CN111272297A - An electronic thermometer - Google Patents

Abstract

An embodiment of the present invention discloses an electronic body temperature gun, comprising an infrared acquisition module, an ambient temperature acquisition module and a temperature compensation module, wherein the infrared acquisition module and the ambient temperature acquisition module are respectively connected to the temperature compensation module, wherein the The infrared acquisition module is used to collect the initial temperature value of the human body; the environmental temperature acquisition module is used to collect the real-time temperature value of the environment; the temperature compensation module is used to use the real-time temperature value of the environment to perform a temperature measurement on the initial temperature value of the human body. Compensation to obtain the target temperature value of the human body. In this way, by using the ambient temperature value to perform temperature compensation on the initial temperature value of the human body, the electronic body temperature gun can display an accurate temperature value in a high and low temperature environment.

Description

An electronic thermometer

technical field

The invention relates to the technical field of detection, in particular to an electronic body temperature gun.

Background technique

When the traditional body temperature gun measures the body temperature, it needs to be measured at a certain ambient temperature. If the ambient temperature is high or low temperature, the problem of inaccurate detection will occur.

SUMMARY OF THE INVENTION

In view of the above technical problems, an embodiment of the present invention provides an electronic body temperature gun, including: an infrared acquisition module, an ambient temperature acquisition module, and a temperature compensation module, wherein the infrared acquisition module and the ambient temperature acquisition module are respectively connected with the temperature compensation module. The modules are connected, wherein the infrared acquisition module is used to collect the initial temperature value of the human body; the environmental temperature acquisition module is used to collect the real-time temperature value of the environment; the temperature compensation module is used to use the real-time temperature value of the environment to Perform temperature compensation on the initial temperature value of the human body to obtain the target temperature value of the human body.

Optionally, the infrared acquisition module is specifically used for:

The initial temperature of the human body is collected by using a thermopile sensor, and the initial temperature of the human body is converted into an output voltage value.

Optionally, the temperature compensation module is specifically used for:

using an amplifier to amplify the initial temperature value of the human body to obtain an amplified value of the human body temperature;

Perform temperature compensation on the human body temperature amplification value by using the ambient real-time temperature value to obtain the human body target temperature value.

Optionally, performing temperature compensation on the human body temperature amplification value using the ambient real-time temperature value to obtain the human body target temperature value specifically includes:

According to the corresponding relationship between the voltage value and the ambient real-time temperature value, the human body target temperature value is calculated.

Optionally, the use of a thermopile sensor to collect the initial temperature of the human body and convert the initial temperature of the human body into a voltage value includes:

Use a 1K potentiometer to adjust the magnification to obtain the resistance of the thermistor;

Specifically:

Among them, Rg is the resistance value of the potentiometer, and G is the magnification.

Optionally, the using a thermopile sensor to collect the initial temperature of the human body and converting the initial temperature of the human body into a voltage value further includes:

The output voltage value is corrected and linearized by the thermistor,

Calculate the relationship between the resistance value of the thermistor and temperature, where:

The calculation formula is:

Among them: Ro=100kΨ (at 25°C), β=3960.

Optionally, the using a thermopile sensor to collect the initial temperature of the human body and converting the initial temperature of the human body into a voltage value further includes:

Calculate the relationship between the output voltage value and the resistance value of the thermistor; specifically:

Among them, Uo is the output voltage; Ua is the input voltage; R represents the resistance value corresponding to the corresponding temperature of the thermistor; Rs is the first preset value, 100kΨ; Rf is the second preset value 1kΨ; RT is the third preset value 100kΨ.

Optionally, calculating the human body target temperature value according to the corresponding relationship between the voltage value and the ambient temperature value includes:

Under different temperatures, obtain voltage values corresponding to the initial temperature value of the human body;

Drawing a graph of the initial temperature value of the human body and the output voltage value;

obtaining the corresponding relationship between the initial temperature value of the human body and the output voltage value;

Specifically: V ₀ =-0.08×T _a -1.95;

Wherein, _Ta is the target temperature value of the human body; Vo is the voltage value of the thermistor.

