Method and system for secondary calibration-free temperature measurement of infrared temperature measurement apparatus after replacement of extended lens

Abstract

The present invention relates to the technical field of infrared temperature measurements, and in particular to a method and system for a secondary calibration-free temperature measurement of an infrared temperature measurement apparatus after the replacement of an extended lens. The method for a secondary calibration-free temperature measurement of an infrared temperature measurement apparatus after the replacement of an extended lens comprises: acquiring the relative transmittance of an original lens element of an infrared temperature measurement apparatus with respect to an extended lens element, and also acquiring an original actually-measured temperature, which is actually measured by an original camera lens, and a target actually-measured temperature, which is actually measured by an extended camera lens; acquiring a spectral radiance calculation formula, and calculating spectral radiance corresponding to each of the target actually-measured temperature and a lens element temperature; performing derivation to obtain a correction formula for a secondary calibration-free temperature measurement of the infrared temperature measurement apparatus after the replacement of the extended lens; and on the basis of target true spectral radiance and the spectral radiance calculation formula, reversely solving a target true temperature, wherein when the difference between the target true temperature and the original actually-measured temperature is within a specified limit, it indicates that a temperature measurement calibration process of the infrared temperature measurement apparatus after the replacement of the extended lens is complete. By means of the present invention, the secondary calibration of an infrared temperature measurement apparatus on a prototype is effectively avoided.

Description

Method and system for eliminating secondary calibration of infrared temperature measurement device after replacing extended lens Technical Field

[0001] This invention relates to the field of infrared temperature measurement technology, and more specifically to a method and system for eliminating the need for secondary calibration after replacing the extended lens of an infrared temperature measurement device. Background Technology

[0002] Infrared temperature measurement devices often require the selection of different types of extended lenses based on actual temperature measurement needs. However, replacing extended lenses often results in a loss of measurement accuracy, necessitating a cumbersome secondary calibration to restore the factory-set accuracy. Unfortunately, current mainstream solutions fail to completely eliminate the necessary secondary calibration step. This forces manufacturers of infrared temperature measurement equipment to frequently dispatch technicians to customer sites to resolve measurement errors caused by lens replacements, significantly increasing the company's human and material costs.

[0003] A similar prior art is disclosed in Chinese patent application CN118089957A, which discloses a temperature compensation test method for lens replacement. The method includes obtaining a first transmittance T1 of a reference lens and a second transmittance T2 of the lens to be compensated; calculating a transmittance compensation coefficient TV; obtaining a first grayscale value G1 of the reference lens after transmittance compensation and a second grayscale value G2 of the lens to be compensated after transmittance compensation; obtaining a third grayscale value G3 of the lens to be compensated after lens compensation; establishing a compensation grayscale value model; obtaining the final grayscale value Gf of the lens to be compensated; obtaining the temperature value calculated from the final grayscale value Gf using a grayscale-to-temperature model; and verifying the temperature of the lens to be compensated based on the temperature value to complete the lens temperature compensation test. However, the temperature measurement accuracy after lens replacement using this invention is not high. Similar prior art includes Chinese patent application CN214251286U, which provides an infrared temperature measurement device, including a housing, a lens for focusing light reflected from a target device, a light processing module for converting the light signal into a first electrical signal, a processor for converting the first electrical signal processed by the light processing module into a second electrical signal compatible with an external display device, and an output terminal for outputting the second electrical signal processed by the processor to an external display device. The lens is mounted on the housing, and the light processing module, processor, and output terminal are all housed within the housing. However, this invention does not consider lens replacement and the temperature measurement accuracy after lens replacement. Therefore, this invention proposes a method and system for eliminating the need for secondary calibration after replacing the extended lens in an infrared temperature measurement device.

[0004] Summary of the Invention

[0005] To better address the aforementioned problems, this invention provides a method for eliminating the need for secondary calibration after replacing the extended lens of an infrared temperature measurement device, which is achieved by performing the following steps:

[0006] Step S1: Obtain the relative transmittance of the original lens of the infrared temperature measuring device relative to the extended lens, and simultaneously obtain the original measured temperature obtained by the original lens and the target measured temperature obtained by the extended lens.

[0007] Step S2: Obtain the formula for calculating spectral radiance, and calculate the spectral radiance corresponding to the measured temperature of the target and the lens temperature based on the formula.

[0008] Step S3: Derive the correction formula for the infrared temperature measurement device after replacing the extended lens to eliminate the need for secondary calibration, and use the corrected spectral radiance of the extended lens temperature measurement as the target true spectral radiance.

