countries for regional patents |
Kind code of ref document: A1 Designated state(s): GH GM KE LS MW SD SZ UG ZW AM AZ BY KG KZ MD RU TJ TM AT BE CH CY DE DK ES FI FR GB GR IE IT LU MC NL PT SE BF BJ CF CG CI CM GA GN ML MR NE SN TD TG |
|
DFPE | Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101) | ||
121 | Ep: the epo has been informed by wipo that ep was designated in this application | ||
WWE | Wipo information: entry into national phase |
Ref document number: 09674401 Country of ref document: US |
|
NENP | Non-entry into the national phase |
Ref country code: KR |
|
REG | Reference to national code |
Ref country code: DE Ref legal event code: 8642 |
|
122 | Ep: pct application non-entry in european phase | ||
NENP | Non-entry into the national phase |
Ref country code: CA |