MITECH MH180 User manual

MITECH CO., LTD.
www.mitech-ndt.com
www.ponpe.com

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CONTENTS
1 Overview............................................................................................................................................2
1.1 Advantages................................................................................................................................................ 2
1.2 Main Application &Testing Range.......................................................................................................... 2
1.3 Technical Specifications...........................................................................................................................2
1.4 Configuration............................................................................................................................................. 3
1.5 Working Conditions...................................................................................................................................3
2 Structure Feature &Testing Principle............................................................................................................. 6
2.1.1 D Type Impact Device........................................................................................................................... 4
2.1.2 Different Types of Impact Device........................................................................................................ 5
2.2 Main Screen...............................................................................................................................................5
2.3 Keypad Definitions....................................................................................................................................5
2.4 Leeb Hardness Testing Principle............................................................................................................6
3 Preparation.............................................................................................................................................................6
3.1 Instrument Preparation and Inspection................................................................................................. 6
3.2 Impact Device Selection.......................................................................................................................... 7
3.3 Preparation of the Sample Surface........................................................................................................7
4 Testing Program................................................................................................................................................... 8
4.1 Start-Up...................................................................................................................................................... 8
4.2 Loading....................................................................................................................................................... 8
4.3 Localization................................................................................................................................................ 8
4.4 Testing.........................................................................................................................................................8
4.5 Read Measured Value..............................................................................................................................8
4.6 Notification..................................................................................................................................................9
5 Operation Detail.................................................................................................................................................... 9
5.1 Power On/Off............................................................................................................................................. 9
5.2 Material Setting......................................................................................................................................... 9
5.3 Hardness/Strength testing.....................................................................................................................10
5.4 Impact Direction Setting........................................................................................................................ 10
5.5 Average Times Setting...........................................................................................................................10
5.6 Data logging.............................................................................................................................................10
5.6.1 Viewing stored file/Group...................................................................................................................10
5.6.2 Deleting selected file/Group.............................................................................................................. 10
5.7 System Reset.......................................................................................................................................... 11
5.8 EL Backlight............................................................................................................................................. 11
5.9 Auto Power Off........................................................................................................................................ 11
5.10 Battery Replacement............................................................................................................................11
5.11Connecting to a Computer....................................................................................................................11
5.12 Error Code Reference..........................................................................................................................11
6 Maintenance & Servicing................................................................................................................................. 12
6.1 Impact Device Maintenance................................................................................................................. 12
6.2 Instrument Maintenance Program....................................................................................................... 12
6.3 Fault Analysis & Evacuation................................................................................................................. 12
6.4 Notice of Transport and Storage Conditions......................................................................................12
APPENDIX................................................................................................................................................................12
Table 1............................................................................................................................................................. 12
Table 2............................................................................................................................................................. 13
Table 3............................................................................................................................................................. 14
Table 4............................................................................................................................................................. 15
User Notes............................................................................................................................................................... 16
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1 Overview
1.1 Advantages
Wide measuring range. Based on the principle of Leeb hardness testing theory. It can measure the
Leeb hardness of all metallic materials.
Large screen LCD, showing all functions and parameters. With EL background light.
Seven impact devices are available for special application. Automatically identify the type of impact
devices.
Test at any angle, even upside down.
Direct display of hardness scales HRB, HRC, HV, HB, HS, HL
Large memory could store 100 groups (Relative to average times 32 ～1 ) information including
single measured value, mean value, impact direction, impact times, material and hardness scale
etc.
Battery information showing the rest capacity of the battery.
User calibration function.
Software to connect to PC via RS232 port. Micro printer support.
Compact plastic case，suitable for use under poor working conditions
Continuous working period of no less than 100 hours with two alkaline batteries(AA size) ；Auto
power off to save energy.
Outline dimensions：150mm×74mm×32 mm
Weight：245g
1.2 Main Application &Testing Range
1.2.1 Main Application
Die cavity of molds
Bearings and other parts
Failure analysis of pressure vessel, steam generator and other equipment
Heavy work piece
The installed machinery and permanently assembled parts.
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
1.2.2 Testing Range
Testing range refer to Table 1 and Table 2 in the Appendix.
1.3 Technical Specifications
Error and repeatability of displayed value see Table1-1 below.
Table 1-1
No.
Type of impact
device
Hardness value of Leeb
standard hardness block
Error of displayed
value
Repeatability
1
D
760±30HLD
530±40HLD
±6 HLD
±10 HLD
6 HLD
10 HLD
2
DC
760±30HLDC
530±40HLDC
±6 HLDC
±10 HLDC
6 HLD
10 HLD
3
DL
878±30HLDL
736±40HLDL
±12 HLDL
12 HLDL
4
D+15
766±30HLD+15
544±40HLD+15
±12 HLD+15
12 HLD+15
5
G
590±40HLG
500±40HLG
±12 HLG
12 HLG
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6
E
725±30HLE
508±40HLE
±12 HLE
12 HLE
7
C
822±30HLC
590±40HLC
±12 HLC
12 HLC
Measuring range：HLD（170～960）HLD
Measuring direction：0°~360°
Hardness Scale：HL、HB、HRB、HRC、HRA、HV、HS
Display：segment LCD
Data memory：max. 100 groups（relative to impact times 32～1）
Working power：3V（2 AA size alkaline batteries）
Continuous working period：about 100 hours（With backlight off）
Communication interface：RS232
1.4 Configuration
Table 1-2
No.
