MBW 973-SF6, Operation Manual

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MBW973-SF6_MANUAL_E_V3.1
23
Measuring Range Limitations
The lower measuring limits of the 973 are approximately 40 ppm
v
(depending on pressure) for
humidity and 80% for volume SF
6
. If the measured value for humidity or % volume SF
6
is below
this measuring limit, the instrument indicates these conditions as follows:
If the measured value of humidity is below the measuring
limit of the 973, the display shows the symbol
<
(“smaller
than”) followed by the lower limit humidity value indicated in
°C frost point and ppm
v
.
This indicates that the actual measured humidity value is
below the displayed value, and below the measuring limit of
the instrument.
If the measured value of % volume SF
6
is below the meas-
uring limit of the 973, the display shows <80 .
This indicates that the actual % volume SF
6
value is below
the measuring limit of the instrument.
If the instrument indicates a reading of
>100 for % Volume
SF
6
, service or calibration may be needed. Please contact
the manufacturer or your local supplier for further infor-
mation.
Alarm Messages
If the gas compartment pressure is too low, or if the SF
6
coupling is not correctly connected to the gas compartment
an underpressure occurs in the sampling tube and the
measurement stops automatically. The 973 displays that
the pressure is too low.
Make sure the sampling tube is correctly connected on both
sides and the minimal gas pressure of at least 120 kPa ab-
solute is available.
If the gas compartment pressure is too high to allow the
pump back, the 973 turns the pump off automatically and
indicates that the compartment pressure is too high. The
maximum pump back pressure is 900 kPa abs.
Connect the 973 to a gas compartment or an SF
6
reclaimer
with a lower pressure to pump back the stored SF
6
.