Fungilab V-Pad User manual

Rotational Viscometer. Instruction Manual

VPAD Manual 2/47
History inspires us in ways that leave a lasting mark on our ideologies and beliefs. We often
look toward the individuals who have come before us and relish in their accomplishments,
remembering their feats and successes as the reasons we are able to flourish and grow. This
motivates us to move forward, to contribute to our field in ways untapped.
Here at Fungilab, we believe that innovation paves the way for a new reality, an alternate
present that starts our future anew. A path that was laid out so clearly is suddenly lacking; a
new road must be paved to accommodate change in all its forms.
So here we are, ready and anxious to spur a change of our own. Decades of experience has
made us masters of our field, but evolution has pushed us to be even better. With locations
all around the world, our global presence is heightened by our commitment to progression
and ingenuity.
At the core of our values is an indelible need to support our customers with the best
experience possible. In a world that can seem so large, Fungilab is ready to bridge the gap
with a creativity and originality that will unite us unlike ever before.
Let’s move forward together.
Fungilab Team

VPAD Manual 3/47
Software Version: 1.0
Manual Version 1.0
Instruction Manual

VPAD Manual 4/47
INDEX
INDEX..................................................................................................................................................................4
1. Introduction ..................................................................................................................................................5
2. Safety Instructions ........................................................................................................................................5
3. Safety Symbols and Precautions ...................................................................................................................6
4. Utilities..........................................................................................................................................................6
5. Specifications ................................................................................................................................................7
6. Conditions for use.........................................................................................................................................7
7. Maintenance...................................................................................................................................................7
8. Equipment presentation.................................................................................................................................9
9. Equipment Description .................................................................................................................................11
9.1 Equipment set-up .......................................................................................................................................13
10. Important rheological information.............................................................................................................14
11. Accessories .................................................................................................................................................19
11.1. Low viscosity adapters (LCP and LCP/B) ..................................................................................................19
11.1.1 Mounting ...............................................................................................................................................20
11.1.2 Dismounting and cleaning .....................................................................................................................21
11.1.3 Technical specification for LCP accessories ...........................................................................................21
11. 2. Small sample adapters APM and APM/B ................................................................................................22
11. 2. 2 Dismounting and cleaning ...................................................................................................................24
11. 2. 3 Technical specifications of APM and APM/B .......................................................................................24
11.3 HELDAL UNIT –Helicoidally Movement Unit ............................................................................................26
12. Model/Spindle correspondence tables.......................................................................................................29
13. Model/spindle/oil calibration tables ..........................................................................................................31
14. VPAD L standard spindle selection table ....................................................................................................32
15. VPAD L Special aerial spindle selection table .............................................................................................33
16. VPAD L Special spindle selection table .......................................................................................................34
17. VPAD L LCP Adaptor table ..........................................................................................................................35
18. VPAD L special Vane spindle selection table...............................................................................................36
19. VPAD L special Heldal spindle selection table ............................................................................................37
20. VPAD R standard spindle selection table....................................................................................................38
21. VPAD R Special spindle selection table.......................................................................................................39
22. VPAD R LCP Adaptor table ..........................................................................................................................40
23. VPAD R special Vane spindle selection table ..............................................................................................41
24. VPAD R special Heldal spindle selection table ............................................................................................42
25. VPAD H standard spindle selection table ...................................................................................................43
26. VPAD H Special spindle selection table.......................................................................................................44
27. VPAD H special Vane spindle selection table..............................................................................................45
28. VPAD H special Heldal spindle selection table............................................................................................46
WARRANTY CERTIFICATE ..................................................................................................................................47

