OfiTE HTHP User manual

OFITE HTHP Viscometer
Part No. 130-77
Instruction Manual
Updated 8/22/2019
Ver. 7
OFI Testing Equipment, Inc.
11302 Steeplecrest Dr. · Houston, Texas · 77065 · U.S.A.
Tele: 832.320.7300 · Fax: [phone] · www.ote.com
©Copyright OFITE 2015

OFITE, 11302 Steeplecrest Dr., Houston, TX 77065 USA / Tel: [phone] / Fax: [phone] / www.ote.com 1
Intro..................................................................................................2
Components....................................................................................3
Specications .................................................................................5
Setup................................................................................................6
Computer ....................................................................................6
Viscometer ..................................................................................7
Control Panel ..................................................................................8
Operation.........................................................................................9
Software Start ...............................................................................14
Calibration.....................................................................................18
Fluid Manager ...........................................................................22
Software ........................................................................................23
Options......................................................................................23
Save Rate Settings ...................................................................26
Test Builder ...............................................................................27
Select Analysis Outputs..........................................................30
Saved Test Data........................................................................31
Calibration History.....................................................................33
Import/Export.............................................................................34
Starting a Test ...........................................................................35
Maintenance..................................................................................36
Disassembly .................................................................................37
Cell............................................................................................37
Rotor .........................................................................................38
Cell Top .....................................................................................40
Coupling....................................................................................41
Remove/Install ..............................................................................42
Angular Contact Bearing...........................................................42
Pivot Bushing ............................................................................43
Rotor Bushing ...........................................................................44
Torsion Assembly ......................................................................45
Appendix ......................................................................................47
Zeroing the Compass................................................................47
Reinstalling Software ................................................................50
Minimum Required Pressures...................................................51
Conversion Charts ....................................................................52
Test Cell Assembly ...................................................................53
Test Cell Assembly - Exploded..................................................54
Warranty and Return Policy ........................................................55
Table of
Contents

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When extremely high-temperature and/or high-pressure viscosity
measurements are required, the OFITE HTHP viscometer is the solution. This
fully-automated system accurately determines the rheological properties of
completion uids and drilling uids in terms of shear stress, shear rate, time,
and temperature at pressures up to 30,000 PSI (207 MPa) and temperatures
up to 500°F (260°C). An optional chiller is available for those situations
in which the uid sample needs to be cooled, rather than heated, further
increasing the exibility of the system.
Like OFITE’s other computer-controlled viscometers, the HTHP Viscometer
features our easy-to-use ORCADA®software. Using this exclusive software,
a computer novice can operate the HTHP Viscometer, and yet the system is
versatile enough for advanced research and demanding test parameters.
The HTHP Viscometer uses a compass to detect the rotation of a magnet at
the top of the torsion assembly. The inuence of the powerful drive magnets
inside of the shield, the earth’s magnetic eld, the magnetic properties of the
shield, spring non-linearities, magnetic elds and masses in the laboratory,
non-ideal uid ow, and small geometry variations all combine to make the
angle display non-linear if not compensated. The microprocessor allows for
easy compensation for those effects.
Your HTHP Viscometer has been shipped with everything you need to begin
testing. It includes a computer with all necessary software already installed.
Intro

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Components #120-00-016-1 Pressure TDR, 50,000 PSI (344.8 MPa)
#120-001 Mineral Oil, 2 Gallons
#120-106 High Pressure Filter
#130-75-71 PC Monitor
#130-76-04 Main Bearing, Qty: 2
#130-76-05 Retaining Ring
#130-76-06 Drive Belt
#130-77-002 O-ring for Cell Assembly, 2" Diameter, Teon, For tests
above 400°F, Qty: 2
#130-77-022 Rupture Disk, 33,000 PSI (227.5 MPa)
#130-77-080 Torsion Spring Module, F1:
#130-77-1 Vee Jewel, Qty: 4
#130-77-2 Cell Assembly:
#130-77-31 Cell Cap
#130-77-32 Cell Body
#130-77-33 Test Cell
#130-77-3 O-ring for Cell Assembly, 1.359" Diameter, Nitrile, Qty: 4
#130-77-4 O-ring for Cell Assembly, 2" Diameter, Viton, Qty: 4
#130-77-5 O-ring for Pressure Ports,   " Diameter, Nitrile, Qty: 8
#130-77-6 O-ring for Outside Cell Assembly, 3" Diameter, Viton, Qty: 4
#130-77-7 Retaining Ring, Stainless Steel, Qty: 3
#130-77-91 Angular Contact Bearing
#130-77-10   " Stainless Steel Ball, Qty: 2
#130-77-11 Shoulder Screw, 10-32 × 0.2495", Qty: 2
#130-77-12 Pivot
#130-77-15 Torque Magnet Assembly
#130-77-20 Rotor Bushing
#130-77-22 Upper Backup Ring, Qty: 3
#130-77-23 Lower Backup Ring, Qty: 3
#130-77-25 Test Stand Assembly
#130-77-28 Drive Magnet
#130-77-36 Port Adapter
#130-77-38 Rotor
#130-77-39 Bob
#130-77-40 Magnet Holder
#130-77-41 Bafe
#130-77-43 Bob Shaft
#130-77-46 Pivot Cap
#130-79-04 DAQ Card for Desktop Computer
#130-79-05 DAQ Cable
#130-79-15 Serial Cable, OB9 M/F
#130-79-42 Transformer, 230 Volt to 115 Volt (For #130-77-230 only)
#132-80 Calibration Fluid, 100 cP, 16 oz, Certied, Qty: 5
#152-37 AC Power Cord, 3-Conductor
#171-84-03 Strap Wrench
#900-1908 Desktop Computer

