BROOKFIELD LFRA TEXTURE ANALYZER Operating Instructions Manual No. M/05-370-B0507 SPECIALISTS IN THE MEASUREMENT AND CONTROL OF VISCOSITY with offices in: Boston • Chicago • London • Stuttgart • Guangzhou BROOKFIELD ENGINEERING LABORATORIES, INC. 11 Commerce Boulevard, Middleboro, MA 02346 USA TEL 508-946-6200 or 800-628-8139 (USA excluding MA) FAX 508-946-6262 INTERNET http://www.brookfieldengineering.com Brookfield Engineering Labs., Inc. Page Manual No.
TABLE OF CONTENTS I. INTRODUCTION.................................................................................................................................................................................... 3 I.1 I.2 I.3 I.4 I.5 I.6 I.7 I.8 Components..................................................................................................................3 Utilities.........................................................................................................................
I. INTRODUCTION The Brookfield LFRA Texture Analyzer measures the resistance of a material to an applied force. The force is applied through a vertical compression of the sample and the resistance is measured through a load cell. This resistance can be interpreted to provide a measure of the texture or other physical characteristics of the material. The LFRA Texture Analyzer is the most recent development of the original Boucher Jelly Tester.
I.2 Utilities Input Voltage: Input Frequency: Power Consumption: Fuse: Power Cord Color Code: Hot (live) Neutral Ground (earth) 115 VAC or 230 VAC 50/60 Hz 150 VA Two 4 amp, 5 x 20mm, Time-lag United States Outside United States Black White Green Brown Blue Green/Yellow Main supply voltage fluctuations are not to exceed ±10% of the nominal supply voltage. I.3 Units The LFRA Texture Analyzer uses the SI system of units for all parameters.
Position: Range: 0-75 mm Resolution: 0.1mm Accuracy: 0.1mm Output: Computer: RS232 Compatible Serial Port Environmental Conditions: 0°C to 40°C temperature range (32°F to 104°F) 20% - 80% relative humidity, non-condensing atmosphere I.5 Installation 1) Prepare a clean, level surface. NOTE: This instrument is a sensitive load measuring device. It should be installed on a clean, solid and level bench surface which is free from external vibrations.
8) Allow the instrument to warm up for 10 minutes. Check calibration according to Section III.8. I.6 Safety Symbols and Precautions Safety Symbols The following explains safety symbols which may be found in this operating manual. Indicates hazardous voltages may be present. Refer to the manual for specific warning or caution information to avoid personal injury or damage to the instrument.
I.7 Key Functions The LFRA Texture Analyzer is operated through two keys and a knob located on the keypad. Additionally, there is an emergency stop button located on the base. RESET / STOP This key is used to stop a test in progress. Display START This key is used to start the test. During the descent of the probe, prior to the trigger point, this key can be used to accelerate the rate of descent. Keypad SELECT / SCROLL This knob has multiple functions: 1.
II. QUICK START 1. Unpack the instrument according to Section I.5. 2. Attach the selected probe. See Section IV.2 for more information. 3. Place the sample on the base table. Adjust the table height so that the surface of the sample is within 5 mm of the probe (see Section III.3). 4. Set the test mode to Normal See Section III.6 for more information. 5. Set the trigger value to 0.5% of the load cell range. For example, use 5g for a 1000g load cell instrument. 6.
III. OPERATION III.1 Principle The Brookfield LFRA Texture Analyzer drives a probe through a set distance at a set speed into a sample material that is placed (or fixed) on the base table. The LFRA offers a variety of probes, fixtures, and test parameters to provide the user with a range of options for evaluating the texture of a sample material. The following section describes the use of the LFRA. III.2 Emergency Stop The LFRA Texture Analyzer can operate with up to 4500g (4.
III.3 Base Table The Base Table is designed to provide quick adjustment of the sample height. There are two methods of adjustment; the Locking Knob and the Locking Nut, see Figure III.2. Base Table Locking Nut Base Table Post Locking Knob Figure III.2 The Locking Knob is used to fix the Base Table in position. To loosen the knob, turn counterclockwise. When the knob is loose, the table may be moved vertically. To tighten the knob, turn clockwise (tighten the knob only finger tight).
III.4 Probes There are a range of probes available for use with the LFRA Texture Analyzer (see Appendix A). All probes are configured with a right hand thread to attach to the LFRA. Attach the probe with care to prevent damage to the threads. Do not overtighten! The probes may be cleaned while attached to the LFRA. Follow recommendations in Section I.8. Do not apply excessive upward, downward or sideways force. Damage may occur to the load cell. III.