Item
Quantity
Remarks
Standard
Configuration
1
Main unit
1
2
D type impact device
1
With cable
3
Standard test block
1
4
Cleaning brush (I)
1
5
Small support ring
1
6
Alkaline battery
2
AA size
7
Manual
1
8
Instrument package case
1
9
Optional
Configuration
11
Cleaning brush (II)
1
For use with G type
impact device
12
Other type of impact
devices and support rings
Refer to Table 3 and
Table 4 in the
appendix.
13
DataPro software
1
14
Communication cable
1
15
Micro Printer
1
16
Print cable
1
1.5 Working Conditions
Working temperature：0℃～＋40℃；
Storage temperature：-30℃～＋60℃
Relative humidity: ≤90％；
The surrounding environment should avoid of vibration, strong magnetic field, corrosive medium and
heavy dust.
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2 Structure Feature &Testing Principle
2.1 Structure Feature
Main unit 2.Keypad 3. LCD display 4 Socket of RS232
Socket of impact device 6. Impact device 7 Label 8. Battery cover
2.1.1 D Type Impact Device
1 2 3 4 5 6 7
1 Release button 2 Loading tube 3 Guide tube 4 Coil unit
5 Connection cable 6 Impact body 7 Support ring
POWER: 2 X 1.5V
HARDNESS GAUGE
0-Steel and Cast Steel
1-Cold Work Tool Steel
2-Stainless Steel
3-Gray Cast Iron
4-Nodular Cast Iron
5-Cast Aluminum Alloys
6-Copper-Zinc Alloys
7-Copper-Aluminum
8-Wrought Copper
9-Wrought Steel
Material Option:
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2.1.2 Different Types of Impact Device
DC DL C D+15 E G
2.2 Main Screen
Below is the main display screen：
Instruction of the Main Display Screen:
Material：The present presetting material.
Impact direction：The present impact direction.
Hardness scale：Hardness scale of the present measured value.
Battery information：Showing the rest capacity of the battery.
Measured value：Display present single time measured value（without showing average icon），
or display the present mean value (with average icon prompting). “-HI-” means over conversion
value or measure range. “-LO-” means lower than conversion value or measure range.
Impact times：Times that have been impacted.
Average Icon：It will appear when showing the mean value of the measured values after reaching
the presetting impact times.
Memory Icon: It appears when operating the instrument memory.
2.3 Keypad Definitions
Table 2-1
Turn on/off the EL
backlight
Data Save or Data
Delete
Turn the instrument
on/off
Hardness Scale
Average Icon
Direction
Battery Info
Impact Times
Measured Value
Material No
Memory Icon
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Material Selection
Hardness/Strength
switch
Plus or Up
Hardness Scale
Selection
Direction change
Minus or Down
Print data
Impact Times set
Data logging or Enter
Press key to store present group of measured value into memory. This operation is only valid
after displaying the mean value.
Press key and could display single measured value.
Press key could switch on of off the background light of LCD.
Press key to set the impact direction.
Press key to change the impact times in one group. The impact times item will flash when first
pressing the key, and then the impact times value will plus or minus when pressing the or
key. Press key finally to exit from changing the impact times process.
Press key to change the hardness scale.
Press key to change the material. Presetting hardness scale recovers to HL automatically after
material presetting changed.
Press key to switch between hardness test and strength test. Only D and DC type of impact
device has the function of strength testing. So hardness testing is the only selection if the impact
device is not D or DC type.
Press key to print out the measured values after measurement.
2.4 Leeb Hardness Testing Principle
The basic principle is to use an impact body of certain weight impacts against the testing surface under
certain test force, then measure the impacting velocity and the rebounding velocity of the impact body
respectively when the spherically test tip is located 1mm above the testing surface.
The calculation formula is as follows:
HL=1000×VB/ VA
Where, HL—— Leeb hardness value
VB—— Rebounding velocity of the impact body
VA—— Impacting velocity of the impact body
3 Preparation
3.1 Instrument Preparation and Inspection
Verification of the instrument is by using standard test block. The error and repeatability of displayed
value should be within the regulation of Appendix table 2. The instrument and impact device must be
calibrated using a standard hardness block before use as the first time, or having not been used for a
long time, or having reset the instrument system.
Press key, meanwhile pressing down the key to power on the system. Then the user calibration
screen shows as left below.
Test for 5 points on the standard hardness block.
It would display the average measured value
after measuring 5 times. Press key to
change to its nominal value.
Press key to confirm the calibration finally. Or
press the key to cancel the calibration.
Range of adjustment: ±30HL.
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3.2 Impact Device Selection
Refer to Appendix Table 1 and Table 3 for selection of impact device.
