ZX-50 Portable Grain Analyzer. Calibration Software Manual Version 2.0

Transcription

1 ZX-50 Portable Grain Analyzer Calibration Software Manual Version 2.0 This manual provides you the information needed to use the provided calibration software and create your own calibrations. ZELTEX, INC. 130 Western Maryland Parkway Hagerstown, Maryland USA Phone: Fax: Zeltex, Inc. 2007

2 Table of Contents Table of Contents...2 Setting up the ZX System Requirements...3 Installation...3 Connecting to the ZX Using the Calibration Software...4 Collecting Data...4 Statistical Analysis...5 Creating/Restoring a Backup File...6 Downloading Saved Samples...6 Downloading Saved Results...7 Transferring Data to an External Spreadsheet...7 Creating your own Calibration...7 Step 1: Obtain samples with Laboratory Analysis...9 Step 2: Create a Constituent File for the lab analysis...9 Step 3: Create a new product setting the number of readings per sample...9 Step 4: Create an Optical Data file and run calibration samples on the ZX Step 5: Merge the Constituent File and the Optical Data file...12 Step 6: Run a Zeltex Regression Analysis to determine Calibration Constants...13 Step 7: Load the K Values into the ZX Step 8: Check the accuracy and make any adjustments if necessary...16 Glossary...17 File Extensions and Meanings...18 Page 2

3 System Requirements Setting up the ZX-50 Windows 98 through Vista 32 MB RAM 1 serial com port or 1 USB port with a USB to Serial adapter CD-ROM drive Installation Before installing the software, make sure you have closed all open applications. 1) Insert the Calibration Software CD into the CD-ROM drive. 2) If the Setup Wizard does not start automatically, select Run from the Start menu and type x:install.exe (where x is your CD-ROM drive letter). 3) Select the ZX-50 and follow the on-screen instructions to complete the installation. Zeltex recommends using the default options throughout installation. Once the installation is complete, you can access the ZX-50 software by selecting Programs from the Start menu, then selecting Zeltex then ZX-50 Calibration Software. Connecting to the ZX-50 1) To connect your computer to the ZX-50, simply connect the RS232 cable from the ZX-50 to a free serial port on your computer. If your computer does not have a serial port you may use a USB to Serial adapter which can be purchased directly from Zeltex or many electronics stores and websites. The ZX-50 Calibration Software is designed to automatically locate the ZX-50. Page 3

4 Using the Calibration Software Collecting Data When using the Calibration Software to collect data you collect the actual optical data collected during a measurement. 1) From the File menu select New then Optical Data (or you can add samples to an existing data file by selecting Open from the File menu). 2) Select Collect from the Data menu. The following questions will appear: Predict a product from the instrument to the screen? If you wish to see the calculated results of a product that has already been calibrated, click Yes and choose the product that you wish to read. Otherwise, click No and you will get the next question: Predict a product from a KS file? If you wish to see the calculated results using a KS file that is stored on your computer, click Yes and the following dialog will appear. Enter your product name and then select up to four KS files for predicting results. Otherwise, click No to continue. 3) The following dialog will appear: Note: Clicking on the Options button sets the COM Port. As stated in Connecting to the ZX-50 the Calibration Software will select the proper port automatically. 4) Enter a sample ID number. This must be a number between 1 and ) Press Collect. Follow the on screen instructions. They will tell you when to press MEASURE, insert the sample, etc. Page 4

5 Once the reading is complete a graph of the optical data will be displayed. You will be asked to save the data then the Collect dialog will reappear. Statistical Analysis Statistical Analysis is used for checking the accuracy of the calibration. This is where one would determine if an adjustment is needed. 1) Obtain samples of the calibration in question that have lab analysis data. 2) Read these samples with the ZX-50 using the method described in Collecting Data, answering Yes when asked to Predict a product from the instrument to screen? 3) Once the product listing is downloaded, select the product in question. 4) Read all of the samples. Write down the predicted results displayed at the top of the screen. 5) Once all of the samples have been read, select New from the File menu and then select Statistics. 6) Enter the data into the spreadsheet portion of the Statistics window. Enter the laboratory values under the Lab column. Enter the predicted values from the ZX-50 under the Zeltex Column. 7) The Statistical Analysis will be displayed in the upper right hand column. A graph of the data will be displayed on the bottom. 8) Examine the Statistical Analysis. You will see a section that looks similar to this: * Zeltex recommends that only * a bias adjustment be made. Slope : Slope Bias : Bias (No slope) : If it is recommended that you make a Slope and Bias adjustment, use these values. If it is recommended that you make only a Bias adjustment, use this value. 9) It is recommended that a backup file be made before making any adjustments to the ZX-50. Refer to Creating/Restoring a Backup File for instructions on creating a backup file. Page 5