[0009] Step S4: Based on the true spectral radiance of the target and the formula for calculating the spectral radiance, the measured temperature of the target object measured by the original lens is obtained by inverse solving and used as the true temperature of the target. When the original measured temperature is below 100℃, the difference between the true temperature of the target and the original measured temperature is within ±2℃. Or when the original measured temperature is 100℃ or above, the difference between the true temperature of the target and the original measured temperature is within ±2%℃. This indicates that the temperature calibration process after replacing the extended lens of the infrared temperature measuring device is completed.

[0010] As a preferred embodiment of the present invention, step S2, obtaining the formula for calculating spectral radiance, includes:

[0011] Based on Planck's blackbody radiation formula, Equation 1 is used to express the spectral radiance of an absolute blackbody at a fixed wavelength λ at temperature T:

[0012] Where C1 represents Planck's first constant, C2 represents Planck's second constant, T represents the temperature of the absolute blackbody, λ represents the fixed wavelength of the spectral band, M(λ,T) represents the spectral radiation of the absolute blackbody at a certain fixed wavelength λ at temperature T, and the absolute blackbody represents a calibrated standard source.

[0013] As a preferred embodiment of the present invention, the formula for calculating spectral radiance further includes:

[0014] Based on Planck's blackbody radiation formula, Formula 2 is used to express the spectral radiation of the absolute blackbody at temperature T within the light wave range [λ1,λ2] that the detector of the infrared thermometer can receive.

[0015] Formula 2 can be expressed in the form of a definite integral:

[0016] The definite integral band [λ1, λ2] is consistent with the spectral band that the infrared thermometer detector can receive.

[0017] As a preferred embodiment of the present invention, step S3, before deriving the correction formula for temperature measurement without secondary calibration after replacing the extended lens of the infrared temperature measuring device, includes:

[0018] According to the radiation balance theory, electromagnetic waves incident on any medium will undergo absorption, reflection, and transmission, satisfying Equation 4. Based on Equation 4, when the infrared radiation of the target object enters the lens of the infrared thermometer, a radiation energy conversion will occur, which is expressed by Equation 3:

[0019] W(T * )=τ lens ·W(T)+(1-τ lens )·W(T lens ) (Formula 3)

[0020] Among them, W(T) * The value () represents the amount of spectral radiation received by the detector focal plane after the target radiation passes through the lens of the infrared thermometer. The temperature measurement result T is obtained by back-calculation based on the formula 2. * W(T) represents the spectral radiance corresponding to the true temperature T of the absolute blackbody target. lens () indicates the lens temperature T lens The corresponding spectral radiance, τ lens The average transmittance of the lens spectrum is indicated, and the spectral bands are all consistent with the spectral bands that the infrared temperature measuring device can receive. The lens temperature refers to the lens temperature of either the original lens or the extended lens.

[0021] As a preferred embodiment of the present invention, step S3, before deriving the correction formula for the infrared temperature measuring device to eliminate the need for secondary calibration after replacing the extended lens, further includes:

[0022] According to the radiation balance theory, electromagnetic waves will be absorbed, reflected and transmitted when incident on any medium, and satisfy α+ρ+τ=1, where α represents the absorptivity, ρ represents the reflectivity and τ represents the transmittance.

[0023] The infrared temperature measuring device satisfies the radiation energy conversion relationship of Formula 3 before and after replacing the extended lens, and the relationship is expressed by Formula 4:

[0024] Among them, W(T1) * W(T2) represents the amount of radiation received by the target radiation through the focal plane of the original lens detector of the infrared thermometer.* T1 represents the amount of radiation received by the detector's focal plane after the target radiation has passed through the infrared thermometer and the extended lens has been replaced. * This indicates the temperature measurement result of the infrared temperature measuring device when it is installed with the original lens, T2. * This indicates the temperature measurement result of the infrared temperature measuring device when it is inserted into the extended lens, T lens1 The temperature of the original lens is represented by T. lens2 τ represents the temperature of the extended lens. lens1 τ represents the average spectral transmittance of the original lens. lens2 This indicates the average transmittance of the extended lens spectral density.

[0025] As a preferred embodiment of the present invention, in step S3, the correction formula for eliminating the need for secondary calibration of the infrared temperature measuring device after replacing the extended lens is derived, including:

[0026] Based on the fact that the infrared temperature measuring device satisfies the radiation energy conversion relationship of Formula 3 before and after replacing the extended lens, the corrected formula for eliminating the need for secondary calibration after replacing the extended lens is derived from Formula 4 and expressed as Formula 5:

[0027] W(T0)=λ·W(T2 * )+(1-λ)·W(T lens ) (Formula 5)

[0028] Where λ=τ lens1 / τ lens2 This indicates the average spectral transmittance of the original lens relative to the extended lens. T2 represents the lens temperature. * The temperature measurement result of the target radiation after replacing the extended lens is the temperature before correction, and W(T0) represents the theoretical spectral radiation that should be incident on the focal plane of the infrared detector after calculation by the formula 5.