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Optional:
#130-77-SP Spare Parts Kit
#130-77-002 O-ring for Cell Assembly, Teon, For tests above 400°F,
Qty: 6
#130-77-080-1 Torsion Spring, F1
#130-77-1 Vee Jewel, Qty: 6
#130-77-10   " Stainless Steel Ball, Qty: 2
#130-77-20 Rotor Bushing, Qty: 6
#130-77-22 Upper Backup Ring, Qty: 4
#130-77-23 Lower Backup Ring, Qty: 4
#130-77-3 O-ring for Cell Assembly, Nitril, Qty: 18
#130-77-4 O-ring for Cell Assembly, Viton, Qty: 24
#130-77-5 O-ring for Pressure Ports, Nitril, Qty: 36
#130-77-6 O-ring for Outside Cell Assembly, Viton, Qty: 12
#130-77-91 Angular Contact Bearing, Qty: 8

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Specications Instrument Geometry True Couette Coaxial Cylinder
Motor Technology Stepper
Motor Speeds Variable: .01 – 1,000 RPM
Speed Accuracy .001 RPM
Shear Rate Range .01 – 1700 sec-1
Automatic Tests API Cementing and Mud Rheologies
Computer Requirements
DB-9 Serial Port, Windows 2000 or
XP. Recommended screen resolution
1024 × 768 pixels.
Rotor / Bob Specications
Rotor Radius, RR, (cm) 1.8415
Bob Radius, RB, (cm) 1.7245
Bob Height, L, (cm) 3.8
Shear Gap, (cm) 0.117
R Ratio, RB/RR 0.9365
Maximum Shear Stress (Dyne/cm2) 1,680
Minimum Viscosity @600 RPM<a> (cP) 0.5<b>
Maximum Viscosity @0.01 RPM<c> (cP) 10,000,000
Shear Rate Constant, KR, (sec-1 per RPM) 1.7023
<a> Lower viscosities can be measured by the HTHP Viscometer, however one must take into account the effect of bearing drag, Taylor vortices, zero
offset, etc. when looking at the expected accuracy of the reading
<b> For practical purposes the minimum viscosity is limited to 0.5 cP due to Taylor Vortices
<c> Maximum viscosity is based on Maximum Shear Stress and Minimum shear rate (RPM). However, due to practical and physical limitations, it may
be difcult to take these measurements.
There is considerable thermal lag within the test cell. The temperature
sensor sits inside the thermowell in the rotor. The test uid surrounds
the sensor and the heaters surround the test uid. It can take several
minutes for the heat from the heaters to reach the innermost portions of
the rotor. Therefore, the temperature reading in the ORCADA®software
always lags behind the actual temperature of the test uid. Because
of this, OFITE recommends only changing temperatures in large
increments (greater than 50°F or 10°C). Making small adjustments to the
test temperature is unlikely to provide useful results.

