Kett 94i-II User manual

Operating Manual
Thank you for purchasing this product.
Please read the operating manual carefully and use this product properly.
Friction Tester
Muse TYPE : 94i-ll

Contents
1. Introduction ...................................................................................................................4
2. Specications ................................................................................................................5
3. External View and Part Names......................................................................................6
4. Measurement Principle..................................................................................................7
5. The VCM Principle .........................................................................................................8
6. Using the Portable Friction Meter .................................................................................9
7. Notes regarding use .................................................................................................... 11
8. Technical information ..................................................................................................13
9. Error display.................................................................................................................15

4
The HEIDON Tribo Gear Muse Type 94i-Ⅱ is a portable measuring device which
makes it easy for anyone to measure the static friction coecient of objects.
In the past, static friction was typically measured using the incline method
and a strain gauge. However, this method posses many diculties when used
in conned spaces such as laboratories, etc. The HEIDON Tribo Gear Muse
Type 94i-Ⅱ is a new type of static friction measuring device which completely
eliminates these diculties.
1. Introduction

5
Model : HEIDON TRIBO GEAR Muse Type: 94i-Ⅱ
Measurement range :Coecient of static friction (0.000 ~ 1.600)
Measurement precision :Refer to graphs provided in part 7, Characteristics and Performance
Display resolution :0.001
Detector : VCM Photo sensor
Display :7 Segment LED (RED), (4 digits)
Materials :Main Unit : ABS, Aluminum
Slider : Brass (hard chrome treated) 30g
Power supply :Alkaline batteries (4 size AA)
Dimensions :188 (W) x 62 (D) x 65 (H) mm
Option :Rubber slider, 6-point ball slider
2. Specications

6
1Display Panel
2 Average Button
3Power Button
4Measure Button
5Main Unit
6Bottom Plate
7Slider
8Battery Case
9Slider Holder
0AC Adapter Connector
!Data Output Connector
0
!
3. External View and Part Names

7
Applying this principle, a VCM (voice coil motor) is used to apply a horizontal force to an object of weight W as
illustrated in Diagram 2. The object will begin to move the instant that the force thus applied exceeds the force
of friction. The force (F) generated at this time is obtained by the formula F = ki. Therefore, the coecient of
static friction is obtained by the formula ki/W.
k : Constant force applied by the VCM
i : Current at the instant the object began to move.
W : Weight of the object (g)
4. Measurement Principle
Static friction is generally measured using the incline method. As illustrated in Diagram 1 below, when an
object of weight W is placed upon a surface which is gradually inclined at an increasing angle, at some angle
of inclination the acceleration of gravity acting upon the object will exceed the static friction which tends to
keep the object in place and the object will begin to slip. This angle q (theta) is referred to as the friction angle.
Taking µs as the coecient of static friction, the force of friction is the vertical force with which the object
pushes down upon the surface (Wcosq) and the area µs (µsWcosq). Therefore, the force with which the object
tends to slip down the slope (Wsinq) is thus tanq. In this way, the coecient of static friction can be obtained
by measuring the friction angle q.
Diagram 1 Diagram 2
Wsinθ=µsWcosθ
µs=Wsinθ/Wcosθ=tanθ
Wtanθ=µsW
µs=Wtanθ/W=tanθ

8
The VCM (voice coil motor) operating principle is an application of Fleming's left hand rule. As illustrated in the
diagram below, the VCM is composed of a magnetic circuit and coil assembly. When a current passes through
the coil placed in the magnetic eld, the current, magnetic eld and force move at right angles to each other.
This results in a force being applied to the coil assembly. This force is proportional to the value of the current
passing through the coil. Because this is ecient, a large force can be generated even with low current levels.
Coil Assembly
Magnetic Circuit
5. The VCM Principle
I : Current
B : Magnetic ux density
F : Force
Force F = BIL F : Force (N)
B : Magnetic Flux Density (T)
I : Current
L : Total length of coil (m)
Fleming's Left-hand Rule VCM Cut Away Diagram

9
1. Attach a Sample
The coecient of friction between to samples can be measured either by attaching the samples to the slider
with two-sided tape or by xing the samples in place using the O ring supplied attached to the slider.
● Axing samples using two-sided tape
Use a piece of two-sided tape pre-cut to a size slightly smaller than the samples to ax
the samples to the slider.
● Axing samples using the O-ring
Remove the O-ring which is attached to the slider and then wrap the O-ring around the
samples so that they are xed in place. This method should only be used for thin samples.
* The displayed coecient of friction is calculated based upon the weight of the slider (30g).
It is therefore necessary to take the weight of the attached samples into consideration.
* When measuring the coecient of friction between samples, a maximum thickness of
1mm of sample material may be attached.
2. Installing the standard slider or 6-point ball slider (option)
1Use a slider holder to install the slider as illustrated in the diagram.
2Install the standard slider or 6 point ball slider in the same way.
● Installing the rubber slider (option)
1 Remove the two bolts which hold the bottom cover in place.
2 Use screws to x the spacers in place (2 locations).
(Refer to diagram 1.)
3 Install the rubber slider. (Refer to diagram 2.)
Diagram 1 Diagram 2
6. Using the Portable Friction Meter