6 10) Once you have created your backup file, refer to the User s Manual on how to make a Slope and/or Bias adjustment to the ZX-50. Creating/Restoring a Backup File Creating a Backup File Any time you make an adjustment to a calibration or create a new calibration it is recommended that you create a backup fie. 1) From the File menu select New and then Instrument Settings. 2) From the Instrument Edit menu select Download From Instrument. 3) Once the download is complete, select Save from the File menu. Enter a filename to describe the file (the date of the backup, for example) and press OK. Restoring a Backup File If for any reason the product data stored in the ZX-50 becomes corrupt or invalid you will need to restore a previously saved backup file. The original backup file for the ZX-50 is located in the Data directory on your Calibration Software CD. 1) From the File menu select Open. 2) Under List files of type: choose Instrument Settings (*.zbk). 3) Find the backup file you wish to restore and select OK. 4) From the Instrument Edit menu select Upload to Instrument. 5) Answer Yes to the warning to begin the upload process Downloading Saved Samples The ZX-50 has the ability to store the Optical Data and sample ID s for 25 samples in battery-backed RAM. The Calibration Software can download these saved samples for further analysis. 1) From the File menu select New then Optical Data 2) From the Data menu select Download Saved Samples. 3) Enter your COM Port number and click OK. If you are unsure of your COM Port number, the software will search for it automatically. Page 6

7 4) Enter a file name for the downloaded samples. The filename can be up to 8 characters long. Click OK. 5) The software will download the saved samples and display them. Once downloaded, the saved samples are erased from the instrument s memory. Downloading Saved Results The ZX-50 has the ability to store the calculated results and sample ID s for 25 samples in battery-backed RAM. The Calibration Software can download these saved samples for further analysis. 1) From the File menu select New then Results. 2) From the Data menu select Download Saved Results. 3) The software will download the saved results and display them. Once downloaded, the saved results are erased from the instrument s memory. Transferring Data to an External Spreadsheet If you would like to copy the optical data into an external spreadsheet program for further analysis follow these simple steps: 1) With your optical data file open, from the Data menu select Grid View. A window similar to the following will open: or 2) If your file has less than 200 samples in it, click on the plain gray box in the upper left corner to select the entire file. Otherwise, click and hold on the first sample number that you wish to copy, and then drag your mouse down highlighting the samples you wish to copy (only 200 at a time). 3) From the Edit menu select Copy. 4) You may now paste the data into your spreadsheet program. Page 7

8 Creating your own Calibration The ZX-50 comes pre-calibrated with any product you order. But there may be some cases where you wish to create your own calibration. To do this, follow these 8 simple steps: 1. Obtain samples with Laboratory Analysis. 3. Create a new product setting the number of readings per sample. 2. Create a Constituent File for the lab analysis. 4. Create an Optical Data file and run calibration samples on the ZX Merge the Constituent File and the Optical Data file. 6. Run a Zeltex Regression Analysis to determine Calibration Constants (K Values). 7. Load the K Values into the ZX Check the accuracy and make any adjustments if necessary. Page 8

9 Step 1: Obtain samples with Laboratory Analysis. The more analyzed samples that you can run through the ZX-50, the better the calibration will be. Zeltex recommends at least 75 samples that cover the range of interest, but 100 to 150 samples would be best. If you are unable to obtain enough samples, contact Zeltex for further assistance. This analysis should be from a lab you trust, as the calibration can never be more accurate than the lab values. Enter the lab analysis information into the Zeltex Calibration Numbering Setup Manual that came with your instrument. Use the numbers assigned in the Calibration Numbering Setup Manual during calibration. Step 2: Create a Constituent File for the lab analysis. A Constituent File contains all of the laboratory information about your product. This file will be merged with the Optical Data File which is created in a later step. 1) From the File menu select New and then Constituent Data. 2) From the Data menu, select Insert. Alternatively, you can simply press the Insert key on your keyboard. 3) Enter the sample ID number that you assigned to the first sample (found in the Calibration Numbering Setup Manual). Then enter the constituent Data for that sample. 4) Repeat steps 2 and 3 for each sample for which you have laboratory analysis. 5) From the File menu, select Save and give this file a name that you will remember. Step 3: Create a new product setting the number of readings per sample. You must now create this new product and set the number of readings per sample. 1) Create a backup file as described under CREATING/RESTORING A BACKUP FILE. 2) Select an empty product and enter your new calibration s name. 3) Click on the button under Con 1 Page 9

