AMETEK M93-270-F0723 Brookfield Spiral Adapter Instruction Manual

AMETEK M93-270-F0723 Brookfield Spiral Adapter

INTRODUCTION

When used with any Standard Brookfield Viscometer/Rheometer, the Spiral Adapter can measure fluid viscosity at various shear rates. Viscosity is a measure of a fluid’s resistance to flow. You will find a detailed description of the mathematics of viscosity in the Brookfield publication “More Solutions to Sticky Problems”, which is available as a pdf file on the Brookfield website.

The Spiral Adapter has an inner, threaded spindle surrounded by a concentric outer cylinder, as shown in Figure 1. This combination causes the sample to be continuously pumped up through the gap between the rotating spindle and the outer cylinder. The material reaches a steady state of flow during which viscosity is measured.

The principle of viscosity measurement is to drive the spiral spindle (which is immersed in the test fluid) through a calibrated spring in the Viscometer/Rheometer. The viscous drag of the fluid against the spindle is measured by the spring deflection.

The measuring range of the Spiral Adapter [in centipoise (cP) or milliPascal seconds (mPa•s)] is determined by the rotational speed of the spindle, the length and effective diameter of the spindle, the length and diameter of the chamber the spindle is rotating in, and the full scale torque of the viscometer’s calibrated spring.

COMPONENTS

The following components are included in the Spiral Adapter Accessory (part number SAA):

A Pivot Cup (part number SAA-BR3) is provided and may be required to accommodate the Spiral Adapter when used with selected legacy instruments. Please check to be sure that you have received all components, and that there is no damage. If any parts are missing, please notify Brookfield Engineering or your local authorized Brookfield dealer immediately. Any shipping damage must be reported to the carrier.

SPECIFICATIONS FOR TEST SET UP

The Spiral Adapter can be used with any Standard Brookfield Viscometer/Rheometer. Selection of the appropriate Viscometer/Rheometer depends upon the viscosity range of the sample fluid over the shear rates at which it will be tested.

There are four basic spring torque series offered by Brookfield as shown in Table 1. The higher the torque range, the higher the viscosity measurement range. The corresponding ranges for viscosity measurement when the spiral spindle is rotating at 1.0 RPM are also shown. Lower spindle speeds are possible, but the pumping action within the spiral chamber may not be sufficient to provide meaningful viscosity data.

Brookfield Viscometer/Rheometer Series Designation| Spring Torque| Spiral Adapter Viscosity Range at 1.0 RPM cP (mPa·s)
---|---|---
dyne-cm| milli Newton-m| minimum| maximum
LV| 673.7| 0.0673| 1.0 x 104| 1.0 x 105
RV| 7,187.0| 0.7187| 1.1 x 105| 1.1 x 106
HA| 14,374.0| 1.4374| 2.2 x 105| 2.2 x 106
HB| 57,496.0| 5.7496| 9.0 x 105| 9.0 x 106

Table 2 provides general information on Brookfield Viscometers/Rheometers and the type of data that can be generated when using the Spiral Adapter.
Measurement accuracy for any viscosity value obtained during a test is ± 2.0% of the full scale viscosity range (i.e. at 100% torque) for the specific rotational speed in use. See Appendix
A for the necessary information to determine full scale range.

Model| Dial| DV-E| DV-I Series| DV-II/2T Series| DV-III/3T Series
---|---|---|---|---|---
Speeds| 8| 18| 18| 54| 2,600
Shear Rate| 0.677 sec-1 per RPM
Signal Options Torque Viscosity Temperature| No No No| No No No| Yes No | Yes Yes Yes| Yes Yes Yes
Software| No| No| No| Yes| Yes
Temperature Probe| No| | Yes

Note: At speeds of 1 RPM and lower, additional time may be required to allow for complete deflection of the torque sensor.

• Available as option when ordering instrument.

INSTALLATION

Install the spiral spindle by lifting and holding the pointer shaft of the Viscometer/Rheometer while screwing the spindle onto it. The threads are left- hand so the spindle must be turned to the left. Gently lift the chamber over the spindle up against the pivot cup until it rests over the locating shoulder. While holding the chamber in place, fasten the assembly clamp onto the pivot cup, thereby securing the chamber in place. The thread in this case is right hand.

