Brookfield BF35 - Manual (Page 17)

Brookfield Engineering Labs., Inc. Page 17 Manual No. M13-10000
Section 6 - Operation
Operation
Measuring Viscosity:
1. 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.
2. 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.
Always start with the higher RPM and work your way down to the lowest RPM.
For example, if you need readings at 100 RPM, 200 RPM, and 300 RPM, record
the measurement at 300 RPM first, then 200 RPM, then 100 RPM, then gel
strengths (if necessary).
Measuring Gel Strength:
1. Mix the sample on the “STIR” setting for 10 minutes.
2. Rotate the knob to “GEL” and immediately shut off the power.
3. As soon as the sleeve stops rotating, wait 10 seconds and turn the power back
on while looking at the dial. Record the maximum dial deflection before the gel
breaks. This is the 10 second gel strength.
When measuring gel properties, the dial does not have to return to zero during
the quiescent period. Therefore, it should not be forced back to the zero setting
if it does not freely do so. When determining the maximum dial deflection, no
allowance needs to be made if the dial did not start at zero. Only the maximum
dial deflection is of interest. Rheological properties and characteristics of the
sample will determine if the dial returns to zero during the quiescent periods of
the gel measurements.
4.
For the 10 minute gel strength, re-stir the fluid and wait 10 minutes before
recording the maximum dial deflection.
API Testing:
1. Mix the sample on the “STIR” setting for 10 seconds.
2. Set the speed to 600 RPM. Wait for the reading to stabilize and then record the
dial reading and temperature.
3. Set the speed at 300 RPM. Wait for the reading to stabilize and then record the
dial reading and temperature.
4. Stir the sample again for 10 seconds.
5. Set the speed to “GEL” and immediately shut off the power.
6. As soon as the sleeve stops rotating, wait 10 seconds and turn the power on while
looking at the dial. Record the maximum dial deflection before the gel breaks.
This is the 10 second gel strength.
7.
For the 10 minutes gel strength, re-stir the fluid and wait 10 minutes before
recording the maximum dial deflection.