DH Instruments FPG8601, Руководство по эксплуатации и обслуживанию

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5. SYSTEM OPERATION
Page 41 © 2007 DH Instruments, a Fluke Company
5.4 SETTING A MEASUREMENT MODE
When the steps in Section 4.6 are followed, the FPG can be switched between gauge and absolute
measurement modes by simply using the corresponding
[Units], [Absolute Mode]
or
[Gauge Mode]
menu option. To set absolute differential mode, just follow the same steps required to set absolute mode,
but select the
[Config], [System Setup], <Use vacuum reference for data logging only>
option
(see Section 6.6.2.1). This prevents the conversion of the FPG differential pressure into an absolute
pressure. In absolute mode, this setting must be
<Use vacuum reference for absolute mode correction>
.
Refer to Section 6.9.2 for details on how FPG Tools changes measurement modes.
When the optional DUT manifold is activated, changing measurement modes in the FPG automatically
changes the measurement mode in the DUT manifold. Make sure the manifold and manifold vacuum
pump (if necessary) are activated in the system setup prior to changing measurement modes.
While setting a measurement mode, the manifold is exposed to the FPG with the bypass valve open.
After the transition is complete, the valves and manifold vacuum pump are adjusted to the state required
by the measurement mode. When setting absolute mode the manifold vacuum pump is turned on and
the lower manifold port is isolated from the FPG. In both gauge and absolute differential measurement
modes, the manifold vacuum pump is turned off and vented and the upper and lower manifold ports are
exposed to the FPG. Refer to the
<DUT Manifold>
display (see Section 6.3.8) to view the current state
of the valves and the effect on the pressure in the manifold.
Only expose the DUT manifold to the FPG when the manifold bypass valve is open and both the
manifold and FPG are in the same state. Failure to do so may overpressure DUTs connected to the
manifold and/or damage the manifold vacuum pump.
Whenever a measurement mode is changed or reset, the VLPC is set to its minimum pressure range for
the selected measurement mode.
5.5 USING A DUT WITH FPG TOOLS
FPG Tools provides features that support automated data acquisition from most DUTs that have an
RS232 or IEEE-488 output. Manual DUTs are also supported by allowing their output to be manually
entered into the software. Although manual DUTs are not automated, the manual DUT features provide a
consistent data file structure that simplifies reporting of data. Follow the steps below to set up and use a
DUT with FPG Tools. Refer to Section 4.10 for pneumatic connections related to using a DUT in a
specific measurement mode.
Set up the DUT using the
[Config], [DUT Editor]
tab (see Section 6.8). Press the
[New]
toolbar
option to create a new DUT or use the
[Copy]
button to begin with a duplicate copy of the DUT.
Enter the necessary DUT information on each of the editor tabs then press the
[Save]
button.
Select
[Config], [DUT Selection]
and select the DUT(s) that will be used. Enter the serial number
and identification of DUTs that are setup as profiles (see Section 6.6.5). If the DUT is RS232, click
the displayed RS232 settings to change the COM port as needed. Press the
[Activate DUT(s)]
button to initialize and poll the output of remote DUTs. Press the
[Deactivate DUT(s)]
button to stop
polling the DUTs.
DUTs can be changed or edited at any time. However, changes to a DUT using the
<DUT Editor>
are not automatically activated to the DUT when it is already being polled by FPG Tools. Use
[Config], [DUT Selection]
to re-activate the DUT with the changes. It is not recommended that
DUTs be modified during tests. Any new DUT settings created after the test has begun are not
logged into the data file.