VPAD Manual 5/47
1. Introduction
Thank you for acquiring the Vpad rotational viscometer model from Fungilab.
The Vpad is a rotational viscometer, based on the torque measurement of a rotating spindle in the sample at
a specified velocity. Three different models (type L, R and H), as well as various accessories, allow it to cover
a wide range of viscosity measurement.
2. Safety Instructions
It is not the purpose of this manual to outline all of the safety instructions recommended for the
use of the rotational viscometer, its accessories and samples. It is the responsibility of the user to
establish health and safety practices and to determine the application’s limits before use.
Fungilab guarantees the satisfactory operation of the viscometers and its accessories if there have
not been any unauthorized adjustments to the mechanical pieces, the electronic components and
the software.
The operator should follow all of the instructions and warnings and of this manual to ensure the
safe and proper operation of the equipment.
Do not use the equipment for any other purpose than those described in this manual.
Do not use any accessory that is not supplied or approved by Fungilab.
Do not use the viscometer or its accessories if there is any suspicion of malfunction. Do not use the
equipment in situations or conditions that can cause personal injuries or material damage.
The rotational viscometer is not flameproof or intrinsically safe (ATEX) instrument and therefore should not
be used in areas where there is an explosion risk.
Before using the viscometer, carefully read and observe the following precautions:
Not following the instructions may cause serious harm or personal injuries.
To avoid an electric shock:
Do not use the rotational viscometer without a solid connection to the ground. The socket by which
the viscometer will be connected should have a ground. Always use a power cable with a ground

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connection! Verify that the voltage and the frequency match with the specifications for the
viscometer. Before turning on the machine, let it sit for some time so that it acclimates to the
surrounding temperature in order to avoid a short-circuit caused by condensation. The fluctuations
of the power source should not surpass ±10 % of the nominal voltage
3. Safety Symbols and Precautions
Safety Symbols
The following symbols are used in this instruction manual:
This symbol warns us of an operational, practical, or similar procedure that, if it is not
carried out properly, may damage the equipment
This symbol indicates hazardous voltages may be present
Precautions
If this instrument is used in a manner not specified by the manufacturer, the protection
provided by the instrument may be impaired
This instrument is not intended for use in a potentially hazardous environment
In case of emergency, turn off the instrument and then disconnect the electrical
cord from the wall outlet
The user should ensure that the substances placed under test do not release
poisonous, toxic or flammable gases at the temperatures which they are subjected to
during testing
4. Utilities
Input Voltage: Universal Power Supply (100-240V)
Input Frequency: 50 / 60 Hz
Power Consumption: 15 VA
Main supply voltage fluctuations are not to exceed ±10% of the nominal supply voltage

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5. Specifications
Speeds: 0.01 –250 RPM
Temperature Sensing Range: -40 °C to 300 °C (-40 °F to 572 °F)
USB A Port for use with temperature probe
Viscosity Accuracy: ±1.0 % of full scale range
The use of accessory items will have an effect on the measurement
accuracy
Viscosity Repeatability: ±0.2 % of full scale range
Temperature Accuracy: ±0.1 °C | -40 °C to 300 °C (-40 °F to 572 °F)
Operating Environment: +5 °C to 40 °C temperature range (41 °F to 104 °F)
Non condensing humidity
Electrical Certifications:
Conforms to CE Standards:
EN 61010: Safety requirements for electrical equipment, for measurement, control and
laboratory use
EN 61326-1: Electrical equipment for measurement, control and laboratory use
Notice to customers:
This symbol indicates that this product is to be recycled at an appropriate collection
center
6. Conditions for use
-Indoor use
-Maximum altitude 2000 m.
-Surrounding temperature range: from +5 to 40ºC.
-The equipment temperature must be kept above the dew point so moisture doesn't condense on or
in it. The power source fluctuations should not surpass 10% of the nominal voltage
-Installation category II
-Pollution level II
7. Maintenance
Always clean all of the parts after each use! Clean and dry the spindles and the spindle guard well.
Make sure that there is not any sample remaining, especially in the delicate zones such as the
spindle connector.
Use detergents or solvents to clean the spindles and the protector:
-For cleaning food samples, use lukewarm water and if necessary, use soft household
detergents

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-Other solvents that generally provide good results are acetone, gasoline, or any solvent
with a high percentage of alcohol
-For the use of any other solvent, make sure that it does not corrode the spindles or the
protector. The spindles are made in AISI 316.
.
Warning: Handle the volatile and flammable solvents with proper cautions. It is the user’s
responsibility to establish safety conditions at work.
Regularly check the spindle’s thread and the viscometer shaft.
During the viscometer’s lifespan, regular maintenance is important. As the manufacturer, we
advise annual check-ups by the technical service of your local distributor.
The viscometer is powered by a MEAN WELL GS25A12-P6J power supply. Do not open, expose,
modify or touch internal circuitry of the power supply.

