Navigator 600 Phosphate
Multi-stream
3 Principle of Operation
IM/NAV6P/MS–EN Rev. F
11
3.4 Single Stream Operation for Maintenance
It may be necessary to switch the analyzer to single stream
mode during commissioning or to carry out maintenance.
Single stream mode is initiated by enabling one stream only. This
stops the multi-stream sequence and results in reading updates
every second. The analyzer is not designed to run in this mode
continuously, but it can be used to check the basic performance
on the analyzer without having to wait for the normal stream
update.
Selecting more than one stream puts the analyzer back into
multi-stream operation.
3.5 Out of Sample
If the analyzer detects that a sample is lost (via the out of sample
switch) during its sampling period, it continues to sample for 10
seconds and then switches to the next enabled stream in the
sequence that has sample present.
If an enabled stream in the sequence is not present the analyzer
skips that stream and goes to the next enabled stream in the
sequence. If all but one stream is out of sample, the duration
between reading updates is the upscale sampling time.
If all streams are out of sample the analyzer shuts down
automatically to prevent air being drawn into the analyzer and to
conserve reagents.
The automatic shutdown procedure is:
1. The reagent pump stops.
2. Zero calibration solution is pumped through the system to
purge the reaction coil of reagents and developed
solution.
3. The sample pump, reaction heater and pre-heater are
switched off.
4. The analyzer waits in standby mode until a sample is
restored.
5. When a sample returns and the analyzer has been out of
all samples for less than 24 hours a purge sequence is
started.
If the analyzer has been out of all samples for more than
24 hours a purge and clean sequence is started.
If all enabled streams are out of sample, but there are disabled
streams with sample present, the analyzer continues to run on
the available disabled stream. The diagnostic message '
No valid
streams available
' is displayed in the diagnostic window. Stream
values are not updated, but the analyzer continues to run and
perform scheduled calibrations and cleans.
As soon as an enabled stream has sample present the
multistream sequence initiates and the readings update
accordingly.
