Lasentec Product Group

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1 Prepared by: Gregor Hsiao Approved on: ECN# 3506 Effective Date: 1/14/2008 Title: Window Reference Procedure for Version and Higher Purpose: Lasentec D600 Probes and FBRM/Raman Probes using version 6.0 and higher FBRM CI Software The focal point position of the FBRM probe must be established to ensure that the measurements are consistent and repeatable for each instrument. The window reference procedures must be performed to calculate the Lasentec instrument focal point position. The measured statistic, #/Sec, No Wt 0-5 (Statistic #5) reaches a maximum value, also called the peak value, when the focal point is located at the window reference position. The procedure described below is the standard calibration procedure used to reference the Lasentec instrument focal point to the window surface. It is for both a D600 Lasentec probe and the Lasentec FBRM/Raman probe that is being used with version 6.0 and higher and higher of the Lasentec Control Interface (CI) software. Use Instruction Sheet for calibration if version 5.4 of the CI software is used. The Window Reference Procedure should be performed: Before running the PVC Reference Procedure If the PVC Reference Procedure indicates the Lasentec FBRM instrument or the FBRM/Raman instrument is out of calibration For non-standard probe orientations (see Orienting the Probe below) Orienting the Probe At the factory, the probe is calibrated in a vertical position with the window pointing down, as it is in the fixed beaker stand. The vertical (window down) window reference position must established before the PVC Reference Procedure can be run. Non-Standard Orientation If the orientation of the process installation is greater than ±30 from a vertical (window down) position, this Window Reference Procedure should be performed with the Lasentec FBRM probe or FBRM/Raman probe in the same orientation as in the process installation (i.e., horizontal, vertical, or at a given angle). Adjusting/Reading the Micrometer that the probe is installed in a Fixed Beaker Stand with the window facing down. The micrometer is used to adjust the focal point position. The scale on the micrometer knob indicates the relative position of the focal point. Each marked increment on the micrometer equals 10 microns (0.01mm). Half-increment positions can be used to adjust the position to the nearest 5 microns (5 µm). The micrometer can make no more than one full turn. The zero reference mark engraved on the probe head (see Figure 1) indicates where to read the current micrometer position Rev K Page 1 of 9

2 On the Lasentec D600 L, P, S, T, or X probes and the FBRM/Raman probe, the micrometer is a knob protruding from the top (probe window facing down) of the probe head. On the D600R probes, the micrometer is a ring. D600L P, S, T, or X and FBRM/RAMAN PROBES D600R PROBE Figure 1 Micrometer Location The window reference procedure finds the zero point of the window. When the instrument is measuring samples or in a process the focus should be set to -20 µm relative to the zero mark. Turning the micrometer knob (ring) clockwise (top view) moves the focal point further into the slurry (positive distance). Turning the micrometer knob (ring) counterclockwise (top view) moves the focal point back into the probe (negative distance). Coating the Window Surface Using the Lasentec Marker Coat the Lasentec probe window with erasable ink before locating the window reference position. 1. Using the Lasentec Dry Erase Marker provided with the Lasentec FBRM hardware, coat the surface of the clean, dry Lasentec probe window with a uniform, thick layer of ink. While most black, dry-erasable markers will do, it is best to use the marker provided by Lasentec to ensure measurement-to-measurement conformity. 2. Allow two minutes for the ink to dry. Configuring version 6.0 and higher of the FBRM CI software to Locate the Window Reference Position Before locating the window reference position, verify that the Acquisition Module of version 6.0 and higher of the FBRM CI software is running and configured per the directions below. With the CI software, the micrometer position can be adjusted while the Lasentec instrument output is monitored. To configure the software for locating the window reference position: Rev K Page 2 of 9