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8. Equipment presentation
-Once the equipment package is received, check and confirm the delivery note. If some
discrepancy or problem is found, immediately notify the supplier.
-Verify that the viscometer model corresponds to the one that was
ordered.
-Carefully read the instruction manual.
-The manufacturer is not responsible for any damages that may result from
modifications or lack of maintenance of any of the machine’s mechanisms
(directive 89/655/CEE).
Fungilab recommends using the carry-case provided with the equipment for making any kind of
delivery. Please, keep the carry-case in a safe location. In case of transporting the equipment or
during long storage periods, always use the carry-case by placing each part as shown in the picture.
In the attached photograph (Figure 1) the position of each piece inside the equipment’s carry-case is
presented. In the case of incorrect packing, the pieces of equipment can suffer some damage; this
damage will not be covered by Fungilab’s guarantee.
Parts included with the equipment standard delivery:
-Viscometer head, with serial number label and a plastic or metal cap protecting the spindle
connector
-Foot or base with 3 height adjustable knobs
-Nut
-Fastening rod
-Standard spindles
-Spindle guard
-Spindle support
-Carrying case
-Calibration Certificate
-Temperature probe and clip
-Power cable
-MEAN WELL GS25A12-P6J power supply
Do not open the power supply due to electrical shock risk and there are not
serviceable parts inside. In case of suspecting that the power supply malfunctions
please contact FUNGILAB for assistance.
-USB-Memory containing the User Manual (PDF file)
-The USB-Memory might contain also the company catalogues.
-Android tablet to control de VPAD. The tablet model and specifications might vary without
prior notice.
It is mandatory to leave enough free space around the equipment ON/OFF switch,
needs to be reachable at any time, especially in case of an emergency or malfunction.
It is very important to treat the silkscreen printed logos carefully when cleaning the
equipment. Please use a soft cloth, with isopropyl alcohol (70%).

VPAD Manual 10/47
Standard spindles
Model L: L1, L2, L3, L4
Models R and H: R2, R3, R4, R5, R6, R7
Fig 1. Viscometer in its carry-case

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9. Equipment Description
Fig. 2 Frontal view of the equipment
1. Levelling knob
2. Nut
3. Control tablet
4. Column
5. Front cover
6. LED display
7. Spindle guard
8. Spindle
9. Temperature probe
10. Base (viscometer stand)
5
6
4
1
3
7
9
10
2
8

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Fig. 3 Back view of the equipment
1. Power switch
2. Power cable slot
3. Warning Label
4. Serial number label
5. Air ventilation
6. USB Temperature probe
connector
Fig. 4. Equipment identification label
Description of the equipment identification label:
1. Viscometer model
2. Viscometer code
3. Electronic equipment, do not throw in trash.
4. Serial number of the equipment
5. Voltage and power requirements AC 125/230V power is converted to 12VDC by the power supply.
1
1
2
3
4
5
3
5
6
2
4

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9.1 Equipment set-up
Remove all of the parts from the carry-case. Note the figure below (fig 5).
Correctly place the three height adjustable knobs (B) on the T-shaped base (A).
Mount the fastening column (C) with the holding screws (D) at the base (A).
Attach the nut (F) to the fastening rod. The viscometer should be connected to the nut (F) by means of its
horizontal rod (E).
Note:
The following process should be done carefully in order to not harm to the shaft of the viscometer.
Immediately remove the shaft’s plastic protector before beginning to use the viscometer.
Note:
For the correct adjustment of the boss head, once introduced into the column, tighten the side screws
(lower right and left screw top) with a M x 1,5mm Allen key supplied in the standard delivery. (fig 5.a)
Insert the horizontal rod of the viscometer (E) into the nut (F).
Fig. 5 Set-up for the viscometer base Fig. 5.a Boss head adjustment
The viscometer should be placed on a stable surface free of vibrations (i.e. caused by other machines
or equipment). Do not put the viscometer in direct contact with sunlight or in the middle of any air
flow (the temperature of the sample can be easily influenced by the surrounding conditions). The
viscometer is designed for indoor use.
Use the height adjustment knobs until the viscometer is correctly levelled.
Plug the power cable into the connector located on the back of the equipment (Fig. 3 position 2) and
plug it into the power source.
WARNING:
The socket in which the viscometer will be connected should have a ground. Always use a power
cable with a ground connection! Verify that the voltage and the frequency coincide with the
specifications of the viscometer (see the identification label Fig. 4, for more information). Before
turning on the machine, let it sit for some time so that it acclimates to the surrounding
temperature in order to avoid a short-circuit caused by condensation. The fluctuations of the
power source should not surpass  10% of the nominal voltage
E
F
C
D
B
A

