New from Brookfield:
- The Ball Bearing Suspension System that can be purchased as an option for new viscometers and rheometers as well as a retrofit on your current instrument!
Details here.
- The EZ-Lock Spindle Coupling System,
perfect for the busy lab and/or multiple user environments, a system
that allows to safely change spindles in less time.
Details here.
Please
contact us if you need pricing or details on the above systems.
-
Can-Am is the exclusive Brookfield Lab
Distributor for Canada
-
Our Technicians are Brookfield Factory Trained &
Certified.
Please call our Service Department at (905) 829-0030 or
1-800-215-4469 for calibration pricing and turnaround time, or email
us at:
-
When sending your Brookfield Instrument to us, print out this
Service Calibration Request Form, complete it and send
it along with the viscometer
Free_Brookfield_Product_Catalog
Request it here!
Standard calibration information for
Brookfield Lab Viscometers
How to perform a Calibration
Verification using the Brookfield Standard Fluid - includes error calculation
Brookfield Viscometers on-line Knowledge Test
STANDARD CALIBRATION FOR A
BROOKFIELD LAB VISCOMETER
Note:
This operation can only be performed by an authorized Brookfield
representative
Whenever you send us your viscometer for re-calibration, we will
perform the following operations:
A general
inspection: shaft straightness, motor and gear box (where applicable),
pivot point and jewel bearing status;
A reading is taken and
compared against our Master Viscometer;
The pivot point and
pivot point support (known as jewel bearing) are replaced;
The unit is cleaned
(including all bearings) and oiled/greased;
The unit is calibrated
and tested;
A Certificate of
Calibration is issued;
If required, a
Before-and-After Report is issued (for a fee) ;
Any accessories shipped
with the unit are inspected, e.g. spindles for straightness.
We recommend re-calibration of the viscometer if one of the following
is true:
- one year has elapsed since the last re-calibration;
- it fails the periodical calibration check using the Brookfield
Standard fluid.
For more information or to arrange for your unit to be sent in,
please call our Service Department at 905-829-0030 (Toll free
1-800-215-4469).
HOW TO PERFORM A 2-POINT
CALIBRATION VERIFICATION ON YOUR VISCOMETER
Procedure for regular spindles
LV1-LV4, RV1-RV7, HA1-HA7 and HB1-HB7; if you use any other spindles
and/or accessories, please
contact us
Note:
you cannot calibrate your viscometer as there is no external
provision for this, e.g. you cannot adjust the span or zero; you can
only verify the calibration
What you need:
What to do:
- pour the Brookfield Standard Fluid into the Griffin beaker (see
the above NOTE) and put the beaker in the bath
- mount the viscometer on its stand beside the bath and level it;
if it is a digital, turn it on, autozero it and input the spindle
code
- attach the spindle you intend to use and, if it's the case, the
guardleg
- immerse to the appropriate depth the spindle + guardleg into the
Brookfield Standard Fluid
- re-level the viscometer
- turn the bath on and set it up to 25 degrees Celsius then wait
for at least 30 min (1 hour recommended) for the Brookfield Standard
Fluid temperature to stabilize
- before taking a reading, recheck the viscometer leveling and
adjust if necessary
- turn the viscometer on (dial) or the motor on (digital) and take
a high-torque % reading after at least 4 spindle rotations; log
reading details: speed, spindle, torque and viscosity
- shift the speed down (typically half of the initial speed) and
allow the spindle to rotate for a few minutes; take a lower-torque %
reading and log it;
- calculate the accuracy ranges for both speeds - see below – and
determine if the readings are within calculated ranges; yes means
pass, no means fail.
Accuracy range
calculation:
The total error is a combined error Standard Fluid - Viscometer. The
accuracy for the Brookfield Standard Fluid is 1% of the actual viscosity
value written on the jar . The accuracy for the Viscometer is 1% of the
maximum range in use (note that is not 1% of the reading!).
| EXAMPLE: |
Suppose we have a dial viscometer RVT and a Brookfield Standard
Fluid of 5000 cps with the actual viscosity of 4990 cps at 25
degrees Celsius. To measure this we use an RV spindle #3 at the
speed of 20 rpm. The reading obtained is 4970 cps. The error for
the fluid is 1% of 4990, that is 49.9 cps, and the error for the
viscometer is 1% of 5000 (maximum range in use given by the
spindle #3 at 20 rpm) , that is 50 cps. The total error is
49.9+50=99.9 cps. To calculate the range, substract and add 99.9
from 4990. The range is (4890.1 to 5089.9) cps. Any reading
within this range means the viscometer is calibrated. In our
example, 4970 cps is within the above range so the viscometer is
OK. |
Below is an example of a MS-Excel® spreadsheet that
can be used to perform a calibration check on your
Brookfield Viscometer/Rheometer. Included are a
calibration table, graph, and troubleshooting tips.
CLICK HERE TO DOWNLOAD THE CALIBRATION SPREADSHEET
During the
calibration check, watch for:
- air bubbles in the Brookfield Standard Fluid; they increase the
reading, so wait for them to clear
- vibrations: if the temperature bath transmits considerable
vibrations to the viscometer, turn the bath off before turning the
viscometer/motor on
- an as-high-as-possible torque percentage for the first
calibration point reading (corresponding to the first speed): the
higher the value (75% and up) the better the accuracy
What to do if the
viscometer appears to be out of calibration:
- check if the temperature bath fluid is indeed 25 C (use a
certified thermometer)
- be sure you waited enough to allow the viscosity standard fluid
temperature to stabilize
- be sure you use the guardleg for LV and RV units, when fluid
value isn't greater than 20,000cps: not using it can cause an up to
20% lower reading!
- be sure the viscometer is leveled properly
- be sure the spindle and guardleg sit approximately in the middle
of the beaker or the guardleg does not touch the beaker's sides or
bottom
- if using the RV spindle #1 (bell shaped) or RV #2 (disc) check
if there are air bubbles trapped under the bell/disc;
- if using a dial viscometer or the digital DV-I be sure you use
the correct spindle factor
- if using a digital viscometer (except the old DV-I) check if you
introduced the correct spindle code
- if using a digital viscometer, be sure you did not autozero with
the spindle attached or, worse, with it immersed into the Brookfield
Standard Fluid
- be sure the accuracy range calculation was done correctly
If you checked all of the above and the viscometer still appears to
be out of calibration, please send it to us for
recalibration. For more information or to arrange for your unit to
be sent in, please call our Service Department at 905-829-0030 (Toll
free 1-800-215-4469). When shipping the viscometer to us, please use
this
Service Calibration Request Form.
