KROHNE OPTIMASS Series Handbook page 70

Under certain conditions, it may not be possible to adjust the zero point, for instance when:
• The medium is in motion, because the shut-off valves etc. are not functioning properly.
• There are still gaseous inclusions in the primary head because it was flushed insufficiently.
In such cases the zero point adjustment will not be accepted. If the zero adjustment was started by the
binary input, the converter will show the message :
ZERO.ERROR
The converter also reports the ZERO.ERROR in the status list.
Under certain circumstances, when the media consists of unevenly mixed components, it might be
difficult to adjust the zero point. In such a case, the zero point adjustment procedure must be carried
out under special conditions:
• Media which tend to vaporise or degas should be kept under higher pressure.
• Two-phase media consisting of a separable solid component (slurry): In such a case it might be
advisable to fill the primary head with the carrier medium only.
• Other two-phase media.
If it is not possible to separate the solid or gaseous components, the operator can fill the measuring
system with a substitute liquid (e.g. with water).
Instrument State Fct. 1.2.
The instrument may be switched to a 'STANDBY' state. Once in this state, all outputs go to their off
state and the mass totaliser is frozen. The main display will have the STANDBY indicator set and will
display either the frozen totaliser or just STANDBY.
Begin from measuring mode
Key Display
Line 1
3.456
↑
↑
Whilst in this state the measuring tube still vibrates and the measurements can come back on line in
an instant.
There is an additional standby state, 'STOP', in this case the drive to the primary head is disabled and
vibrations cease. However, when leaving STOP the converter has to return to STARTUP before
measurements can resume.
The instrument can be switched to STANDBY or STOP either by the keys on the display or by the
control input signal (see section 5.4). STOP can only be set by the keys.
To set STANDBY or STOP:
Begin from measuring mode
Key Display
Line 1
Fct. 1.(1)
→ x 2
Fct. 1.(2.).
↑
→
↑
↑
Use the ↑ key to select the desired mode.
Fct. 1.(2)
↵
If STANDBY or STOP was selected the instrument goes immediately into that state.
To return to measurement, go back to Fct. 1.2 and select MEASURE.
Line 2
STANDBY
kg (Frozen Totalizer)
STANDBY
Line 2
ZERO CAL.
INST. STATE
MEASURE
(STANDBY)
(STOP)
STANDBY
Installation and Operating Instructions OPTIMASS 69