VPAD Manual 14/47
10. Important rheological information
To obtain precise results it is necessary to know the most important rheological properties of the
sample.
Newtonian fluids
The viscosity of these fluids does not depend on the shear rate meaning that at any speed the
viscosity is the same. Only temperature affects the viscosity; changes of 1ºC can provoke a change in
the viscosity of up to 10%.
Non-Newtonian fluids
The viscosity of this type of products changes with the speed variable. Due to this inconsistency, the
term Apparent Viscosity is habitually used.
Within the classification you can find two different groups:
Time-independent non-Newtonian fluids
Time-dependent Newtonian fluids
Time-independent non-Newtonian fluids
The viscosity of a time-independent non-Newtonian fluid depends on the temperature and the speed
gradient.
Pseudo plastic Fluids:
The viscosity diminishes when the speed gradient increases.
Practical examples: paints, shampoos, fruit juice concentrate, adhesives, polymers, grease,
starch, etc.
Dilatants-Fluids:
The viscosity increases with the speed gradient.
Practical examples: clay, sweets components, etc.
Plastic Fluids:
These fluids only start to flow after having been submitted to a certain force (shearing force).
They behave like solids in static conditions.
Practical example: Ketchup.
Time-dependent non-Newtonian fluids.
The viscosity of time-dependent non-Newtonian fluids is dependent on the temperature, on the speed
gradient and on time.
Tixotropical fluids:
In these substances the viscosity diminishes with time when the fluid is subjected to a
constant speed gradient. These substances tend to return to their previous viscosity once the
speed gradient ceases to be applied.
Practical examples: Many products in industrial food production (yogurt, etc.)
Reopectic fluids:
In these fluids, the viscosity increases with time when the fluid is subjected to a constant
speed gradient.
These substances tend to return to their previous viscosity once the speed gradient ceases to
be applied.
These fluids are not very common.

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NOTE: The turbulent behaviour of a fluid can produce falsely high results in
viscosity tests. Normally, turbulent behaviour is due to an excessively high rotation
speed in relation to the viscosity of the sample (see detailed Warning further on).
FACTORS AFFECTING VISCOSITY
There are many variables that affect the rheological properties of products, so it is very important to
take the following factors into account.
Temperature
Temperature is one of the most obvious factors affecting rheological behaviour.
It is essential to consider the effects of temperature on viscosity in the evaluation of materials that are
subject to changes in temperature during its use or other processes. Some examples of this are motor
oils, greases and adhesives.
Shear Rate
When a fluid is subjected to variations in the speed gradient during its process or use, it is essential to
know its viscosity at the projected speed gradients.
Examples of materials, which are subjected to and affected by important variations in speed gradient
during its process or use, are: paints, cosmetics, liquid latex, some food products such as ketchup and
blood in the human circulatory system.
Measurement conditions
The measurement conditions of a material during its viscosity reading can have a considerable effect
on the results of this measurement. Consequently, it is important to be careful and control the
environment and conditions of any sample subjected to analysis.
Variables such as the type of viscometer, the speed/spindle combination, the sample’s container, the
absence or presence of a spindle protector, the temperature of the sample and the sample
preparation techniques, etc, can affect not only the precision of the reading but also the real viscosity
of the sample.
Time
Ageing under the same speed gradient conditions affects tixotropical and reopectical fluids.
In some fluids the action of time combined with the proportion of the shear is very complex. In these
cases, one can observe, with time, a return to the original fluid state.
Previous conditions
The conditions that the sample is subjected to before the viscosity reading can significantly affect the
results, especially with heat-sensitive fluids or ageing.
Thus, the storage condition and the sample preparation techniques should be conceived to minimize
effects on the viscosity measurements.
Composition and additives
A material’s composition is a determining factor in its viscosity. When the composition is altered,
whether this is by changing substance proportions that compose it or adding other substances,
important changes can be observed in their viscosity.
For example, adding solvent to printing ink reduces the viscosity of the ink and other types of
additives are used to control the rheological properties of paints.
VISCOSITY MEASURING PROCEDURES
Data history
We recommend documenting the following information each time you take a viscosity measurement:
-Model or type of viscometer

