Product Description

MITECH MH180 Portable Leeb Hardness Tester

MH180 portable Leeb hardness tester, based on Leeb hardness measuring principle, quick and easy,on-site test the hardness of series metal materials, support free conversion between Leeb, Brinell, Rockwell hardness scale and others,It uses high-contrast segment LCD to display , small size, light,portable, stable and reliable performance.It is widely used in failure analysis of metal processing and manufacturing, special equipment, permanent assembly, inspection and other fields.It can meet the regular hardness testing of industrial production , quality and cheap, which is the first choice for practical and economical models.

Function & 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.
• Requirements of formal original record for test results.
• Material identification in the warehouse of metallic materials.
• Rapid testing in large range and multi-measuring areas for large-scale work piece.

Working 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

Working Conditions

• Working temperature：- 10℃～＋50℃；
• Storage temperature：-30℃～＋60℃
• Relative humidity: ≤90％；
• The surrounding environment should avoid of vibration, strong magnetic field, corrosive medium and heavy dust.

Features MITECH MH180 Portable Leeb Hardness Tester

• Surface temperature can’t be overheat, less than 120 ℃.
• Surface roughness should not be too large, otherwise it will cause errors. The surface of the work piece must be exposed metallic luster, smoothing and polish, without oil.
• The specimens with 2-5kg or thin-walled specimens overhangs should be supported with some object in order to avoid the pecimen deformation ,bending and movement caused by impact , for medium-sizedwork piece ,it shall be placed on a flat and hard surface, the sample must be placed absolutely smoothly, without any shake, for heavy samples more than 5kg, it can be measured directly without any support
• Portable Leeb hardness tester has strict requirements for sample thickness , the minimum thickness shall comply with regulatory (see instructions).
• For work piece with hardened layer on surface,the depth of hardened layer should conform to regulatory..
• For lighter parts,please make it tightly coupled with support, two coupled surface must be flat and smooth, the coupling gel should not be too much, the direction of the test shall be perpendicular to the coupling plate; if the work piece is a large plate, pole or bending material, even if the weight and thickness is ok ,it may still cause deformation and instability, resulting in test values error, it should be reinforced or supported at the back of the test points.
• Magnetic of work piece should be less than 30 gauss.

Operating Method and Attentions

• 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.
• 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.
• Localization
  Press the impact device supporting ring firmly on the surface of the sample, the impact direction should be vertical to the testing surface.
• 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.

• 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.
• 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 Maintenance

After 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.

Specifications MITECH MH180 Portable Leeb Hardness Tester