DH Instruments MOLSTIC-S, Руководство по эксплуатации и обслуживанию

Страница: 35 / 44

3. MOLSTIC-S OPERATION
Page 29 © 2004-2007 DH Instruments, a Fluke Company
3
3
.
.
M
M
O
O
L
L
S
S
T
T
I
I
C
C
-
-
S
S
O
O
P
P
E
E
R
R
A
A
T
T
I
I
O
O
N
N
3.1 SYSTEM PRESSURIZATION AND REGULATOR
ADJUSTMENT – PRESSURE REDUCING REGULATOR
During system operation, be extremely careful not to apply pressure in excess of the maximum
operating pressure of the molbox: 600 kPaa (87 psia) for molbox1-A700K; 250 kPaa (36 psia) for
molbox1-A350K.
Once the test system with molbloc-S and molstic-S has been completely interconnected, the following
procedure should be used for its safe pressurization and operation.
The outlet pressure of a pressure reducing regulator is controlled by adjusting the position of the control knob.
Rotating the knob in the clockwise direction raises the outlet (control) pressure. Counterclockwise rotation,
coupled with venting of the downstream side of the regulator plumbing, lowers the outlet pressure.
molstic-S regulators are NOT self-venting so the outlet pressure will not decrease with counterclockwise
rotation of the control knob unless the downstream gas is allowed to escape.
Make final adjustments of control pressure in the direction of increasing pressure in order to obtain the
most accurate and stable set point.
3.1.1 SYSTEM PRESSURIZAION
Begin with system pressure vented: Make sure that the system pressure is vented.
Set inlet pressure to minimum: Turn the regulator’s adjustment knob counterclockwise
until the spring force has been relieved.
Turn on gas supply: Apply the supply pressure to the pressure control regulator.
Open molstic-S flow control/shut off valve(s): Valves must be open to allow test gas
to fill the test system.
Isolate from vacuum system: If the outlet plumbing of the molstic-S flows into a
vacuum pump, disconnect or otherwise isolate from the vacuum system. When capping
off ISO-KF style flanges use overpressure rings to insure a leak free connection at
positive line pressure.
Plug-off/cap-off system: Place a plug or cap (as applicable) on the outlet fitting of the
test system.
Open DUT’s flow control valve: If the test system contains a DUT that has flow control
capability,
it must be opened slightly in order to allow pressure to pass through. All that is
necessary is a small flow to allow the system to fully pressurize.
Display system pressure: Monitor the system pressure as measured by molbox by
pressing the [P&T] function until the pressure is displayed. Refer to molbox Operation
and Maintenance Manual for details.
Turn on gas supply: Apply the supply pressure to the pressure control regulator.