3 1. From the Setup Menu, select Meas. Config. 2. For Measurement Duration, select 5 sec (or 10 sec if using a low-speed optical line driver). 3. For Time Averaging, select No Time Averaging. 4. For Channel Grouping, select µm 200 Linear Ch. 5. Click the Open File for Save button. 6. Open file C:\Fbrm6?\Backup\ SN-X-mmddyy-WRP 1 and click Save. 7. For When Saving to File, save every v Measurements, set it to save every 1 measurement. 8. Press the NOT measuring, Press to Start button. 9. From the Setup Menu, select Stat. Config. 10. Press the Load Stats. Config button. 11. From the C:\Fbrm6?\Statistics Setup Files folder, select the default0-100-lin.sta statistics setup (the measured statistic #/sec, No Wt 0-5 will reach a maximum value when the focal point is located at the window reference position) and click Open. 12. From the Display Menu, select Stats. 13. In the Show column, make sure there is an X next to the #/sec, No Wt 0-5 statistic (Statistic #5). This will create a trend plot in the trend display. 14. De-select all other statistics by clicking on any existing Xs in the Show column. De-selecting a statistic will remove the trend from the trend display. 15. Under X-axis Scale (located below the trend display), select Record. 16. Under Buffer Length, type in To autoscale the X- and Y-axes, push both toggle switches (under the Trend Display graph) to the right. 18. From the Setup Menu, select Annotation. 19. Make sure the box next to Save with All Records contains an X. 20. Click the Y-axis applies to: box (located below the trend display) and select the #5 statistic. 21. Press the Measuring: Press to Stop button. 1 SN = the instrument s serial number X = electronics type (F or C) mmddyy = current date WRP = window reference procedure (A file name of 550-F WRP means the file is the calibration procedure for the unit with serial number 550, using F electronics, taken on January 1, 2001.) Rev K Page 3 of 9

4 Locating the Window Reference Position The window reference position must be carried out continuously without interruption. It takes less than 25 minutes to perform the procedure. If the procedure is interrupted you must start over from step 1 of the Coarse Adjustment procedure as described below. Important! To eliminate the effects of hysteresis, always reach the micrometer position on a Lasentec D600 or FBRM/Raman probe turning to the left. If you pass the desired micrometer position, move the rotating dial at least 50 µm (5 increments on the rotating dial) to the right and then find the correct point moving to the left. Coarse Adjustment During the coarse adjustment, increase the micrometer position in 20-micron increments (2 marked increments on the micrometer knob) in an attempt to pass the peak value for Statistic #5. You will likely make several coarse adjustments before the peak value is passed. To perform coarse adjustment of the micrometer: 1. Set the initial micrometer position by turning the micrometer knob to the right until it reaches the stop. Do not force it past this point. This point should be approximately -70 µm on the micrometer. 2. Type the micrometer position in the Annotation field (e.g., micrometer = -70 µm). 3. Press the NOT Saving, Press to AutoSave button to begin saving to the data file. 4. Press the NOT Measuring, Press to Start button to begin measuring. 5. Wait until the # Meas Since Start box displays 5 (i.e., 5 measurements have been taken), then click the Saving Data: Press to Stop button to stop saving and the Measuring: Press to Stop button to terminate the measurement. 6. Increase the micrometer position by 20 microns (2 marked increments) by rotating the micrometer knob to the left. 7. Type over the previous entry to record this micrometer position (+20 µm greater than the last recorded measurement) in the Annotation field (e.g., micrometer = -50 µm). 8. Repeat steps 3 through 7 (coarse adjustment) while watching the trend display graph. It may take several coarse adjustments before data will display in this graph and counts will begin to register in the Current Value box. Continue to watch the trend display graph, performing another coarse adjustment after every five measurements. Once counts begin to register in the trend display graph you ll notice that they fluctuate up and down by small increments with each measurement and increase dramatically with each adjustment of the micrometer position. If the trend line disappears off the graph at any point, click the Scale All Trends box to reset the Y-axis range. Once the peak value is reached, counts displayed in the Current Value box will begin to decrease and a definite peak will be seen in the trend display graph. Once you see the peak, perform three additional coarse adjustments to verify there is no higher peak, then proceed to step Rev K Page 4 of 9

