A method and system for calibration verification of a near infrared spectrometer

Abstract

The present application discloses a near-infrared spectrometer calibration verification method and a calibration verification system, which uses a micro distillation apparatus and a vibrating liquid density instrument as a special standard device, directly constructs calibration logic for oil distillation and density core indicators, ensures the consistency of standard values and predicted values through the same oil sample, avoids the technical problem that the calibration is qualified but the actual detection is not accurate, makes the calibration result fully meet the scene requirements of oil testing, realizes the quantitative representation of the error range of the calibration result, and more scientifically reflects the actual measurement capability of the instrument compared with the traditional single difference judgment, and provides rigorous technical support for quantity traceability. Moreover, the calibration verification system of the present application supports portable integrated design, does not need to rely on laboratory fixed equipment, can complete calibration on site at the grassroots level, simplifies the operation process, and takes into account the technical rigor and on-site practicality.

Description

Technical Field

[0001] This invention relates to the field of metrology and calibration technology, specifically to a calibration and verification method and system for a near-infrared spectrometer. Background Technology

[0002] Near-infrared spectrometers, as a core module of aviation fuel testing kits, are widely used for on-site prediction of key quality indicators such as fuel distillation range and density, thanks to their rapid and non-destructive testing advantages. Their prediction accuracy directly determines whether fuel meets military equipment standards. However, existing technologies largely rely on general spectrometer procedures, calibrating only general parameters such as wavelength accuracy and baseline stability, without designing specific calibration schemes for fuel-specific indicators like distillation range and density. This leads to the common problem of near-infrared spectrometers exhibiting "general parameters being qualified, but fuel indicator predictions being inaccurate"—for example, even after wavelength calibration is successful, density prediction errors may still exceed ±2 kg / m³, far exceeding the allowable range of ±1.2 kg / m³, thus failing to provide a reliable basis for fuel quality judgment. Summary of the Invention

[0003] This invention provides a calibration and verification method and system for a near-infrared spectrometer to solve the technical problems of poor adaptability to various scenarios and low operational efficiency in existing technologies.

[0004] To achieve the above objectives, the present invention provides the following technical solution: A calibration and verification method for a near-infrared spectrometer, comprising: The same oil sample was measured using a micro-distillation range meter and a vibrating liquid density meter to obtain the standard values ​​of the distillation range and density of the oil sample, respectively. The same oil sample was measured using a calibrated near-infrared spectrometer to obtain the predicted distillation range and density of the oil sample. The predicted distillation range is compared with the standard distillation range value to calculate the distillation range indication error, and the predicted density is compared with the standard density value to calculate the density indication error. Based on the distillation range indication error and the density indication error, determine whether the near-infrared spectrometer is qualified.

[0005] A near-infrared spectrometer calibration and verification system, comprising: The standard device module, including the micro-distillation range meter and the vibrating liquid density meter, is used to measure the same oil sample to provide standard values; The data acquisition and processing module includes the near-infrared spectrometer, used to acquire the standard values ​​of distillation range and density measured by the standard device module; acquire the predicted values ​​of distillation range and density for the same oil sample measured by the near-infrared spectrometer being calibrated; compare the predicted values ​​with the corresponding standard values, and calculate the indication error; The determination module is used to determine whether the near-infrared spectrometer is qualified based on the indication error.

[0006] Beneficial effects This invention discloses a calibration and verification method and system for a near-infrared spectrometer. Using a micro-range distillation apparatus and a vibrating liquid density meter as dedicated standard devices, it directly constructs calibration logic targeting the core indicators of oil distillation range and density. By comparing the standard values ​​with predicted values ​​using the same oil sample, it ensures consistency and avoids the technical problem of calibration being qualified but actual detection being inaccurate. This ensures that the calibration results fully meet the needs of oil analysis scenarios, achieving a quantitative characterization of the calibration result error range. Compared to traditional single-value difference judgments, this method more scientifically reflects the instrument's actual measurement capabilities and provides rigorous technical support for traceability of measurement values. Furthermore, the calibration and verification system of this invention supports a portable integrated design, eliminating the need for fixed laboratory equipment. Calibration can be performed on-site at the grassroots level, simplifying the operation process and balancing technical rigor with practical application. Attached Figure Description

