WO2017151066A1

WO2017151066A1 - System and method for quality determination of cup lump by near infrared spectroscopy

Info

Publication number: WO2017151066A1
Application number: PCT/TH2016/000016
Authority: WO
Inventors: Ronnarit RITTIRON
Original assignee: Premier System Engineering Co Ltd
Current assignee: Premier System Engineering Co Ltd
Priority date: 2016-03-01
Filing date: 2016-03-01
Publication date: 2017-09-08
Anticipated expiration: 2018-09-01

Abstract

A system and method for quality measurement of cup lump using Near Infrared (NIR) Spectroscopy are disclosed. The system comprises a scanning head (104 )mounted close to a sample of cup lump (102), a scanning head (104) comprising a light source (116), and a Near Infrared spectrophotometer (106), which includes types of dispersives (e.g. grating monochromators), either interferometric or non-thermal，which can generate light within a specific wavelength (e.g. light emitting diodes, laser diodes and lasers) as well as NIR hyperspectral imaging for resolving the reflected light and transmitting it into light of a discrete wavelength; a database containing calibration equations constructed from the relationships between absorbance and qualities of cup lump; control equipment and data processing may be either computer or microcontrollers or other devices performing in the same manner. The control equipment and data processing are used to control system and measure cup lump qualities by application of calibration equations. The invention also comprises a method for online and offline measurement of qualities of cup lump using NIR spectroscopy and a network system, as mentioned above. The system and method are particularly suited for measurement-interested qualities of cup lump.

Description

TITLE OF THE INVENTION

SYSTEM AND METHOD FOR QUALITY DETERMINATION OF CUP LUMP BY NEAR INFRARED SPECTROSCOPY

TECHNICAL FIELD

[0001] The invention relates to a system and a method for determining quality of cup lump, and more particularly, it relates to determination of quality of cup lump by using near infrared spectroscopy.

CITATION LIST

PATENT LITERATURE

PTL 1 U.S. Pat. No. 7,907,273 B2

PTL 2 U.S. Pat. No. 5,842,150 A

PTL 3 U.S. Pat. No. 7,067,811 B2

PTL 4 U.S. Pat. No. 6,630,672 Bl

BACKGROUND OF THE INVENTION

[0002] Para rubber is an economic crop for Thailand, especially in the southern, eastern and northeastern parts. This is due to the fact that Para rubber is used as a raw material for processing in several industries, such as rubber threads, tires, gloves, and even the medical supply industry. For commercial trade, Para rubber is available in several types, such as concentrated latex, standard Thai rubber (STR), rubber smoked sheet, raw rubber sheet, crepe rubber, etc. Furthermore, cup lump is one type of rubber that agriculturists in northeastern Thailand prefer to produce because of the lower cost, consumption of water, and labor costs, as well as for quicker sales than rubber sheet. In addition, cup lump can be used as a raw material for STR production. Cup lump production starts from tapping a rubber tree, then the latex flows into a cup and coagulated latex by adding an acid solution. Cup lump obtained from this process is white in color, but if it is left longer, the moisture content decreases and the color will be darker. The price of cup lump in commercial trade changes in direct relation to the dry rubber content (DRC) and reverse variation to moisture content, meaning that in cup lump with high moisture content, the DRC is low, and the purchase price is also low. Moreover, the adulteration of vulcanized rubber in cup lump is also an important parameter for trading, because it has an effect on the quality of either cup lump or STR. [0003] The quality of cup lump is determined in a laboratory. The DRC and moisture content are analyzed by drying cup lump in a hot air oven, which is time consuming. Meanwhile, the adulteration of rock, gravel, sand, earth and bark in cup lump is determined by observation with the naked eye by skilled analysts and by using a chemical solution for adulteration of the vulcanized rubber. This traditional method is time, chemical and energy consuming, and also requires skilled analysts.

