5.
MAINTENANCE, ADJUSTMENTS AND CALIBRATION
Page 179
© 1998-2008 DH Instruments, a Fluke Company
5.2.2
PISTON POSITION DETECTION ADJUSTMENT
PURPOSE
To adjust the piston position measurement system.
PRINCIPLE
The PG7000 piston position measurement operates on the LVDT principle. There are coils
mounted on either side of the piston-cylinder module mounting post and a ring on the inside
of the mass loading bell acts as the sensor element. As the bell moves, the LVDT signal
changes proportionally to bell position, and therefore piston position. The signal is translated
into relative position in the
±
4.5 mm stroke of the piston (see Section 3.5). The piston
position and fall rate can be viewed in the
[SYSTEM]
run screen (see Section 3.9.5).
The piston position indication system can be realigned by an automated on-board routine.
This routine sets and records the LVDT output at the piston hi and lo stop positions.
When an AMH mass set is used, it is important to follow a specific procedure to adjust the
piston position detection system. See Special Considerations When Using an AMH Mass Set in
the OPERATION Section below.
OPERATION
Refer to piston stroke schematic Figure 8.
If the PG7000 Platform is equipped with an AMH mass set, be sure to see Special
Considerations When Using an AMH Mass Set.
To automatically adjust the PG7000 piston position indication system, load the mass bell only
on the piston. Then press
[SPECIAL]
,
<7cal>
,
<5Pposition>
,
<2cal>.
The prompt
<Hold piston at max down stop>
appears. Place the piston in the fully down
position (be sure to compress the springs so that the piston is truly at the low stop position by
pressing down firmly on the piston or loading at least 5 more kg of mass). Press
[ENTER]
.
The prompt
<Hold piston at max up stop>
appears. Place the piston in the fully up position
(be sure to compress the springs so that the piston is truly at the high stop position by
applying pressure underneath the piston that is the equivalent to at least 5 kg greater than
the pressure required to float the piston with the current load). Press
[ENTER]
.
Pressing
[SPECIAL]
and select
<7cal>
,
<5Pposition>
,
<1view>
allows current piston
position and fall rate (see Section 3.9.5.1) to be viewed on the bottom line of the display.
Position is on the left and fall rate is on the right.
Special Considerations When Using an AMH Mass Set
The tubular binary masses of an AMH mass set have some influence on the piston position
detection system so it is important to adjust the piston position detection system with all the
binary masses loaded.
Содержание PG7000
Страница 10: ...PG7000 OPERATION AND MAINTENANCE MANUAL 1998 2008 DH Instruments a Fluke Company Page VIII N NO OT TE ES S ...
Страница 44: ...PG7000 OPERATION AND MAINTENANCE MANUAL 1998 2008 DH Instruments a Fluke Company Page 34 N NO OT TE ES S ...
Страница 182: ...PG7000 OPERATION AND MAINTENANCE MANUAL 1998 2008 DH Instruments a Fluke Company Page 172 N NO OT TE ES S ...
Страница 210: ...PG7000 OPERATION AND MAINTENANCE MANUAL 1998 2008 DH Instruments a Fluke Company Page 200 N NO OT TE ES S ...
Страница 214: ...PG7000 OPERATION AND MAINTENANCE MANUAL 1998 2008 DH Instruments a Fluke Company Page 204 N NO OT TE ES S ...
Страница 224: ...PG7000 OPERATION AND MAINTENANCE MANUAL 1998 2008 DH Instruments a Fluke Company Page 214 N NO OT TE ES S ...