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Setup
Computer
1. Connect the monitor, mouse, and keyboard to the computer and connect
the monitor and computer to an AC power outlet. The computer and
monitor were shipped with the appropriate power cords.
2. Turn the monitor and computer on.
3. Connect the DB-9 cable to the viscometer and the computer COM port 1.
This connection can be found on the right panel of the unit.
4. Connect the 68-pin cable to the viscometer and the computer. On the unit,
this connection can be found next to the DB-9 connection. There will be a
matching connection on the back panel of the computer.
5. Plug the viscometer unit into an AC power outlet and turn it on.
6. Run the ORCADA®software by double-clicking the ORCADA®icon on the
computer desktop.
If this is a fresh install, you will be asked to select a hardware
conguration. Select “Model 77” and click “OK”.
7. From the Main Screen, click the “Utilities” menu and then click “Calibrate
Shear Stress”. To check if a signal is being transmitted from the
unit, simply observe if the value displayed in the “Temperature” eld
corresponds to room temperature.

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Setup
Viscometer
1. Place the unit on a solid, level surface away from any large motors or
strong magnetic elds.
2. The HTHP Viscometer is designed to test samples at elevated
temperatures and pressures. It requires an air supply of 100 PSI (150 PSI
maximum) to drive the pump and a water source (standard tap water) to
cool the unit and the test sample. The panel on the left-hand side of the
unit has 3 ttings, ¼" (6.35 mm) NPT, for the air supply, water source, and
drain.
The viscometer requires a constant air supply throughout the test.
3. Connect the DB-9 cable to the viscometer and the computer COM port 1.
This connection can be found on the right panel of the unit.
4. Connect the 68-pin cable to the viscometer and the computer. On the unit,
this connection can be found next to the DB-9 connection. There will be a
matching connection on the back panel of the computer.
5. Make sure the viscometer power switch is in the “off” position. Connect
the power cord to the unit and an AC power source.
6. Turn the unit on. The power switch is located on the lower right panel.
Once the unit is turned on, you will immediately hear both fans operating
inside the tower and a beep from the electronics.
Before running a test on the viscometer, you must zero the compass
and then run a calibration procedure. For detailed instructions, see
page 18 for calibrating the unit and page 47 for zeroing the
compass.
Transducer Housing
Tower
Pressure Release
Valve
Test Cell
Data Acquisition
Cable
Serial Communication
Cable
Viewing Ports (Oil Level)

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Control Panel During a test, the computer will be continuously adjusting the pressure inside
the cell. As the pressure increases due to thermal expansion, the computer
will allow pressure to bleed. Likewise, if pressure begins to drop, the
computer will add pressure to keep it within the target range.
The Regulator on the control panel controls the air pressure into the pump.
This should be set between 100 – 150 PSI (690 – 1,034 kPa) as indicated on
the Air Pressure gauge.
Throttle Valve (Inside) - This valve gives you tighter control over the
pressure going into the pump. Use this valve to ne-tune the pressure control
system. To access this valve, remove the panel directly to the left of the
control panel.
When operating at the lower end of the pressure range (less than 10,000
PSI /68.95 MPa), a single cycle of the pump could add far too much pressure
to the cell. If this is the case, the throttle valve should be closed slightly.
This will reduce the pressure to the pump, which will reduce the amount of
pressure added to the cell in each pump cycle.
When operating at the higher end of the pressure range (above 10,000 PSI
/ 68.95 MPa), a single cycle may not be enough to add pressure to the cell.
In this case, open the regulator slightly to increase the air supply to the pump
and increase the pressure added to the cell in each pump cycle.

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Operation 1. Remove the entire test cell from the heating well and place it in the
preparation stand.
2. Remove the cell and the cell cap from the coupling.
3. Place a small amount of high-temperature thread lubricant (#165-44) on
all of the threads on the entire cell assembly. This includes the bottom
threads for the test cell, the top threads for the cell cap, the threads on the
three ports, the threads on the bob and bob shaft, and the threads on the
screws holding the torsion spring module to the cell coupling.
4. Place an o-ring (#130-77-4) into the o-ring groove inside the cell, just
above the rotor.
Carefully inspect all o-rings before use. Replace any that show signs
of damage or wear. O-rings are most likely to be damaged after tests
above 400°F (204°C).
5. Place the metal cell backup ring (#130-77-23) on top of the o-ring with the
at surface facing up.
The backup ring is designed to prevent o-ring extrusion. Extrusion
could cause the seal to fail or complicate the opening of the cell
after a test. The backup ring is easily damaged and must be handled
carefully to avoid bending it.
6. If the rotor is not already in the cell, carefully lower it in with the magnet
end at the bottom.
The easiest way to hold the rotor is to insert two ngers inside and apply
pressure outward. Do not let it drop.
Test Cell on
Preparation Stand O-ring Groove