[0029] As a preferred embodiment of the present invention, in step S4, the measured temperature of the target object obtained by the original lens is obtained by inverse solving and used as the true temperature of the target:

[0030] The corrected spectral radiance W(T0) is calculated based on Formula 5. The spectral radiance W(T0) is then substituted into the spectral radiance calculation formula to solve the inverse solution and obtain the actual temperature of the target object measured by the original lens, which is then used as the true temperature of the target.

[0031] As a preferred embodiment of the present invention, step S1, obtaining the relative transmittance of the original lens of the infrared temperature measuring device relative to the extended lens, includes:

[0032] The average spectral transmittance of the extended lens and the original lens can be obtained through original factory spectral testing. Based on the average spectral transmittance, the relative transmittance of the original lens relative to the extended lens can be calculated.

[0033] As a preferred embodiment of the present invention, step S2, calculating the spectral radiance corresponding to the measured target temperature and the lens temperature, includes:

[0034] Substitute the measured target temperature and the lens temperature into Formula 1 or Formula 2 respectively to calculate the spectral radiance corresponding to the measured target temperature and the spectral radiance corresponding to the lens temperature.

[0035] This invention also provides a system for eliminating the need for secondary calibration of an infrared temperature measurement device after replacing the extended lens, the system comprising:

[0036] The transmittance acquisition unit is used to acquire the relative transmittance of the original lens of the infrared temperature measuring device relative to the extended lens, and to acquire the original measured temperature obtained by the original lens and the target measured temperature obtained by the extended lens.

[0037] The radiation calculation unit is used to obtain the spectral radiation calculation formula and calculate the spectral radiation corresponding to the measured temperature of the target and the lens temperature based on the spectral radiation calculation formula.

[0038] The calibration correction unit is used to derive the correction formula for the infrared temperature measuring device to eliminate the need for secondary calibration after replacing the extended lens, and to use the spectral radiance after the temperature measurement of the extended lens is corrected to eliminate the need for secondary calibration as the target true spectral radiance.

[0039] The radiation inverse calculation unit is used to inversely solve for the measured temperature of the target object by the original lens and use it as the true temperature of the target. When the original measured temperature is below 100℃, the difference between the true temperature of the target and the original measured temperature is within ±2℃. Or when the original measured temperature is 100℃ or above, the difference between the true temperature of the target and the original measured temperature is within ±2%℃. This indicates that the temperature calibration process of the infrared temperature measuring device after replacing the extended lens is completed.

[0040] Compared with the prior art, the beneficial effects of the present invention are at least as follows:

[0041] The technical solution of this invention studies infrared spectral radiation theory, applying the law of conservation of energy and Kirchhoff's law of thermal radiation to specific infrared temperature measurement scenarios. A theoretical modeling approach is used to establish a mapping model between the temperature measurement results of the original lens and the relative transmittance, lens temperature, and temperature measurement results of the extended lens. This enables the extended infrared lens to achieve radiation temperature measurement functionality on a prototype infrared temperature measurement device of the same model. Compared to the original factory lens, the temperature measurement accuracy is within ±2℃ at temperature points below 100℃, and within ±2%℃ at temperature points of 100℃ and above. On one hand, this invention establishes a theoretical calibration model based on radiation theory, effectively avoiding secondary calibration on the prototype and facilitating the replacement of the extended lens in the infrared temperature measurement device. On the other hand, this invention is applicable to all infrared temperature measurement devices with extended lenses, possessing universality and wide applicability in the field of infrared temperature measurement. Attached Figure Description

[0042] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0043] Figure 1 is a flowchart of the steps of a method for temperature measurement without secondary calibration after replacing the extended lens of an infrared temperature measuring device provided by the present invention.

[0044] Figure 2 shows the curve relationship between the temperature measurement results of the original lens and the extended lens provided by the present invention and the target temperature.

[0045] Figure 3 is a structural diagram of the infrared temperature measurement device provided by the present invention, which eliminates the need for secondary calibration after replacing the extended lens. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0047] It is understood that the terms "first," "second," etc., used in this application may be used herein to describe various elements, but unless otherwise specified, these elements are not limited by these terms. These terms are used only to distinguish one element from another. For example, without departing from the scope of this application, a first script may be referred to as a second script, and similarly, a second script may be referred to as a first script.