See Figure 2 which shows an assembly schematic for the Spiral Adapter.

Turn on the Viscometer/Rheometer and rotate the spindle at various speeds. Observe the spiral spindle to make sure there is no interference with steady and even rotation. If the spindle does not run “true”, then inspect the spindle and Viscometer/Rheometer shaft for straightness. Rotate the Viscometer/Rheometer shaft without the spindle and confirm that the rotation is steady and even.

Notify Brookfield or your local authorized Brookfield dealer if you experience any difficulty in performing the above procedure.

The spiral spindle code number is 70. If you have a Brookfield digital viscometer or rheometer, which does not contain this number, you must do the following:

• For DV-I and Dial Viscometers, use the torque reading and manually convert to a viscosity value using the table in Appendix A.
• For DV-II Viscometers, use the spindle 99 entry. Enter the following values:
  SMC (Spindle Multiplier Constant)= 105
  SRC (Shear Rate Constant) = .677

Note: Customers who use the Brookfield Spiral Adapter may need to have their Brookfield Viscometer/Rheometer serviced before using this accessory device. All Brookfield digital viscometers/rheometers with serial number lower than 24250 may not have proper alignment between bearings and pivot cup. The same applies to all Brookfield dial viscometers.

This does not present any problem for normal Brookfield Viscometer/Rheometer use. However, it may result in erroneous data when using the Spiral Adapter. For this reason, please return your Brookfield Viscometer/Rheometer to Brookfield for servicing before using it with the Spiral Adapter.

OPERATION

Theory

The Spiral Adapter has an inner, threaded spindle surrounded by a concentric outer cylinder, as shown previously in Figure 1. This combination causes the sample to be continuously pumped up through the gap between the rotating spindle and the outer cylinder. The material reaches a steady state of flow during which viscosity is measured.

At its various rotating speeds, the Brookfield Viscometer/Rheometer with the Spiral Adapter provides viscosity data at different shear rates. The resulting rheogram from an up/down speed ramp supplies important information on the pseudoplastic and thixotropic behavior of the test material which may correlate with actual use in a process. In addition, the measurement method may be less sensitive to sample handling and minor material variations than other viscosity measuring methods.

Test Procedure

Ensure that the test material has been prepared properly in accordance with your prescribed procedure. Lower the Spiral Adapter into the test fluid as shown in Figure 1.

Start the Viscometer/Rheometer and allow it to run at high speed for quick flooding of the chamber. This speed will vary with the nature of the test fluid, but will typically be between 20 and 60 RPM for 2 to 10 minutes. The speed and time of the flood cycle may be an important part of the test procedure. This is because the fluid in the chamber will experience a shear history before the start of the test.

When the chamber is flooded, you will observe test fluid covering the top of the spindle.
Stop the Viscometer/Rheometer and allow a settling period per your defined procedure.
Run the viscosity test and record the data. An example of a test procedure is as follows:

Data Gathering

Brookfield offers applications software for comprehensive data gathering with any IBM compatible PC.

Brookfield software will capture and display the following data in tabular and/or graphical format when used with the appropriate Brookfield Viscometer.

• Viscosity in centipoise (cP) or milliPascal seconds (mPa•s)
• % scale (Brookfield units)
• RPM
• Shear rate (sec-1)
• Shear stress (dynes/cm2 or N/m2)
• Temperature (°F or °C)

The data from a Brookfield dial reading, DV-E or DV-I+ (or DV-I) Viscometer can be manually entered into one of our software applications.

Contact Brookfield Engineering or your local authorized dealer for more details on the appropriate software to use with your viscometer/rheometer.

Application Example – Solder Paste

Applying solder paste is a printing operation that shears the materials as the paste “rolls” on the stencil surface. Solder paste typically shows pseudoplastic behavior (exponential decrease in viscosity with increasing shear rate) as shown in Figure 4.

A plot of viscosity vs. RPM on a log/log scale approximates a straight line as shown in Figure 5. The slope of the line provides information about the shear thinning of the paste. The absolute value of the slope is called the “shear sensitivity factor”.
Experimental correlations of these slope values to actual printing properties allow the user to establish acceptable ranges of the shear sensitivity factor.
The plots shown in Figures 4 and 5 can be generated easily when using Brookfield application software. There is a math model (IPC Paste Analysis) included in the software, which converts viscosity vs. RPM data (Figure 4) into a log/log plot (Figure 5) and automatically computes the “shear sensitivity factor.”

