MITECH MH320 User Manual

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MITECH CO., LTD.

www.mitech-ndt.com

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CONTENTS

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1 Overview................................................................................................................................................................. 3

1.1 Advantages...................................................................................................................................................3

1.2 Main Application &Testing Range.............................................................................................................3

1.2.1 Main Application....................................................................................................................................... 3

1.2.2 Testing Range...........................................................................................................................................3

1.3 Configuration................................................................................................................................................4

1.4 Working Conditions.....................................................................................................................................4

1.5 Safety Instructions.......................................................................................................................................4

2 Structure Feature &Testing Principle............................................................................................................. 5

2.1 Structure Feature........................................................................................................................................ 5

2.1.1 The Hardness Tester Appearance........................................................................................................ 5

2.1.2 Parts of the Main body............................................................................................................................ 5

2.1.3 D Type Impact Device.............................................................................................................................6

2.1.4 Different Types of Impact Device.......................................................................................................... 6

2.2 Leeb Hardness Testing Principle.............................................................................................................. 6

3 Technical Specifications.................................................................................................................................... 6

4 Preparation & Testing..........................................................................................................................................8

4.1 Preparation & Inspection before Testing................................................................................................. 8

4.1.1Preparation of Sample Surface.............................................................................................................. 8

4.1.2 System Setting......................................................................................................................................... 8

4.1.3Presetting Testing condition.................................................................................................................... 8

4.2 Testing Program.......................................................................................................................................... 8

4.2.1 Start-Up..................................................................................................................................................... 8

4.2.2 Loading......................................................................................................................................................9

4.2.3 Localization............................................................................................................................................... 9

4.2.4 Testing........................................................................................................................................................9

4.2.5 Read measured value.............................................................................................................................9

4.2.6 Power Off................................................................................................................................................ 10

5 Advice....................................................................................................................................................................10

6 Operation in Details...........................................................................................................................................10

6.1 Power On....................................................................................................................................................10

6.2 Power Off....................................................................................................................................................10

6.3 Testing.........................................................................................................................................................10

6.3.1 Instruction of the Main Display Interface............................................................................................11

6.3.2 Testing Operation at the Main Display Interface...............................................................................11

6.3.3 Key Operation at the Main Display Interface.................................................................................... 11

6.4 Menu Structure.......................................................................................................................................... 11

6.5 Test Set....................................................................................................................................................... 13

6.6 Print Function.............................................................................................................................................15

6.7.Memory Manager......................................................................................................................................15

6.8 Browsing Memory Data Groups............................................................................................................. 17

6.9 System Set.................................................................................................................................................18

6.10 Software Information..............................................................................................................................19

6.11 System Calibration..................................................................................................................................19

6.12 EL Background Light..............................................................................................................................20

6.13 Auto Power Off........................................................................................................................................ 20

6.14 Paper Loading......................................................................................................................................... 20

6.15 Battery Charge........................................................................................................................................ 20

6.16 Battery Replacement..............................................................................................................................21

6.17 Connection of Data Transmission Cable............................................................................................ 21

7 Fault Analysis & Evacuation...........................................................................................................................21

8 Servicing & Maintenance................................................................................................................................. 21

8.1 Impact Device Servicing.......................................................................................................................... 21

8.2 Normal Maintenance Program................................................................................................................21

9 Calibration............................................................................................................................................................21

10 Notice of Transport and Storage Conditions........................................................................................... 21

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APPENDIX................................................................................................................................................................22

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Table 1............................................................................................................................................................... 22

Table 2............................................................................................................................................................. 23

Table 3............................................................................................................................................................. 24

Table 4............................................................................................................................................................. 25

User Notes............................................................................................................................................................... 26

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1 Overview

 Wide measuring range. Based on the principle of Leeb hardness testing theory. It can measure the

 Large screen(128×64 dot matrix LCD), showing all functions and parameters.



Test at any angle, even upside down.



Direct display of hardness scales HRB, HRC, HRA, HV, HB, HS, HL.

 Seven impact devices are available for special application. Automatically identify the type of impact



Large capacity memory could store 500 groups (Relative to average times32 ～ 1 ) information

 Upper and lower limit can be preset. It will alarm automatically when the result value exceeding the



Battery information indicates the rest capacity of the battery and the charge status.

 User calibration function.



Software to connect with PC via USB port.

 With EL background light.



Thermal printer integrated, convenient for in field printing.

 NI-MH rechargeable battery as the power source. Charge circuit integrated inside the instrument.



Auto power off to save energy.

 Outline dimensions：212mm×80mm×32mm

 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

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1.1 Advantages

Leeb hardness of all metallic materials.

devices.

including single measured value, mean value, testing date, impact direction, impact times, material
and hardness scale etc.

limit.