[0048] Infrared temperature measurement devices often require the selection of different types of extended lenses based on actual temperature measurement needs. However, replacing extended lenses often results in a loss of measurement accuracy, necessitating a cumbersome secondary calibration to restore the factory-set accuracy. Unfortunately, current mainstream solutions fail to completely eliminate the necessary secondary calibration step. This forces manufacturers of infrared temperature measurement equipment to frequently dispatch technicians to customer sites to resolve measurement errors caused by lens replacements, significantly increasing the company's human and material costs.

[0049] To address the aforementioned technical problems, this invention proposes a method for temperature measurement without secondary calibration after replacing the extended lens of an infrared temperature measuring device, as shown in Figure 1. This method is implemented by performing the following steps:

[0050] Step S1: Obtain the relative transmittance of the original lens of the infrared temperature measuring device relative to the extended lens, and simultaneously obtain the original measured temperature obtained by the original lens and the target measured temperature obtained by the extended lens.

[0051] Specifically, spectral testing refers to original factory spectral testing. Through original factory spectral testing, the average spectral transmittance of the extended lens and the original lens can be obtained. Based on the average spectral transmittance, the relative transmittance of the original lens relative to the extended lens can be calculated to obtain the temperature measurement difference of the same target object under the two lenses, and its relative transmittance is used as the calibration standard for the infrared temperature measurement device.

[0052] Under a fixed ambient temperature, the infrared thermometer, equipped with its original lens, was used to perform temperature calibration on blackbody targets with actual temperatures of 20℃, 50℃, 100℃, 200℃, 350℃, and 600℃. In this embodiment, the infrared thermometer's detector has a receivable wavelength range of 8–14 μm, the blackbody target is a blackbody radiometer, and the fixed temperature environment was set in a walk-in constant temperature test chamber. The calibration results are shown in Table 1.

[0053] Table 1

[0054] The relative transmittance of the original lens relative to the extended lens, as measured by the infrared spectrometer, is 0.89. The spectral band measured by the infrared spectrometer is consistent with the receivable band of the infrared thermometer detector, both being 8–14 μm. The relative transmittance is the ratio of the average spectral transmittance of the original lens relative to the extended lens measured in this band.

[0055] After the infrared temperature measuring device was equipped with an extended lens, temperature tests were conducted on blackbody targets with actual temperatures of 20℃, 50℃, 100℃, 200℃, 350℃, and 600℃. The test results are shown in Table 2.

[0056] Table 2

[0057] Step S2: Obtain the formula for calculating spectral radiance, and calculate the spectral radiance corresponding to the measured temperature of the target and the lens temperature based on the formula.

[0058] Specifically, a functional relationship is established between spectral radiance, spectral band, and absolute blackbody temperature, serving as the basis for calculating spectral radiance. The spectral radiance corresponding to the measured target temperature and lens temperature are calculated separately, providing a foundation for calculating the spectral radiance of the extended lens after temperature measurement without secondary calibration correction.

[0059] Step S3: Derive the correction formula for temperature measurement without secondary calibration after replacing the extended lens of the infrared temperature measurement device, and use the corrected spectral radiance after the extended lens temperature measurement without secondary calibration as the true spectral radiance of the target.

[0060] Specifically, the correction formula for temperature measurement without secondary calibration after extending the lens is used to correct the difference in temperature measurement under the extended lens. Then, based on the spectral radiance corresponding to the actual measured temperature of the target and the spectral radiance corresponding to the lens temperature, the corrected spectral radiance can be calculated, which is the true spectral radiance of the target. This true spectral radiance of the target is closer to the actual spectral radiance of the measured target object.

[0061] Step S4: Based on the target's true spectral radiance and the spectral radiance calculation formula, the measured temperature of the target object measured by the original lens is obtained by inverse solving and used as the target's true temperature. When the original measured temperature is below 100℃, the difference between the target's true temperature and the original measured temperature is within ±2℃. Or when the original measured temperature is 100℃ or above, the difference between the target's true temperature and the original measured temperature is within ±2%℃. This indicates that the temperature calibration process after replacing the extended lens of the infrared temperature measuring device is complete.

[0062] Specifically, using the corrected spectral radiance, i.e. the target's true spectral radiance and the formula for calculating spectral radiance, the target's true temperature is obtained by inverse solving. Under ideal conditions (i.e., all other influencing factors are taken into account), this target's true temperature should be equal to the original measured temperature. This process verifies the effectiveness of the corrected formula.