[0004] NIR spectroscopy is an interesting and attractive method that is rapid, accurate and reliable. Theoretically, NIR measures the absorbance of constituents-related molecules at specific wavelengths in the NIR region. Therefore, absorbance looks like a fingerprint of the sample. From that reason, NIR is applied to use in many agro-industries, such as measuring starch gelatinization in a feed production system (U.S. Pat. No. 7,907,273 B2) and the determination of quality parameters in pulp and paper and/or the organic content in effluents from pulp and paper production (U.S. Pat. No. 5,842,150 A). Furthermore, there are many applications that use NIR to analyze the constituent of a sample in a chemical process, such as the analysis of bitumen and solvent-diluted bitumen from froth treatment during oil sands processing (U.S. Pat. No. 7,067,811 B2). NIR is also used in agriculture production, such as determination of the parameter of interest in sugar cane, including offline and online systems (U.S. Pat. No. 6,630,672 Bl).

[0005] It is apparent now that numerous innovations for determining quality of cup lump and use of NIR spectroscopy have been developed in the prior art that are adequate for various purposes. Furthermore, even though these innovations may be suitable for the specific purposes to which they address, accordingly, they would not be suitable for the purposes of the present invention as heretofore described. Thus a system and method for offline or online quality determination of cup lump using NIR spectroscopy is needed. BRIEF SUMMARY OF EMBODIMENTS OF THE INVENTION

[0006] It is an object of the present invention to provide a system and a method for quality measurement of cup lump using NIR spectroscopy.

[0007] According to first embodiment of the invention is to provide a system for the measurement of the quality parameters of cup lump. The system comprises a scanning head, an NIR spectrophotometer, a database and a control device. Wherein the scanning head comprises a light source, which generates light in the NIR wavelength region, and a detector, which is used to collect, reflected or transmitted light from cup lump. The NIR spectrophotometer includes the type of dispersive (e.g. grating monochromators), whether interferometric or nonthermal, which can generate light within a specific wavelength (e.g. light emitting diodes, laser diodes and lasers) resolving the reflected light and transmitting it into light of a discrete wavelength. NIR hyperspectral imaging, which combines conventional digital camera and spectrograph in a single system, is also included. The position of the NIR spectrophotometer mounting depends on each system. The NIR spectrophotometer and light source are mounted on the same side for a reflection system (FIG. 1) and on opposite sides for a transmission system (FIG. 2). The database comprises calibration equations, which are constructed from the relation between the absorbance of the sample in each wavelength and quality parameters of interest, whereas the calibration model is constructed from the relation between the absorbance of the sample in each wavelength and group of cup lump quality. The control device and data processing device may be a computer, microcontroller or other device performing in the same manner. This part uses a control system and analyzes cup lump quality with the aid of calibration equations or a calibration model database based on the NIR absorbance (spectra) of the cup lump.

[0008] According to second embodiment of the invention is to provide , a method for the development of a calibration equation database. The method comprises the steps of, obtaining the NIR absorbance, also known as NIR spectra, of cup lump, the sample of which shall be truly representative of the cup lump population that is expected to be found in the future, obtaining laboratory testing of the cup lump qualities, such as the dry rubber content (DRC), moisture content, and adulterated cup lump. These qualities can be analyzed by a standard analytical method or another reliable method that is accepted by industries. The calibration equation or calibration model is developed by a software program using regression; either linear regression, such as Multiple Linear Regression (MLR) or Partial Least Squares (PLS) regression, or non-linear regression, such as Artificial Neural Network (ANN) etc. Samples for database construction are separated into two sets. The calibration set is used to develop the calibration equation or calibration model and the validation set is used to validate the accuracy and precision of the developed calibration equation or calibration model. Conducting statistical testing for the measurement of accuracy and precision of constructed database, standard error of prediction (SEP), bias and slope obtained from the validation set are tested as follows: ISO 12099: 2010, which is a guideline for the application of NIR spectrometry for constituent measurement of the sample. [0009] According to third embodiment of the invention is to provide a method for the measurement of quality parameters of cup lump using the stored database. The database is validated statistically, given the above, and is suitable to be used industrially. The method comprises obtaining NIR absorbance of cup lump, which is measured by an NIR spectrophotometer, then applying appropriate calibration equation or calibration model to the NIR spectrum of cup lump to analyze the quality parameters of interest. Further, the analyzed results are considered reliable when the spectrum conforms to the set of spectra used to derive the calibration equation, wherein the spectrum obtained is useable for as many parameters as calibrations are available. [0010] The system according to the second and third embodiments of the invention can be incorporated into a network. In such a network, a centralized database provides reference calibration equations or models to other processing streams in the network, provided that NIR spectrophotometers are standardized against the NIR spectrophotometers on which the calibration equations were developed, the latter can be used as a master instrument within the network. A network of systems according to the invention is particularly advantageous in measuring the parameter of interest in cup lump processing. Cup lump quality measurement in the purchasing process may be part of the network system. The network is convenient for industrial operations, because the data in the master instrument can be exchanged and accessed from all slave instruments. [0011] It is another object of the present invention to provide a system for the measurement of the quality parameters of cup lump, wherein the system comprises a scanning head, an NIR spectrophotometer, a database and a control device.