[0007] 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 some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0008] Figure 1 This is a flowchart of the calibration and verification method for a near-infrared spectrometer according to an embodiment of the present invention; Figure 2 This is a flowchart of a calibration and verification method for a near-infrared spectrometer according to other embodiments of the present invention; Figure 3 This is a flowchart of a calibration and verification method for a near-infrared spectrometer according to another embodiment of the present invention; Figure 4 This is a block diagram of the calibration and verification system for a near-infrared spectrometer according to an embodiment of the present invention. Detailed Implementation

[0009] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0010] like Figure 1 As shown, this application proposes a calibration and verification method for a near-infrared spectrometer, comprising: S100: Use a micro-distillation range meter and a vibrating liquid density meter to measure the same oil sample and obtain the standard value of the distillation range and the standard value of the density of the oil sample, respectively. S200: Using a calibrated near-infrared spectrometer, the same oil sample is measured to obtain the predicted distillation range and density of the oil sample. S300: Compare the predicted distillation range value with the standard distillation range value to calculate the distillation range indication error, and compare the predicted density value with the standard density value to calculate the density indication error; S400: Determine whether the near-infrared spectrometer is qualified based on the distillation range indication error and density indication error.

[0011] Among them, a micro-distillation range meter refers to a specialized device used to accurately determine the distillation range temperature of an oil sample. Specifically, an automatic micro-distillation range meter conforming to ASTM D86 standards can be used. It obtains the standard distillation range value by measuring the temperature corresponding to different recoverable volumes during the evaporation process of the oil sample. A vibratory liquid density meter is an instrument that measures liquid density based on the principle of vibration frequency change. Specifically, a U-tube vibratory density meter can be used. It calculates the standard density value by measuring the vibration period of the oil sample at a constant temperature. A single oil sample refers to a sample packaged from the same batch of oil that has not undergone any changes in physical properties. The original oil sample is divided into multiple parallel subsamples using a sample divider to ensure the consistency of data sources between the standard value and the predicted value. The distillation range indication error refers to the absolute difference between the near-infrared spectral predicted value and the distillation range standard value. Calculating this difference quantifies the instrument's prediction deviation of the distillation range temperature. The density indication error refers to the absolute difference between the near-infrared spectral predicted value and the density standard value. Calculating this difference quantifies the instrument's prediction deviation of the density index.

[0012] In practical applications, a micro-range measuring instrument and a vibrating liquid density meter perform high-precision measurements of the distillation range and density of oil samples, generating traceable standard data. A near-infrared spectrometer, under calibration, scans the same oil sample and calculates predicted distillation range and density values ​​using a built-in model. During the comparison between the predicted and standard values, the distillation range indication error reflects the instrument's accuracy in predicting the oil's evaporation characteristics, while the density indication error reflects the instrument's accuracy in predicting the oil's mass-volume relationship. This comprehensive assessment of both error indicators ensures that the calibration results are directly linked to the core requirements of oil testing, avoiding the problem of general parameter calibration being disconnected from actual oil testing objectives.

[0013] In another embodiment, such as Figure 2 As shown, step S100, which involves measuring the same oil sample using a micro-distillation range meter and a vibrating liquid density meter, includes: S101: Divide the oil sample into at least two parallel subsamples; S102: Use the micro-distillation range meter to measure the distillation range value of each of the parallel samples, and calculate the average value as the standard value of the distillation range; S103: Measure the density value of each of the parallel samples using the vibratory liquid density meter, and calculate the average value as the density standard value.