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7. Check the movement of the rotor. To test for resistance, move a magnet
or magnetized metal object around the outside of the cell at the same
level as the rotor magnet. The rotor should turn freely inside the cell as
the outside magnet moves.
If the rotor does not move freely, remove it from the cell. Thoroughly clean
the rotor and magnet and inspect the bearing inside the outer race on the
rotor (see page 38). Also check the rotor bushing for damage or wear.
8. Pour 140 mL of test uid into the cell.
Be careful not to get any of the sample on the threads or seals. The
uid level should be about   " below the top of the rotor.
9. Check the movement of the rotor again (see step 7 above). This will help
the test uid ll the void space between the cell wall and the rotor.
10. Slide the bob shaft up through the coupling and screw it into bottom of the
torsion spring assembly.
11. Slide the cell body under the coupling and screw it into place.
Watch the torque magnet closely as you turn the cell. Just before the
cell tightens completely, the torque magnet should lift up about 3 - 5 mm.
This is caused by the pivot on the test cell inner race engaging with the
jewel bearing on the bob. The pivot will push up on the bob and bob shaft
which are connected to the spring assembly.
Once the torque magnet begins to lift, stop tightening the cell. Check the
movement of the torsion magnet. It should move up and down slightly. If it
does not, the pivot may not have properly engaged with the jewel bearing.
Unscrew the test cell and try again.
Once you conrm that the pivot has properly engaged with the jewel
bearing, nish tightening the test cell.
If you feel resistance while screwing in the cell, stop immediately
and slowly unscrew it. Never force the cell to tighten. Make sure
the threads are lubricated with high-temperature thread lubricant
(#165-44).

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12. Place an o-ring (#130-77-3) into the designated groove on top of the
coupling. Place a metal seal ring (#130-77-22) on top of the o-ring.
Remember, the at side of the seal ring should face up.
Carefully inspect all o-rings before use. Replace any that show signs
of damage or wear.
13. Tighten the screws on the torsion assembly to secure it to the coupling.
14. Set the pivot cap on the torsion assembly. Make sure the vee jewel sits on
top of the pivot.
The magnet should not move from side to side. If it does, carefully tighten
the screw on top of the pivot cap until you see the torsion assembly move.
As soon as the torsion assembly moves, stop screwing and loosen it a
little. You want to tighten the bearing just until it engages with the pivot, no
more.
15. Test the movement of the torsion magnet. It should turn freely.
16. Screw the cell cap onto the coupling and tighten it completely.
If you feel resistance while screwing in the cell cap, stop
immediately and slowly unscrew it. Never force the cell cap to
tighten. Make sure the threads are lubricated with high-temperature
thread lubricant (#165-44).
17. Inspect the heating well to make sure nothing has plugged the drain holes
around the temperature sensor which projects up in the center.
18. Place an o-ring (#130-77-6) around the outer base of the coupling. This
will seal the heating well and prevent steam from escaping during cooling.
19. Remove the cell from the preparation stand and carefully place it into the
heating well.
The entire cell assembly is very heavy. Be very careful when removing
it from the preparation stand. Use both hands to avoid dropping it.

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20. For tests above 200°F (93.3°C), screw the two clamps into the holes on
the bulkhead to secure the cell in place.
21. Inspect the o-rings (#130-77-5) on the two pressure port connectors on
the test station for damage and replace them if necessary.
22. Line up the inlet and outlet ports with the two pressure lines and tighten
the connections.
The ports and pressure lines are designed to only line up one way. If they
do not t correctly, rotate the cell within the heating well until they are in
position.
23. Tighten the cell locking screw to hold the cell in place during the test.
24. Swing the transducer housing around so that it rests above the test cell.
The distance between the bottom of the transducer housing and the
top of the tower should be 8.5" (22 cm). If it is not, adjust the arm of the
transducer housing to raise or lower it to the correct position.
8.5"

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25. Fill a syringe with test uid. Inject 15 mL of the test uid into the “Front”
port.
This step is only necessary when testing drilling uids to prevent solid
particles from damaging the o-rings. If you are preparing the unit for
a calibration, you can ll the rotor up to the o-ring instead of injecting
addition uid into the cell.
26. Inspect the o-ring (#130-77-5) on the sample port plug for damage.
Replace it if necessary. Screw the sample port plug into place and hand-
tighten.
27. Check the “Raw Signal” on the “Calibrate Shear Stress” screen. The
value should be 150 to 300. See page 18 for instructions.