5 9. To determine the final micrometer position of the coarse adjustment, minimize the Acquisition Module, open the Data Review Module and from the Setup Menu, select Meas Config. 10. Click the Open File button. 11. Select the data file created while the window reference position was being located (C:\Fbrm6?\Backup\ SN-X-mmddyy-WRP) and click Open. 12. For Time Averaging, select No Time Averaging. 13. Click the Apply Time Averaging box. 14. For Channel Grouping, select µm 200 Linear Ch. 15. From the Setup Menu, select Stat. Config. 16. Press the Load Stats. Config button. 17. From the C:\Fbrm6?\Statistics Setup Files folder, select the default0-100-lin.sta statistics setup (the measured statistic #/sec, No Wt 0-5 will reach a maximum value when the focal point is located at the window reference position) and click Open. 18. From the Display Menu, select Stats/Trend. 19. In the Show column, make sure there is an X next to the #/sec, No Wt 0-5 statistic (Statistic #5). This will create a trend plot in the trend display. 20. De-select all other statistics by clicking on any existing Xs in the Show column. De-selecting a statistic will remove the trend from the trend display. 21. From the Y Axis applies to: box, select the #5 statistic. 22. Under X-axis Scale (located below the trend display), select Record. 23. Click the Scale All Trends box to reset the Y-axis. 24. Make sure the Lock Cursor box is not checked (i.e., an X is not displayed), select the + from the trend toolbar (located below the Trend Display), and move the Current Record crosshair on the trend display graph to the peak value measurement of the trended statistic as determined by the coarse adjustment. 25. From the Setup Menu, select Annotation. 26. Look at the Annotation field for the micrometer reading at this maximum value. This is the peak micrometer position of the coarse adjustment. In some cases, the maximum value of the trended statistic may be observed at more than one consecutive micrometer position. If a plateau is observed, the first micrometer position encountered at the maximum value of the statistic (i.e., the left-hand side of the plateau in the trend display) should be used as the final micrometer position of the coarse adjustment Rev K Page 5 of 9

6 Fine Adjustment The micrometer position is increased in one-half micron increments to confirm the peak value for Statistic #5. (One-half an increment on the micrometer know.) Usually, several fine adjustments must be made before the peak value is confirmed. To eliminate the effects of hysteresis, always reach the micrometer position going to the left. If you pass the desired micrometer position, move the micrometer to the right at least 50 microns (5 marked increments) and then find the correct point by moving the micrometer to the left. To perform the fine adjustment of the micrometer: 1. With the software set to the Acquisition Module, turn the micrometer knob to the right to the stop (approximately 70 µm), then carefully turn the knob to the left to set the micrometer position 30 microns (3 marked increments) before the peak micrometer position found in the coarse adjustment (e.g., if the peak micrometer position of the coarse adjustment is +50 µm, set the micrometer position at +20 µm). 2. Type the new micrometer position in the Annotation field (e.g., micrometer = +20 µm). 3. Press the NOT Saving, Press to AutoSave button to begin saving to the data file. 4. Press the NOT Measuring, Press to Start button to begin measuring. 5. Wait until the # Meas Since Start box displays 5 (i.e., 5 measurements have been taken), then click the Saving Data: Press to Stop button to stop saving and the Measuring: Press to Stop button to terminate the measurement. 6. Increase the micrometer position by 5 microns (one-half of one marked increment) by rotating the micrometer knob to the left. 7. Type over the previous entry to record this new micrometer position in the Annotation field (e.g., micrometer = +25 µm). 8. Look at the trend display graph. The counts should be higher than those achieved in the coarse adjustment (i.e., the trend line going up). If the trend line has disappeared off the top of the graph, click the Scale All Trends button to reset the Y-axis. 9. Repeat steps 3 through 8 until the peak value established in the coarse adjustment is passed by 20 microns (20 µm). You will see gradual stair-step increases before the line in the trend display graph gradually decreases. After the peak, the counts will likely fluctuate up and down again, but will not reach as high as they did at the peak. If counts fluctuate so multiple peaks are observed, re-coat the window with the Dry Erase Marker and repeat the fine adjustment from step Once the peak value from the coarse adjustment has been passed by 20 microns (20 µm), open the Data Review Module to determine the exact micrometer position of the maximum peak value using the trend display graph. 11. From the Setup Menu, select Meas Config. 12. Click the Open File button Rev K Page 6 of 9