Continuous working period of no less than 150 hours (EL off and no printing).

1.2 Main Application &Testing Range

1.2.1 Main Application

1.2.2 Testing Range

Testing range refer to Table 1 and Table 2 in the Appendix.

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1.3 Configuration

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

Battery Charger

1

9V 500mA

7

Paper for printing

1

8

Manual

1

9

Instrument case

1

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

Data-Pro software

1

14

Communication cable

1

15

16



Working temperature： -10℃～＋50℃;



Storage temperature：-30℃～＋60℃;



Relative humidity: ≤90％;



The surrounding environment should avoid of vibration, strong magnetic field, corrosive medium



The instrument can only work with the specially designed battery pack and power adapter (charger)

 Do not cast the battery pack into fire and do not short circuit, disassemble or heat the battery pack,



Do not open the cover of the paper compartment or come into contact with the heating head of the

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Table 1-1

1.4 Working Conditions

and heavy dust.

1.5 Safety Instructions

supplied by Mitech Co. LTD. Working with others may result in damage of the instrument, battery
leakage, fire or even explosion.

otherwise battery leakage, fire or even explosion may occur.

printer by hand or any part of your body to avoid burns due to high temperature when the printer is
printing.

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2 Structure Feature &Testing Principle

1. Main unit

2. Impact device

1 Socket of impact device 2 Socket of USB 3 LOGO 4 Paper compartment cover 5 LCD display

6 Keypad 7 Battery switch 8 Power jack 9 Serial Number 10 Product label 11 Battery

compartment cover

DEL

SAVE

ESC

MENU

ENTER

MAT

DIR

FEED

PRT

1

M iT ec h

2

MODEL: MH320
BATTERY: 6V NI-MH

HARDNESS TESTER

CAUTION:

1 Do not disassemble

3 Use only supplied AC-DC adapter

for charging

CHARGER: 9V DC

2 Do not dispose of in fire or water

SCALE

DEL

SAVE

ESC

MENU

ENTER

MAT

DIR

FEED

PRT

11

10

9

8

7

6

5

4

3

2

1

OFF---ON

HL0108070811

M iT ec h

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2.1 Structure Feature

2.1.1 The Hardness Tester Appearance

2.1.2 Parts of the Main body

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2.1.3 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

DC DL C D+15 E G

 Error and repeatability of displayed value see Table 3-1.

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2.1.4 Different Types of Impact Device

2.2 Leeb Hardness Testing Principle

The basic principle is: 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:

Where, HL—— Leeb hardness value

3 Technical Specifications

HL=1000×VB/ VA

VB—— Rebounding velocity of the impact body

VA—— Impacting velocity of the impact body

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Table 3-1

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

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：360°



Hardness Scale：HL、HB、HRB、HRC、HRA、HV、HS



Display：dot matrix LCD，128×64 dots



Data memory： 500 groups max.（relative to impact times 32～1）

 Printing paper: width is （57.5±0.5）mm, diameter is 30mm

 Battery pack: 6V NI-MH



Battery charger: 9V/500mA



Continuous working period：about 150 hours（With backlight off, no printing）

 Communication interface：USB1.1

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4 Preparation & Testing



In the preparation processing for sample surface, the hardness effect of being heated or cold

 Too big roughness of the being measured surface could cause measure error. So, the surface of the

 Support of test sample. Support is no necessary for heavy sample. Medium-weight parts must be

 Curved surface: The best testing surface of sample is flat. When the curvature radius R of the



The sample should have enough thickness, minimum thickness of sample should conform to Table



For the sample with hardened layer on surface, the depth of hardened layer should conform to Table

 Coupling. Light-weight sample must be firmly coupled with a heavy base plate. Both coupled



Magnetism of the sample itself should be avoided.

 Insert the plug of the impact device into the socket of impact device on the tester.

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4.1 Preparation & Inspection before Testing

4.1.1Preparation of Sample Surface

Preparation for sample surface should conform to the relative requirement in the Appendix Table 3.

processing on the surface of sample should be avoided.

sample to be measured must appear metallic luster, smoothing and polish, without oil stain.

set on the smoothing and stable plane. The sample must set absolutely equability and without any
wobble.

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.

3.

3.

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.

4.1.2 System Setting

See 6.9 for details.

4.1.3Presetting Testing condition

See 6.5 for details.

4.2 Testing Program

Verification of the tester is by using standard test block. The error and repeatability of displayed value
should be within the regulation of Appendix table 2.

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 software calibration to adjusting.

4.2.1 Start-Up