[0063] Using the measured temperature of the extended lens and the lens temperature, the corresponding spectral radiance is calculated based on the spectral radiance acquisition module. The calibrated temperature is then obtained using the extended lens temperature measurement correction module (no secondary calibration required) and the spectral radiance inverse temperature calculation module. The lens temperature is obtained from the temperature sensor inside the infrared temperature measurement device. In this embodiment, the lens temperature stabilizes at 33.2℃. Compared with the data in Table 1 of the original lens, the temperature measurement results show a difference within ±2℃ when the blackbody temperature is below 100℃, and within ±2%℃ when the blackbody temperature is 100℃ or above. The accuracy is within the standard range. Specific correction results are shown in Table 3.

[0064] Table 3

[0065] Through the coordination of the above steps, the present invention effectively avoids secondary calibration on the prototype, realizes the convenience of replacing the extended lens of the infrared temperature measurement device, and is also applicable to all infrared temperature measurement devices with extended lenses, thus possessing universality and being widely used in the field of infrared temperature measurement.

[0066] Furthermore, in step S2 above, the formula for calculating the spectral radiance includes:

[0067] Based on Planck's blackbody radiation formula, Equation 1 is used to express the spectral radiance of an absolute blackbody at a fixed wavelength λ at temperature T:

[0068] Where C1 represents Planck's first constant, C2 represents Planck's second constant, T represents the temperature of the blackbody, λ represents the fixed wavelength of the spectral band, M(λ,T) represents the spectral radiance of the blackbody at temperature T at a fixed wavelength λ, and the blackbody represents the calibrated standard source.

[0069] Specifically, the target object in this invention is represented by an absolute blackbody. A blackbody is an idealized object that can completely absorb and radiate electromagnetic waves of all wavelengths at any temperature, and the radiated energy is proportional to the temperature. In infrared thermometry, blackbodies are often used as a standard source for calibration and reference to ensure the accuracy of infrared thermometry devices.

[0070] Furthermore, the formula for calculating spectral radiance also includes:

[0071] Based on Planck's blackbody radiation formula, Formula 2 is used to express the spectral radiation of an absolute blackbody at temperature T within the light wave range [λ1,λ2] that the detector of an infrared thermometer can receive.

[0072] Formula 2 can be expressed in the form of a definite integral:

[0073] Among them, the definite integral band [λ1,λ2] is consistent with the spectral band that the infrared thermometer detector can receive.

[0074] Specifically, by substituting the measured target temperature and the lens temperature into Formula 1 or Formula 2, the spectral radiance corresponding to the measured target temperature and the spectral radiance corresponding to the lens temperature can be obtained, providing a basis for calculating the spectral radiance after the extended lens temperature measurement is corrected without secondary calibration.

[0075] Furthermore, in step S3 above, before deriving the correction formula for eliminating the need for secondary calibration of the infrared temperature measurement device after replacing the extended lens, the following steps are included:

[0076] According to the radiation balance theory, electromagnetic waves incident on any medium will undergo absorption, reflection, and transmission, satisfying Equation 4. Based on Equation 4, when the infrared radiation from a target object enters the lens of an infrared thermometer, a radiation energy conversion will occur, expressed by Equation 3:

[0077] W(T * )=τ lens ·W(T)+(1-τ lens )·W(T lens ) (Formula 3)

[0078] Among them, W(T) * The value () represents the amount of spectral radiation received by the detector focal plane after the target radiation passes through the lens of the infrared thermometer. The temperature measurement result T is obtained by back-calculation based on Formula 2. * W(T) represents the spectral radiance corresponding to the true temperature T of the absolute blackbody target. lens () indicates the lens temperature T lens The corresponding spectral radiance, τ lens It represents the average transmittance of the lens spectrum. The spectral bands are consistent with the spectral bands that the infrared thermometer can receive. The lens temperature represents the lens temperature of either the original lens or the extended lens.

[0079] Specifically, infrared lenses often undergo special coating processes to increase their transmittance in the effective spectral band of the infrared temperature measuring device detector, while greatly reducing their reflectance in the same band. As a result, the reflection effect of the infrared lens is negligible compared to its transmission effect. Furthermore, according to Kirchhoff's thermal radiation theory, the emissivity of any medium is equal to its absorptivity. Therefore, the radiation energy conversion that occurs when the infrared radiation of the target object enters the lens of the infrared temperature measuring device can be described by the above formula 3.

[0080] Furthermore, in step S3 above, before deriving the correction formula for eliminating the need for secondary calibration of the infrared temperature measuring device after replacing the extended lens, the following is also included:

[0081] According to the radiation balance theory, electromagnetic waves will be absorbed, reflected and transmitted when incident on any medium, and satisfy α+ρ+τ=1, where α represents the absorptivity, ρ represents the reflectivity and τ represents the transmittance.