3.3 Preparation of the Sample Surface
Preparation for sample surface should conform to the relative requirement in Appendix Table 3.
In the preparation processing for sample surface, the hardness effect of being heated or cold
processing on the surface of sample should be avoided.
Too big roughness of the being measured surface could cause error. So, the surface of the sample
to be measured must appear metallic luster, smoothing and polish, without oil stain.
Support of test sample. Support is no necessary for heavy sample. Medium-weight parts must be
set on the smoothing and stable plane. The sample must set absolutely equability and without any
wobble.
Curved surface: The best testing surface of sample is flat. When the curvature radius R of the
surface to be tested is smaller than 30mm (D, DC, D+15,C, E and DL type of impact device) and
smaller than 50mm (G type of impact device), the small support ring or the shaped support rings
should be chosen.
The sample should have enough thickness, minimum thickness of sample should conform to Table
3.
For the sample with hardened layer on surface, the depth of hardened layer should conform to Table
3.
Coupling. Light-weight sample must be firmly coupled with a heavy base plate. Both coupled
surface must be flat and smooth, and there is no redundant coupling agent existing. The impact
direction must be vertical to the coupled surface. When the sample is a big plate, long rod or
bending piece, it can be deformed and become unstable, even though its weight and thickness is
big enough, and accordingly, the test value may not be accurate. So the sample should be
reinforced or supported at its back.
Magnetism of the sample itself should be avoided.
Note ：Use a calibrated hardness tester, test the standard test block downward vertically for 5
times, the arithmetical average value compare with the value of standard test block. If this value
exceeds the standard value, could use the function of user calibration to adjust.
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4 Testing Program
4.1 Start-Up
Insert the plug of the impact device into the socket of impact device on the instrument.
Press the key，now power is on. The instrument is in working mode.
4.2 Loading
Pushing the loading-tube downwards until contact is felt. Then allow it to slowly return to the starting
position or using other method locking the impact body.
4.3 Localization
Press the impact device supporting ring firmly on the surface of the sample, the impact direction
should be vertical to the testing surface.
4.4 Testing
Press the release button on the upside of the impact device to test. The sample and the impact
device as well as the operator are all required to be stable now. The action direction should pass the
axis of the impact device.
Each measure area of the sample usually need 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, contrastive test
is needed to get conversion relations for the special material. Use inspection qualified Leeb
hardness tester and corresponding hardness tester to test at the same sample respectively. For
each hardness value, each measure homogeneously 5 points of Leeb hardness value in the
surrounding of more than three indentations which need conversion hardness, using Leeb hardness
arithmetic average value and corresponding hardness average value as correlative value
respectively, make individual hardness contrastive curve. Contrastive curve at least should include
three group of correlative data.
Table 4-1
Type of Impact
Device
Distance of center of the two
indentations
Distance of center of the
indentation to sample edge
Not less than (mm)
Not less than (mm)
D、DC
3
5
DL
3
5
D+15
3
5
G
4
8
E
3
5
C
2
4
4.5 Read Measured Value
After each impact operation, the LCD will display the current measured value, impact times plus one, the
buzzer would alert a long howl if the measured value is not within the valid range. When reaching the
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presetting impact times, the buzzer will alert a long howl. After 2 seconds, the buzzer will alert a short
howl, and display the mean measured value.
NOTE:HL values tested by different impact devices are different,eg.780HLD≠780HLC
4.6 Notification
Replacing the impact device must be done during Power off. Otherwise the main body could not
identify the type of the impact device, and it may damage the circuit board of the main body.
You could not save the current test value if the impact time is less than the presetting times value.
Only type D and type DC of impact device have the function of strength test option. You can not
change the setting to strength testing when using other types of impact device. The setting would be
set to hardness testing automatically after replacing the impact device whether the setting is
hardness testing or not before.
Not all materials could convert to all hardness scale value. The hardness scale is reset to HL
automatically after changing the material. So select material firstly before changing the hardness
scale.
5 Operation Detail
5.1 Power On/Off
Press to power on the instrument. Be sure to plug in the impact device before powering on. The
system would automatically detect the type of the impact device during power up, and would display this
information on the screen. Users should pay attention to the probe type displayed on the screen. After
pausing for several second, the screen will exit and enter the main display screen as following:
The instrument can be turned off by pressing the key while it is working. The tool has a special
memory that retains all of its settings even when the power is off.
5.2 Material Setting
Press key to change the material to the one you want to preset. Hardness scale recovers to HL
automatically after material presetting changed. Please select material firstly, then select hardness
scale.
In hardness testing, The relationship between the material number displayed on the instrument screen
and the material is as follows:
Table 5-1
Material No.
Material
Material No.
Material
0
Steel and cast steel
5
Cast aluminum alloys
1
Cold work tool steel
6
Copper-Zinc alloys
2
Stainless steel
7
Copper –Aluminum alloys
3
Gray cast iron
8
Wrought copper
4
Nodular cast iron
9
Wrought steel
In strength testing, The relationship between the material number displayed on the instrument screen
and the material is as follows:
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