MH320 Leeb Hardness Tester
Mitech
MH320
（170～960）HLD
±6HLD
500 measurement series.(Relative to average times 32～1) USB
About 150 hours（with default brightness）
370g
212*80*32mm
36.5*29*12.5cm
5.5kg
Product
Overview
Graphic
Technical
Configuration
Related
Product
- Overview
- Graphic
- Technical
- Configuration
- Related
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Product OverviewMH320 portable Leeb hardness tester is based on Leeb hardness measurement principle, it can be quickly and easily used for on-site testing hardness of metallic materials and support free conversion between Leeb, Brinell, Rockwell hardness and other scales. It uses 128 × 64 dot matrix LCD screen, rich information, intuitive, stable performance and integrated high-speed thermal printer, which enables printing with instant measurement results.It can be widely used in metal processing and manufacturing, special equipment, permanent component failure analysis, inspection and other fields. It is particularly suitable for large parts and non-removable part of the on-site hardness testing. It is to improve production efficiency and pass rate and is a wise choice to save the cost of production.
Function & applicationl Die cavity of molds
l Bearings and other parts
l Failure analysis of pressure vessel, steam generator and other equipment
l Heavy work piece
l The installed machinery and permanently assembled parts.
l Testing surface of a small hollow space
l Requirements of formal original record for test results
l Material identification in the warehouse of metallic materials
Rapid testing in large range and multi-measuring areas for large-scale work piece
Working PrincipleThe energy quotient is quoted in the hardness unit HL and is calculated from comparing the impact and rebound velocities of the impact body. It rebounds faster from harder samples than from softer ones, resulting in a greater energy quotient which is defined as 1000×Vr/ Vi.
HL=1000×Vr/ Vi
Where:
HL— Leeb hardness value
Vr — Rebound velocity of the impact body
Vi — Impact velocity of the impact body
Working Conditionsl Working temperature： -10℃～＋50℃；
l Storage temperature：-30℃～＋60℃
l Relative humidity: ≤90％；
The surrounding environment should avoid of vibration, strong magnetic field, corrosive medium and heavy dust.
Instrument Featuresl Based on the principle of Leeb hardness testing theory. It can measure the Leeb hardness of all metallic materials.
l One main unit can match to 6 impact devices
l Support Steel ,when using D/DC sensor to test steel,it can show HB directly.
l Preset on up and low limit of hardness value lower limits, it will alarm automatically if it is out of range alarm,which is convenient for the user to do more testings.
l Chinese-English converting, simple menu-driven operation, and convenient.
l High brightness, easy to use in dimly lit environments and intense sunlight.
l 500 groups (impact times 32 ~ 1) hardness measurements, each set of data includes single testing value, average value,
measurement date / time, impact direction, frequency, material, hardness, and other information.
l Integrated thermal printer with the instrument as a whole, and quiet operation, fast print speeds, you can print the test report on-site.
l Software calibration automatically
l Built-in NI-MH ,it can work for not less than 150 hours; standby with automatic screen, automatic sleep, automatic shutdown and other power-saving features.
l Real-time display the remaining battery power, charging progress is displayed while charging.
l USB interface can do transmission measurements, the measured value storage management, statistical analysis of the measured value, the measured value of the print report and batch set the instrument parameters through the PC data processing software, to meet the higher demand for quality assurance and management.
l Small size, portable, highly integrated, stable and reliable performance, suitable for harsh environment field operations, prevent from vibration, shock and electromagnetic interference.
l Dimension:221mm×80mm×32mm
Operating Method and Attentions1 Start-Up
----Insert the plug of the impact device into the socket of impact device on the instrument.
----Press the power key，now power is on. The instrument is in working mode.
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.
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 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.
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
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 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.
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.
Instrument MaintenanceAfter the impact device has been used for 1000 to 2000 times, please use the nylon brush provided to clean the guide tube and the impact body. Follow these steps when cleaning the guide tube,
1.unscrew the support ring
2.take out the impact body
3.spiral the nylon brush in counterclockwise direction into the bottom of guide tube and take it out for 5 times
4.install the impact body and support ring when complete.
Release the impact body after use.
Any lubricant is prohibited inside the impact device.