[0082] The infrared temperature measuring device satisfies the radiation energy conversion relationship in Formula 3 before and after replacing the extended lens, and the relationship is expressed by Formula 4:

[0083] Among them, W(T1) * W(T2) represents the amount of radiation received by the original lens detector of the infrared thermometer after passing through the focal plane of the target radiation. * T1 represents the amount of radiation received by the detector's focal plane after the target radiation has passed through the infrared thermometer and the extended lens has been replaced. * This indicates the temperature measurement result of the infrared thermometer when the original lens is installed. T2 * This indicates the temperature measurement result of the infrared thermometer after the extended lens is inserted. (T) lens1 This indicates the temperature of the original lens element, T. lens2 T represents the temperature of the extended lens. lens1 τ represents the average spectral transmittance of the original lens. lens2 This indicates the average transmittance of the extended lens spectral density.

[0084] Specifically, the original lens of the infrared temperature measurement device should undergo a temperature calibration process at the factory, and its temperature measurement result T1 * The actual target temperature should be used. Under the condition that the lens temperature is stable, the curve relationship between the temperature measurement results of the original lens with a spectral average transmittance of τ1 and the extended lens with a spectral average transmittance of τ2 and the target temperature is shown in Figure 2. The slope of the curve is positively correlated with the spectral average transmittance of the lens, and all such curves take the lens temperature as the inversion point.

[0085] Furthermore, in step S3, the correction formula for eliminating the need for secondary calibration of the infrared temperature measurement device after replacing the extended lens is derived, including:

[0086] Based on the fact that the infrared temperature measuring device satisfies the radiation energy conversion relationship of Equation 3 before and after replacing the extended lens, the corrected formula for eliminating the need for secondary calibration after replacing the extended lens is derived from Equation 4 and expressed as Equation 5:

[0087] W(T0)=λ·W(T2 * )+(1-λ)·W(T lens ) (Formula 5)

[0088] Where λ=τ lens1 / τ lens2This indicates the average spectral transmittance of the original lens relative to the extended lens. T2 represents the lens temperature. * This represents the temperature measurement result of the target radiation after replacing the extended lens, i.e. the temperature before correction. W(T0) represents the theoretical spectral radiation that should be incident on the focal plane of the infrared detector after calculation using Formula 5.

[0089] Specifically, before the infrared temperature measuring device reaches thermal equilibrium, its lens temperature is in a drifting state. The above-mentioned energy conversion relationship remains dynamically balanced during the unsteady drift of the lens temperature. Since the unsteady drift of the lens temperature is only related to the coupling effect of the internal mechanism's self-heating and the ambient temperature, it can be considered that the extended lens has undergone the same unsteady drift as the original lens, and has the same initial temperature when powered on and the same steady-state temperature after thermal equilibrium. Therefore, the corrected formula 5 for temperature measurement without secondary calibration after replacing the extended lens can be derived from the above formula 4.

[0090] Furthermore, in step S4 above, the measured temperature of the target object obtained by the original lens is calculated using inverse kinematics and used as the true temperature of the target:

[0091] The corrected spectral radiance W(T0) is calculated based on Formula 5. Substituting the spectral radiance W(T0) into the spectral radiance calculation formula, the measured temperature of the target object by the original lens is obtained by inverse solution and used as the true temperature of the target.

[0092] Further, in step S1, obtaining the relative transmittance of the original lens of the infrared temperature measuring device relative to the extended lens includes:

[0093] The average spectral transmittance of the extended lens and the original lens can be obtained through original factory spectral testing. Based on the average spectral transmittance, the relative transmittance of the original lens relative to the extended lens can be calculated.

[0094] Further, in step S2, calculating the spectral radiance corresponding to the measured target temperature and the lens temperature includes:

[0095] Substitute the measured temperature of the target and the lens temperature into Formula 1 or Formula 2 respectively to calculate the spectral radiance corresponding to the measured temperature of the target and the spectral radiance corresponding to the lens temperature.

[0096] This invention also provides a system for eliminating the need for secondary calibration of an infrared temperature measurement device after replacing the extended lens, the system comprising:

[0097] The transmittance acquisition unit is used to acquire the relative transmittance of the original lens of the infrared temperature measuring device relative to the extended lens, and to acquire the original measured temperature obtained by the original lens and the target measured temperature obtained by the extended lens.

[0098] The radiation calculation unit is used to obtain the spectral radiation calculation formula and calculate the spectral radiation corresponding to the measured temperature of the target and the lens temperature based on the spectral radiation calculation formula.