Optionally, calculating the human body target temperature value according to the corresponding relationship between the voltage value and the ambient temperature value includes:

calculating the corresponding relationship between the output voltage value, the human body target temperature value and the ambient temperature;

Specifically:

Wherein: T _a is the target temperature value of the human body; Vo is the voltage value of the thermistor;

K ₀ is the coefficient value; V is the output voltage value corresponding to the initial temperature value T ₀ .

Optionally, calculating the human body target temperature value according to the corresponding relationship between the voltage value and the ambient temperature value includes:

Wherein: T _a is the target temperature value of the human body; Vo is the voltage value of the thermistor;

K ₀ is the coefficient value; V is the output voltage value corresponding to the initial temperature value T ₀ .

In the technical solution provided by the embodiment of the present invention, an electronic body temperature gun is provided, which includes an infrared acquisition module, an ambient temperature acquisition module and a temperature compensation module, wherein the infrared acquisition module and the ambient temperature acquisition module are respectively connected with the temperature compensation module. wherein the infrared acquisition module is used to collect the initial temperature value of the human body; the ambient temperature acquisition module is used to collect the real-time temperature value of the environment; the temperature compensation module is used to use the real-time temperature value of the environment to The initial temperature value is temperature compensated to obtain the target temperature value of the human body. In this way, by using the ambient temperature value to perform temperature compensation on the initial temperature value of the human body, the electronic body temperature gun can display an accurate temperature value in a high and low temperature environment.

Description of drawings

1 is a schematic structural diagram of an electronic body temperature gun according to an embodiment of the present invention;

2 is a schematic diagram of a thermopile amplifying circuit according to an embodiment of the present invention;

3 is a schematic diagram of a thermistor amplifying circuit according to an embodiment of the present invention;

FIG. 4 is a schematic diagram of the relationship between output voltage and temperature according to an embodiment of the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts shall fall within the protection scope of the present invention.

The electronic body temperature gun provided by the embodiment of the present invention adds an environmental temperature acquisition module, which can accurately measure the body temperature of the human body in a high and low temperature environment.

Due to the non-contact measurement method, infrared temperature measurement has high requirements on the ambient temperature and is easily disturbed by the ambient temperature, which affects the accuracy. All objects with a temperature higher than absolute zero are constantly emitting infrared radiation energy to the surrounding, and the distribution of its energy according to the wavelength is closely related to the surface temperature of the object. Its surface temperature can be accurately measured. It is generally understood that infrared measurement is the temperature of the object, and its essence is the difference between the temperature of the target and the sensor or the environment. According to Planck's principle, the magnitude of the radiation energy of an object is directly related to the temperature of the object, specifically proportional to the fourth power of the thermodynamic temperature of the object.

The human body mainly radiates infrared rays with a wavelength of 9 to 10 μm. By measuring the infrared energy radiated by the human body, the surface temperature of the human body can be accurately determined. Since the light in this wavelength range is not absorbed by the air, the infrared energy radiated by the human body can be used to accurately measure the surface temperature of the human body.

The infrared sensor that receives radiant energy adopts a thermopile sensor. The thermopile is manufactured by a semiconductor integrated circuit (IC) process and a micro-mechanical electronics (MEMS) process, which can be equivalent to a number of thermocouples connected in series. The temperature measurement point of the thermocouple increases in temperature after receiving the infrared radiation energy, the Thomson electromotive force will be generated on the same conductor of the thermocouple due to the temperature gradient, and the electromotive force will be generated at the connection of the two metals due to the difference in electron density. Therefore, a thermoelectric electromotive force will be generated at both ends of the thermocouple. Its output voltage is proportional to the temperature of the measuring point. Therefore, by measuring the infrared energy radiated by the object itself, its surface temperature can be accurately measured, which is the theoretical basis on which infrared temperature measurement is based.

Referring to FIG. 1, the electronic body temperature gun provided by the embodiment of the present invention includes: an infrared acquisition module 101, an ambient temperature acquisition module 102, and a temperature compensation module 103. The infrared acquisition module 101 and the ambient temperature acquisition module 102 are respectively connected with the The temperature compensation module 103 is connected to the temperature compensation module 103, wherein the infrared collection module 101 is used to collect the initial temperature value of the human body; the ambient temperature collection module 102 is used to collect the real-time temperature value of the environment; the temperature compensation module 103 is used to use the environment The real-time temperature value of the human body performs temperature compensation on the initial temperature value of the human body to obtain the target temperature value of the human body.