7 13. Select the data file created while the window reference position was being located (C:\Fbrm6?\Backup\ SN-X-mmddyy-WRP) and click Open. 14. For Time Averaging, select No Time Averaging. 15. Click the Apply Time Averaging box. 16. For Channel Grouping, select µm 200 Linear Ch. 17. From the Setup Menu, select Stat. Config. 18. Press the Load Stats. Config button. 19. From the C:\Fbrm6?\Statistics Setup Files folder, select the default0-100-lin.sta statistics setup (the measured statistic #/sec, No Wt 0-5 will reach a maximum value when the focal point is located at the window reference position) and click Open. 20. From the Display Menu, select Stats/Trend. 21. In the Show column, make sure there is an X next to the #/sec, No Wt 0-5 statistic (Statistic #5). This will create a trend plot in the trend display. 22. De-select all other statistics by clicking on any existing Xs in the Show column. De-selecting a statistic will remove the trend from the trend display. 23. From the Y Axis applies to: box, select the #5 statistic. 24. Under X-axis Scale (located below the trend display), select Record. 25. Click the Scale All Trends box to reset the Y-axis. 26. The trend display should look similar to Figure 2 below, with two distinct peaks displayed. The left peak is from the coarse adjustment and the right peak is from the fine adjustment. 27. Make sure the Lock Cursor box is not checked (i.e., an X is not displayed), select the + from the trend toolbar (located below the Trend Display), and move the Current Record crosshair on the trend display graph to the peak value measurement of the trended statistic as determined by the fine adjustment. 28. From the Setup Menu, select Annotation. 29. Look at the Annotation field for the micrometer reading at this maximum value. The micrometer position corresponding to this value is the window reference position (e.g., +45 µm). In some cases, the maximum value of the trended statistic may be observed at more than one consecutive micrometer position. If a plateau is observed, the first micrometer position encountered at the maximum value of the statistic (i.e., the left-hand side of the plateau in the trend display) should be used as the window reference position (WRP) Rev K Page 7 of 9

8 Figure 2 Example of Trend Display in the Data Review Module Window Reference Procedure Repeatability While all measurements of the window reference position should be within a range of ±5 microns (i.e., ±0.005 mm or one-half of an increment on the rotating dial), due to inconsistencies in ink application, you should not expect actual counts achieved to be the same each time. Contact a Mettler-Toledo Technology and Application Consultant if there is a greater than ±5-micron discrepancy in the measurement of the window reference position. Setting the Micrometer at the Standard Focal Point Position The focal point position defines the location of the focal point relative to the external surface of the Lasentec FBRM probe window and the window of the FBRM/Raman probe. The standard focal point position for both probes is 20 microns (2 marked increments) inside the sapphire window surface. Unless there is a specific, application-based need for an alternate position, use the standard focal point position for all applications. To set the micrometer at the required focal point position for a Lasentec D600 FBRM probe or FBRM/Raman probe: 1. Turn the micrometer knob at least 50 microns to the right from the window reference position (e.g., if the WRP was +45 µm, turn the micrometer to the right to 5µm). 2. Next, turn the micrometer knob to the left to the WRP minus 20 microns (e.g., turn the micrometer to the right from 5 µm to +25 µm). This is the standard focal point position Rev K Page 8 of 9

9 To eliminate the effects of hysteresis, you must always reach the final micrometer position going to the left. If you pass the required focal point position, repeat steps 1 and 2 above. Determining a Clean Probe Window For the purpose of this procedure, the probe window is considered clean if counts are less than 150 per second and not repeated in a single channel when the probe tip is immersed in de-ionized (DI) water. If acetone or other solvents are required to clean the probe window, the solvent should be thoroughly rinsed away with DI water. For other applications, see the section called Cleaning the Probe Window in the hardware manual Rev K Page 9 of 9