VPAD Manual 16/47
-Spindle (and accessory)
-Rotation speed
-Sample container
-Sample temperature
-Sample preparation procedure (if existent)
-Spindle protection use
The process is necessary in the event of comparison of results with other organizations, in the interest
of being able to guarantee the possibility of reproduction of the results obtained.
The spindle and its protection
Examine each spindle before using it. If it’s damaged or eroded in such a way that its dimensions are
changed, it will provide false results for your viscosity reading.
The spindle protector (provided with every Fungilab rotational viscometer) protects the spindle and
the viscometer axle and it is important for the reading of low viscosities with standard spindles.
The protector should always be used. In the event that it is not used, its absence must be reported in
the measurement procedure notes.
The protector isn’t used with most of the accessories.
Speed selection and spindle
If there is no described work procedure, the best method for the selection of the spindle for each
speed is “trial and error”. The objective is a torque reading between 15 and 95%, according to the
type of product in question and a percentage higher than 50% is recommendable.
If you know the fluid’s approximate viscosity, the quickest spindle/speed selection method is referring
to the tables of maximum approximate viscosity.
When you do tests at different speeds, you should select a spindle with which all of the speeds show a
torque reading of between 15 and 95%
GENERALLY:
RPM INCREMENT READING PRECISION INCREMENT
SPINDLE SIZE-REDUCTION READING PRECISION INCREMENT
(Except for the non-Newtonian fluids that change their viscosity value when the rotational speed is
modified. In these cases we recommended measuring with a determined speed and using a
comparison method.)
Size of the sample container
For measurements using the Fungilab viscometer, we recommend working with containers with an
interior diameter of 83 mm or more. The usual container is a 600 ml precipitation vase.
If a smaller container is used, the viscosity values could be greater, especially with low-viscosity fluids.
Sample conditions
The sample should be free of air bubbles.
It should be exposed to a constant and uniform temperature. Before doing the viscosity readings,
make sure that the spindle and its protection are the same temperature. Usually, thermostatic baths
are used to maintain the sample at the desired temperature.
The sample should have the properties of a homogeneous liquid; this means that it cannot have
particles capable of being precipitated, deformed by the shear rate or decomposed into smaller
particles.
The measured substances shouldn’t be subject to chemical or physical changes during the
measurement.
Other essential conditions

VPAD Manual 17/47
Experiments in conditions in which turbulent behaviour can be encountered should be avoided.
The condition should be that of stationary fluid. Accelerations or retarding processes are excluded
from the parameters of measurement.
Spindle immersion
The standard spindle should be submerged to the halfway mark in the axle. An erroneous immersion
can compromise the result of the viscosity measurement.
With the disc spindles you should avoid the creation of air bubbles, which could remain under the disc.
To this end you should insert the spindle laterally and smoothly and bring it over to the centre of the
sample. Once it is there, attach it to the viscometer’s axle.
Precision and Repetition
FUNGILAB viscometers guarantee a precision of 1% from the bottom of the speed/spindle
combination scale and a repetition of 0.2%.
The precision of temperature measurement is ±0.2 ºC.
Getting a viscosity reading
Before working with the viscometer you should make sure of the following points:
The viscometer is properly fastened to the stick and level.
Both spindle and speed are selected. (read attentively the section about speed and spindle selection).
The spindle is carefully placed and fastened.
The instructions and necessary parameters for obtaining a viscosity reading have been carefully read
in the user’s manual.
Once the readings have been initiated, allow some time for stabilization, the length of which will be in
function of the rotational speed during the measurement.
IMPORTANT WARNING
When you wish to obtain viscosity reading with FUNGILAB rotational viscometers, there are two
considerations to take into account:
The obtained viscosity results must be between 15% and 100% of the torque range, for whichever
spindle/rotational speed combination.
The viscosity reading must be executed under laminar flow condition, not turbulent flow conditions.
The first consideration is linked to the precision of the instruments. All of the FUNGILAB rotational
viscometers guarantee a precision of () 1% from the bottom of any spindle/rotational speed
combination scale.
Working with less than 15% of the bottom of the scale is not recommended due to that the potential
() 1% error in the viscosity is relatively big compared to the equipment reading.
The second consideration has to do with fluid mechanics. All of the rheological measurements of fluid
flow properties must be taken under laminar flow conditions. Laminar flow is when all of the
movements of the fluid particles are in sheets, directed by an external applied force.
The flow lines represent speed and fluid flow direction.
Laminar flow: “straight” flow lines. Relatively easy to predict. Generally slow.

