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7.3
LOW FLOW ERROR:
The flow through the sensor is controlled by the vacuum pump. The level of vacuum
required to maintain the required flow can be seen in the lower LH screen. Should the
sample intake of the sensor be partially or totally blocked, the instrument will first try to
compensate by increasing the vacuum. If unsuccessful, an error is reported.
You have the choice to confirm one of the following instructions: TRY TO CONTINUE
Instrument will try to resume normal operation. This is useful if the blockage can be
overcome with a higher vacuum. The LOW FLOW ERROR may also occur if the sensor
cap was changed for the capillary probe, this needs higher vacuum to maintain the
sample flow.
BEFORE changing probes and sensors ALWAYS switch OFF
.
The ideal vacuum levels for a clean filter are: -100 to -300mb.
To fit the capillary probe, FIRST switch the instrument off. This allows the new flow levels
to be automatically compensated.
7.4
FLARE STALL:
This relates to sensor condition. Two reasons are possible for this.
1
Very high concentration of SF6 many times above the measuring range.
2
High vacuum in the probe caused by a partially blocked or aged sensor.
The instrument will attempt to compensate for these until a level is reached where the
detector will stall. At this point the instrument must be switched OFF and the sensor
changed.
7.5
LOW BATTERY VOLTAGE:
If the battery becomes discharged, the operator is warned of the pending shut down.
If main’s power cannot be made available, operation can be resumed for a short time, but
the instrument may now shut down at any time without further warning.
7.5
SWITCHING OFF:
During system shutdown, the processor updates the memory, releases vacuum, and
turns OFF the touch-screen. To shutdown, press one of the on/off keys for several
seconds. A time bar on the screen visualises the hold time.
When the time bar is complete, the button should be released. If it was held down longer,
the shutdown sequence will not finish properly.
8.0
SWITCHING OFF IN CASE OF FAULT:
Normally, shutdown is controlled as described above. Should this process be changed by
a serious failure, the instrument can still be switched off under hardware control. This
activates whenever one of the on/off keys is continuously held down for approx. 10
seconds.