Once the test mode is selected the test parameters must be set. •Normal requires: Trigger, Distance, Speed. •Hold Time requires: Time, Trigger, Distance, Speed. •Cycle Count requires: Count, Trigger, Distance, Speed. •Bloom is a fixed test with preset parameters. •Static Load is for verifying calibration and does not require any parameters. The test parameters are defined as follows: Trigger: The load, in grams, measured by the LFRA to indicate that the probe is in contact with the sample.
Data entry is accomplished by setting each digit individually. For example: to set a value of 57.0 as the target distance, rotate the Select / Scroll Knob until the “D” in “Distance” is blinking. Depress the Select / Scroll knob to get to the tens digit, then rotate the knob to the value 5. Depress the Select / Scroll knob again to get to the ones digit, then rotate the knob to the value 7. Depress the Select / Scroll knob to get to the tenths digit, and depress it again to leave the value at 0.
A test may be repeated by simply pressing the Start button while viewing the results. The test may be stopped at any time by using the Stop / Reset button or by pressing Emergency Stop. We recommend that the Stop / Reset button be used for normal operation. The Emergency Stop is intended for emergency use only. III.8 Results Two parameters will be displayed at the conclusion of a test: Peak Load and Final Load. Both Peak and Final Load are displayed in units of grams (g).
Note: The Start button may be used to zero the LFRA at any time during the Static Load test. If you remove the weights and Hanger and the display does not return to zero, press Start to zero. Be sure to remove the weights and Hanger prior to zeroing the LFRA. The display will change to show Static Load active parameters once the zero process is complete (see Figure III.9). The Hanger should be fixed to the Hanger Mount.
Example of Calibration Verification 1000 gram LFRA Texture Analyzer, accuracy according to Table III.2, ±5 grams, 1500 gram calibrated weight set Weight Hanger 150 250 500 Calibrated Value 99.76g 149.22g 248.76g 497.53g Brookfield Engineering Labs., Inc. Total Weight 99.76g 248.98g 497.74g 995.27g Page 16 Measured Value -99.3g -249.5g -495.5g 1000.3g Result pass pass pass pass Manual No.
IV. TEST METHOD DEVELOPMENT The measurement results provided by the LFRA Texture Analyzer will be dependent on several factors relating to the sample, the test probe, and the test parameters. A variation on any of these elements may result in a change in measurement results. For good test repeatability it is suggested that a clear and complete test method be developed. The following sections describe these elements.
Within a probe category, variations of geometry can be significant. It may require a larger force to drive a cone of shallow angle as compared to a cone of steep angle. Similarly, a cylinder of large diameter may require a larger force than a cylinder of small diameter. The selection of the probe (type and size) will affect the test result. IV.3 Test Parameters The LFRA Texture Analyzer will require the setting of several parameters depending upon the test method selected (see Table III.1).
V. APPLICATIONS This applications section should be used as a guide to the development of techniques specific to your own application and requirement. These notes are empirical in nature. Deviation from the described test configurations (parameter settings, sample size, shape, formulation, etc.) will result in deviations from the observations discussed in each application. V.1 Comparison of Low Fat and Virtually Fat Free Yogurt Consistencies PRODUCT: Low-fat (1%) and virtually fat-free (0.
NOTE: Samples were tested with original containers as supplied. Use of different dimension holding vessels will change results obtained, therefore, operators must be consistent with the test configuration used.
PARAMETERS: HARDNESS CONSISTENCY (Total Positive Area) Force necessary to attain a given deformation Internal strength of bonds within a product ADHESIVENESS (Total Negative Area) Work necessary to overcome attractive forces between surface of the food and the materials with which it comes into contact. ADHESIVE FORCE Force required to “pull” probe from sample (suction). MODULUS Ratio of stress divided by strain during the first compression cycle (e.g., the slope of the force: deformation curve).
RELATED TESTS: Sample conditions which will effect results generated: 1. Fat content 2. Protein content 3. pH 4. Set/Stirred product 5. Syneresis and surface characteristics 6. Presence of inclusions e.g. fruit 45° cone penetrometer test utilizing hold until time function to determine relaxation. BIBLIOGRAPHY AND REFERENCES: Anon. 1988. Facts About Yogurt. National Dairy Council, London. Anon. 1996. Yogurt: A Technical Profile. National Dairy Council, Education Department. Bylund, G.