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Software Start 1. Double-click the “ORCADA®” icon on the desktop.
2. If this is a fresh install, you will be asked to select a hardware
conguration. Select the appropriate device and click “OK”. You will now
see the Main Screen.
3. The Windows XP rewall may try to block the ORCADA®software from
communicating with the viscometer. If the rewall shows the following
alert, select “Unblock”.
Windows XP Firewall Alert
Main Screen
Communication
Indicator
StatusLog IndicatorAvailable Tests
Key
Manual Mode
Controls
Analysis Data Process Variables
“Start Test” - This button starts a test in Auto Mode. Once a test is started,
this button becomes the “Abort Test” button. Click here to stop the test.
“Cement” - This button performs a standard cement test based on API
specications for analysis model RP 10B.
“Mud” - This button performs a standard mud test based on API
Specications for analysis model RP 13D.

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The “Mud” and “Cement” tests ignore the “Dead Time” and “DAQ Time”
settings on the Options screen. Temperature and pressure control, which
are disabled during custom Auto-Mode tests, are available during a “Mud” or
“Cement” test.
“Progress” - This button opens the Test Progress window, which shows all of
the steps of the current test and highlights the one currently in process.
“Status” - This box at the top of the screen shows the current status of the
test.
“Comm Timeout” - This light will be off when the PC is successfully
communicating with the viscometer. If communication is interrupted for any
reason, the light will shine red to indicate a problem.
“Start Logging” - This button is available in manual mode only. Click here to
begin recording test data. The light next to this button will shine green while
logging is in progress.
“Cond Pause” - This button will pause a test during the conditioning phase
and put the software into Manual Mode. While the test is paused, the motor
and heat controls can be controlled in the same manner as in a standard
Manual Mode test.
To resume the test, click the “Cond Pause” button again. You will be asked if
you want to “Continue” the test with the remaining conditioning time or if you
want to “Override” the remaining time and extend the effective conditioning
time. If you choose to “Continue”, the time remaining in the conditioning cycle
will appear as though the test was never paused. If you choose to “Override”,
the time remaining in the conditioning cycle will resume at the point where the
test was paused.

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For example, assume a test has a conditioning time of 10 minutes and the
test is paused at the 5 minute mark for 1 minute. If the test is unpaused
using the “Continue” option, the time remaining in the conditioning cycle will
be 4 minutes. However, if the test is unpaused using the “Override” option,
the time remaining in the conditioning cycle will be ve minutes, making the
effective total conditioning time 11 minutes.
“Raw File Save Period” - This eld determines how often data is recorded
during a test.
“Experiment Name” - The entry in this eld will be the le name for the
saved test data. This eld is required before starting a test in Auto Mode or
starting logging in Manual Mode. Do not attempt to change the experiment
name during a test.
“Bob” - Select the type of bob currently being used in the unit. An incorrect
value in this eld will adversely affect your test results. This is the only place
where the bob selection can be changed.
“Key” - The checkboxes next to the graph key enable and disable graphing
of the indicated values. For example, to exclude RPM from the graph,
uncheck the “RPM” box. You can also customize the appearance of the lines
on the graph by clicking on the line example on the right side of the key.
“Manual Mode Controls” - The manual mode controls, in the bottom left-
hand corner or the screen, adjust the rotor speed, temperature, and pressure
while the unit is operating in manual mode.
“Rotation” - This eld determines the rotational speed. The drop-down
box beneath the eld set the units to either RPM or  s.
“Enable” - Place a check in this box to engage the motor. Uncheck the
box to stop the motor.
“Temp” - This eld determines the test temperature. The drop-down list
beneath the eld sets the units to either °F or °C.
“Enable” - Place a check in this box to enable temperature control. If
the value in the “Temp” eld is higher than the sample temperature, the
heaters will engage to heat the sample.

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“PreHeat” - This eld is not used on the HTHP Viscometer.
“Cool” - Place a check in this box to activate the cooling solenoid and
begin cooling the sample. The value in the “Temp” eld must be lower
than the sample for the software to initiate cooling.
“Pressure” - This eld determines the test pressure. The drop-down list
beneath the eld set the units to either PSI or kPa.
“Enable” - Place a check in this box to enable pressure control.
“Prime” - Place a check in this box during initial pressurization. This
function allows the cell to be pressurized without being interrupted by the
“Low Pressure Limit” (see page 23). During initial pressurization, the
pressure will be below the “Low Pressure Limit”. If “Prime” is not checked,
the test will be aborted immediately.
“Clear” - This button removes all data from the graph.
“Analysis Model” - This eld, below the graph, displays the current Analysis
Model being used in the test. This variable is set in the Test Builder (refer to
page 27 for more information).
“Analysis Data” - This chart shows the calculated values based on the
Analysis Model being used for the test. This data will not display until after the
analysis sweep is completed.
“Temperature”, “Shear Stress”, “Viscosity”, “Shear Rate”, “RPM” -
These elds display the current value for these variables. They are display
only. The drop-down box next to the “Shear Stress” eld changes the units of
the Shear Stress variable. The units can be set to: Dyne/cm2, lb/100ft2, Pa.,
Dial Reading, lb/ft2

