OPERATING INSTRUCTIONS
FOR
HT DIGITAL UNIVERSAL TESTING MACHINE
(CAPACITY 200KN/ 400KN)
APPLICATION:
HT Universal Testing Machine is designed
for testing metals and other materials under tension, compression, bending,
transverse and shear loads.
PRINCIPLE OF OPERATION:
Operation of the machine is by hydraulic
transmission of the load from the test specimen to separately housed load
indicator.
Load is applied by a hydrostatically
lubricated ram. Main cylinder pressure
is transmitted to the digital load indicator housed in a pumping unit. The load transmitted to the cylinder from the
pressure transducers, microprocessors based.
The machine consists of Straining Unit and Control Panel.
STRAINING UNIT:
This consists of hydraulic cylinder,
motor driven chain and sprocket drive and a table coupled with the ram of the
hydraulic cylinder, mounted on to a robust base. The cylinder and the ram are individually
lapped to eliminate friction. The upper
cross head is rigidly fixed to the table by two straight columns.
The lower cross-head is connected to two
screwed columns which are driven by a motor.
Axial loading of the ram is ensured by relieving the cylinder and ram of
any possible side loading by the provision of ball seating.
An elongation scale, with a minimum
graduation of 1mm, is provided to measure the deformation of the specimen.
Tension test is conducted by gripping
the test specimen between the upper and lower cross-heads and other tests are
conducted between the lower cross head and the table.
The lower cross head can be raised or
lowered rapidly by operating the screwed columns, thus facilitating ease of
fixing of the test specimen.
Please note:
The machine supplied with compression platens for compression test,
tension grips, jars for 1 set, bending
attachment for 1 set. Other attachments
can be supplied on extra cost.
Load
verification of the testing machine meets the requirements of IS
1828-1975. Margin of error is ± 1% over
1/5th of the adjusted measuring range.
The machine consists of two units, viz.
the loading unit is A and the Control panel is B.
NOTE:
·
The jaws should be always released slowly.
·
The upper and lower jaws are non-interchangeable.
The Compression platens viz. upper and
lower are provided for conducting compression test. The lower compression plate is to be kept on
the lower table in the location hole provided and the upper compression plate
is to be clamped to the bottom of the lower crosshead. For clamping this plate, take the jaw in the
lower cross head to their bottom-most position-keep the top plate on the top of
lower crosshead, place in such a position that its protected portion fits
correctly in the chuck slot, resulting in correct position of control hole. Now
insert the clamp stud from the bottom through the hole of the lower plate. The clamp stud will come out from the central
hole of the lower plate. Now screw the
upper compression plate to the clamp stud and tighten it against the lower
plate by the nut from above.
The space between the lower table and
the lower cross head is used from compression, bend, shear and hardness tests,
and the space between the lower and upper cross heads is used for tension
test. In any test, the up and down motion
of the lower table and upper cross head assembly performs the loading
action. The mechanical up and down
motion of the lower cross head is provided for rapid initial space adjustment
depending on the length or height of the tension and compression test specimen
respectively.
Bending table, bending rollers and
bending pane are provided as an attachment for carrying out bend test.
An elongation scale is kept sliding on
the scale rod which is fixed between the lower table and the upper cross
head. The elongation indicating pointer
is fixed to the lower cross head. The
scale can slide on the rod when the screw as its back is loosened and can be
set to indicate zero, before staring the loading on the specimen.
PUMPING UNIT:
Digital pumping unit is an elegant
console wired for 220 V, single phase 50Hz power supply. Two plungers with reciprocating motion
operate to pump oil. The plungers are
operated by cam activated by motor. An
oil reservoir has a total cap of 15 ltr (approx) and is sent with a full charge
of multigrade oil of grade 20/40. A
transparent tube oil level indicator is provided on the tank. A load indicator of Four Digital LED display
if fitted on the panel with facility of overload
cut off. The load indicator is
calibrated by certified proving ring. A
pressure release valve is provided to start loading when open, the oil will
return to the pump even when pump are pumping.
A slow fast knob, a flow adjustment valve is provided to adjust rate of
flow. A clock wire rotation increased
flow and thereby rate of loading and anti-clockwise, position allows no flow of
oil from pump. A power on switch and
power off switch is provided to indicate that power has gone into the
unit. The loading unit assembly is
connected to the console with the help of a high pressure pipe.
Make the foundation of the machine as
per the hole provided in the machine and see there is a space to sit for a
person in case of any servicing, as there should be sufficient space in between
the loading unit and the pumping unit.
Connect console to 220 V single phase
50Hz AC supply. The red indicator lamp
glows showing the console has received power supply.
·
Switch on the digital indicator.
·
Press the zero and the peak button to enter the peak
hold mode.
·
Close the release valve.
·
Place the specimen i.e. compression/ tension/ bending
as per the instruction mentioned above.
·
Switch on the machine pump to start apply load on the
specimen.
·
Adjust the slow/fast knob for proper rate of loading.
·
Peak value is stored in the memory as soon as the
specimen is broken/ crushed.
·
Switch off the machine and release the pressure with
the help of release valve.
·
Allow the piston to come down.
·
Clean the platens.
·
Reset the peak button to bring the digital back to
zero.
MAINTENANCE:
·
The machine should always be kept clean.
·
The platens and unpainted parts should be greased when
not in use to prevent rusting.
·
The oil level in the pump should be maintained between
the oil indication levels.
·
In no case the pump should be operated when there is
no oil in the pump or the oil level is below the lower mark.
·
Hydraulic oil Servo System 526 of Indian oil
Corporation is filled in the machine.
This oil or any equivalent oil should be used only.
·
When oil starts leaking from the jack cylinder piston,
the seal should be replaced.
·
The oil in the system should be changed half yearly as
a normal practice but this period can be increased and decreased according to
the use of the machine.
·
Over tightening the pressure release valve should be
avoided. It should be kept a couple of
turn unscrewed when not being used.
·
Care should be taken not to take out the ram more than
250mm (maximum limit).
·
The machine should never be over loaded beyond its
capacity.
·
Due to constant R & D, specifications and features
are subject to change without any notice.
·
If, the machine runs on generating set, there is no
guarantee for microprocessor based digital indicator. It is advised, to keep
load voltage stabilizer when running on such a system.
This is dummy text. It is not meant to be read. Accordingly, it is difficult to figure out when to end it. But then, this is dummy text. It is not meant to be read. Period.
ConversionConversion EmoticonEmoticon