METHOD: Biscuits approximately 6 mm thick were located beneath the probe and clamped to the analyzer bed using low pressure clips. The probe then penetrated sample to target distance and the profile of characteristics was recorded through the interface package. READING: F X Quantity.of.Fractures Y Hardness (H1) Calculate.mean.of.all.values (HAV) Fracture.Point Final Distance H1/HAV.=.Indication.of.Crispiness (Crispiness.becomes.a.function.of.hardness) Relate.the.mean.value.of.peaks.obtained.to.
PARAMETERS: HARDNESS Force necessary to attain a given deformation CONSISTENCY Internal strength of bonds within a product CRISPINESS Internal ruptures and fracture of sample as structure is broken. Indicative of sample hardness and internal bond strength RESULTS: HARDNESS MEAN OF PEAKS CONSISTENCY CRISPINESS RATIO Chocolate Plain 736 633.9 2460.2 1.16 973 657.5 3917 1.
LFRA SETTINGS: MODE: PLOT: SPEED: DISTANCE: OPTION: TRIGGER: Measure force in compression Final 0.1 mm/s 2, 4, or 6 mm Normal Auto 4g pre-set PROBE REF: Stainless steel needle probe, 10° Taper (Ref: TA9) Confectionery holding rig METHOD: Samples were removed from wrappers and broken into individual chunks. The individual chocolate piece was then held within jaws of confectionery holder clamped to adjustable bed of LFRA approximately 2mm below surface probe. READING: F HARDNESS Peak.+ve.
RESULTS: PARAMETER UNIT 2mm HARDNESS (g) 334 CONSISTENCY (gs) 3192.3 ADHESION (g) -18 FORCE ADHESIVENESS (gs) -0.4 4mm 6mm 722 1278.6 -60 1159 23878.9 -15.1 -4.1 -180 where: gs = work NOTE: Adhesion forces give greatest differentiation. CONCLUSIONS: This empirical procedure generates key information related to the parameters of chocolate hardness and consistency, while additional information relating to adhesion is also formed.
Appendix A - Probes and Fixtures Probes Standard Probe kit comes complete with the following probes: Cylindrical TA4/1000 TA5 TA10 TA11/1000 General TA25/1000 TA39 TA41 TA44 Spherical TA18 TA43 Special Purpose TA26 TA7 TA9 Conical TA2/1000 TA15/1000 TA17 Figure A-1: Part No. A-P-KIT2, Standard Probe Kit. Includes: Cylinder, Conical, Spherical, and General Probes with Carrying Case Cylinder Probes TA3/100 25.4 mm D, 35 mm L, Clear Perspex (low mass) TA3/1000 25.4 mm D, 20 mm L, Clear Perspex TA4/100 38.
Conical Probes TA2/100 60°, 30 mm D, Clear Perspex (low mass) TA2/1000* 60°, 30 mm D, Clear Perspex TA15/100 45°, 30 mm D, Clear Perspex (low mass) TA15/1000* 45°, 30 mm D, Clear Perspex TA16 40°, 28 mm D, Clear Perspex TA17* 30°, 25 mm D, Clear Perspex TA27 20°, 12 mm D, Clear Perspex TA29 15°, 8 mm D, Stainless Steel TA32/100 90°, 30 mm D, Clear Perspex (low mass) TA32/1000 90°, 30 mm D, Clear Perspex Spherical Probes TA8 6.35 mm D, Stainless Steel TA18* 12.
Appendix B - Troubleshooting If no power to the instrument: Check: • User replaceable fuses: two (2) fuses, 4 amp, 5 x 20mm, time-lag • Fuses located within power entry module on the rear of the instrument. • If fuses blow continually, serious damage to the instrument could result. Contact repair services immediately.
Appendix C - Use with TexturePro Lite Software The following screens show the startup procedure for use of TexturePro Lite Software with the LFRA Texture Analyzer. TexturePro Lite can be used to run automated tests, collect data and perform analytical calculations. Brookfield Engineering Labs., Inc. Page 30 Manual No.
TEXTUREPRO.LITE.README.FILE THIS.FILE.APPEARS.DURING.INSTALLATION.AND.MAY.BE VIEWED.AT.ANY.TIME.FROM.THE.HELP.FILE ***.PLEASE.NOTE.*** =================== .... MICROSOFT.EXCEL.MACRO.VIRUS.PROTECTION •....The.security.level.for.macro.virus.protection.must.be.set.to. function.properly. Medium .or. Low .for. TextureProLite. .TextureProLite •....When.set.to.medium,.a.warning.message.will.appear.each.time.the started. •Select.the.'ENABLE.MACROS'.option.to.run .TextureProLite .to .software.is . •....
