M&A HM-6561 User manual

Leeb Hardness Tester
User's Manual
ALL RIGHTS RESERVED © 2010
To maximize the benefits of your new tester,
please take some time to read these Operating
Instructions.

CONTENTS
......................................
1 Features and Specifications 1
..................................................
1.1 Typical Applications 1
.......................................................
1.2 Testing Features 1
............................................
1.3 Technical Specifications 1
.............................
1.4 Measuring and Converting Ranges 2
...........................................................
1.5 Configuration 2
.........................
2 Structure Feature &Testing Principle 2
......................................................
2.1 Structure Feature 2
................................
2.2 Leeb Hardness Testing Principle 4
................
2.3 Symbols and illustrations of hardness scale 4
…………………………...........……
2.4 Symbols of materials 5
...............................................................
3 Preparation 5
...............................................
3.1 Weight Requirements 5
.................................... . ...
3.2 Roughness Requirements 6
........................................
3.3 Cleanliness Requirements 6
..............................................
3.4 Stability Requirements 6
...................................
3.5 Samples with curved surfaces 7
...........................................
3.6 Test Samples Properties 7
..............................................
4 Operation of the Tester 7
...........................................................
4.1 Power On/Off 7
................................ . ...
4.2 Setting your Impact Direction 7
..................................................
4.3 Selecting a material 8
........................................
4.4 Choosing a hardness scale 8
..............................................
4.5 Average Times Setting 8
...............................................
4.6 Measuring Procedure 8
......................................................
4.7 Data Memorizing 10
.........................................................
4.8 Memory Recall 10
..............................................
4.9 Delete Data in Memory 10
............................................ ... ......
4.10 Download to PC 10
................................................. ......
4.11 Auto Power Off 10
..............................................
4.12 Battery Replacement 10
................................................................
5 Calibration 10
...........................................
6 Maintenance & Servicing 11
Table A
No. Type
Sketch of
non-conventional
Supporting ring
Remarks
1
2
3
4
5
6
7
8
9
10
11
12
Z25-50
Z10-15
Z14.5-30
HZ11-13
HZ12.5-17
HZ16.5-30
K10-15
K14.5-30
HK11-13
HK12.5-17
HK16.5-30
UN
For testing cylindrical outside
surface R10～R15
For testing cylindrical outside
surface R14.5～R30
For testing cylindrical outside
surface R25～R50
For testing cylindrical outside
surface R11～R13
For testing cylindrical outside
surface R12.5～R17
For testing cylindrical outside
surface R16.5～R30
For testing spherical outside
surface SR10～SR15
For testing spherical outside
surface SR14.5～SR30
For testing spherical outside
surface SR11～SR13
For testing spherical outside
surface SR12.5～SR17
For testing spherical outside
surface SR16.5～SR30
For testing cylindrical
outside surface,
radius adjustable R10～ a
8
12

Please note: If the measurement error comes within the range of
accuracy specification, please do not make calibration easily.
6 Maintenance & Servicing
* After the impact device has been used for 1000--2000 times, please
use the nylon brush provided to clean the guide tube and impact body.
When cleaning the guide tube, unscrew the support ring first, then take
out the impact body, spiral the nylon brush in counter-clock direction into
the bottom of guide tube and take it out for 5 times, and then install the
impact body and support ring again.
* Release the impact body after use.
* Any lubricant is absolutely prohibited inside the impact device.
* When results from repeated testing on a standard hardness test block
are consistently higher than the actual hardness value, the Impact Body
is probably worn. In such a case, it is necessary to replace an impact
body.
11
Quick Start Guide
To quickly configure the tester and start taking
readings. Please follow the procedures below.
1. Preparation for work pieces to be tested
Thick, heavy, and solid workpieces are preferred for
testing whenever possible. the surface must be polished
and limited to Ra≤ 2µm. The light workpiece to be
tested should be fixed to a bearing or support to avoid
bending, deformation, and displacement during testing.
2. Operation of the tester
2.1 Fit batteries
Install batteries paying careful attention to polarity.
2.2 Power on
Press the POWER/MENU key to power the tester on.
2.3 Set Impact Direction by press DIR/SHIFT key
2.4 Select a material code See Part 4.3
2.5 Select a hardness scale See part 4.4
2.6 Place the tester onto the surface to be measured
2.7 Load
2.8 Release
Notes:
1. Never try to let tester strike any tungsten steel or harder
materials. Otherwise the impact body will be damaged
forever.
2. Under no circumstances should you press the release
button if the tester was not against the work piece.
Otherwise the support ring would be loose easily.