[0012] It is a further object of the present invention to provide a method for the development of a calibration equation database, wherein the calibration equations are constructed from the relation between the absorbance of the sample in each wavelength and quality parameters of interest. The calibration equation or calibration model is developed by a software program using regression; either linear regression, such as Multiple Linear Regression (MLR) or Partial Least Squares (PLS) regression, or non-linear regression, such as Artificial Neural Network (ANN) etc. The calibration model is constructed from the relation between the absorbance of the sample in each wavelength and group of cup lump quality. Further the calibration set is used to develop the calibration equation or calibration model and the validation set is used to validate the accuracy and precision of the developed calibration equation or calibration model. [0013] It is another object of the present invention to provide a method for the measurement of quality parameters of cup lump using the stored database, wherein the method comprises obtaining NIR absorbance of cup lump, which is measured by an NIR spectrophotometer, then applying appropriate calibration equation or calibration model to the NIR spectrum of cup lump so as to analyze the quality parameters of interest.

[0014] It is another object of the present invention to provide a system measuring the parameter of interest in cup lump by developing a calibration equation database and measurement of quality parameters of cup lump using the stored database can be incorporated into a network, wherein a centralized database provides reference calibration equations or models to other processing streams in the network.

[0015] It is another object of the present invention to provide a method of offline and online measurement of a parameter in cup lump, wherein spectrum used is a single spectrum or the average of the plurality of the obtained spectra which is obtained from the reflectance or transmittance measurement. The spectrum is measured over or partially the range of 700 to 2,500 nm.

[0016] It is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings, since the invention is capable of other embodiments, and of being practiced or carried out in various ways within the scope of the claims. Also, it is to be understood that the phraseology and terminology employed herein is for the purpose of description and not of limitation.

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The invention will now be described, by way of example, with reference to the accompanying drawings, in which:

[0018] FIG. 1 illustrates a schematic representation of a reflection system of the invention; and [0019] FIG. 2 illustrates a schematic representation of a transmission system of the invention.

[0020] Like reference numerals refer to like parts throughout the various views of the drawings. DETAILED DESCRIPTION OF THE EMBODIMENTS OF THE INVENTION

[0021] The following detailed description is merely exemplary in nature and is not intended to limit the described embodiments or the application and uses of the described embodiments. As used herein, the word "exemplary" or "illustrative" means "serving as an example, instance, or illustration." Any implementation described herein as "exemplary" or "illustrative" is not necessarily to be constructed as preferred or advantageous over other implementations. All of the implementations described below are exemplary implementations provided to enable persons skilled in the art to make or use the embodiments of the disclosure and are not intended to limit the scope of the disclosure, which is defined by the claims. For purposes of description herein, the terms "upper," "lower," "left," "rear," "right," "front," "vertical," "horizontal," and derivatives thereof shall relate to the invention as oriented in FIG. 1 and FIG. 2. Furthermore, there is no intention to be bound by any expressed or implied theory presented in the preceding technical field, background, brief summary or the following detailed description. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification, are simply exemplary embodiments of the inventive concepts defined in the appended claims. Specific dimensions and other physical characteristics relating to the embodiments disclosed herein are therefore not to be considered as limiting, unless the claims expressly state otherwise.

[0022] A method and a system 100 for quality measurement of cup lump sample 102 using NIR spectroscopy is described in FIG. 1 and FIG. 2. The system 100 comprises a scanning head 104, an NIR spectrophotometer 106, a database 108 and a control device 110. The scanning head of the NIR spectrophotometer in the reflection and transmission system is mounted adjacent to the sample as shown in Fig. 1 and Fig. 2, respectively.