SETTING.VISUAL.BASIC.TRUSTED SOURCES.FOR.MICROSOFT.OFFICE . THE.EXAMPLE.SHOWN.IS.FOR.OFFICE.XP TEXTURE.PRO.LITE.SOFTWARE IS.BASED.UPON.MICROSOFT.EXCEL LFRA.MENU.CONTAINS.ALL.COMMANDS NECESSARY.TO.SETUP.TESTS,.RUN.SAMPLES AND.ANALYZE.DATA Brookfield Engineering Labs., Inc. Page 32 Manual No.
SETTING.UP.A.TEST Define.Test.Parameters Enter.test parameters ENTER.TEST.TYPE ENTER.TARGET.UNIT FILL.IN.APPROPRIATE FIELDS,.THEN.SAVE.TEST DEFINITION TPA : a special type of 2 cycle test Compression : a simple compression test SETTING.UP.A.TEST Define.Test.Parameters Enter.test parameters ENTER.TEST.TYPE ENTER.TARGET.UNIT FILL.IN.APPROPRIATE FIELDS,.THEN.SAVE.TEST DEFINITION Load : compress until a certain load force is reached Distance : compress a certain distance into the sample %.
SETTING.UP.A.TEST Define.Test.Parameters Enter.test parameters ENTER.TEST.TYPE ENTER.TARGET.UNIT FILL.IN.APPROPRIATE FIELDS THEN.SAVE.TEST DEFINITION Hold.Time : probe holds at its target for some length of time Trigger.point : a load force indicating the surface of the sample Test.speed:. probe speed during compression Target.value:. related to Target Unit SETTING.UP.A.TEST Define.Sample.Parameters Enter.sample.information as.appropriate Then.save.Sample Definition Brookfield Engineering Labs., Inc.
SETTING.UP.A.TEST Define.Sample.Parameters Enter.sample.information as.appropriate Then.save.Sample Definition WHILE.TEST.IS.RUNNING.A.PREVIEW.GRAPH OF.THE.TEST.RESULT.WILL.APPEAR DATA ACQUISITION IS. NOT COMPLETE UNTIL.THIS WINDOW APPEARS, EVEN THOUGH.THE TEST.MAY HAVE ALREADY FINISHED ALWAYS SAVE.DATA AT.END.OF TEST Brookfield Engineering Labs., Inc. Page 35 Manual No.
SHORTCUT.MENU.BUTTONS DATA.ANALYSIS.AND.OPERATION TEST.PROPERTIES DEFINE.NEW.TEST OPEN.A.SAVED.TEST VIEW.METHOD.FOR CURRENT.DATA CURRENT.DATA SHORTCUT.MENU.BUTTONS DATA.ANALYSIS.AND.OPERATION SAMPLE.PROPERTIES DEFINE.A.NEW.SAMPLE OPEN.A.SAVED.SAMPLE VIEW.PROPERTIES.OF CURRENT.SAMPLE CURRENT.DATA Brookfield Engineering Labs., Inc. Page 36 Manual No.
SHORTCUT.MENU.BUTTONS DATA.ANALYSIS.AND.OPERATION ADJUST.PROBE.POSITION MANUALLY..UP/DOWN CURRENT.DATA SHORTCUT.MENU.BUTTONS DATA.ANALYSIS.AND.OPERATION LOCATE.BASE.TABLE REQUIRED.WHEN.MEASURING SAMPLE.LENGTH.IS.DESIRED CURRENT.DATA Brookfield Engineering Labs., Inc. Page 37 Manual No.
SHORTCUT.MENU.BUTTONS DATA.ANALYSIS.AND.OPERATION START.TEST EXECUTES.THE.DEFINED TEST.METHOD CURRENT.DATA SHORTCUT.MENU.BUTTONS DATA.ANALYSIS.AND.OPERATION GRAPHING LOAD. vs .DISTANCE DISTANCE. vs .TIME LOAD. vsTIME CURRENT.DATA Brookfield Engineering Labs., Inc. Page 38 Manual No.
