DDS CALORIMETERS OPERATIONS MANUAL V1.1
2022
Website:
www.ddscalorimeters.com
63
Digital Data Systems (Pty) Ltd.
CAL3K Advanced Bomb Calorimeters
www.ddscalorimeters.com
90 PRESS ZERO ADJST 1
An
CAL3K-AP
command. The pressure is measured with a transducer which has a zero offset of +-1bar.
This error can be eliminated by using this command. The offset can be checked when the lid is open and
the ‘READ PRESSURE’, CMD=89., it should read ZERO. +-0.2bar. If not use the ‘PRESS ZERO ADJ’ to set it
to zero.
91
DEFLATE SYSTEM
1
The pressure in the
CAL3K-AP
piping is deflated by opening all valves until ESC.
92 PRESS DEFLAT.SEC 1
The command applies to the
CAL3K-AP
. After the main period the vessel is deflated. The time is
monitored and if the limit is exceeded a warning is displayed. It could be that the filter or the exhaust
valve is blocked. The default setting is 20 seconds.
93 PRESS FLUSH SEC 1
The vessel can be flushed with oxygen after deflating. The flushing removes harmful gases from the
pipes and vessel. The flush cycle is time based. A zero entry eliminates the flush cycle, otherwise the
vessel is filled for the specified time in seconds and then deflated. Default value is 3 seconds. In the
CAL3K-S/ST
models the flushing is applied before a determination
.
94 SYSTEM LEAK TEST 1
Note that the filling is much slower because the vessel is filled. Monitor the pressure and if it is steadily
declining than a leak is present. It is normal that the pressure declines rapidly in the beginning and then
settles down. This is because a flow restriction is present in the vessel lid.
95 PRESS FILL LEAK 1
This command applies to the
CAL3K-AP
. After filling the vessel with oxygen, the pressure is monitored
and if it declines (leaks) by more than the limit a warning is issued. Theoretical the pressure should be
constant, but it requires approx. 1 bar to equalise. The default setting is 1.5bar.
96 PRESS FILL MIN 1
An
CAL3K-AP
command. The minimum filling pressure specifies the limit at which the unit stops
working. It allows for slow filling and near empty oxygen bottles. The default is 20bar, which is sufficient
for avoiding oxygen starvation at 26KJ/g
Samples.
97 PRESS FILL SECND 1
An
CAL3K-AP
command. The filling time is monitored and when it exceeds the limit the operator is
warned. The reason for slow filling could be: Empty oxygen bottle or blocked inlet filter. The filter (and
filling restrictor) are a very unlikely reason for slow filling and the oxygen pressure should be
investigated first.
