1.7
Calibration
There are two calibration methods that can be used,
depending on your particular situation. Calibration
Procedure A will require mov-ing the level from the 0%
point (4 mA) to the 100% point (20 mA). Calibration
Procedure B allows you to start at a level greater than 0%
and stop at a level less than 100%. To attain the best
accuracy and linearity use Calibration Procedure A. The
following is a list of abbreviations and definitions used in
the procedures.
L0
The level of the media in the vessel which corresponds
to the 0% (4 mA) point
L3
100%
L1
A media level higher than L0
L2
A media level higher than L0 and L1 but less than L3
L3
The level of the media in the vessel which corresponds
to the 100% (20 mA) point
L2
less than
100%
Calibration
Procedure
B
A
L1
L0
greater
than
0%
0%
Refer to Figure 9.
The output current can be measured either by inserting
a milliammeter into the loop, or by measuring across
TP1 (+) and TP2 (–). The intensity of the LED between
the test points is a relative indicator of current flow. (The
LED will not light with a meter across the test points.)
NOTE: Prior to starting any calibration procedure, turn all poten-
tiometers Zero Coarse, Zero Fine, and Span Fine, 20 turns
clockwise. Place the Span Coarse DIP switches in the open
position. The Zero Coarse DIP switch should have only the
“low” position closed.
Figure 9
F
HIGH
MED
LOW
3
OPEN
2
1.7.1 Calibration Procedure A
1
closed dip switch
Figure 10
open dip switch
1. Move the media level in the vessel to the 0% (4 mA) point.
2. Turn potentiometer Zero Coarse counterclockwise until
the loop output is between 4.00 mA and 4.50 mA.
3. If the loop current can not be decreased to at least 4.50 mA,
turn the Zero Coarse potentiometer fully clockwise, close
DIP switch positions “MED” and “HIGH” sequentially
(ONLY ONE SWITCH POSITION SHOULD BE
CLOSED AT A TIME—THE OTHER TWO POSITIONS
MUST REMAIN OPEN). Repeat Step 2. See Figure 10.
4. Turn potentiometer Zero Fine counterclockwise until the
loop output reads exactly 4.00 mA.
5. Move the media level in the vessel to the 100% (20 mA)
point.
6. Turn the Span Fine potentiometer counterclockwise until
the loop current is exactly 20.00 mA.
9
50-613 Kotron Series 82 CE RF Level Transmitter
MAGNETROL [ MAGNETROL INTERNATIONAL, INC. ]