10
3. Check the Power Supply Voltage
After turning on the power, check to make sure that the LED display reads "0.000".
The batteries need to be replaced if the LED display reads "Lo" or "8.888". To replace the batteries, use the
supplied screwdriver to remove the screws which hold the battery case cover in place. (The battery case
cover is located on the bottom of the main unit.) Pull out the battery holder and replace the 4 batteries. Use
only new size AA alkaline batteries. After replacing the batteries, insert the holder back into the unit, replace
the cover and then replace the screws which hold it in place.
4. Measurement Method
Place the object to be measured upon a horizontal surface and set the unit down gently. (The center of the
slider is located directly below the LED display panel.)Press the Measure button. The value displayed is the
coecient of static friction.
5. The Average Function
Press the average button after marking number of measurements.
The coecient of static friction is a rough guide to the friction between objects. Measured values may vary
depending upon conditions under which measurements are performed. Therefore, taking the average of
several measurements provides a more accurate value.

11
7. Notes regarding use
1. Precautions on main unit
● Do not drop or give a strong impact to the unit.
Failure to observe this may cause a malfunction because this product has a precise structure.
● Do not attempt to disassemble or modify the unit.
Failure to observe this may cause a malfunction because the sensor section and VCM section of this
product have a precise structure.
● Do not expose this product to water.
Do not expose this product to water because this product uses electric parts in the sensor section and
VCM section.
● When this product is not used for a long period of time, store it in the case.
When this product is not used for a long period of time, store it in the case because it should be
protected from dust.
2. Precautions in measuring
● Conduct measurement at a horizontal and vibration-free place.
Measurement cannot be correctly conducted at a non-horizontal or vibrating place because of its
structure. Measurement at an inclined or vibrating place leads to variation in data, and therefore, be sure
to select a horizontal and vibration-free place for measurement.
● Be careful about temperature and humidity.
A coefficient of friction varies with ambient temperature and humidity. Attention needs to be paid
especially for paper and wood because they are likely to be aected.
● Do not damage the slider.
If there is a surface aw on the slider, the measurement data may be changed.
Be sure to put a sample on the slider and then conduct measurement.

12
3. Precautions on sample
● Be careful about the sample surface.
If the sample surface has unevenness or wrinkles, measurement results may be aected.
If there is a burr on the surface, it is caught and correct data cannot be obtained. Pay attention when
processing or putting a sample.
● Clean the sample surface.
If the sample surface is dirty, measurement results may be aected, and correct measurement cannot be
conducted. When cleaning the sample surface, use a soft cloth with alcohol soaked to wipe the surface.
If the sample surface is still dirty even after the operation above (stained with grease, for example), use
an organic solvent such as thinner and benzine to wipe the surface.
● Be careful about the "grain" of a sample.
There is the "grain" of even metals and resins as well as paper and wood in some treatments or
processing methods, and the result may differ depending on the grain direction. The presence or
absence of attention to the "grain" of a sample is determined by the purpose of measurement.
When you cannot recognize the presence or absence of the "grain" even if you touch a sample, conduct
measurement several times while changing the direction, and then, conduct the measurement in
question.

13
8. Technical information
● Driving force generated by VCM calculated using a strain gauge (Actual measurement example)
1. Characteristics and Performance
● VCM driving force constant calculated using a strain gauge (Actual measurement example)
● Calculation error due to circuit resolution.

14
2. Selection of slider
Slider selection is signicantly important for measuring a coecient of friction. The measurement results
may be completely opposite depending on sliders.
For example, the coecient of friction on a rough surface is generally larger than that on a smooth surface.
When measurement is conducted with the use of the standard slider, however, the measurement result may
be reversed.
The rough texture felt by your nger is caused by that your nger is caught by unevenness on the surface.
However, when measurement is conducted with the standard slider, the slider slides on the convex part of
the uneven surface, the contact area narrows, and nally the coecient of friction becomes smaller.
In this case, a catching state needs to be intentionally created like nger touching. The same result as nger
touching may be obtained by measuring with the use of the standard slider with cloth or paper put, with the
use of a rubber slider, or with the use of others.

15
9. Error display
Display Cause Remedy
Err1 Power supply voltage Battery needs to be replaced.
Err2 Communication function Check the cable.
Err3 Zero return incapability error A malfunction occurred.
Contact our sales division.
Lo Insucient power supply voltage Battery needs to be replaced.
8888 Insucient power supply voltage Battery needs to be replaced.

MEMO

MEMO

MEMO

060422
Caution
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mission.
● Thecontentsofthismanualaresubjecttochangewithoutnotice.
● Theappearances,screens,etc.ofthe product and accessories
displayedonthismanualmaydifferfromtheactualones,however,
operationsandfunctionsarenotaffected.
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accurate.However,ifyounoticeanyparttobeunclear,incorrect,omit-
ted,orthelikeinthismanual,pleasecontactus.
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