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Measuring range （170～960）HLD Impact direction vertically downward, oblique, horizontal, oblique, vertical upward, automatically identify Error D，±6 HLD Repeatability D，6 HLD Material Steel and cast steel,Cold work tool steel,Stainless steel,Grey cast iron,Nodular cast iron,Cast alu Hardness Scale HL、HB、HRB、HRC、HRA、HV、HS Impact energe D----11mJ Impact weight D----5.5g/7.2g Impact ball hardness D----1600HV Impact ball diameter D----3mm Impact ball material D----Tungsten carbide Sample surface roughness D----1.6μm；C----0.4μm Min depth of harness layer D≥0.8mm；C≥0.2mm Display 128×64 dots, adjustable backlight Storage 500 measurement series.(Relative to average times 32～1) Calibration Single-point calibration Data printing Thermal printing on site Power voltage 6V Ni-MH battery pack Power supply 9V/500mA Power consumption Low-power design Standby period About 150 hours（with default brightness） Commumication port USB1.1 Working language English Shell material ABS plasic Dimensions 212mm×80mm×32mm Weight 5.5KG PC software Have -
D Type Standard Hardness Block The D type standard hardness block is the standard configuration for Mitech series portable leeb hardness testers. With size of 90x55mm and weight of 2.67kg.It is mainly used to judge whether the measuring error of leeb hardness tester is in the permitted range by national standards or international standards. Each standard hardness block is engraved with the serial number and hardness values which are consistent with qualified certificates one by one, to ensure the traceability for the national standards or International standards. The standard block is specially made with plating harden layer process. With high quality material, its hardness value is stable and reliable. Strictly made accordance with related standards, the D type hardness block is mainly used for the calibration and verification of the D type impact device. It can also be applied to the C, DC, D+15, DL and other types of impact devices. With conversion table, it can get relevant standard reference value. Mitech standard hardness block D type is the standard basis for daily hardness testing and calibration application, the essential accessories to ensure the accurate hardness measurement. 
Attached files Mitech Series portable leeb hardness testers with customized attached files including product certificate, warranty card, product manual, packing list. The attached files adopt the special printed paper. The manual is with graphic design, beautiful, easy to understand, easy to save for a long time.
Note: The electronic version of Mitech attached files can be downloaded from www.mitech-ndt.com.
Ni-MH rechargeable battery Ni-MH rechargeable battery is special made for MH500 / MH310 portable leeb hardness tester. With 6V working voltage, it can continuous work over 200 hours.Support repeated charging operations, large capacity, long life, energy saving and environmental protection. 
D type impact device The D type impact device of Mitech portable hardness tester, height: 147mm, weight: 50g,diameter: 20mm, has build-in impact body, bottome with detachable support ring which can be replaced at any time according to the demand. It is suitable for hardness measurements for conventional workpiece with smooth surface, above 5Kg weight, more than 5mm thickness and over 0.8mm hardened layer thickness. It can be widely used for hardness testing for automobile chassis, installed mechanical or permanently assembly parts, rapidly testing for multiple measuring parts in large range of the large-scale workpiece, failure analyzing for pressure vessel, steam generator and other equipment, production line for bearings and other parts, material indentifying in warehouse for metallic materials, quality controlling for heat treatment workpiece and etc. It can realize the precise measurements for Leeb, Brinell, Rockwell and others. 
Printing paper Suitable for MH500 / MH310 portable leeb hardness tester, it is installed in the integrated thermal printer.
Printing paper width: (57.5 ± 0.5) mm; Printing paper roll diameter: 30mm.
Imported long-term printing paper roll is favorable for data long-term storage , not easy to fade.
Battery charger Suitable for the special battery charging for MH500 / MH310 portable Leeb hardness tester 
Mitech ABS Instrument Case The instrument case of Mitech series portable leeb hardness, length 35.5cm, width 19cm, height 11cm, weight of 1.5kg.
Adopt ABS engineering plastic, It has excellent peroformance like waterproof, shockproof, excellent heat resistance and low temperature resistance. It can effectively prevent oil, dust and corrosion in harsh environment. Its size is in accordance with the standards for aviation and train carrying (capable of putting under the seat and on the luggage rack), it is safe, reliable and stable.
Small support ring Small support ring is the standard configuration used for curved workpieces.If the measured surface radius R is less than 30mm, the small support ring should be used during measurement. It can make the tested workpiece stable, the impact body and the workpiece well connected to ensure the accuracy of the hardness value of the tested workpiece.If the workpiece with special surface or others, it needs to use the specific support ring. 
