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2.3.3
molbox1+ to molbloc Connections
There are two molbloc connection channels on molbox1+.
connections (upstream and downstream) and one electrical/data connection.
channel to use or connect a separate molbloc to each channel.
For the pressure connections, use the molbox1+ to molbloc pressure tubes (P/N 3069560)
supplied with the molbox1+. Following the color coding on the pressure lines, connect the
upstream (HI) molbox1+ rear panel quick connector to the upstream port of the molbloc and
the downstream (LO) quick connector to the downstream port.
connectors, first pull back the knurled sleeve on the quick connector body, then insert the
quick connector stem and push firmly on the quick connectors until they click into place to
assure that the connection is properly completed.
For the electrical/data connection, use the molbox to molbloc electrical/data connection cable
(P/N 3068683). Connect the cable to the molbloc and then to molbox1+ rear panel connector
labeled molbloc.
Avoid making or breaking molbloc electrical connections to the molbox1+
while the molbox power is ON. Damage to the molbloc EEPROM may result.
2.3.4
Gas Supply and Flowpath Connections
Connect a gas supply to the molbloc. Gas supply requirements are:
•
The gas supply must be clean and dry (especially free from oil and particulates) to avoid
contaminating the molbloc.
•
For correct measurements, the gas must be of the same species as that selected by the
molbox1+ GAS function (see Section 3.4.2).
uncertainty of flow measurements as molbox1+ uses the thermodynamic properties of
the flowing gas in its flow calculations. Generally, gases with purity of 99.9 % or better
are used for molbloc measurements. Except when using ambient air with molbloc-S, the
test gas should be free of any humidity (dewpoint less than – 40 °C).
•
If the molbloc is connected upstream of the DUT, the supply pressure must be regulated
and stable within the limits of the molbloc-L pressure dependent calibration type (see
Section 1.2.5.1.2.1) or molbloc-S calibration type (see section 1.2.5.2.2). If the molbloc is
connected downstream of the DUT, use regulators and valves to make sure that the
pressure that is delivered to the molbloc will be within the limits of the molbloc calibration type.
•
Care should also be taken to make sure that the pressure and flow supplied to the
molbloc are always low enough to avoid over pressuring the molbox1+ RPTs(see
Sections 1.2.2, 3.1.4). If a DUT upstream of the molbloc is operated at high pressure, a
pressure reducing regulator should be connected between the DUT and the molbloc to
ensure that even momentary high pressure spikes do not reach the molbox RPTs.
•
The gas supplied to the molbloc should be clean and dry. Contamination
of the molbloc flow passage with liquids, particulates or any other matter
will alter the molbloc calibration and can lead to out of tolerance flow
measurements.
•
NEVER connect a pressure source to the molbloc that is greater than the
overpressure limit of your molbox1+. molbox1+ A350K overpressure limit
is 300kPa absolute/200 kPa gauge (44 psig/29 psig). molbox1+ A700K
overpressure limit is 650 kPa absolute/550 kPa gauge (95 psia/80 psig).
Overpressure can damage the molbox1+ internal RPTs (see Section 1.2.2,
3.1.4).
Caution
Gas purity affects the measurement
Caution
Page 27
© 1995 - 2010 Fluke Corporation, DH Instruments Division
2. INSTALLATION
Each has two pressure
Select a
To connect the quick
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