Table of Contents
Advertisement
MOLBOX1+™/MOLBOX1+S, MOLBLOC TERMINAL OPERATION AND MAINTENANCE MANUAL
Therefore, the SYSTEM LEAK CHECK is most effective when the volume of the
closed system is minimized.
During molbloc-L operation, the SYSTEM LEAK CHECK also measures flow through
the molbloc to help determine whether a leak is present upstream or downstream of
the molbloc. Since molbloc-S is not capable of calculating meaningful flow values
with the very small differential pressure present during this test, the SYSTEM LEAK
CHECK operates differently for molbloc-L and molbloc-S operation, as described in
the OPERATION sections immediately below.
To access the system leak check press [TARE] and select <3leak check>,
<2system>. The display is:
This display is intended to assist the operator in setting the leak check pressure.
molbox1+ has actuated internal valves to connect the upstream and downstream
RPTs together, so they are both measuring an equal system pressure. (see Figure 9).
Close an isolation valve downstream or plug the exhaust of the flow system that
is being tested (downstream of the molbloc anxxxxd the DUT if the
molbloc/molbox is being used to test another device).
Using the molbox1+ display to read the pressure, set the pressure to the normal
operating pressure.
© 1995 - 2010 Fluke Corporation, DH Instruments Division
The SYSTEM LEAK CHECK function uses molbox1+'s high
precision pressure and flow measurement capabilities to help
determine whether a leak exists in the system to which the
molbloc is connected. This feature is to assist the operator in
flow measurement and calibration. The system to which the
molbloc is connected is the responsibility of the user. Failures
in the system leak check do not normally indicate defects in the
molbox1+ or molbloc itself. The molbox1+ leak check is used to
identify molbox1+ failures.
OPERATION – molbloc-L Operation
The pressure read by the upstream RPT (left),
1.
the downstream RPT (right) and the pressure
unit of measure (middle).
Figure 9. molbox1+ Internal Pneumatic Schematic
- SYSTEM LEAK CHECK - CHECKING OFFSET AND STABILITY
Page 60
Note
347.589 kPaa 347.580
<ENTER> when ready
1. Channel A High Isolation: Open
2. Channel A Low Isolation: Open
3. Channel B High Isolation: Closed
4. Channel B Low Isolation: Closed
5. Bypass: Open
Advertisement
Table of Contents