[0023] As shown in FIG. 1, the scanning head 104 of the NIR spectrophotometer 106 is mounted adjacent to the cup lump sample 102 to receive the reflected lights 112 from the sample 102 after part of the light 114 in the NIR wavelength region from the light source 116 is being reflected from the cup lum 102. A detector 111, which is used to collect, reflected light 112 from cup lump 102. An average spectrum is produced for each sample scan. The cup lump qualities, such as dry rubber content (%), moisture content (%) and adulterated cup lump, are determined by the standard analytical method which is actually used in the factory. A calibration equation is developed and stored in a database 108, such as the equation for the determination of dry rubber content (DRC), equation for the determination of moisture content, and model for classification of adulterated cup lump 102. A database 108 is developed from the relation between the NIR spectra obtained by the spectrophotometer 106 and the quality parameters obtained from the standard method by using a control device and data processing unit 110 such as a CPU, a computer or a microcontroller, with the aid of chemometrics. The near infrared spectrophotometer 106 further includes types of dispersives (e.g. grating monochromators), interferometric or non-thermal) which, generates light within a specific wavelength (e.g. light emitting diodes, laser diodes and lasers) for resolving the reflected 112 or transmitted light 118 into the light of a discrete wavelength. The processor 110, such as the computer, the microcontroller or the other similar device measures the parameter by application of the calibration equation or calibration model to the obtained spectrum for a sample 102. The calibration equation database 108 created for each parameter must collect characteristic features of the spectra associated with the parameter of interest. After that, this database will be stored in order to be further utilized for routine analysis.

[0024] As shown in FIG. 2, the scanning head 104 of the NIR spectrophotometer 106 is mounted adjacent to the cup lump sample 102 to receive the transmitted lights 118 from the sample 102 after a part of the light 114 in the NIR wavelength region from the light source 116 is being absorbed by the sample 102 and another part of the light 118 is transmitted through the cup lump 102. Light 114 is resolved into a light of discrete wavelength using various methods, including dispersive (e.g. grating monochromators), interferometric or non-thermal, which can generate light within a specific wavelength (e.g. light emitting diodes, laser diodes and lasers) over or partial wavelength region of 700-2,500 nm. An average spectrum is produced for each sample scan. The cup lump qualities are determined by using the similar method as described in the FIG. 1. Further analysis of the spectrum data associated with the parameter of interest by the use of control device and data processing unit 110 such as a CPU, a computer or a microcontroller, with the aid of chemometrics, such as Multiple Linear Regression (MLR(, Partial Least Square regression (PLS), Artificial Neural Network (ANN) or discriminant model development by Partial Least Square Discriminant analysis (PLSD A) or Principal Component Analysis (PCA), etc. Further the system 100 can be incorporated into a network having a centralized database, which provides reference calibration equations or models to other processing streams in the network, provided that NIR spectrophotometers 106 are standardized against the NIR spectrophotometers 106 on which the calibration equations were developed. Cup lump quality measurement in the purchasing process may be part of the network system. The computer system, the processor, the server or the like 110 associated With the Centralized database acts as a master instrument within the network. The data in the master instrument can be exchanged and accessed from all slave instruments that are associated with the sample for analysis of the spectrum data and is particularly advantageous in measuring the parameter of interest in cup lump 102 processing.

[0025] According to first aspect of the invention is to provide a system 100 for the measurement of the quality parameters of cup lump 102. The system 100 comprises a scanning head 104, an NIR spectrophotometer 106, a database 108 and a control device 110. Wherein the scanning head 104 comprises a light source 116, which generates light 114 in the NIR wavelength region, and a detector 111, which is used to collect, reflected 112 or transmitted light 118 from cup lump 102. The NIR spectrophotometer 106 includes the type of dispersive (e.g. grating monochromators), whether interferometric or non-thermal, which can generate light 114 within a specific wavelength (e.g. light emitting diodes, laser diodes and lasers) resolving the reflected light 112 and transmitting it into light of a discrete wavelength. The position of the NIR spectrophotometer 106 mounting depends on each system. The NIR spectrophotometer 106 and light source 116 are mounted on the same side for a reflection system (FIG. 1) and on opposite sides for a transmission system (FIG. 2). The database 108 comprises calibration equations, which are constructed from the relation between the absorbance of the sample in each wavelength and quality parameters of interest, whereas the calibration model is constructed from the relation between the absorbance of the sample in each wavelength and group of cup lump quality. The control device and data processing device 110 may be a computer, microcontroller or other device performing in the same manner. This part uses a control system 110 and analyzes cup lump quality with the aid of calibration equations or a calibration model database based on the NIR absorbance (spectra) of cup lump 102.