[0014] Parallel subsamples refer to the preparation of multiple samples with identical physicochemical properties from the same oil sample through physical division. This can be achieved using a separatory funnel or an automatic sampler, to eliminate the influence of local inhomogeneities in the oil sample on the measurement results. A micro-range analyzer is an instrument capable of determining distillation range parameters with a small amount of oil sample. This can be achieved using an automatic distillation range analyzer with a micro-flow control module, to ensure measurement accuracy while reducing sample consumption. A vibratory liquid density meter is a device that determines liquid density based on changes in vibration frequency. This can be achieved using a U-tube vibratory density meter, to capture minute density differences through high-frequency vibration signals. Mean calculation refers to the arithmetic averaging of multiple sets of parallel measurement data. This can be achieved using a mean algorithm built into the data acquisition system, to suppress the influence of random errors in a single measurement on the standard value.

[0015] In practical applications, after an oil sample is uniformly divided into two or more parallel subsamples, each subsample requires independent measurement of its distillation range and density. A micro-distillation range analyzer measures the distillation range parameters of each subsample throughout the entire process, recording complete data including the initial boiling point, each recovery temperature point, and the final boiling point. A vibrating liquid density analyzer measures the density of each subsample under isothermal conditions, ensuring that the impact of temperature fluctuations on the density value is effectively controlled. The measurement data of all subsamples are synchronously transmitted to the data processing system. The system automatically removes outliers and performs an arithmetic mean calculation on the valid data. The final output standard values ​​for distillation range and density contain the statistical characteristics of multiple independent measurement results.

[0016] In other embodiments, step S400 is followed by: S500: Perform uncertainty analysis to calculate the combined standard uncertainty of distillation range error and / or the combined standard uncertainty of density error; S600: Calculate the expanded uncertainty based on the combined standard uncertainty to quantify the reliability of the calibration results.

[0017] The combined standard uncertainty refers to the comprehensive uncertainty obtained by combining multiple uncertainty components using statistical methods. Specifically, it can be achieved using the variance synthesis method. For example, a formula can be used to calculate the sum of squares and root of the standard uncertainty component of the micro-distillation range instrument and the repeatability component of the near-infrared spectrometer measurement. This calculation method accurately reflects the superposition effect of different error sources. Expanded uncertainty refers to the index of expanding the combined standard uncertainty by a factor to obtain a higher confidence level. Specifically, it can be achieved by multiplying the combined standard uncertainty by the coverage factor. For example, choosing a coverage factor of 2 corresponds to a 95% confidence probability. This expansion process can quantify the potential error range of the calibration results.

[0018] In practical applications, after determining the indication error, a systematic analysis of the sources of errors in distillation range and density measurement is first conducted. For distillation range error, the variance of the standard uncertainty component of the micro-distillation range meter and the repeatability component of the near-infrared spectrometer is combined to obtain the combined standard uncertainty characterizing the overall fluctuation range. For density error, the same method is used to combine the standard uncertainty component of the vibrating liquid density meter with the repeatability component of the spectrometer density measurement. Subsequently, the combined standard uncertainty is multiplied by a coverage factor to obtain the expanded uncertainty. For example, a coverage factor of 2 is used to expand the combined standard uncertainty to a 95% confidence level, thus forming a quantitative index covering the potential error range. This process uses mathematical modeling to comprehensively evaluate both inherent instrument errors and random measurement errors, establishing a quantitative boundary for error fluctuations.

[0019] In another embodiment, in step S500, the combined standard uncertainty of the distillation range error is determined by the formula... Calculated, where The uncertainty component introduced by the micro-distillation rangefinder. The uncertainty component introduced for the repeatability of the near-infrared spectrometer's measurement of the distillation range; the combined standard uncertainty of the density error is expressed by the formula Calculated, where The uncertainty component introduced for the vibratory liquid density meter. The uncertainty component introduced to the repeatability of density measurements by the near-infrared spectrometer.

