The Infratec. Network Concept

Transcription

1 Giving grain its fair value Network Concept The Infratec Grain Network Concept In the grain business, you can only know exactly what you re paying for and what you ve got to sell if you have precise and accurate analytical results. And on a larger scale, a proven solution is to be member of a unified network using a quality assurance system for both instruments and calibrations. Giving grain its fair value is a task that involves a long chain of events and quality control procedures. For an individual owner of a near infrared analyzer this can be a time consuming and complicated issue. Trained staff, laboratory access, skill to develop calibrations and the time to verify that everything is correct can often be too much. It is simply not cost effective for grain traders and grain elevators to focus on these tasks instead of their regular business. Offering FOSS customers a simpler and more cost effective solution was one of the main objectives when the first Infratec Grain Network was introduced in There was also a need to obtain an all-important element of trust into analytical results, achieving objectivity for all involved, i.e. farmers, traders, customers and grain authorities. Thus, main goals were transferability of calibrations, a feedback system for corrective actions, accepted reference laboratories and quality control checkpoints throughout the procedure. Since then, the quality control concept in the Grain Network has been further developed by addition of international ring tests, Internet based quality assurance systems, global ANN calibrations etc. You can rely on fair trade on all levels when you are part of an Infratec Grain Network. The number of Infratec Grain Networks as well as the number of units within each network has increased steadily. The calibration work today is concentrated on developing global calibrations, based on internationally accepted and approved methods using reference data from all over the world where the aim is that identical calibrations can be used all over the world. The Infratec grain quality assurance concept has made it easy and safe to handle grain transactions ensuring fairness on all levels.

2 Network structure An Infratec network consists of one master instrument and one or more slave instruments. The master instrument is used to scan samples to monitor and update calibrations. It is normally placed at the reference laboratory. All slave instruments can be called up from a central computer over a telephone modem, via LAN or diskette, whenever adjustments are required. The calibrations on the master instrument are adjusted to the level of the reference laboratory. All slave instruments are then adjusted to the level of the master instrument and thus automatically to the level of the reference laboratory. With this standardization process the network certifies that every connected Infratec obtains truly comparable results, thus assuring fair assessment of the tested grain. The network solution also prevents non-relevant adjustments of the Infratec units. Steering Committee International Ring Tests Reference Laboratory Calibration Center Certification Network Administration Center Infratec 1241

3 Four task groups The main tasks in each network are divided between different organizations: Steering Committee takes overall responsibility for the network. It makes decisions about calibrations, certification and network organization. Reference Laboratory analyzes checksamples, gives advice to the steering committee, and monitors the performance of the master instrument. Calibration Center develops new calibrations and can make recommendations about calibration adjustments. Administration Center handles database maintenance and communication with the instruments. Calibration Monitoring Steering Committee The steering committee has overall responsibility for the network operations and organization. Members of the committee should represent the different user groups within the network, the reference laboratory and the calibration center. Normally the members from the calibration center and the reference laboratory are only present as advisors and do not take an active part in making decisions. The committee should have a technical focus. One main task of the committee is to decide on new calibrations and on adjustments to existing calibrations based on statistics from the calibration center and the reference laboratory. The steering committee is also responsible for organization of sample collection plans for calibration monitoring and for development of new calibrations. Cooperation with plant breeding companies, steering committees of other networks and other key organizations may be advisable in order to create the most optimal plan. Organization of standardizations and the development of certification strategies, often together with metrological institutes, are other important tasks for the steering committee. The steering committee should approve individual adjustments before they are transferred to the instruments. The steering committee normally has financial responsibility for the network, covering costs such as reference analysis, preparation of standardization samples and general services given to the network. Instrument Monitoring