Nylon brush (A) The Mitech hardness tester special-used nylon brush A, mainly used for cleaning the inner wall of the impact devices except for the G type impact device. -
DataPro software Data processing software, the standard configuration for the MH200 / MH500 / MH600 / MH660,it can quickly and conveniently do data exchange and parameter setting with PC .
It has rich features like measurement storage management, statistical analysis of measured value, printing measurement report and so on. It is suitable for steel manufacturing, ship-building, automobile manufacturing, aircraft manufacturing, high pressure vessels, electric devices, bearings, standard parts, metal textile accessories and instrumentation accessories and production enterprises related with metal material products. With the analysis results provided by the software, it can make the process of quality control has more scientific basis and higher traceability. Improving the quality of enterprise information management level. it is the effectively guarantee for enterprise to analyse the product qualification rate and improve the quality monitor.The software can also be used as effective tools in scientific research units related with metal materials, manufacturing plants, universities and other departments engaged in theoretical teaching, experimental analysis and basic scientific research.
DL type impact device The DL type impact device of Mitech portable hardness tester, height 204mm, weight 50g, diameter 20mm, has build-in DL impact body, front side is slim device, it is suitable for hardness measurement of the narrow parts (like holes, slits) of the workpiece with weight above 5kg, thickness above 5mm. It is widely used for the narrow part of the installed machinery or permanently assembled parts, rapidly testing for multiple measuring parts in large range of the large-scale workpiece, hardness testing for gear tooth root and other slender narrow grooves or hole. It can realize the precise measurements for Leeb, Brinell, Rockwell and others. 
Nylon brush B Mitech hardness tester special-used Nylon brush B, it is mainly used in cleaning the inner wall of the G type impact device. 
DC type impact device The DC type impact device of Mitech portable hardness tester,height: 86mm, weight: 50g,diameter: 20mm, has build-in DC impact body. The load device of the impact body is designed at the outside of the impact device. With small volume, DC type impact device is suitable for hardness measurement of the marrow parts (like holes, slits) of the workpiece with weight above 5kg, thickness above 5mm. It is widely used for the narrow parts of the installed machinery or permanently assembled parts, rapidly testing for multiple measuring parts in large range of the large-scale workpiece, hardness testing for gear tooth root and other slender narrow grooves or hole. It can realize the precise measurements for Leeb, Brinell, Rockwell and others. 
The D+15 type impact device The D+15 type impact device of Mitech portable hardness tester,length: 162mm, weight: 80g, diameter 20mm, has build-in D+15 impact body. It is the type between the D and DL impact device. Compared with the standard impact device, it lengthened 12mm at the front, mainly used for the measurement of narrow grooves and concave surface. It can realize the precise measurements for Leeb, Brinell, Rockwell and others. 
G type impact device Portable hardness tester G type impact device, height: 255mm Weight: 250g Diameter: 30mm.
Built-in G-type impact device, G-type impact body and G-type ball is larger than the other impact body, the impact force is about 9 times of the D-type ball. the impact is heavier, has low requirement to the surface .
Applied to the casting and forging with weight of more than 15kg, the thickness of 10mm or more, more than 1.2mm hardened layer, larger and rougher surface.
Main applications:car chassis hardness testing;the installed machinery and permanently assembled parts;rapid testing in large range and multi-measuring areas for large-scale work piece;failure analysis of pressure vessel, steam generator and other equipment;bearings and other parts;material identification in the warehouse of metallic materials;heat treatment workpiece of quality control;
It can realize the precise measurements of Leeb, Brinell, Rockwell and others.
C type impact device The C type impact device of Mitech portable hardness tester, length: 141mm, weight: 75g, diameter:20mm, has build-in small C impact body. The impact force of C impact device is smaller, only 1/4 of the D impact ball. It is suitable for the hardness testing for the small and thin parts and surface hardened layers with weight above 1.5kg, the thickness above 1mm and above 0.2mm hardened layer. It makes minimal damage to workpiece surface and does not destroy the hardened layer.
It can realize the precise measurements for Leeb, Brinell, Rockwell and others.
USB communication cable The USB communication cable for Mitech hardness tester is used to connect the PC with the main unit to realize the applciations of computer communication, analysis and data storage.