[0026] According to second aspect of the invention is to provide a method for the development of a calibration equation database 108. The method comprises the steps of, obtaining the NIR absorbance, also known as NIR spectra, of cup lump 102, the sample of which shall be truly representative of the cup lump population that is expected to be found in the future, obtaining laboratory testing of the cup lump qualities, such as the DRC, moisture content, and adulterated cup lump 102. These qualities can be analyzed by a standard analytical method or another reliable method that is accepted by industries. The calibration equation or calibration model is developed by a software program using regression; either linear regression, such as Multiple Linear Regression (MLR) or Partial Least Squares (PLS) regression, or non-linear regression, such as Artificial Neural Network (ANN) etc. Samples for database construction are separated into two sets. The calibration set is used to develop the calibration equation or calibration model and the validation set is used to validate the accuracy arid precision of the developed calibration equation or calibration model. Conducting statistical testing for the measurement of accuracy and precision of constructed database, standard error of prediction (SEP), bias and slope obtained from the validation set are tested as follows: ISO12099: 2010, which is a guideline for the application of NIR spectrometry for constituent measurement of the sample.

[0027] According to third aspect of the invention is to provide a method for the measurement of quality parameters of cup lump 102 using the stored database 108. The databasel08 is validated statistically, given the above, and is suitable to be used industrially. The method comprises obtaining NIR absorbance of cup lump 102, which is measured by an NIR spectrophotometer 106, then applying appropriate calibration equation or calibration model to the NIR spectrum of cup lump 102 so as to analyze and quantify the presence of the quality parameters of interest, and then statistically validating the spectrum obtained as being represented by the calibration equation or calibration model. Further the analyzed results are considered reliable when the spectrum conforms to the set of spectra used to derive the calibration equation, wherein the spectrum obtained is useable for as many parameters as calibrations are available.

[0028] The system 100 according to the second and third aspects of the invention can be incorporated into a network (not shown). In such a network, a centralized database provides reference calibration equations or models to other processing streams in the network, provided that NIR spectrophotometers are standardized against the NIR spectrophotometers on which the calibration equations were developed, the latter can be used as a master instrument within the network. A network of systems according to the invention is particularly advantageous in measuring the parameter of interest in cup lump processing. Cup lump quality measurement in the purchasing process may be part of the network system. The network is convenient for industrial operations, because the data in the master instrument can be exchanged and accessed from all slave instruments.

[0029] Another aspect of the invention is to provide a system 100 for the measurement of the quality parameters of cup lump 102 , wherein the system 100 comprises a scanning head 104, an NIR spectrophotometer 106, a detector 111, a database 108 and a control- device 110. [0030] Still another aspect of the invention is to provide a method for the development of a calibration equation database, wherein the calibration equations are constructed from the relation between the absorbance of the sample in each wavelength and quality parameters of interest. The calibration equation or calibration model is developed by a software program using regression; either linear regression, such as Multiple Linear Regression (MLR) or Partial Least Squares (PLS) regression, or non-linear regression, such as Artificial Neural Network (ANN) etc. The calibration model is constructed from the relation between the absorbance of the sample in each wavelength and group of cup lump quality. Further the calibration set is used to develop the calibration equation or calibration model and the validation set is used to validate the accuracy and precision of the developed calibration equation or calibration model.

[0031] Further another aspect of the invention is to provide a method for the measurement of quality parameters of cup lump 102 using the stored database 108, wherein the method comprises obtaining NIR absorbance of cup lump 102, which is measured by an NIR spectrophotometer 106, then applying appropriate calibration equation or calibration model to the NIR spectrum of cup lump 102 so as to analyze the quality parameters of interest.

[0032] Another aspect of the invention is to provide a system measuring the parameter of interest in cup lump 102 by developing a calibration equation database 108 and measurement of quality parameters of cup lump 102 using the stored database 108 can be incorporated into a network, wherein a centralized database provides reference calibration equations or models to other processing streams in the network.