[0020] The uncertainty component introduced by the micro-distillation range meter refers to the systematic error caused by the inherent accuracy limitations of the instrument when measuring the distillation range of an oil sample. Specifically, it can be obtained by dividing the expanded uncertainty provided in the calibration certificate by the coverage factor, and is used to characterize the reliability of the standard value. The uncertainty component introduced by the repeatability of distillation range measurement by the near-infrared spectrometer refers to the dispersion of multiple spectral measurements of the same oil sample. Specifically, the standard deviation can be calculated using the Bessel formula, and is used to quantify the measurement variability of the spectrometer itself. The uncertainty component introduced by the vibrating liquid density meter refers to the traceability error of the density standard value, which can be determined through inter-laboratory comparisons or verification with standard substances, and is used to establish the benchmark accuracy of density measurement. The uncertainty component introduced by the repeatability of density measurement by the near-infrared spectrometer refers to the experimental standard deviation of the density prediction value, which can be calculated by repeatedly measuring the density prediction value of the same oil sample ten times, and is used to reflect the stability of the spectrometer's density model.

[0021] In practical applications, to synthesize distillation range error, the same oil sample is first measured multiple times in parallel using a micro-distillation range meter, and its standard deviation is calculated as... Simultaneously, the same oil sample was scanned ten times using a near-infrared spectroscopy instrument, and the standard deviation of the predicted values ​​was calculated as... The combined standard uncertainty u∆T is obtained by squareding both values, summing them, and taking the square root. For the density error, the same method is used to obtain the values ​​from the vibrating liquid density meter. and near-infrared spectrometer The orthogonal synthesis formula is used to calculate u∆ρ. This process uses statistical methods to quantify and superimpose the contributions of the two independent error sources, avoiding the risk of misjudgment caused by a single error criterion.

[0022] In another embodiment, in step S300, the standard value of the distillation range includes at least one of the following: 10% recovery temperature T10, 50% recovery temperature T50, 90% recovery temperature T90, and final boiling point FBP.

[0023] The 10% recovery temperature (T10) refers to the temperature at which 10% of the light components of the oil sample evaporate during distillation. This is achieved by measuring the corresponding volume fraction temperature value on the distillation curve using a micro-range distillation apparatus, and is used to characterize the evaporation characteristics of the light components. The 50% recovery temperature (T50) refers to the temperature at which 50% of the medium components of the oil sample evaporate. This is achieved by recording the temperature value at the midpoint of the distillation curve using a micro-range distillation apparatus, and is used to reflect the mid-stage evaporation performance of the oil sample. The 90% recovery temperature (T90) refers to the temperature at which 90% of the heavy components of the oil sample evaporate. This is achieved by capturing the temperature inflection point at the end of the distillation curve using a micro-range distillation apparatus, and is used to characterize the endpoint of heavy component evaporation. The final boiling point (FBP) refers to the highest temperature at which the oil sample completely stops evaporating. This is achieved by detecting the stable point where the temperature no longer rises during distillation using a micro-range distillation apparatus, and is used to represent the limiting temperature of complete evaporation of the oil sample.

[0024] In practical applications, by selecting characteristic temperature points at different stages of oil sample evaporation as calibration benchmarks, key quality indicators for detecting oil distillation range characteristics are covered. For example, using T10 as the calibration point verifies the near-infrared spectrometer's predictive ability for the evaporation characteristics of light components; using T90 as the calibration point verifies its accuracy in detecting the evaporation endpoint of heavy components. Since different temperature points correspond to changes in the different physicochemical properties of oil samples, selecting at least one key temperature point for specific calibration allows for targeted evaluation of the spectrometer's predictive bias at specific distillation stages, avoiding incomplete calibration coverage issues caused by relying solely on a single temperature point or general parameters.

[0025] In other embodiments, step S400, determining whether the near-infrared spectrometer is qualified, includes: If the distillation range indication error is within the first preset error range and the density indication error is within the second preset error range, then the near-infrared spectrometer is deemed qualified.

