Tech Support
11
Macro
Vickers
Model
No.
900
‐
398
Hardness
Tester
NOTE: The 900-398 has memory for setting the zero. The only time you need to reset
the zero is when the instrument is restarted.
Measurement of Diagonal length of indentation:
3.4.12
Observe the indentation in the eyepiece; rotate the handwheel to focus until the
image quality becomes clear.
3.4.13
Rotate the left drum wheel to make the inner side of the LEFT graduated line
tangent to the diagonal line of the indentation, See Fig 8.
3.4.14
Rotate the right drum wheel to make the inner side of the RIGHT graduated line
tangent to the right tip of the indentation as shown in Fig9.
3.4.15
Press the measure button on the micro eyepiece. Now the D1 on the screen displays
the length of the diagonal line.
3.4.13 Rotate the micro eyepiece clockwise by 90
º
. The inner line should remain on the tip
of the indentation without any space between them and begin to measure the other
diagonal line in the same way as shown above . When it is determined, press the
button on the micro eyepiece. And the D2 on the screen indicates the length of this
diagonal line. The 900-398 will automatically compute the hardness value (HV).
The hardness value indicated is calculated by instrument according to the
arithmetic mean of the length of two diagonal lines.
If the operator is not sure of the correctness of the measurement, press SPEC key
and then press DEL key to repeat a new measurement.
At the end of your measurement, lower the elevating table and prepare to take a
new test.
3.4.14 When the indentation observed in the micro eyepiece is too large or too small to
measure precisely, it is necessary to re-select the test force to suit the requirement
of the test. The other way is to use the 10
╳
objective to measure a large
indentation.
If the numbers of test N>1, the results can be printed on the built-in micro printer.
Press SPEC key first and then press PRT key. If you need to send output via RS232,
you must set RS232 Hyper Terminal as described in the section below.