The ambient temperature acquisition module may be a temperature sensor, and the infrared acquisition module may be a thermopile sensor.

The electronic temperature gun provided by the embodiment of the present invention includes an infrared acquisition module, an ambient temperature acquisition module, and a temperature compensation module. The infrared acquisition module and the ambient temperature acquisition module are respectively connected to the temperature compensation module, wherein the infrared acquisition module and the ambient temperature acquisition module are respectively connected to the temperature compensation module. The acquisition module is used to collect the initial temperature value of the human body; the environmental temperature acquisition module is used to collect the real-time temperature value of the environment; the temperature compensation module is used to perform temperature compensation on the initial temperature value of the human body by using the real-time temperature value of the environment, Obtain the target temperature value of the human body. In this way, by using the ambient temperature value to perform temperature compensation on the initial temperature value of the human body, the electronic body temperature gun can display an accurate temperature value in a high and low temperature environment.

Another embodiment of the present invention specifically introduces the above solution.

Optionally, the infrared acquisition module is specifically used for:

The initial temperature of the human body is collected by using a thermopile sensor, and the initial temperature of the human body is converted into an output voltage value.

Optionally, the temperature compensation module is specifically used for:

using an amplifier to amplify the initial temperature value of the human body to obtain an amplified value of the human body temperature;

Perform temperature compensation on the human body temperature amplification value by using the ambient real-time temperature value to obtain the human body target temperature value.

Optionally, performing temperature compensation on the human body temperature amplification value using the ambient real-time temperature value to obtain the human body target temperature value specifically includes:

According to the corresponding relationship between the voltage value and the ambient real-time temperature value, the human body target temperature value is calculated.

The ZTP135S-R sensor proposed in the embodiment of the present invention is an infrared thermopile sensor. The sensor is used to realize the non-contact measurement of human body temperature. A new temperature compensation algorithm for the ZTP135S-R sensor is proposed, and the experimental proof.

ZTP135S-R infrared temperature sensor is a kind of device specially used for measuring temperature produced by GE. It is mainly composed of two parts, a thermopile and a thermistor. It has a package of 4 pins, two of which are the voltage values output by the thermopile. The thermopile has 60 thermocouples connected in series. The hot end of the couple forms a circle in the central part of the heating plate and is welded together, and the sum of the thermoelectric potential of all the couples can be obtained from the lead wire. Such a structural design has less thermal inertia and higher sensitivity. The other two pins are negative temperature coefficient thermal regulators (Thermister), which mainly output resistance values for ambient temperature compensation.

1.1 Amplifier circuit design

Since the internal resistance of the ZTP135S-R thermopile is high (about 60kΨ) and the output voltage is very small (about 1mV), it can be known that the sensor's own output is about 0.08mV/℃. And to control the precision at 0.1℃, the amplifier input should be at 50mV/℃, then the gain of the amplifier is 50/0.08=625 times.

Considering that the error of the sensor output is ±30%, the gain of the amplifier should be controlled at 500 to 1000 times. Select AD620 to amplify the thermopile signal. The amplifier circuit is shown in Figure 2.

Use a 1K potentiometer to adjust the magnification. According to the performance of AD620, G is the magnification, and Rg is the potentiometer resistance value (kΨ), and the amplification is adjusted.

Use a 1K potentiometer to adjust the magnification to obtain the resistance of the thermistor;

其中，Rg为电位器阻值，G为放大倍数。Specifically:

Among them, Rg is the resistance value of the potentiometer, and G is the magnification.

Since the thermister is a standard negative temperature coefficient thermistor, a common amplifier circuit can be used to amplify the signal to a voltage value that the microprocessor can handle, and then linearize it. The linearization circuit is shown in Figure 3.

The output voltage value is corrected and linearized by the thermistor,

Calculate the relationship between the resistance value of the thermistor and temperature, where:

The calculation formula is:

其中：Ro＝100kΨ(25℃时),β＝3960。

Among them: Ro=100kΨ (at 25°C), β=3960.