[0033] Another aspect of the present invention is to provide a system 100 for offline and online measurement of a parameter in cup lump 102, wherein the system 100 comprises, a scanning head 104 mounted adjacent to a continuous stream of cup lump 102, the scanning head 104 comprising a light source 116 and reflected 112 or transmitted light 118 gathering and detector 111; a near infrared spectrophotometer 106 which includes types of dispersives (e.g. grating monochromators), interferometric or non-thermal, which can generate light within a specific wavelength (e.g. light emitting diodes, laser diodes and lasers) for resolving the reflected 112 or transmitted light 118 into the light of a discrete wavelength; a database 108 containing a reference calibration equation linking absorption characteristics by wavelength and quantified presence of the parameter of interest; a database 108 containing a reference calibration model linking absorption characteristics by wavelength and qualities of cup lumps 102; and a processor 110, such as a computer, microcontroller or other device, performing in the same manner for measuring the parameter by application of the calibration equation or calibration model to the obtained spectrum for a sample 102.

[0034] Another aspect of the present invention is to provide a method of offline and online measurement of a parameter in cup lump 102, wherein spectrum used is a single spectrum or the average of the plurality of the obtained spectra which is obtained from the reflectance or transmittance measurement. The spectrum is measured over or partially the range of 700 to 2,500 run.

[0035] Another aspect of the present invention is to provide a method of offline and online measurement of a parameter in cup lump 102, wherein the scanning head 104 is remote from said spectrophotometer 106 and is linked thereto by a fiber optics cable (not shown).

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0036] The present invention will now be more fully described with reference to the accompanying examples. It should be understood, however, that the following description is illustrative only and should not be taken in any way as a restriction on the generality of the invention specified above.

[0037] A scanning head 104 of the NIR spectrophotometer 106 in the reflection and transmission system is mounted adjacent to a cup lump sample 102 as shown in FIG. 1 and FIG. 2, respectively. Light 114 obtained from the light source 116 in the NIR wavelength region illuminates the sample 102, and part of the light 114 is absorbed within the sample 102, while part of the light is reflected 112 (or transmitted 118) and consigned into the NIR spectrophotometer 106. Light 114 is resolved into a light of discrete wavelength using various methods, including dispersive (e.g. grating monochromators), interferometric or non-thermal, which can generate light within a specific wavelength (e.g. light emitting diodes, laser diodes and lasers) over or partial wavelength region of 700-2,500 nm. An average spectrum is produced for each sample 102 scan. The cup lump 102 qualities, such as dry rubber content (%), moisture content (%) and adulterated cup lump 102, are determined by the standard analytical method which is actually used in the factory. The calibration equation is developed and stored in a database 108, such as the equation for the determination of DRC, equation for the determination of moisture content, and the model for classification of adulterated cup lump 102. This database 108 is developed from the relation between the NIR absorbance (or NIR spectra) obtained from this invention and the quality parameters obtained from the standard method. This step is achieved using a control device and data processing unit 110 such as a CPU, a computer or a microcontroller, with the aid of chemometrics, such as Multiple Linear Regression(MLR(, Partial Least Square regression (PLS), Artificial Neural Network( ANN) or discriminant model development by Partial Least Square Discriminant analysis (PLSDA) or Principal Component Analysis (PCA), etc. The calibration equation database created for each parameter must collect characteristic features of the spectra associated with the parameter of interest. After that, this database 108 will be stored in order to be further utilized for routine analysis. [0038] An Example of the present invention of the system and method to the measurement of cup lump 102 qualities is provided below:

EXAMPLE

Measurement of the Quality Parameters of Cup Lump 102

[0039] In this example, the development of calibration equations for dry rubber content and moisture content in prepared cup lump 102 is described. All cup lump samples 102 are actually found in the factory, since they are purchased from an agriculturist. The example also verifies the accuracy of the method and verifies that the method is suitable for factory use. Nevertheless, the development of robust calibration equations require to store samples which are expected to be found in the future. After completing the sampling and sample preparation, all cup lump samples 102 are measured for their NIR spectra using this invention by putting the measuring head 104 close to the sample 102. The NIR spectra obtained from the NIR spectrophotometer 106 will gather all constituents, which are contained in the sample. Then, the dry rubber content of all samples 102 is determined, as is the moisture content using drying, which is the standard analytical method and accepted by factories. Calibration equations are developed by the aid of a computer 110 and chemometrics. For calibration equation development, all samples are divided into two sets randomly; the calibration set is used to develop calibration equations and the validation set is used to verify the accuracy and precision of the developed equations. The laboratory statistics of both sets are shown in Table 1. Table 1

