ABB LWT300 series, Руководство пользователя

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Configuring the instrument
45
Setting dynamic variables
The LWT instrument can monitor up to four variables. These variables are identified as primary (PV),
secondary (SV), tertiary (TV), and quaternary (QV).
If you initially configured your LWT instrument with the help of the
Easy Setup
menu, you have already
defined the primary variable (PV). The primary variable is often the most important value that you want
to measure. You can also monitor three more variables.
Setting variables
Variables are set in the
Device Setup
menu.
To set one of the variables:
1
From the
Device Setup
menu, select
Dynamic Variables > Set
(
PV
,
SV
,
TV
or
QV
)
2
Press
Edit
and, from the list of variables that appear, highlight the variable that you want to monitor.
NOTICE
As is commonly accepted practice, the first two variables ( PV and SV ) relate to variations
on distance measurements ( Level , Distance , Ullage , Interface , Thickness , Interface
Distance ) whereas the last two variables ( TV and QV ) allow for monitoring of additional
variables ( Amplitude , Electronics Temperature , Interface Amplitude , GPC Dynamic
Factor , External Temperature [linked to pt100 external temperature sensors; see “PT100
temperature sensors” on page E99]). Available variables depend on configuration
choices made elsewhere (application category, linearization status or output type, etc.
3
Press
OK
. The variable is set and will be monitored and measured from now on.
Setting variable units
Variable measurement units are set in the
Device Setup
menu. They releate to four different types of
measurement: level, flow, volume and temperature.
To set variable units
1
From the
Device Setup
menu, select
Dynamic Variables >
the unit that you want to set (
Level Unit
,
Flow Unit
,
Volume Unit
,
Temperature Unit
).
2
Press
Edit
and, fromt he list of units that appear, highlight the unit that you want to assign to a
specific variable.
NOTICE
Variable units are specific to the type of variable (e.g., you will not find flow units in the
Volume Unit menu).
3
Press
OK
. The unit is set and you return to the previous menu.