Cleaning the Spiral Adapter

Support the chamber and remove the clamp. Carefully lower the chamber off the spindle. Soak in appropriate solvent. Remove spindle by lifting the lower shaft and holding it firm. Turn the spindle nut to the right (counter- clockwise) to remove. Clean by wiping and soaking in appropriate solvent. A soft brush is provided to aid in cleaning the threads. This brush should also be cleaned in solvent.

APPENDIX A – Spiral Spindle Factors for Torque (% Scale) Measurements

Table A-1 applies to Brookfield Viscometer models with series designation LV, RV, HA, and HB. The procedure for converting a torque value (% scale) into a viscosity value (cP) is accomplished by multiplying the appropriate factor shown in Table A-1 by the torque reading on your Brookfield Viscometer.

Table A-1

The full scale viscosity measurement range (in cP or mPa•s) for any given speed is obtained by multiplying the corresponding spiral spindle factor in the above table by 100.

APPENDIX B – Online Help and Additional Resources

www.brookfieldengineering.com**
The Brookfield website is a good resource for additional and self-help whenever you need it. Our website offers a selection of “how-to” videos, application notes, conversion tables, instructional manuals, material safety data sheets, calibration templates and other technical resources.

http://www.youtube.com/user/BrookfieldEng
Brookfield has its own YouTube channel. Videos posted to our website can be found here as well as other “home-made” videos made by our own technical sales group.

Viscosityjournal.com
Brookfield is involved with a satellite website that should be your first stop in viscosity research. This site serves as a library of interviews with experts in the viscosity field as well as Brookfield technical articles and conversion charts. Registration is required, so that you can be notified of upcoming interviews and events, however, this information will not be shared with other vendors, institutions, etc..

Article Reprints

Available in Print Only
– Brookfield has an extensive library of published articles relating to viscosity, texture and powder testing. Due to copyright restrictions, these articles cannot be emailed. Please request your hardcopy of articles by calling our customer service department directly or by emailing: marketing@brookfieldengineering.com

Available Online
– Brookfield has a growing number of published articles that can be downloaded directly from the Brookfield website. These articles can be found on our main site by following this path: http://www.brookfieldengineering.com/support/documentation/ article reprints

More Solutions to Sticky Problems
Learn more about viscosity and rheology with our most popular publication. This informative booklet will provide you with measurement techniques, advice and much more. It’s a must have for any Brookfield Viscometer or Rheometer operator. More Solutions is available in print and also as a downloadable pdf on the Brookfield website by following this path: http://www.brookfieldengineering.com/support/documentation

Training/Courses
Whether it is instrument-specific courses, training to help you better prepare for auditing concerns, or just a better understanding of your methods, who better to learn from than the worldwide leaders of viscosity measuring equipment? Visit our Services section on our website to learn more about training.

** Downloads will require you to register your name, company and email address. We respect your privacy and will not share this information outside of Brookfield.

APPENDIX C – Warranty Repair and Service

The Brookfield Spiral Adapter is guaranteed for one year from date of purchase against defects in materials and workmanship. The Spiral Adapter must be returned to AMETEK Brookfield. or to the Brookfield dealer from whom it was purchased for a warranty evaluation. Transportation is at the purchaser’s expense. The Spiral Adapter should be shipped together with all components originally provided with the system. If returning to Brookfield, please contact us for a return authorization number prior to shipping.

For a copy of the Repair Return Form, go to the Brookfield website, www.brookfieldengineering.com

Customer Support

For repair or service in the United States return to:

PROCESS & ANALYTICAL INSTRUMENTS DIVISION
Fluid Analysis Business Unit
11 Commerce Boulevard, Middleboro, MA 02346 USA
Email: ma-mid.sales@ametek.com
Phone: 508-946-6200 or 800-628-8139
www.brookfieldengineeringwwom

For repair or service outside the United States consult the AMETEK Brookfield website at www.brookfieldengineering.com. or the dealer from whom you purchased the instrument.

References

• AMETEK Brookfield

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