Laboratory Statistics of Cup Lump Qualities in Calibration and Validation Sets

Calibration Set Validation Set

Quality Parameters Standard Standard

Range Average Range Average

Deviation Deviation

Dry rubber content, 56.75- 59.60-

69.23 5.80 70.32 5.98 DRC (%) 88.88 84.41

Moisture content 11.12- 18.18-

29.93 6.31 29.54 5.02 44.98 37.85

[0040] The calibration equations developed from the calibration set are stored in the database 108 and are used to predict the quality parameters of cup lump 102 in the validation set. The NIR spectra of the sample in the validation set which is measured by the NIR spectrophotometer 106 is processed in the stored database 108. This will verify the accuracy of the developed calibration equations based on statistics. The results of the database 108 development and verification are shown in terms of correlation coefficient (R(, standard error of calibration (SEC(, standard error of prediction (SEP(, and bias (Table 2). This example showed that NIR spectroscopy is accurate and has a high potential to actually be used in either laboratory or industrial uses.

Table 2

Result of Calibration Equation Database for Measurement of Qualities of Cup Lump 102

Calibration Set Validation Set

Parameters

R SEC R SEP Bias

Dry rubber content, DRC (%) 0.66 4.34 0.77 3.89 -0.11

Moisture content (%) 0.72 4.59 0.84 2.85 -0.15

[0041] Because many modifications, variations, and changes in detail can be made to the described preferred embodiments of the invention, it is intended that all matters in the foregoing description and shown in the accompanying drawings be interpreted as illustrative and not in a limiting sense. Thus, the scope of the invention should be determined by the appended claims and their legal equivalence.

Claims

1. A method of offline and online measurement of a parameter in cup lump, the method comprising the steps of:

(a) obtaining an NIR spectrum from cup lump;

(b) applying an appropriate calibration equation or calibration model to the spectrum to quantify the presence of the parameter of interest; and

(c) statistically validating the spectrum obtained as being represented by the calibration equation or calibration model.

2. The method according to claim 1 , wherein said spectrum is obtained from the reflectance or transmittance measurement.

3. The method according to claim 1 , wherein said parameter is selected from the dry rubber content (DRC), moisture content and adulteration of vulcanized cup lump.

4. The method according to claim 1, wherein said spectrum is a single spectrum or the average of the plurality of the obtained spectra.

5. The method according to claim 1 , wherein said spectrum is measured over or partially the range of 700 to 2,500 nm.

6. A system for offline and online measurement of a parameter in cup lump, the system comprising:

(a) a scanning head mounted adjacent to a continuous stream of cup lump, the scanning head comprising a light source and reflected or transmitted light gathering and transmission apparatus;

(b) _; a near infrared spectrophotometer which includes types of dispersives (e.g. grating monochromators), interferometric or non-thermal, which can generate light within a specific wavelength (e.g. light emitting diodes, laser diodes and lasers) as well as hyperspectral imaging for resolving the reflected or transmitted light into the light of a discrete wavelength;

(c) a database containing a reference calibration equation linking absorption characteristics by wavelength and quantified presence of the parameter of interest;

(d) a database containing a reference calibration model linking absorption characteristics by wavelength and qualities of cup lumps; and (e) a processor, such as a computer, microcontroller or other device, performing in the same manner for measuring the parameter by application of the calibration equation or calibration model to the obtained spectrum for a sample.

7. The system according to claim 6, wherein said scanning head is remote from said spectrophotometer and is linked thereto by a fiber optics cable.

8. The system according to claim 6, wherein said database comprises- a plurality of reference calibration equations or calibration models.

9. A network comprising a plurality of systems according to claim 6, said spectrophotometer (slave) of said network being standardized to one spectrophotometer (master) within said network, which serves as a master spectrophotometer.