1 Features and Specifications
1.1 Typical Applications
* Die cavity of molds
* Inspection of bearing and other mass produced parts on a
production line
* Failure analysis of pressure vessel, steam generator and
other equipment
* Inspection of installed machinery, permanent parts of
assembled systems and heavy work pieces.
* Testing surface of a small hollow space
* Material identification in the warehouse of metallic materials
* Rapid testing in large range and multi-measuring areas for
large-scale work piece
1.2 Testing Features
* Palm size for narrow space.
* Test at any angle, even upside down.
* Direct display of hardness scales HRB, HRC, HV, HB, HS,
HL.
* Large memory could store 250 groups including single
measured value, impact direction, material and hardness
scale etc.
* User recalibration function allowed.
* Can communicate with PC computer for statistics and
printing by the optional cable.
* Manual or automatic shut down.
* Low battery indication.
1.3 Technical Specifications
Display: 12.5mm LCD with back light
Accuracy: Display error ±0.8% atHLD=900
Measuring range: 200-900HLD
Conversion: HL-HRC-HRB-HB-HV-HSD
Materials: 9 different common materials
With RS232C interface
Memory: 250 data can be stored and re-readable
Impact device: D Will handle the majority of hardness testing
applications. Weight: 75g
Power supply: 2x1.5V AAA size battery
Dimension: 146×65×36mm
Weight: 130g (not including batteries)
Working temperature： - 10℃ ～ ＋50℃
Storage temperature：- 30℃～ ＋60℃;
Relative humidity: ≤90％
1
RD/
4.7 Data Memorizing
When taking measurements, all values will be stored automatically in
memory and the number of stored reading is accordingly increased by 1.
The tester can store up to 250 groups of data with measurement
conditions. If the memory is full, the tester will auto save the new reading
and discard the oldest one. That means the tester only hold the last 250
groups of data in memory.
4.8 Memory Recall
Under measuring mode marked by ‘M’ on the display , press key to
enter into mode of viewing stored values marked by ‘R’. Press key
or key to recall stored values forwards and backwards. To return
to the measurement state, just press the POWER/MENU key .
4.9 Delete data in memory
In the measurement state marked by ‘M’ on the display , the new reading
can be deleted by pressing key , and the number of stored reading
is accord i n g l y decreas e d b y 1. To c l e a r memory, just pr e s s and
hold key for 3 seconds till the number of stored reading becomes
000.
4.10 Download to PC
This tester can communicate with a PC by optional USB or RS232C
cable and software. All the memorized data can download to your PC
every time when in a measurement state, you press key to enter
the viewing memorized state.
4.11 Auto Power Off
The instrument features an auto power off function designed to conserve
battery life. If the tool is idle (neither measuring nor any key operation)
for 3 minutes, it will turn itself off.
4.12 Battery Replacement
When the battery symbol appears on the display, it is time to replace the
batteries. Slide the Battery Cover away from the instrument and
remove the batteries. Install batteries paying careful attention to
polarity.
5. Calibration
After a long period of use, especially for measuring harder materials, the
ball tip of impact body will be worn which may lead the tester have more
or less error on accuracy. At this moment, this tester is designed to allow
recalibration. The calibration can be made in the following way.
5.1 pressing POWER/MENU key for 8 seconds into item CAL, and the
tester now is in the calibration mode.
5.2 Take measurements on the standard test block.
5.3 Use key or key to adjust the reading on the display to
the standard value.
5.4 Repeat 5.2 till the measurement readings are accurate.
5.5 Press POWER/MENU key to quit from the calibration mode and
return to the measurement mode.
RD/
DEL/
DEL/
DEL/
RD/
DEL/
RD/
10

