14
13
Cleaning and Lubrication
Protect the tester with dust-proof cover when it will not be used for a longer period of time.
Fill adequate machine oil to the contacts between lead screw and hand wheel periodically.
The friction surfaces should be lubricated regularly, 2 times per month.
The decelerator should be filled with grease #20 once every half year. (industrial Vaseline)
14
Cautions for operation
Fitting Indenter: All the indenters are composed of fixing rod, fixing nut and tungsten carbide ball (Fig-2). Before
fitting indenters, the ball groove of fixing rod and the carbide must be cleaned with acid-free gasoline and make it
dry. Paint some acid-free Vaseline into the groove, fit the carbide ball and tighten the fixing nut. During the testing,
check occasionally whether the carbide ball is loose in the indenter. In case the ball is loose, the test is invalid.
During the process of loading, dwelling and unloading, never turn the rotation turret. Otherwise, the indenter may
be damaged.
Selection of power voltage: the voltage should be 220V (or 110V, 380V according to request) and must be
grounded properly.
Temperature of specimen: The temperatures of specimen shall be kept at normal atmospheric temperature during
the testing. In other special circumstances, the temperature of ferrous metals should not exceed 100
℃
, but that of
non-ferrous metals must be kept under ambient temperature.
The diameter of tungsten carbide ball shall be inspected regularly in case of exceeding its tolerance. When the
diameter is 2.5mm, the tolerance should not be more than
±
0.003mm. When the diameter is 5mm, the tolerance
should be less than
±
0.004mm. When the diameter is 10mm, the tolerance should be less than
±
0.005mm the
surface finish Rz should be no more than 0.2 micron.
Distance between the surface of specimen and the indenter: 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.
15
Troubleshooting
In case of breakdown, the following may be of help to find out the reason of breakdowns and recommend the
remedies. If not successful, contact our aftersales service department rather than dismantle the tester by yourself.
Table 7 Troubleshooting Guideline
Breakdowns
Reasons
Remedies
Screw rod not
elevating fluently
Rusty or chips
Remove the chips around lead screw and hand wheel, and then fill some
lubricants
Test results not
precise
Distance of indentations
The centers of two adjacent indentations are too close to each other
Indenter
Replace the indenter if damaged
Worktable
Check whether there are foreign materials at the contacts of work table and
lead screw
Check whether the selected anvil is suitable for the specimen or not
The protective sleeve of lead screw has propped up the work table
Specimen
Test force is applied to the specimen perpendicularly or not
Whether there are burrs on the back
Too thin
Surroundings
Mechanical vibration around
Ambient temperature kept at 10-30
º
C
Others
Calibrate with standard hardness block
