BROOKFIELD MODEL BF35 Installation, Operation and Maintenance Instructions Manual No.
TABLE OF CONTENTS Section 1: Introduction......................................................................................................7 Description....................................................................................................................7 Section 2: Specifications..................................................................................................8 Section 3: Safety..........................................................................................
The information in this document is believed to be accurate and reliable. However, Brookfield Engineering Laboratories, Incorporated, cannot accept any financial or other responsibilities that may result from the use of this information. No warranties are granted or extended by this document. Brookfield Engineering Laboratories, Incorporated reserves the right to change any or all information contained herein without prior written notice. Revisions may be issued at the time of such changes and/or deletions.
Section 1 - Introduction Introduction Description The BF35 Viscometer is extensively used worldwide in both the field and laboratory for the precise measurement of rheological properties of fluids. The BF35 Viscometer determines the flow characteristics of oils and drilling fluids in terms of shear rate and shear stress over various time and temperature ranges at atmospheric pressure.
Section 2 - Specifications Specifications Viscometer Specifications Instrument Geometry True Couette Coaxial Cylinder Speed Accuracy (RPM) .001 8 Fixed Speeds (600, 300, 200, 100, 60, 30, 6, and 3) Motor Speeds (RPM) Readout Direct Dial Power Requirements 13 - 16 VDC Weight (kg) 6.0 Dimensions (cm) 15.2 x 17.8 x 40.6 Shipping Weight (kg) 20.4 Shipping Details (cm) 55.9 x 25.4 x 40.6 Range of Measurement for BF35 Rotor - Bob R1B1 R1B2 R1B3 R1B4 Rotor Radius, RR, (cm) 1.8415 1.8415 1.
Shear Rate Range R1B1 R1B2 R1B3 R1B4 1.7023 0.3770 0.2682 0.2682 5.11 1.13 0.80 0.80 10.21 2.26 1.61 1.61 30 RPM 51.07 11.31 8.05 8.05 60 RPM 100 RPM 200 RPM 300 RPM 600 RPM 102.14 170.23 340.46 510.69 1021.38 22.62 37.70 75.40 113.10 226.20 16.09 26.82 53.64 80.46 160.92 16.09 26.82 53.64 80.46 160.92 Viscosity Ranges R1B1 R1B2 R1B3 R1B4 Minimum Viscosity @600 RPM 0.5 4.5 12.7 25 Maximum Viscosity @0.
Shear Stress Conversions To convert from units on left side to units on top, multiply by factor @ intercept Dyne/cm2 Pa lb/100ft2 lb/ft2 DR Dyne/cm2 1 0.1 0.2084 0.002084 0.1957 Pa 10 1 2.084 0.02084 1.957 lb/100ft2 4.788 0.4788 1 0.01 0.939 lb/ft2 478.8 47.88 100 1 93.9 DR 5.107 0.5107 1.065 0.01065 1 What Bob and Spring Should I Use? There is often confusion or misunderstanding about what a viscometer can actually measure.
Section 3 - Safety Safety Explanation of Symbols Caution: Risk of Danger - This symbol directs the operator to consult the instruction manual for safety related warnings. (ISO-7000-0434) Whenever this symbol is used on the equipment, the user must consult the manual to determine the nature of the hazard and any actions which have to be taken. Fuse: This is the internationally recognized symbol for a userreplaceable fuse.
Electrical Requirements The BF35 Viscometer is to be powered by a DC power source capable of providing between 13 and 16 volts DC. The equipment is current limited to 4 amps by a user-replaceable fuse. However, we suggest that the power supply be current limited to less than 4 amps to provide additional protection to the equipment.
Caution - Risk of Danger: This equipment produces sound pressure in excess of 85 dBA. Protective measures (such as hearing protection, noise-reducing baffles, or a hood) should be considered. Equipment Operation Caution - Risk of Danger: The (13 - 16 VDC) power cord and the DC inlet are the emergency disconnect devices. Do not position the equipment such that it is difficult to operate the emergency disconnect devices.
