Setup and connection procedures for the molbloc/molbox system.
About this task
The molbloc/molbox system consists of a molbox terminal (molbox1+ or
molbox1+S) and one or more molbloc flow measuring elements (molbloc-L laminar
or molbloc-S sonic). This procedure covers the physical installation and
connections required before the system can be powered on. For complete details,
refer to the Fluke molbox1+/molbox1+S Operation and Maintenance Manual.
Procedure
-
Install the molbox on a stable surface at a convenient height for display
viewing.
The front feet extend so the display inclines toward the operator. The
molbox can also be rack-mounted using a standard 19-inch rack mount kit
(Fluke P/N 3069903).
-
Position the molbloc flow element within reach of the molbox connection
cables and pressure tubing.
The distance between the molbloc and molbox is limited by the length of
the electrical cable and pneumatic lines. If the molbox is at a
different height than the molbloc, a small head pressure correction may
be required.
-
Connect the power cord to the power connection module on the rear
panel.
-
Connect the molbloc electrical/data cable from the rear panel to the
molbloc.
The molbox supports two molbloc channels (A and B). Use the Channel A
connectors (items 14–16 on the rear panel) or Channel B connectors
(items 11–13) as appropriate.
-
Connect the pressure tubing between the molbox rear panel HI and LO
pressure ports and the corresponding ports on the molbloc.
-
Connect the gas supply to the upstream side of the molbloc and install a
shutoff valve between the gas supply and the molbloc.
Important: Flow direction through the molbloc must match the
arrow engraved on the molbloc body.
CAUTION: If a device under test is connected upstream of the
molbloc, ensure the gas supply is clean before flowing. Contaminants
can alter the molbloc calibration. Consider installing a filter between
the DUT and the molbloc.
- Optional:
For molbloc-S operation requiring reduced downstream pressure, connect a
vacuum pump downstream of the molbloc.
A downstream vacuum allows critical flow to be achieved at lower
upstream pressures, extending the usable flow range. Install a shut-off
valve and, ideally, a check valve with very low cracking pressure
between the molbloc and the vacuum pump. Ensure facilities prevent gas
from flowing into the pump when it is not running.
Results
CAUTION: Operation at pressures outside the molbloc calibration type
limits may produce out-of-tolerance flow measurements. Refer to the molbloc
Calibration Report to determine the applicable calibration type and pressure
range.