4.6.2 Placement
Holding the tester between your thumb and index finger, hold the tester
against the Work piece. Please note: the impact device must be firmly
against the surface and the impact direction should be vertical to the
testing surface or you may get unsatisfied value.
4.6.3 Releasing
Press the release button lightly on top of the tester and take
measurement. The measuring value will be displayed on LCD. To be sure
that while releasing the triggering button, the work piece, the impact
device and the impact body are all stable and the starting force coincides
with the axis of the impact device.
POWER
MENU
RD
DIR
SHIFT
DEL
MATE SCAL E
If the test results are outside the ranges listed in Table 1.1, the screen
will display E.
Note: Under no circumstances should you press the release button
if the tester was not against the work piece. Otherwise the support
ring would be loose easily.
Each measure area of the sample usually needs 3 to 5 times of testing
operation. The result data dispersion should not more than mean
value±15HL.
The distance between any two impact points or from the center of any
impact point to the edge of testing sample should conform to the
regulation of Table 4.1
If want accurate conversion from the Leeb hardness value to other
hardness value, Just operate as per procedures listed in part 4.4
Table 4.1
Not less than (mm) Not less than (mm)
D35
Type of Impact
Device
Distance of center of the
two indentations
Distance of center of the
indentation to sample edge
9
Fig 4.4
1.4 Measuring and Converting Ranges
Table 1.1
Material HL HRC HRB HB HS HV
2
30D 2
10D
Steel & Cast St.
C.W. Tool Steel
ST.STEEL
Gray Cast Iron
Nodular Cast Iron
Cast Aluminum
Brass
Bronze
Copper
80~940
80~898
80~802
32.5~99.5
20~159
45~315
60~290
40~173
80~647
85~655
93~334
131~387
300~900
200~690
300~700
200~550
174~560
400~660
360~650
300~800
300~840
20.0~68.0 38.4~99.5
20.4~67.1
19.6~62.4
46.5~101.7
13.5~95.3
Table 1.2
2 Structure Feature &Testing Principle
2.1 Structure Feature
1
2
14
4
5
6
7
8
9
10
11
12
13
3
2
Fig 2.1
1.5 Configuration
Standard
Configuration
Optional
Configuration
No.
1
2
3
4
5
Item
Main unit
Cleaning brush
Small support ring
Manual
Carrying case
6
1
2RS232C or USB
cable +Software
Other type of impact
devices and support
rings
Standard test block
Quantity Remarks
Refer to Table A in
the appendix.
1
1
1
1
1
3Impact body
Included in the main unit
1

1 Calibration mode
2 Measuring value
3 Average times set
th
4 n measuring value
5 Impact type
6 Measuring state
7 Browsing state
8 Average Symbol
9 Measuring symbol
10 Battery indicator
11 Hardness scale
12 Material
13 Direction
14 Number of memorized data
Release buttom
Load tube
Guide tube
Main unit
Impact ball head
Coil
Support ring
Test workpiece
POWER
MENU
RD
DIR
SHI FT
DEL
MATE SC ALE
Load tube
Release button
Battery compartment/cover
Display
Jack for RS232C interface
Power/Menu key
Read/Plus key
Direction/Shift key
Delete/Minus key
Support ring
3
Fig 2.3
Fig 2.2
4.3 Selecting a material
Press the DIR/SHIFT key first and not release it. T hen press
key to scroll down the list until the desired material is reached.
4.4 Choosing a hardness scale
Press the DIR/SHIFT key first and not release it. Then press key
to scroll down the list until the desired hardness scale is reached.
Press DIR/SHIFT key + DEL/ key
4.5 Average Times Settin g
After pres s i n g POW E R / M ENU key for 6 s e conds into i t e m AVE,
press key or key in turn to select the average times from
2-9, selecting 0 means no mean values. Press POWER/MENU key
finally to exit from the operation
This function allows you to view the average of the amount of tests you
entered.
Example: If you chose “3”. The tester will show the average after 3
consecutive tests.
4.6 Measuring Procedure
Use standard test block to check your hardness tester prior to a
hardness test.
4.6.1 Loading
Push the Loading Tube towards the support ring to lock the impact body.
Then, while still holding on to the loading tube, slowly return it to its
original position.
Caution: Returning the Loading Tube back to its original position too
quickly may damage the tester’s parts. ALWAYS hold onto the Loading
Tube and slowly guide it back in a controlled fashion.
HL HRC HRB HV HB HS
RD/
DEL/
RD/
DEL/
POWER
MENU
RD
DIR
SHIF T
DEL
MATE SCAL E
8
Fig 4.3