[0099] The calibration correction unit is used to derive the correction formula for the infrared temperature measuring device to eliminate the need for secondary calibration after replacing the extended lens, and to use the spectral radiance after the temperature measurement of the extended lens is corrected to eliminate the need for secondary calibration as the target true spectral radiance.

[0100] The radiation inverse calculation unit is used to inversely solve for the measured temperature of the target object by the original lens and use it as the true temperature of the target. When the original measured temperature is below 100℃, the difference between the true temperature of the target and the original measured temperature is within ±2℃. Or when the original measured temperature is 100℃ or above, the difference between the true temperature of the target and the original measured temperature is within ±2%℃. This indicates that the temperature calibration process of the infrared temperature measuring device after replacing the extended lens is completed.

[0101] In summary, this invention, through the study of infrared spectral radiation theory, applies the law of conservation of energy and Kirchhoff's law of thermal radiation to specific infrared temperature measurement scenarios. It employs theoretical modeling to establish a theoretical mapping model between the temperature measurement results of the original lens and the relative transmittance, lens temperature, and temperature measurement results of the extended lens. This enables the extended infrared lens to achieve radiation-based temperature measurement on a prototype infrared temperature measurement device of the same model. Compared to the original lens, it achieves a temperature measurement accuracy within ±2℃ at temperatures below 100℃ and within ±2%℃ at temperatures of 100℃ and above. On one hand, this invention establishes a theoretical calibration model based on radiation theory, effectively avoiding secondary calibration on the prototype and facilitating the replacement of the extended lens in the infrared temperature measurement device. On the other hand, this invention is applicable to all infrared temperature measurement devices with extended lenses, possessing universality and wide applicability in the field of infrared temperature measurement.

[0102] It should be understood that although the steps in the flowcharts of the various embodiments of the present invention are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the various embodiments may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least a portion of the sub-steps or stages of other steps.

[0103] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, storage, databases, or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), dual data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), RAMbus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and RAMbus dynamic RAM (RDRAM), etc.

[0104] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0105] The above-described embodiments are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

[0106] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for infrared temperature measurement without secondary calibration after replacing an extended lens of an infrared temperature measurement device, characterized in that, The method includes: Step S1: Obtain the relative transmittance of the original lens of the infrared temperature measuring device relative to the extended lens, and simultaneously obtain the original measured temperature obtained by the original lens and the target measured temperature obtained by the extended lens. Step S2: Obtain the formula for calculating spectral radiance, and calculate the spectral radiance corresponding to the measured temperature of the target and the lens temperature based on the formula. Step S3: Derive the correction formula for the infrared temperature measurement device after replacing the extended lens to eliminate the need for secondary calibration, and use the corrected spectral radiance of the extended lens temperature measurement as the target true spectral radiance. Step S4: Based on the true spectral radiance of the target and the formula for calculating the spectral radiance, the measured temperature of the target object measured by the original lens is obtained by inverse solving and used as the true temperature of the target. When the original measured temperature is below 100℃, the difference between the true temperature of the target and the original measured temperature is within ±2℃. Or when the original measured temperature is 100℃ or above, the difference between the true temperature of the target and the original measured temperature is within ±2%℃. This indicates that the temperature calibration process after replacing the extended lens of the infrared temperature measuring device is completed.

2. The method of claim 1, wherein, In step S2, the formula for calculating spectral radiance includes: Based on Planck's blackbody radiation formula, the spectral radiance of an absolute blackbody at a fixed wavelength λ and temperature T is given by Equation 1: Where C1 represents Planck's first constant, C2 represents Planck's second constant, T represents the temperature of the absolute blackbody, λ represents the fixed wavelength of the spectral band, M(λ,T) represents the spectral radiation of the absolute blackbody at a certain fixed wavelength λ at temperature T, and the absolute blackbody represents a calibrated standard source.

3. The method of claim 2, wherein, The formula for calculating spectral radiance also includes: Based on Planck's blackbody radiation formula, Formula 2 is used to express the spectral radiation of the absolute blackbody at temperature T within the light wave range [λ1,λ2] that the detector of the infrared thermometer can receive. The formula 2 is expressed in the form of definite integral: The definite integral band [λ1, λ2] is consistent with the spectral band that the infrared thermometer detector can receive.

4. The method of claim 3, wherein, In step S3, before deriving the correction formula for the infrared temperature measuring device to eliminate the need for secondary calibration after replacing the extended lens, the following steps are included: When the infrared radiation from the target object enters the lens of the infrared thermometer, a radiation energy conversion occurs, which is represented by Formula 3: W(T * ) = τ lens ·W(T) + (1 - τ lens )·W(T lens ) (Equation 3) Among them, W(T) * The value () represents the amount of spectral radiation received by the detector focal plane after the target radiation passes through the lens of the infrared thermometer. The temperature measurement result T is obtained by back-calculation based on the formula 2. * W(T) represents the spectral radiance corresponding to the true temperature T of the absolute blackbody target. lens () indicates the lens temperature T lens The corresponding spectral radiance, τ lens The average transmittance of the lens spectrum is indicated, and the spectral bands are all consistent with the spectral bands that the infrared temperature measuring device can receive. The lens temperature refers to the lens temperature of either the original lens or the extended lens.