Section 4 - Setup Setup 1. Connect the instrument to a 13 - 16 VDC, current-limited power source. 2. With the instrument turned off, place the splash guard onto the bob shaft with the short tube end pointed up towards the bearings. Push up. 3. Screw on the appropriate bob with the tapered end up towards the splash guard. 4. Place the sleeve onto the rotor over the bob. The threads assure the rotor will attach evenly and uniformly each and every time. 5. The power switch is located on the back panel.
Section 5 - Calibration Calibration The BF35 Viscometer can lose calibration while in service if the bob shaft bearings become contaminated or if the bob shaft itself is bent. If the dial does not read zero when it should or if there is excessive dial deflection when the main shaft is turning, this may indicate that the bob shaft bearings are sticking. If the spring appears to be non-linear, the bob shaft may be bent. Your viscometer will require servicing if it exhibits any of these symptoms.
setting until the thermometer reading becomes stable to within ± 0.2˚F (0.1˚C) per seconds. Note and record the temperature reading. 6. Once the temperature has stabilized, operate the viscometer at 600 RPM and then at 300 RPM. Note and record the dial readings to the nearest 0.5 dial unit. 7. Using the temperature-viscosity chart supplied with the calibration fluid, determine the certified viscosity to the nearest 0.5 centipoise. a. b.
Section 6 - Operation Operation Measuring Viscosity: 1. 2. Mix the sample on the “STIR” setting for 10 seconds while heating or cooling the fluid. Monitor the temperature with a thermometer. Continue to mix until the sample reaches the target temperature. Rotate the knob to one of the speed settings. When the dial reading stabilizes, record the reading and the temperature. Repeat this step for any other speeds that your test requires.
Section 7 - Calculations Calculations Plastic Viscosity (PV), cP = 600 RPM reading - 300 RPM reading Yield Point (YP), lb./100 ft2 = 300 RPM reading - Plastic Viscosity (PV) Apparent Viscosity (AV), cP = 600 RPM reading / 2 Gel Strength, 10 second, lb./100 ft2 = the maximum dial deflection after 10 sec. Gel Strength, 10 minute, lb./100 ft2 = the maximum dial deflection after 10 min. Brookfield Engineering Labs., Inc. Page 18 Manual No.
Section 8 - Disassembly Disassembly Clean the viscometer after every test. 1. Remove the sleeve from the rotor. 2. Remove the bob. 3. Once the bob is removed, remove the splash guard and wipe down the bob shaft. Clean all removed parts with soap and water and dry them thoroughly. Keep the instrument upright at all times, especially when cleaning so that water does not get into the bearings. Brookfield Engineering Labs., Inc. Page 19 Manual No.
Section 9 - Maintenance Maintenance From time to time, the bearings will need to be changed. Complete the following to determine if it is time to perform this maintenance procedure: 1. The viscometer should have a zero dial reading when placed in an upright position with the sleeve not immersed in fluid prior to running tests. 2. With the instrument in this position, rotate the sleeve at 600 RPM. The dial reading in air should not exceed one. 3.
If you are replacing only the torsion spring, discard the old spring, and skip to step 20 to complete the process. Set Screws (Step 5) Aluminum Clamp Sleeve Set Screw (Step 4) Stop Block Bridge Torsion Spring Set Screw (Step 6) Dial Brass Bearing Mount 8. Remove the four screws from the bridge and lay it gently to the right side. Do not touch the encoder that encircles the flywheel. 9.
Do not touch the bearing with bare hands. Dirt, oils, and other contaminants can damage the bearing. 13. Replace the brass bearing mount back onto the two pins and tighten the two screws. 14. Remove the Splash Guard, loosen the set screw on the lower brass bearing shield (one turn counter-clockwise), and slide the lower bearing down the bob shaft to remove all three components. 15. Use surgical gloves to apply a new lower bearing onto the bob shaft. 16.
20. Gently slide the torsion spring through the aluminum clamp sleeve and into the dial. Make sure the bottom of the torsion spring is seated properly inside the dial. Tighten the set screw located at the top of the dial to secure the torsion spring. 21. Replace the stop block and the two screws. Make sure that the zero dial reading is aligned with the fill on the stop block. 22. Press down on the torsion spring until it is flush with the Aluminum Clamp Sleeve and tighten the set screw. 23.