10 4) Enter the name for this constituent and press OK. 5) Repeat steps 3 and 4 for each constituent that you wish to analyze. 6) Enter 4 for the value under # Cycles (sample readings per measurement). 7) From the File menu, select Save and give this file a name. Then from the Instrument Edit menu select Upload to Instrument. 8) Close the backup file. Change to the new product on the ZX-50. Step 4: Create an Optical Data file and run calibration samples on the ZX- 50. This is when you must decide which cup to use for your product. Use the following chart to determine the proper cup for your product: PRODUCT CUP Wheat Standard Black molded cup (16mm) Corn, Soybean Black molded cup w/windows on outside (25mm) Barley, Milo, Sorghum Cup with sliding windows set to 13mm (see next chart) Flax, Mustard, Cup with sliding windows set to 10mm (see next chart) Soymeal Canola, Rapeseed Cup with sliding windows set to 8mm (see next chart) Page 10

11 Use the following chart to match the correct windows with the correct width for the variable path-length cup (the cup with sliding windows). Window # A A A A A A A A A A Shaded boxes indicate preferred window combinations. It is best to contact Zeltex if you are unsure of the type of window to use. Now you must run all of your analyzed calibration samples (remember to use the sample numbers from the Calibration Numbering Setup Manual). Create a new Optical Data file and analyze each sample as described in the section Collecting Data. There are a few things to keep in mind during this step: 1) The samples do not all have to be run the same day; the file can be saved and additional samples added later. 2) Temperature variation during a calibration is very important. Because of temperature variations in the field, you vary the instrument temperature and the sample temperature during the calibration To vary instrument temperature, place heating pads, set on high, around the instrument for about 30 minutes or until the instrument temperature reaches a temperature that will reflect the highest temperature expected during normal use. (See To check instrument temperature below.) Remove the heating pads and continue running samples. At another point in the calibration, wrap the instrument with plastic and surround it with ice packs for 30 minutes or until the instrument temperature is lowered to a temperature that will reflect the lowest temperature expected during normal use. (See To check instrument temperature below.) Remove the ice packs and continue running samples. The sample temperatures must also be varied during calibration. Zeltex recommends using 3 to 5 different temperature ranges of samples during calibration covering the warmest to the coldest sample temperatures that will happen during normal use. To check instrument temperature, collect data from a sample and allow the graph of the sample reading to appear. The bottom of the window lists the sample and instrument temperatures respectively in ºC. Page 11

12 3) The shapes of the sample curves are very important. The easiest way to tell if the instrument is functioning properly or if the sample that was just analyzed was good is to observe the curves. They should generally curve gradually rather than peaking sharply. To view all of the curves at the same time, select Overlay from the Plot menu. Observe the following examples: Example 1: In this example, all curves shown are similar in shape and are acceptable. Example B: In this second example, the highlighted curve is clearly bad. This can be caused by operator error, poor energy settings, or incorrect window thickness. Delete this sample and run it again. Step 5: Merge the Constituent File and the Optical Data file. Once you have analyzed all of your samples over varying temperature ranges it is time to merge that data with the laboratory values stored in the Constituent File. 1) With your Optical Data File open, select Merge Constituents from the Data menu. 2) Select your Constituent File and click OK. Your data will be merged and saved automatically. Page 12

13 Step 6: Run a Zeltex Regression Analysis to determine Calibration Constants. The Zeltex Regression Analysis is used to determine the constants that calculate the final results (Protein, etc.). You must do this for each constituent in your calibration. 1) With the Optical Data File still open, go to the Data menu and select Reduce. The following dialog will appear: 2) The number of tumbles, type of tumbles, and filters are the values recommended by Zeltex. The other settings can be adjusted by you. Tumbles: Refers to the number of samples to be tumbled from the regression. Samples which are statistical outliers should be eliminated from the regression so that they do not adversely affect the calibration. Type: Refers to the tumbling method. The Slow type will generally give you better results. Filters: This option was designed for use by Zeltex researchers only. All the filters listed should have a checkmark. Constituents: These are the constituents for the product that you are calibrating. It is possible to do a Regression Analysis on more than one constituent at a time, but it is recommended that you only do one at a time. Exclude: Click on this button to specify specific sample numbers that should be eliminated from the regression. You might choose to do this for samples that have no lab value or a questionable lab value for a particular constituent or have a bad curve. After typing each sample number, click ADD to confirm its exclusion. When all the sample numbers to be excluded are listed, click OK to close the Exclude Sample dialog. 3) Once you have satisfactorily set all of these settings, click on the OK button. If the file contains a large number of samples this may take a few minutes. Page 13