VPAD Manual 18/47
Turbulent flow: “non-linear” flow lines. Impossible to predict the exact movement of the fluid. Very
quick.
For rotational systems, this means that the fluid’s movement must be circumferential. When the
internal forces of a fluid end up being too great, the fluid can become a turbulent flow, in that the
particles that make it up become unpredictable, making it impossible to analyse it with standard
mathematical models.
This turbulence creates a false reading which is a lot higher than the real one, without linear growth
and totally unpredictable.
For the following geometries, these transition points have been found to be approximate to turbulent
flow:
1) Spindle L1: 15 cP to 60 rpm
2) Spindle R1: 100 cP to 50 rpm
3) Adaptor LCP: 0.85 cP to 60 rpm
Turbulent flow conditions will always exist in these conditions as long as the RPM/cP ratio exceeds the
values listed above.

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11. Accessories
11.1. Low viscosity adapters (LCP and LCP/B)
Low viscosity adapters (LCP and LCP/B) are not included in the standard delivery. Any of these two versions
(with or without thermostatic flow jacket) must be ordered as an additional accessory. Both LCP and LCP/B
accessories are supplied complete with a spindle.
Low viscosity adapters allow more precise measurements than using the standard spindle. The viscometer can
measure very low viscosity levels, from 1 cP (when using the L model).
Thanks to its cylindrical geometry shape, it is possible to determine Shear Rate and Shear Stress.
Only a small quantity of a sample is required (16 ml.)
Fig. 7: LCP Spare parts

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11.1.1 Mounting
The mounting process is different according to the types of low viscosity accessories (LCP and LCP/B).
The difference between them only remains that the LCP has a thermostatic flow jacket (J) and a container (K)
and the LCP/B only incorporates a container (K). The LCP screw its thermostatic flow jacket (J) to the connector
(G), on the other hand, the LCP/B screws the container directly to the connector (G). The LCP assembly process
is detailed below:
Close the sample (K) container with the stopper (M).
Insert the container (K) to the lower part, in the circulation jacket (J) by turning it gently.
Fasten the circulation jacket (J) to the connector (G).
Fill the sample container with a 20 ml syringe or less and fill the 16 ml sample container.
Connect the hook (H) and the spindle (L)
Insert the spindle (L) in the circulation jacket (See the note * below)
Fasten the connector (G) to the hole in the back of the viscometer’s metallic base. (See the
note ** below)
Screw it with the viscometer axle by turning it clockwise.
Check the level of the sample. It should be approximately in the middle of the cone, which is connected to the
spindle connector (H). Figure 10 shows more information about this.
Place the upper stopper (N) over the sample container.
Fig. 10: Full LCP adapter.
*Important:
Do this slowly since the spindle must be inserted correctly in the sample. When working with a more viscous sample
be careful to avoid pulling the spindle upwards. Hold the spindle connector.
**Important:
The piece named G has two possible holes for the upper screw.
The top hole is a Universal hole to screw our low viscosity adapter to other brand viscometers.
The bottom hole is to screw to Fungilab pieces.
NOTE:
Before starting with the measurements, make sure the viscometer is correctly balanced (check it with the
bubble level). The spindle that should be selected is ‘LCP/SP’.