BROOKFIELD KF10 and KF20 Falling Ball Viscometer Operating Instructions Manual No. M09-352-B0411 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 Components . ......................................................................................................................................3 Specifications .....................................................................................................................................4 Details on Viscosity Measurement Range .
I. INTRODUCTION Falling Ball Viscometer, Models KF10 and KF20, comply with the German industry standard DIN 53015. The measuring principle, according to Höppler, is to determine the falling time of a ball in a cylindrical glass tube filled with liquid. The working angle of the falling tube in the KF10 is fixed in the DIN 53015 position of 80° relative to horizontal.
Wire Cleaning Brush for Sample Tube Brush to clean loose debris from Falling Balls Leather cloth for polishing Falling Balls Sealant ring (perbunane) A 16x20 Sealant ring (silicone) 10x14x2 Thermometer, 0°C to +100°C* Operator Manual Instrument Case Latex rubber tubing, 5/16 I.D. x 1/16 wall Certificate of Calibration FB53 FB52 FB70 FB31 FB32 TM1 M09-352 FB71 FB69 ____ 1 1 1 4 1 1 1 1 1 1 *Other temperature measurement options are available. Contact your Brookfield dealer for information. I.
I.3 Details on Viscosity Measurement Range Per DIN 53015, the Falling Ball method is suitable for measuring dynamic viscosities ranging from 0.6 mPa•s to 250,000 mPa•s at temperatures from -60ºC to 150ºC. Use is made of six balls having different diameters, each ball covering part of the range. All guideline values and referenced parameters in the following table are per DIN 53015. Ball No. Viscosity measurement range (guideline value) (mPa•s) 1 0.
b. c. eliminate the formation of air bubbles avoid a build up of pressure (see Fig. 3 and 4) 5. Mounted on the lower plate are tubes (10) to which the circulating temperature bath tubing is attached. NOTE: Any alteration, modification or replacement of the sample tube, water jacket, falling tube screw fittings, tension rods or balls renders the ball constants invalid and requires the re-calibration of the viscometer. See Appendix B. 6.
13 12 11 7 9 2 6 14 50° 8 10 60° 70° DIN 22 5 15 3 1 4 Figure 2: Falling Ball Viscometer KF10 1. Stand 2. Viscometer 3. Bubble level 4. Leveling screw 5. Adjustment screw for angle (KF20 only) 6. Sample tube 7. Upper plate 8. Lower plate 9. Water jacket 10. Tubes for connection to water bath 11. Fastening screw for thermometer 12. Screw neck Brookfield Engineering Labs., Inc. Page 13. Sealing washer 14. Bearing for viscometer rotation 15. Nuts 16. Upper locking plug 17.
Figure 3: Sample tube screw fitting (top) Figure 4: Sample tube screw fitting (bottom) Brookfield Engineering Labs., Inc. Page Manual No.
I.5 Safety Symbols and Precautions Safety Symbols The following explains safety symbols which may be found in this operating manual. Refer to the manual for specific warning or caution information to avoid personal injury or damage to the instrument. Precautions If this instrument is used in a manner not specified by the manufacturer, the protection provided by the instrument may be impaired. This instrument is not intended for use in a potentially hazardous environment.
II. GETTING STARTED II.1 Choice of Balls The balls are chosen in such a way that the minimum falling time is not less than what is shown in the table and the maximum falling time is not greater than 300 s. The DIN 53015 indicates that a falling time greater than 300 s is allowed, but for practical reasons, a shorter test time makes more sense. Ball No. 1 2 3 4 5 6 Diameter [mm] Minimum falling time [s] 15.81 15.60 15.60 15.20 14.00 11.00 60 30 30 30 30 30 Lower measuring range limit [mPa•s] 0.5 2.
to the air bubbles. Due to the design of the upper locking plug, air bubbles cannot get into the sample tube. • The sample must be free of air bubbles between the two locking plugs. The lid of the upper locking plug is attached and the temperature control (desired test temperature) must be achieved. After proper temperature control is achieved, the upper cap is screwed on. Do not heat the sample with the upper lid attached as pressure may build in the tube.
II.4 Measuring the Falling Time Before beginning the measurement, the upper cap is loosened (unscrewed) again to let off possible pressure. The time which the balls take to run between the top and bottom ring marks in the sample tube is determined with a stop watch (resolution 0.01 s). It is recommended that you record the passage of the lower ball point using the ring marks as follows. Position your eyes at the same height as the ring marks so that these appear as a line.
III. CALCULATIONS III.1 Dynamic Viscosity With Newtonian liquids absolute values of the dynamic viscosity are calculated, where as, for non-Newtonian liquids, relative values of the dynamic viscosity (apparent viscosity) are calculated.
III.2 Kinetmatic Viscosity The conversion of the dynamic viscosity into the kinematic viscosity is accomplished using the following equation: Equation 2: ν = η ρ2 ν Kinematic viscosity [mm2/s] η Dynamic viscosity [mPa•s] ρ2 Density of the sample [g/cm3] Brookfield Engineering Labs., Inc. Page 14 Manual No.
IV. DETERMINATION OF THE NON-NEWTONIAN BEHAVIOR Non-Newtonian behavior can be determined when different measurement times are recorded with repeated tests. IV.1 Thixotrophy/Rheopexy Thixotropy (rheopexy) is indicated if the travelling times for a ball decreases (increases) when repeated measurements are made on the same volume of sample. NOTE: If temperature control is not done correctly, thixotropy or rheopexy can be inferred by mistake.
Appendix A - Maintenance A.1 Exchanging the Sample Tube Caution Glass Components. Excessive force may result in broken glass. 1. Loosen the two setscrews of the sample tube screw fittings (above and below). a. Empty the water jacket and sample tube. Make sure the water jacket is clean on the inside surface before reassembling. 2. Unscrew both of the sample tube screw fittings using a ring nut key. 3. Pull off the rubber seal (washer) on one end of the sample tube. 4.
Appendix B - Calibration of the Ball Constants Re-calibration of the ball constants is required if: 1. changes in the sample tube or water jacket were made 2. one or more balls were replaced The calibration requires the use of a Newtonian viscosity standard. Choice of the viscosity standard is according to the ball; the standards are provided in 100 mL bottles and can be obtained from your Brookfield dealer. BALL NO.
Appendix C - Warranty Repair and Service Brookfield Viscometers are guaranteed for one year from date of purchase against defects in materials and workmanship. They are certified using primary viscosity standards traceable to the National Institute of Standards and Technology (NIST). The Viscometer 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.