[0026] The first preset error range refers to the allowable deviation between the predicted value and the standard value of the oil sample's distillation temperature. Specifically, this can be achieved using the maximum allowable error value for distillation temperature specified in aviation fuel testing standards, such as controlling the temperature deviation of T10, T50, T90, or FBP within ±3℃. This range ensures that the fuel's volatility meets combustion performance requirements by constraining the prediction accuracy of key recovery temperature points at each distillation point. The second preset error range refers to the allowable deviation between the predicted value and the standard value of the oil sample's density. Specifically, this can be achieved using the maximum allowable error value for density specified in military fuel density testing standards, such as controlling the density deviation within ±1.2 kg / m³. This range ensures the accuracy of the fuel's energy density index by limiting the difference threshold between the predicted density value and the measured value from the vibratory density meter.

[0027] In practical applications, when a calibrated near-infrared spectrometer measures the same oil sample, its output predicted distillation range value must be compared item by item with the standard distillation range value measured by a micro-range analyzer. If the prediction error for all distillation range temperature points does not exceed the first preset error range, and the density prediction error meets the second preset error range, then the equipment is deemed calibrated successfully. This dual-judgment mechanism avoids situations where one parameter is acceptable while the other is out of tolerance by independently constraining the upper limit of errors for both distillation range and density. For example, if the spectrometer only meets the density error range but the distillation range T50 error exceeds ±3℃, it is still deemed unacceptable, thus ensuring the comprehensive reliability of the predicted results for key oil quality indicators.

[0028] like Figure 3 As shown, this application also discloses a near-infrared spectrometer calibration and verification system for implementing the near-infrared spectrometer calibration and verification method of the embodiments of the present invention, including: The standard device module 700, including the micro-distillation range meter 701 and the vibrating liquid density meter 702, is used to measure the same oil sample to provide standard values; The data acquisition and processing module 800 includes the near-infrared spectrometer 801, which is used to acquire the standard value of distillation range and the standard value of density measured by the standard device module 700; acquire the predicted value of distillation range and the predicted value of density for the same oil sample measured by the near-infrared spectrometer being calibrated; compare the predicted value with the corresponding standard value, and calculate the indication error; The judgment module 900 is used to determine whether the near-infrared spectrometer is qualified based on the indication error.

[0029] The standard device module 700 refers to the hardware combination integrating a micro-distillation range meter 701 and a vibrating liquid density meter 702. Specifically, it can be implemented using an ASTM D7345 standard micro-distillation range meter and an ISO 12185 standard vibrating density meter. This standard device module 700 directly generates benchmark data for the distillation range and density of oil samples through physical measurement, providing a traceable metrological standard for calibration. The data acquisition and processing module 800 refers to an embedded system with a multi-channel data interface, specifically implemented using an ARM architecture processor and Modbus communication protocol. This data acquisition and processing module 800 establishes an error calculation model by synchronously acquiring standard and predicted values, ensuring that the calibration process focuses on the actual application indicators of the oil. The judgment module 900 refers to a logical judgment unit with a preset error threshold, specifically implemented using a comparator circuit or software conditional judgment statements. This judgment module 900 forms a closed-loop calibration verification mechanism by setting pass / fail judgment conditions.

[0030] Specifically, during the operation of the near-infrared spectrometer calibration and verification system of this invention, the micro-distillation range meter 701 of the standard device module 700 accurately determines the distillation temperature of the oil sample, and the vibrating liquid density meter 702 simultaneously measures the density of the oil sample, generating a standard value with metrological traceability. The near-infrared spectrometer 801 of the data acquisition and processing module 800 performs spectral scanning on the same oil sample and outputs predicted values ​​of distillation range and density through a built-in model. The data acquisition and processing module 800 inputs the two sets of data into the error calculation unit to calculate the distillation range indication error and density indication error, respectively. The judgment module 900 compares the error data with preset thresholds. When the distillation range error does not exceed ±3℃ and the density error does not exceed ±1.2kg / m³, a calibration qualified signal is output. The entire process achieves accurate calibration of oil-specific indicators through the synergy of hardware measurement and software algorithms.

