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Fig-14 Zeroing of micrometer
Note: this step is not worth repeating for every measurement point. However, it must be repeated whenever
the tester is restarted.
While observing the indentation through ocular lens, in case the indentation image is not clear, turn elevation hand
wheel for micro-adjustment until the indentation can be seen clearly. Then turn micro-adjustment hand wheel so
that one division line is tangent to one side of indentation. And then turn the larger hand wheel so that the other
division line is tangent to the other side of indentation as shown in Fig-15. Then press Reading button, and the
LCD screen will display one diameter of indentation d1=x.xxx:
Fig-15 Measurement of indentation
Turn the micrometer clockwise 90
°
and repeat the above steps, press Reading button once again, the LCD will
display the diameter along the other direction d2=x.xxx . At the same time, the hardness value of specimen
HBW=xxx.x will also be displayed on LCD.
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Testing procedures
1) Select suitable work table as per sizes of specimen, turn power on and select right indenter, test force and
retaining time.
2) Zeroing the micrometer and calibrate the tester with standard hardness block.
3) Clean the supporting surface of specimen and put it onto the worktable. Turn the hand wheel to move the
worktable up slowly until the specimen is 0.2 mm to 0.4mm away from the indenter, or the surface of specimen can
be observed clearly from the 2X objective lens. It is recommended that 0.2mm to 0.4mm be controlled at the
beginning. After certain period of repeated operation, when the operator is able to judge the position of specimen
through the image of ocular lens, the 2X objective lens can be used.
4) In case the indenter is not aligned to the axis of worktable, press “ENTER” key and the rotation turret will rotate
automatically. No matter where the indenter is, it will make the indenter be coaxial with the worktable. Now press
key to turn to 2X objective lens, and press
key to turn to 1X objective lens.
5) Press START key to apply test force and get the indentation. Only when the wordings “Allow Start” appears, can
the START key be pressed. No matter where the indenter is, it will turn to the front and start testing. The following
information will be displayed on LCD:
“LOADING”
“DWELLING”
“UNLOADING”
After the above process, it will return the interface as Fig-8.
6) Turn the objective lens to the position of indentation and measure the diameter of indentation to get Brinell
hardness value. If the diameter of indentation is more than 3mm, 1X objective lens shall be selected. Otherwise, 2X
objective lens should be selected.