In addition, the relationship between the input voltage U0 and the thermistor R can be calculated according to the designed linearization amplifier circuit diagram (Figure 3) and formula (1) (see Table 1).

Calculate the relationship between the output voltage value and the resistance value of the thermistor; specifically:

Among them, Uo is the output voltage; Ua is the input voltage; R represents the resistance value corresponding to the corresponding temperature of the thermistor; Rs is the first preset value, 100kΨ; Rf is the second preset value 1kΨ; RT is the third preset value 100kΨ.

Table 1

According to Table 1, it can be seen that within a certain range, the resistance characteristic of the thermistor tends to be linear. As long as it is selected within a certain useful temperature range, temperature compensation can be processed. From the data in Table 1, the relationship between the output voltage and temperature of such a thermistor can be approximated:

V ₀ =-0.034*(T ₀ -68.65)

V ₀ represents the output voltage value when the ambient temperature is T0, unit: V; T ₀ represents the ambient temperature value, unit: °C.

1.2 Temperature compensation method

Digital algorithms can achieve very high accuracy (±0.1°C). The relationship between thermopile sensor temperature and output voltage can be derived in Figure 4. It can be seen from Figure 4 that the internal resistance of the infrared thermopile sensor remains basically unchanged within the range of measuring body temperature (35 ℃ ~ 42 ℃), which is 60kΨ. When the room temperature is 25°C, the output voltage and temperature have a linear relationship within the range of measuring body temperature. See Table 2.

Table 2

Using the data in Table 2, the formula for temperature and voltage at 25°C can be derived:

V ₀ =-0.08*T _a -1.95;

That is, at different temperatures, obtain voltage values corresponding to the initial temperature value of the human body;

Drawing a graph of the initial temperature value of the human body and the output voltage value;

Obtain the corresponding relationship between the initial human body temperature value To and the output voltage value Vo;

The unit of V is mV; the unit of temperature is Celsius;

Calculate the corresponding relationship of the output voltage value, the human body target temperature value and the ambient temperature:

Specifically:

Wherein: T _a is the target temperature value of the human body; Vo is the voltage value of the thermistor;

K ₀ is the coefficient value; V is the output voltage value corresponding to the initial temperature value T ₀ .

The measured temperature is within a certain ambient temperature range, and the control accuracy is 0.2 °C. The higher the ambient temperature, the lower the corresponding Ko value. It is necessary to further correct the parameter values and improve the measurement algorithm.

Digital processing can be performed in a microprocessor, and the measured corresponding voltage V of the infrared thermopile and the corresponding voltage V0 of the thermistor can be A/D converted into digital quantities, and the value of human body temperature can be calculated by computer programming to realize temperature compensation. function.

In the existing scheme, the ambient temperature is detected by the temperature sensor; the temperature curve is drawn by studying the ambient temperature and the sensor, and the compensation of the temperature curve is provided to the thermopile sensor, so that the thermopile sensor can be used in different environments. It can accurately detect the temperature of the human body, which greatly improves the scope of application of the body temperature gun. And 0.4-0.8 seconds infrared temperature measurement, using imported professional infrared temperature measurement sensor, scanning more than 8500 times per second without touching the measured object, to avoid cross infection. So that the body temperature gun can measure the body temperature statically while ensuring safety no matter in the high temperature and low temperature environment.

The electronic body temperature gun provided by the embodiment of the present invention includes an infrared acquisition module, an ambient temperature acquisition module, and a temperature compensation module. The infrared acquisition module and the ambient temperature acquisition module are respectively connected to the temperature compensation module, wherein the infrared acquisition module and the ambient temperature acquisition module are respectively connected to the temperature compensation module. The acquisition module is used to collect the initial temperature value of the human body; the environmental temperature acquisition module is used to collect the real-time temperature value of the environment; the temperature compensation module is used to perform temperature compensation on the initial temperature value of the human body by using the real-time temperature value of the environment, Obtain the target temperature value of the human body. In this way, by using the ambient temperature value to perform temperature compensation on the initial temperature value of the human body, the electronic body temperature gun can display an accurate temperature value in a high and low temperature environment.