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Calibration The HTHP Viscometer is designed to be calibrated with certied calibration
uids available from OFITE. These uids are Newtonian silicone oils and are
available in a number of viscosities. The viscosity tables supplied with the
uids are traceable to the National Institute of Standards (NIST).
The viscometer will retain its calibration as long as the torsion spring Module
is not disassembled and is kept clean and corrosion free. Removing the
spring Cage Assembly from the top of the Coupling as a unit should have
only a minor effect on the mechanical zero.
The ORCADA®calibration program should be run prior to running any test on
the unit. It is suggested that a calibration should be performed when:
- The unit has been sitting unused for several weeks.
- The unit has been serviced.
- Periodically go into the “Calibrate Shear Stress” screen and check the
“Shear Stress Raw” value. If the calibration signal drifts greater than
50% from original setting, recalibrate.
According to API Recommended Practice 10B-2, viscometers being used
for testing well cement should be calibrated quarterly. API Recommended
Practice 13B-1 and 13B-2 specify viscometers being used for drilling uids
should be checked monthly.
The calibration uid should be stored at room temperature and away from
direct sunlight. The shelf life of the calibration uid is 2 years. The calibration
uid used during the calibration program should be checked for suspended
solids and clarity prior to being stored. Cloudy calibration uid should be
disposed of properly.
If you intend to re-use the calibration uid, pour the used uid into a clean,
sealable bottle for storage. This will prevent the used uid from contaminating
the new uid. Then, for the next calibration, pour the used uid into the test
cell and, if necessary, top off with new uid. Do not mix used uid with new.
The ORCADA®software has an automated calibration program that will work
with calibration uids of known viscosity.
1. Turn on the power to the viscometer and let the unit warm up for
approximately 15 minutes.
2. Prepare for a test by following the instructions on page 9.
3. From the main screen in the ORCADA® software, choose “Calibrate
Shear Stress” from the “Utilities” menu.
4. Notice the “Shear Stress Raw” reading, it should display a value of 150 to
300. If the signal reading does not fall within this range, the unit must be
zeroed for calibration.

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To zero the unit, loosen the bolts on the transducer housing and rotate
the hood slightly while observing the “Shear Stress Raw” value. When the
signal is within the acceptable range, tighten the bolts to secure the hood.
5. Select a calibration uid from the “Cal Fluid Batch” drop-down list. Open
the “Fluid Manager” and conrm that the settings match the data sheet
that was provided with the uid.
If the list is empty, click the “Fluid Manager” button to add new uid
batches. Refer to page 22 for more information.
If the “Temp Out of Range” light shines red, the current sample
temperature is out of the specied range for the calibration uid. The
sample will have to be heated or cooled to be within the acceptable range
before calibration.
Do not attempt a calibration if the sample is not within the
appropriate temperature range.
6. 6. Choose a set of calibration rates from the “Rate Set”
drop-down list.
To create or edit a rate set, click the “Calibration Rates”
button. To create a new set, click the “New” button and
enter a name and the rotational speeds. To edit a set,
select it in the “Rate Set” list, then change the rotational
speeds as necessary.
Due to mechanical limitations, calibrating at shear rates lower than
10 RPM or higher than 300 RPM is very likely to provide poor results.
7. Click the “Start Calibration” button to begin the calibration.
Once the calibration has started, the software will begin lling in the chart
and plotting the results on the graph.
8. As the calibration proceeds, the software will begin to display the
collected data in the chart. At the end of the calibration, the software will
calculate the “r^2” and “r^2C” values, which measures the accuracy of the
calibration. If “r^2C” is less than 0.9990, recalibrate the unit.
If this value is still low, remove the test cell and check the movement of
the rotor. The rotor should turn freely. If the unit still does not calibrate, it
will require servicing by an OFITE technician.
9. When the calibration is complete, check the r^2C value to make sure it
is greater than .9990. If it is, click the “OK” button and enter a title for the
calibration.
Rate Sets