14 4) Once the Regression Analysis is complete, a screen similar to this will appear: There will be a file created for each tumble. The file containing the constants that you should use will be the first one displayed. The actual constants and other statistical analysis will be displayed in the left panel. A plot of these results will be displayed on the right. You may look at the results of the other tumbles by choosing them in the dropdown box at the top. Zeltex recommends you print these results for the next step. 5) Repeat this process until you have results for all constituents in your calibration. Page 14

15 Step 7: Load the K Values into the ZX-50. Once you have constants for each constituent, it is time to load them into the product that you created earlier. 1) Open the backup file that you created with the new product added to it. 2) Click on the button for the first constituent. 8) Repeat steps 2 through 7 for all constituents in the calibration. 3) For Variance Level enter 6.25 if it is wheat, otherwise enter ) Enter the highest laboratory value for Too High Value. 5) Enter the lowest laboratory value for Too High Value. 6) Click on the Load Ks button, this will bring up a browse dialog. Choose the K Values that were created for this constituent by the Regression Analysis and select OK to load them. 7) Click OK to close this dialog. Page 15

16 9) For the Point values, you must look at your optical data. Point 1 should be a wavelength that is always one of the highest values. Point 3 should be a wavelength that is always one of the lowest values. Point 2 should be a value that is always between Point 1 and Point 3. Using the optical data shown here as an example. You can see that 1000 is always one of the highest points on each curve. 944 is always one of the lowest. 910 is always in the middle. 10) Hi AT should be set to the highest ambient temperature achieved during calibration. 11) Lo AT should be set to the lowest ambient temperature achieved during calibration. 12) Hi ST should be set to the highest sample temperature achieved during calibration. 13) Lo ST should be set to the lowest sample temperature achieved during calibration. 14) If you wish to view readings in a Constant Moisture basis, enter that value into the CM Basis column. 15) When complete, save the file and select Upload to Instrument from the Instrument Edit menu. Step 8: Check the accuracy and make any adjustments if necessary. Once the completed calibration is uploaded to the ZX-50, you must check the accuracy of the calibration and make any adjustments that are needed. 1) Take ten lab-analyzed samples (preferably ones that were not included in the calibration) and analyze them with the ZX-50 using the Predict from Instrument method described under Statistical Analysis. 2) Again, following the instructions under Statistical Analysis, enter all of the lab and predicted values. If an adjustment is recommended, make the adjustment following those instructions. 3) If an adjustment was made, once again save the backup file and upload the new file to the ZX-50. The ZX-50 is now calibrated. Page 16

17 Glossary Accuracy Refers to how closely the readings of the known samples match the samples predetermined lab values in a given instrument. Bias The average overall shift of the calculated results from the ideal laboratory values. A Bias Adjustment will compensate for this. Constants (also referred to as K values) Figures determined during calibration of the instrument which are used in the equation: Result = K 0 + (K 1 OD 1 + K 2 OD K N OD N ) Constituent One of the properties of the product being measured, such as Protein or Moisture. Data Link The mode that the ZX-50 must be in to communicate with the Calibration Software. ID s The identification numbers of the samples. Multiple Linear Regression (MLR) The mathematical process to fit the optical data to the lab data. Optical Data (OD s) The data obtained by the instrument from each of its filters which it then applies to the above equation. Precision Refers to how closely the same sample repeats its readings in a given instrument Reduce / Reduction See Multiple Linear Regression Regression See Multiple Linear Regression Slope and Bias More than just an average overall shift of the calculated results from the ideal laboratory values. A Slope and Bias adjustment will compensate for this. Thermistor The probe in the sample chamber that measures the sample temperature. Page 17

18 File Extensions and Meanings *.dt1 Optical Data File. These files contain the data obtained by the instrument. *.ks1 K Files. Contains the K values, or constants, that are used to calculate the final results. *.con Constituent File. These files contain laboratory analysis used during calibration. *.zbk Backup Files. These files contain all of the calibration information stored on the instrument. *.st1 Statistical Analysis Files. Contains saved statistical analysis. *.r50 Saves the downloaded calculated results from the instrument. Page 18