The above embodiments are only used to illustrate the technical solutions of the present invention, but not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: The recorded technical solutions are modified, or some technical features thereof are equivalently replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims (10)

1. An electronic body temperature gun, characterized by comprising at least: the temperature compensation device comprises an infrared acquisition module, an environment temperature acquisition module and a temperature compensation module, wherein the infrared acquisition module and the environment temperature acquisition module are respectively connected with the temperature compensation module, and the infrared acquisition module is used for acquiring an initial temperature value of a human body; the environment temperature acquisition module is used for acquiring an environment real-time temperature value; the temperature compensation module is used for performing temperature compensation on the human body initial temperature value by using the real-time temperature value of the environment to obtain a human body target temperature value.

2. The electronic electron temperature gun of claim 1, wherein the infrared collection module is specifically configured to:

the method comprises the steps of collecting human body initial temperature by using a thermopile sensor, and converting the human body initial temperature into an output voltage value.

3. The electronic electron temperature gun of claim 2, wherein the temperature compensation module is specifically configured to:

amplifying the human body initial temperature value by using an amplifier to obtain a human body temperature amplification value;

and performing temperature compensation on the human body temperature amplification value by using the environment real-time temperature value to obtain the human body target temperature value.

4. The electronic thermometer of claim 3, wherein the obtaining of the target temperature value by performing temperature compensation on the amplified human body temperature value by using the real-time ambient temperature value specifically comprises:

and calculating the human body target temperature value according to the corresponding relation between the voltage value and the environment real-time temperature value.

5. The electron thermal gun according to claim 2, wherein said collecting the initial temperature of the human body by the thermopile sensor and converting the initial temperature of the human body into a voltage value comprises:

adjusting the amplification factor by using a potentiometer of 1K to obtain the resistance value of the thermistor;

the method specifically comprises the following steps:

wherein Rg is the resistance of the potentiometer, and G is the amplification factor.

6. The electron thermal gun of claim 5, wherein the collecting of the initial temperature of the human body by the thermopile sensor and the converting of the initial temperature of the human body into a voltage value further comprises:

the thermistor is used for correcting the output voltage value and carrying out linearization,

calculating the relationship between the resistance value and the temperature of the thermistor, wherein:

the calculation formula is as follows:

wherein Ro is 100k psi (at 25 deg.C), β is 3960.

7. The electron thermal gun of claim 4, wherein the collecting of the initial temperature of the human body by the thermopile sensor and the converting of the initial temperature of the human body into a voltage value further comprises:

calculating the relation between the output voltage value and the resistance value of the thermistor; the method specifically comprises the following steps:

wherein Uo is the output voltage; ua is the input voltage; r represents the resistance value corresponding to the corresponding temperature of the thermistor; rs is a first preset value, 100k psi; rf is a second preset value 1k psi; RT is the third preset value 100k Ψ.

8. The electronic thermometer of claim 4, wherein said calculating the target temperature value of the human body according to the corresponding relationship between the voltage value and the ambient temperature value comprises:

acquiring voltage values corresponding to the human body initial temperature values at different temperatures;

drawing a curve chart of the human body initial temperature value and the output voltage value;

obtaining the corresponding relation between the human body initial temperature value and the output voltage value;

the method specifically comprises the following steps: v₀＝-0.08×T_a-1.95；

Wherein, T_aThe human body target temperature value is obtained; vo is the voltage value of the thermistor.

9. The electronic thermometer of claim 8, wherein said calculating the target temperature value of the human body according to the corresponding relationship between the voltage value and the ambient temperature value comprises:

calculating the corresponding relation among the output voltage value, the human body target temperature value and the environment temperature;

the method specifically comprises the following steps:

wherein: t is_aThe human body target temperature value is obtained; vo is the voltage value of the thermistor;

K₀is a coefficient value; v is an initial temperature value T₀The corresponding output voltage value.

10. The electronic thermometer of claim 9, wherein said calculating the target temperature value of the human body according to the corresponding relationship between the voltage value and the ambient temperature value comprises:

wherein: t is_aThe human body target temperature value is obtained; vo is the voltage value of the thermistor;

K₀is a coefficient value; v is an initial temperature value T₀The corresponding output voltage value.

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