SHORTCUT.MENU.BUTTONS DATA.ANALYSIS.AND.OPERATION OVERLAY.FILES LOADS.OR.CLEARS.UP.TO.NINE ADDITIONAL.DATA.FILES.FOR COMPARISON: GRAPHS STATISTICAL.TABLES CURRENT.DATA SHORTCUT.MENU.BUTTONS DATA.ANALYSIS.AND.OPERATION CREATE.TEST.REPORT FOR.CURRENT.DATA SHOWS.PREFORMATTED.TEST REPORT.OF.CURRENT.DATA CURRENT.DATA Brookfield Engineering Labs., Inc. Page 39 Manual No.
SHORTCUT.MENU.BUTTONS DATA.ANALYSIS.AND.OPERATION OPEN.STORED.DATA.FILE LOADS.A.STORED.DATA.FILE.INTO CURRENT.DATA.COLUMNS CURRENT.DATA SHORTCUT.MENU.BUTTONS DATA.ANALYSIS.AND.OPERATION CLEARS.CURRENT.DATA CLEARS.CURRENT.DATA.COLUMNS CURRENT.DATA Brookfield Engineering Labs., Inc. Page 40 Manual No.
SUMMARY.OF.SHORTCUT.MENU.BUTTONS TEST.PROPERTIES: DEFINE A NEW TEST, OPEN A SAVED TEST OR VIEW TEST PARAMETERS OF CURRENT DATA GRAPHING: SHOWS X/Y GRAPH OF LOAD vs.DISTANCE, DISTANCE vs TIME, or LOAD vsTIME* SAMPLE.PROPERTIES: DEFINE A NEW SAMPLE, OPEN A SAVED SAMPLE OR VIEW PROPERTIES OF CURRENT SAMPLE OVERLAY.FILES: LOAD UP TO NINE DATA FILES FOR COMPARISON IN GRAPHS, OR IN STATISTICAL TABLE OF TEST RESULTS ADJUST.PROBE.POSITION UP/DOWN CREATE.TEST.
TEXTURE.RESULTS Selecting.Results.for.Reports CHECK.ALL.DESIRED RESULTS GENERAL .and. USER DEFINED.RESULTS .OFFER ADDITIONAL.OPTIONS GREYED.OUT.RESULTS.DO NOT.APPLY.TO.CURRENT TEST.METHOD THEN.SAVE.TEST.METHOD DEFINITION PREFORMATTED.TEST.REPORT Brookfield Engineering Labs., Inc. Page 42 Manual No.
PREFORMATTED.TEST.REPORT.(continued) VIEWING.TEST.RESULT.STATISTICS.FROM.MULTIPLE.DATA.FILES STATISTICS UP.TO.NINE.ADDITIONAL.DATA FILES.MAY.BE.LOADED.BESIDE.THE CURRENT.DATA THE.STATISTICS.BUTTON.WILL SHOW.STATISTICS.FOR.ALL SELECTED.RESULTS CURRENT.DATA Brookfield Engineering Labs., Inc. OVERLAYED.DATA Page 43 Manual No.
TO.COMPARE.RESULTS.OF.MORE.THAN.10.DATA FILES,.HIGHLIGHT.THE.ENTIRE.STATISTICS.TABLE AND.COPY.THE.CELLS.TO.A.NEW.WORKBOOK … PASTE.INTO.NEW.WORKSHEET.AS.AN.*.XLS.FILE …USING.THE. “ PASTE.SPECIAL ” .FUNCTION.FROM.THE.EDIT.MENU, CHECK. “ VALUES ” .TO.EXPORT.ONLY.THE.CELL.CONTENTS. …AND.CLICK.OK YOU.WILL.THEN.HAVE.YOUR.DATA.IN.EXCEL.FORMAT.FOR FURTHER.MANIPULATION.OR.COMPARISON Brookfield Engineering Labs., Inc. Page 44 Manual No.
SEE.THE.TEXTUREPRO.HELP.FILE.FOR.MORE.DETAILS.ON.ALL ASPECTS.OF.TEXTURE.TESTING.AND.RESULTS Brookfield Engineering Labs., Inc. Page 45 Manual No.
Appendix D - Warranty and Repair Service Brookfield Texture Analyzers are guaranteed for one year from date of purchase against defects in materials and workmanship. The Texture Analyzer must be returned to Brookfield Engineering Laboratories, Inc. or the Brookfield dealer from whom it was purchased for no charge warranty service. Transportation is at the purchaser’s expense. For repair or service in the United States return to: Brookfield Engineering Laboratories, Inc.