[0031] In another embodiment, the data acquisition and processing module 800 is also used to perform uncertainty analysis and calculate the combined standard uncertainty and expanded uncertainty of the calibration results.

[0032] The combined standard uncertainty refers to the composite uncertainty calculated by integrating the uncertainty components introduced by the standard devices such as the micro-distillation rangefinder 701 and the vibrating liquid density meter 702 with the measurement repeatability error of the near-infrared spectrometer 801. Specifically, it can be achieved by taking the square root of the sum of squares of each independent error source using the variance synthesis method, which is used to systematically characterize the cumulative effect of all error sources during the calibration process. The expanded uncertainty refers to the range obtained by multiplying the combined standard uncertainty by the coverage factor. Specifically, it can be calculated using a coverage factor of k=2 with a confidence probability of 95%, used to quantify the reliability boundary of the calibration results at a specific confidence level.

[0033] In practical applications, the data acquisition and processing module 800 collects repeatability data of the standard value of the oil sample distillation range measured by the micro-distillation range meter 701, and calculates its standard deviation as... Simultaneously, multiple distillation range predictions for the same oil sample were collected using a near-infrared spectrometer 801, and their standard deviations were calculated as... Then through the formula The combined standard uncertainty of the distillation range error is obtained. The density error is calculated using the same method. Furthermore, the combined standard uncertainty is multiplied by the coverage factor k=2 to obtain the expanded uncertainty U=2u∆T or U=2u∆ρ, and finally the reliability range of the calibration result is output in the form of "indication error ±U".

[0034] Compared to existing technologies, traditional calibration methods judge equipment qualification solely by comparing the indicated error with a preset threshold, without considering the impact of the standard device's own errors and measurement repeatability on the results. This scheme, through dual uncertainty analysis, not only quantifies the fluctuation range of calibration results but also reveals the error contribution of each step through an error propagation model, providing data support for optimizing the measurement process.

[0035] In another embodiment, the micro-distillation range meter 701 and the vibrating liquid density meter 702 are integrated into a portable case.

[0036] The portable enclosure refers to an integrated equipment shell that is both protective and easy to carry. Specifically, it can be achieved using a combination of an aluminum alloy frame and a shock-absorbing filling layer. The interior of the enclosure includes instrument mounting slots and shock-absorbing pads to maintain the relative stability of the two instruments during transport. Integration refers to the physical spatial consolidation of two originally independent standard measuring devices. This can be achieved by sharing a power module and centrally arranging data interfaces, allowing the heating unit of the micro-distillation range meter and the vibration sensor of the density meter to form independent working areas within the enclosure that do not interfere with each other.

[0037] In practical applications, during on-site oil testing, operators can simultaneously access both standard instruments simply by opening the enclosure. When the micro-distillation range meter 701 heats the oil sample in stages, its vapor conduit connects to the receiver via an internal heat-insulating channel within the enclosure, preventing heat conduction from affecting the temperature-sensitive element of the density meter. The U-tube sensor of the vibratory liquid density meter 702 maintains its operating temperature through a constant-temperature protective layer on the side wall of the enclosure, and its measurement data is transmitted to the processing module via an integrated data interface. With the enclosure closed, the core components of both instruments are protected from dust and moisture, and the multi-point buffer structure inside the enclosure absorbs external vibration energy during transportation.

[0038] In some embodiments, the portable case may be equipped with a foldable handle and wheels on the top, and a removable battery compartment inside, such as a lithium battery pack, to provide power for more than 6 hours of continuous operation for both instruments. Temperature and humidity sensors may be installed on the side walls of the case, automatically activating the built-in thermoelectric cooler to regulate the microenvironment inside the case when the ambient temperature exceeds a set threshold.

