Hach BioTector B3500s User Manual page 122

PRESSURE CHCK FAULT
FLOW WARNING
REACTOR PURGE CHECK
REACTOR PURGE BAND
▪ At the end of each reaction during operation, BioTector
6.0l/h
automatically pressurizes the system with oxygen gas and uses
its mass flow controller to detect any gas leak in the system. If
the measured flow is less than or equal to the programmed
PRESSURE CHECK FAULT flow level (locked to 6.0 l/h by
default) during the test, the pressure check passes. The
PRESSURE CHECK FAULT acts a safety function, to ensure
that there is no gas leak in the system and it is safe to start the
next analysis reaction.
▪ The pressure check cycle cannot be disabled in the system.
▪ If the flow measured during the pressure check is greater than
the programmed PRESSURE CHECK FAULT level (greater than
6.0 l/h) the pressure check fails, and BioTector generates a
"06_PRESSURE CHCK FAIL" fault and stops. This fault is
logged in the fault archive.
45.0l/h ▪ Each time BioTector is started up and everyday during online
operation at the programmed TIME above, oxygen gas flows
through the system and mass flow controller is used to detect
any blockage in the system. If the measured flow is greater than
or equal to the programmed FLOW WARNING level (45.0 l/h by
default), the flow test passes.
▪ If the measured flow is less than the programmed FLOW
WARNING setting, the flow test fails, and BioTector generates a
"22_FLOW WARNING - EX" or "23_FLOW WARNING - SO" in
the fault archive and continues to run. This warning is logged in
the fault archive.
▪ In TC – TIC systems, BioTector generates a "24_TIC FLOW
WARN - EX" or "25_TIC FLOW WARN - SO" if TIC reactor flow
test fails.
4s ▪ During the two Pressure Release phases of the Reactor Purge
carried out at the end of each analysis cycle described in section
8.3.2 System
for 4 seconds (by default) with the REACTOR PURGE CHECK
function. This is carried out to detect any irregularities in the gas
flow, which may indicate a possible blockage or restriction in the
reactor and/or in the sample out lines, which includes Reactor
Valve (MV3) and Sample Valve (MV4).
3.0l/h ▪ If the monitored oxygen gas flow readings during the REACTOR
PURGE CHECK are not stable and move outside the REACTOR
PURGE BAND, which is programmed as ±3 l/h by default,
during the first Pressure Release phase for three consecutive
times, a "128_REACTOR PURGE WARN" warning is logged in
the fault archive and BioTector keeps running.
▪ If the monitored oxygen gas flow readings are not stable and
move outside the REACTOR PURGE BAND during the second
Pressure Release phase and if a flow problem has already been
detected during the first Pressure Release phase of the same
Reactor Purge cycle, a "129_REACTOR PURGE FAIL" fault is
logged in the fault archive and BioTector stops.
Program, BioTector monitors the oxygen gas flow
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