Alternative procedure:
calibration with the
vessel almost full
The level of the vessel must be known as accurately as possible and should be as
high as possible. A level which is too low reduces the accuracy of the upper point
(corresponding to a full vessel). An ammeter must be connected to the electronic
insert at Terminals 4 - 5.
Assuming that the level is at 90 %, the current value corresponding to a 90 % level
must now be determined. The upper current value can be varied by pressing the two
pushbuttons on the right. The following calculation is used:
➀
The lower current value (= empty vessel, 0 %) is 4 mA.
➁
The upper current value (= full vessel, 100 %) is 20 mA.
➂
This gives a measuring range (‘span’) of 16 mA for a change from 0 to 100 % or
a 0.16 mA increase in current for every 1 % rise in level.
➃
For a 90 % level this is 90 % x 0.16 mA/% or 14.4 mA. This must be added to the
4 mA to give the current value required:
14.4 mA + 4 mA = 18.4 mA
(The upper current value can also be used and
10 % x 0.16 mA/% = 1.6 mA is to be subtracted from 20 mA)
➄
The value 18.4 mA (check with the ammeter) is set by pressing the two pushbut-
tons on the right. Pressing pushbutton (+) increases the current and pressing
pushbutton (-) decreases the current.
Note!
•
No indication is given on the green LED when using this variation.
•
If the operating status is unclear due to an incorrect setting, then all settings should
be reset to factory-set values and the basic calibration carried out again.
Locking the parameters
Press simultaneously the pushbutton for empty calibration (+) and the pushbutton for
full calibration (-). The settings of the electronic insert can now be called up at any
time using the handheld terminal but not changed. This condition is indicated in the
handheld terminal by the appearence of the code 9999 in Menu Level 2
"EXTENDED
CALIBRATION"
, Field 8
"SECURITY LOCKING"
(see Section 5).
Unlocking the
parameters
Press simultaneously the pushbutton for empty calibration (-) and the pushbutton for
full calibration (+). All settings of the electronic insert can now be called up and
changed using the handheld terminal. This condition is indicated in the handheld
terminal by the appearence of the code 12 in Menu Level 2
"EXTENDED CALIBRATION"
,
Field 8 "
SECURITY LOCKING
" (see Section 5).
Note!
4 Calibrating
Electronic insert FEC 12 (HART)
10
Hauser