[0039] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0040] The above are merely preferred embodiments of the present invention and do not limit the scope of the patent. Any equivalent structural or procedural transformations made based on the description and drawings of the present invention, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of the present invention.

Claims

1. A calibration and verification method for a near-infrared spectrometer, characterized in that, include: The same oil sample was measured using a micro-distillation range meter and a vibrating liquid density meter to obtain the standard values ​​of the distillation range and density of the oil sample, respectively. The same oil sample was measured using a calibrated near-infrared spectrometer to obtain the predicted distillation range and density of the oil sample. The predicted distillation range is compared with the standard distillation range value to calculate the distillation range indication error, and the predicted density is compared with the standard density value to calculate the density indication error. Based on the distillation range indication error and the density indication error, determine whether the near-infrared spectrometer is qualified.

2. The calibration and verification method for a near-infrared spectrometer according to claim 1, characterized in that, The measurement of the same oil sample using a micro-distillation range meter and a vibrating liquid density meter includes: The oil sample is divided into at least two parallel subsamples; The distillation range of each of the parallel samples was measured using the micro-distillation range meter, and the average value was calculated as the standard value of the distillation range. The density value of each of the parallel samples was measured using the vibratory liquid density meter, and the mean value was calculated as the density standard value.

3. The calibration and verification method for a near-infrared spectrometer according to claim 1 or 2, characterized in that, After determining whether the near-infrared spectrometer is qualified based on the distillation range indication error and the density indication error, the method further includes: Perform uncertainty analysis to calculate the combined standard uncertainty of the distillation range error and / or the combined standard uncertainty of the density error; The expanded uncertainty is calculated based on the combined standard uncertainty to quantify the reliability of the calibration results.

4. The calibration and verification method for a near-infrared spectrometer according to claim 3, characterized in that, The combined standard uncertainty of the distillation range error is expressed by the formula... Calculated, where The uncertainty component introduced by the micro-distillation rangefinder. The uncertainty component introduced for the repeatability of the near-infrared spectrometer's measurement of the distillation range; the combined standard uncertainty of the density error is expressed by the formula Calculated, where The uncertainty component introduced for the vibratory liquid density meter. The uncertainty component introduced to the repeatability of density measurements by the near-infrared spectrometer.

5. The calibration and verification method for a near-infrared spectrometer according to claim 1, characterized in that, The standard distillation range values ​​include at least one of the following: 10% recovery temperature T10, 50% recovery temperature T50, 90% recovery temperature T90, and final boiling point FBP.

6. The calibration and verification method for a near-infrared spectrometer according to claim 1, characterized in that, The determination of whether the near-infrared spectrometer is qualified includes: If the distillation range indication error is within the first preset error range and the density indication error is within the second preset error range, then the near-infrared spectrometer is deemed qualified.

7. A near-infrared spectrometer calibration and verification system for implementing the method as described in any one of claims 1 to 6, characterized in that, include: The standard device module, including the micro-distillation range meter and the vibrating liquid density meter, is used to measure the same oil sample to provide standard values; The data acquisition and processing module includes the near-infrared spectrometer, used to acquire the standard values ​​of distillation range and density measured by the standard device module; acquire the predicted values ​​of distillation range and density for the same oil sample measured by the near-infrared spectrometer being calibrated; compare the predicted values ​​with the corresponding standard values, and calculate the indication error; The determination module is used to determine whether the near-infrared spectrometer is qualified based on the indication error.

8. The calibration and verification system for a near-infrared spectrometer according to claim 7, characterized in that, The data acquisition and processing module is also used to perform uncertainty analysis and calculate the combined standard uncertainty and expanded uncertainty of the calibration results.

9. The calibration and verification system for a near-infrared spectrometer according to claim 7 or 8, characterized in that, The micro-distillation range meter and the vibratory liquid density meter are integrated into a portable case.

Images