VA
VB
IMPACT
REBOUND
TIME
VELOCITIES
2.2 Leeb Hardness Testing Principle
An impact body with a spherical test tip made of tungsten carbide is
propelled against the sample surface by a spring force and then
rebounds back. At a distance of 1mm from the sample surface, the
impact and rebound velocity of the impact body are measured by the
following method: A permanent magnet embedded in the impact body,
when passing through the coil in its coil holder, induces in the coil an
electric voltage proportional to the velocities of the magnet. Leeb
hardness is expressed by the following formula:
HL=1000×(V /V )
B A
Where: HL is Leeb Hardness
V is the rebound velocity of the impact body
B
V is the impact velocity of the impact body
A
The voltage characteristic of output signal, when the impact body
passes through the induction coil is illustrated in the following figure:
Voltage Characteristic of output signal
A Leeb’s Hardness Tester measures the hardness of sample material in
terms of Hardness Leeb (HL), which can be converted into other
Hardness units (Rockwell B and C, Vicker, Brinell and Shore D).
When measuring the hardness of a sample material using the traditional
static hardness testing method, a change of applied pressure will result
in a change in the hardness reading. This will also happen during a
Leeb’s Hardness test when you change the impact device. In measuring
the hardness of the same test sample with different impact devices, the
Leeb’s hardness values obtained will vary.
For Example: 760 HLD≠760HLC≠760HLG
2.3 Symbols and illustrations of hardness scale
Fig 2.4
Symbols Illustrations
Leeb hardness value used with impact device D
Brinell hardness value
Rockwell B hardness value
Rockwell C hardness value
Shore hardness value
Vicker hardness value
LD
HB
HRB
HRC
HSD
HV
4
R
R
3.5 Samples with Curved Surfaces
The larger the curvature of the workpiece’s surface, the easier the
testing operation. Under normal conditions, testing can be done directly
with the standard support ring to a curvature with radius of 1 3/16”
(30mm) or longer.
For a workpiece with a radius of less than 1 3/16” (30mm), a special
support ring should be used for testing.
For impact device type D , R =30mm
min
3.6 Test Sample Properties
Table 3.1
4 Operation of the tester
4.1 Power on/off
* Press the POWER/MENU key, now power is on. The instrument is in
working mode.
* The LCD will display the same settings that were previously set. If the
display meets your current testing requirements, you can start the test
immediately. If not, you can enter your required settings using the
keypad.
* The tester can be turned off by pressing the POWER/MENU key for 3
seconds while OFF shows on the display.
4.2 Setting your Impact Direction
Use the DIR/SHIFT button to move the cursor until you reach the desired
direction.
Press DIR/SHIFT key
Sample
Impact
Device
D
Needs
Support
Needs to
be
stabilized
No stren-
gthening
needed
Sample Weight
(kg)
Min. Thickness
(mm)
Sample Hardened
layer ISO Ra Rz
Max. Roughness
(or Min. Fineness)
0.05-2 2.5 >5 3 0.8 N7 2µm 10µm ∇6
7
Fig 3.2
Fig 3.2

2.4 Symbols of materials
Symbol Illustrations
1 Steel and cast steel
2 Cold work tool steel
3 Stainless steel and high temperature-resistant steel
4 Cast iron with lamellar graphite (grey cast iron GG)
5 with spheroidal and nodular graphite (GGG)Cast iron
6 Cast aluminum alloys
7 Copper - zinc alloys (brass)
8 Copper-alu /copper-tin alloys (bronze)
9 Copper
3 Preparation
Selection of the workpiece to be tested and preparation of its surface
prior to testing will help insure accuracy. Magnetism of the sample itself
should be avoided. The surface temperature of sample should be less
than 120 °C.
3.1 Weight Requirement
To achieve correct test results, select thick, heavy, and solid workpieces
for testing whenever possible. The surface area where the impact body
strikes should have an even hardness.
A solid workpiece that weighs more than 11lbs. (5Kg) can be tested on
directly with the this hardness testers. Support is not necessary for
heavy sample.
A workpiece that weighs 6 to 11lbs. (3 to 5Kg) should be fixed to a
bearing or support weighing over 11lbs (5kg) to avoid bending,
deformation, and displacement during testing.
A workpiece that weighs less than 4 lbs. (2Kg) should be secured to a
workbench or a stable support. The surface between the workpiece and
the support must be hard, clean, and smooth. To secure the workpiece,
apply petroleum jelly or yellow grease to the adjoining surfaces of the
workpiece and support, press the workpiece firmly onto the support, and
eliminate any air between the two surfaces by moving the workpiece
back and forth.
Proper coupling requires a little experience. Insufficiently coupled
samples produce large variations of individual measurements, HL-
values which are too low and the operation is characterized by a rattling
noise upon impact of the test tip.
For the coupling operation, the following prerequisites must be fulfilled:
* The contact surface of the sample and the surface of the base
plate must be flat, plane parallel and ground.
* The direction of the test impact must be perpendicular to the coupled
5
surface.
* Minimum thickness of the sample for coupling (3mm).
3.2 Roughness Requirement
To eliminate measurement errors which could result from the roughness
of the test surface, the surface should be polished so that a metallic
luster appears. The roughness (Ra) of the surface must be limited to ≤
2µm. Note that the rougher the surface of the workpiece, the lower the
hardness test results.
3.3 Cleanliness Requirements
To ensure test accuracy, the test surface of the workpiece must be clean
and free of any oil stains, rust, and remains from electro-plating or paint.
3.4 Stability Requirements
To avoid displacement during testing, the workpiece should be firmly
fixed with its test surface perpendicular to the impact direction. Due to
the impact of the Impact Body, the test area may deform or vibrate, even
for some workpieces with suitable weight and thickness.
The tested hardness may be lower than normal. This is especially true
for workpieces such as a large plate, a long bar or a rod, and workpieces
with a curved surface. Some testing recommendations for these
workpieces are shown in figure 3.1
(1)PIPE
(2)PLATE
(3)ROD or LONG BAR
Note:
This indicates an
improper test.
Otherwise, test
method is accurate.
6
Fig 3.1