4 Reference Laboratory The main task for the reference laboratory is to scan and make reference analyses of checksamples and to report the results to the calibration center and the steering committee. Scans of checksamples can be used for calibration updates if necessary. The reference laboratory should be able to interpret calibration performance (especially in relation to the accuracy of the reference method) and to provide technical advice to the steering committee. The laboratory should also participate in ring tests to ensure that their own results are accurate. A ring test between reference laboratories from many Infratec networks in the world is carried out each year. It is also important for the reference laboratory to regularly check the stability of the master instrument. The choice of reference laboratory is very important. For example, a reference laboratory belonging to the local ministry of agriculture can give the network an official status, but an independent laboratory with a good reputation may also be a good choice. It is crucial for the network that the members of the network accept the results from the laboratory since all Infratecs are adjusted to the level of the reference laboratory. To ensure accurate results on the networked instruments the latest generations of updated calibrations must always be used and calibration results must be regularly and properly evaluated. Calibration Center The calibration center is responsible for calibration development and the distribution of the calibrations to the local network organizations. Calibration development can be split between the calibration center at FOSS and a local calibration center (e.g. FOSS developing the global ANN calibrations and the local organization developing regional PLS calibrations for other constituents). Alternatively, FOSS alone or the local center can take responsibility for calibration development. The calibration center is responsible for monitoring the calibration results during harvest periods, as well as other times of the year. Performance statistics based on the results reported from the reference laboratory should be compiled regularly. SEP (standard error of prediction), bias (systematic difference) etc., should be calculated each time for all samples from the current harvest year. This means that the statistics are based on just a few samples at the beginning of the harvest but on a large number by the end. The results are normally presented to the steering committee in graphs showing Infratec results plotted against reference results together with all statistics. If there is a bias problem but the SEP is OK, a simple bias adjustment can be made. If the SEP is too high the calibration should probably be updated. The calibration center can give recommendations to the network committee about adjustments of the calibrations but the steering committee should always make the decisions. Administration Center The locally based administration center is responsible for the maintenance of the instrument database and for the communication with the instruments in the network. Using the ODIN support software, the administrator can register instruments, application models and instrument owners. The calibration models are connected to the instruments and data can be transferred to and collected from the instruments. The administration center should have competence to do bias adjustments, based on the decisions from the steering committee, and to load and distribute new calibration models supplied by the calibration center. The administration center also collects standardization files from each instrument. Calculation of standardization data can be made either by the administration center or the calibration center.

5 Certification When developing strategies for certification, recommendations from metrological institutes, the performance of the calibration and the commercial aspects must be taken into account. Commercially, a very high degree of agreement between instruments is required for payment parameters, whereas some differences between instruments can be accepted for parameters used only for classification purposes. Main objectives are: To check the performance of all instruments To minimize instrument-to-instrument variation To collect optical data to allow standardization of future calibration models and transferability tests during the development of new calibrations Certification that slave instruments in the network operate at the same level as the master instrument can be obtained by a standardization procedure. For each commodity, samples covering as wide a concentration range as possible for the most important constituents should be used. The samples are split into as many subsets as are needed for the network, and a subset is scanned on each instrument including the master. Scans are collected from all instruments and predicted against the actual calibration. The individual predictions for each instrument are compared with the predictions from the master instrument or the reference analysis. Statistical data such as SDD (standard deviation of differences), bias, slope and correlations are calculated for each instrument. The data are approved by the steering committee and adjustments are made on units having a significant bias versus the master unit. Certification is normally performed once a year.

6 Making analysis easy Operating a successful Unified Grain Network requires a certain degree of organization. But once the correct structure and procedures are in place, the network will run smoothly. The outcome in terms of grain quality assurance certainly makes the set-up stage more than worthwhile. The FOSS Unified Grain Network solution is characterized by its ease of use. The system has been developed over more than a decade. Feature after feature has been added to increase control and reliability, with a minimum of effort from members and operators. FOSS is the only company in the world that supplies a truly functional and complete solution covering all aspects, from instrumentation for approved reference analysis, to rapid non-destructive testing, complemented with a fully developed system for Quality Assurance in grain. For more information about establishing or joining a Unified Grain Network, contact your local FOSS representative E Dedicated Analytical Solutions FOSS Tecator AB Box 70, SE Höganäs, Sweden T F E info@foss.tecator.se