5. The method of claim 4, wherein, In step S3, before deriving the correction formula for the infrared temperature measuring device to eliminate the need for secondary calibration after replacing the extended lens, the following steps are also included: The infrared temperature measuring device satisfies the radiation energy conversion relationship of the formula 3 before and after the replacement of the extension lens, and the relationship is expressed by a formula 4. Among them, W(T1) * W(T2) represents the amount of radiation received by the target radiation through the focal plane of the original lens detector of the infrared thermometer. * T1 represents the amount of radiation received by the detector's focal plane after the target radiation has passed through the infrared thermometer and the extended lens has been replaced. * This indicates the temperature measurement result of the infrared temperature measuring device when it is installed with the original lens, T2. * This indicates the temperature measurement result of the infrared temperature measuring device when it is inserted into the extended lens, T lens1 The temperature of the original lens is represented by T. lens2 τ represents the temperature of the extended lens. lens1 τ represents the average spectral transmittance of the original lens. lens2 This indicates the average transmittance of the extended lens spectral density.

6. The method of claim 5, wherein, In step S3, the correction formula for eliminating the need for secondary calibration of the infrared temperature measuring device after replacing the extended lens is derived, including: The infrared temperature measuring device satisfies the radiation energy conversion relationship of Formula 3 both before and after replacing the extended lens. The corrected formula for eliminating the need for secondary calibration of the infrared temperature measurement device after replacing the extended lens, derived from Formula 4, is expressed in Formula 5: where λ = τ lens1 / τ lens2 represents the spectral average transmittance of the original lens relative to the extended lens, represents the temperature of the lens, T2 * represents the temperature of the target radiation, T0represents the temperature of the target radiation after the lens is replaced, and W(T0) represents the theoretical spectral radiant flux that should be incident on the focal plane of the infrared detector after the formula 5 is calculated.

7. The method of claim 6, wherein, In step S4, the measured temperature of the target object by the original lens is obtained by inverse solving and used as the true temperature of the target: The corrected spectral radiance W(T0) is calculated based on Formula 5. The spectral radiance W(T0) is then substituted into the spectral radiance calculation formula to solve the inverse solution and obtain the actual temperature of the target object measured by the original lens, which is then used as the true temperature of the target.

8. The method of claim 1, wherein, In step S1, obtaining the relative transmittance of the original lens of the infrared temperature measuring device relative to the extended lens includes: The average spectral transmittance of the extended lens and the original lens can be obtained through original factory spectral testing. Based on the average spectral transmittance, the relative transmittance of the original lens relative to the extended lens can be calculated.

9. The method of claim 3, wherein, In step S2, calculating the spectral radiance corresponding to the measured target temperature and the lens temperature includes: Substitute the measured target temperature and the lens temperature into Formula 1 or Formula 2 respectively to calculate the spectral radiance corresponding to the measured target temperature and the spectral radiance corresponding to the lens temperature.

10. An infrared temperature measurement device replacement extended lens temperature measurement secondary calibration-free system, characterized in that, The system includes: The transmittance acquisition unit is used to acquire the relative transmittance of the original lens of the infrared temperature measuring device relative to the extended lens, and to acquire the original measured temperature obtained by the original lens and the target measured temperature obtained by the extended lens. The radiation calculation unit is used to obtain the spectral radiation calculation formula and calculate the spectral radiation corresponding to the measured temperature of the target and the lens temperature based on the spectral radiation calculation formula. The calibration correction unit is used to derive the correction formula for the infrared temperature measuring device to eliminate the need for secondary calibration after replacing the extended lens, and to use the spectral radiance after the temperature measurement of the extended lens is corrected to eliminate the need for secondary calibration as the target true spectral radiance. The radiation inverse calculation unit is used to inversely solve for the measured temperature of the target object by the original lens and use it as the true temperature of the target. When the original measured temperature is below 100℃, the difference between the true temperature of the target and the original measured temperature is within ±2℃. Or when the original measured temperature is 100℃ or above, the difference between the true temperature of the target and the original measured temperature is within ±2%℃. This indicates that the temperature calibration process of the infrared temperature measuring device after replacing the extended lens is completed.

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