5
2. Depress UP or DW buttons on Z until meter reads 4.00mA.
(24 - 12)
Do not change the zero controls from now on. If changed,
mA = -------------- x 16 + 4 = 6.28
the material will have to be returned to the H (100%) level.
(96 - 12)
The correct loop current is 6.28mA.
If a 4.00mA value cannot be reached, then perform
OFFSET AND RESET functions.
2. Depress Z-UP or Z-DW buttons on ZERO until meter
reads 8.00mA. Do not change the ZERO controls
3. Fill the tank to the highest point possible (under 100%), and
from now on. If changed, the material will have to
record this level as H1. The most accurate calibration will be
be returned to the L (0%) level.
obtained with the greatest separation between L and H1.
If a 6.28mA value cannot be reached, then perform OFFSET
The loop current may not rise in proportion to the lower-
AND RESET functions.
ing material level in tank. Instead it may rise more rapid-
ly or more slowly than the material level. The SPAN,
3. Fill the tank to the lowest point possible (under 100%) and
S- UP or S-DW buttons may be used occasionally to
record this level as H1. The most accurate calibration will be
maintain the loop current approximately proportional to
obtained with the greatest separation between L and H1.
the tank emptying or just below the 20.00mA reading.
The loop current may not rise in proportion to the rising
4. To determine the loop current at L1 level use the following
material level in tank. Instead it may rise more rapidly or
formula:
more slowly than the material level. The SPAN, S-UP or
S-DW buttons may be used occasionally to maintain
(H1 - L)
the loop current approximately proportional to the tank
mA = ------------- x 16 + 4
filling or just below the 20.00mA reading.
(H - L)
4. To determine the loop current at H1 level use the following
Example: L = 12” (30.5 cm) from the bottom of the tank
formula :
H1 = 72” (183 cm) from the bottom of the tank
H = 96” (244 cm) from the bottom of the tank
(H1 - L)
mA = ------------- x 16 + 4
(72-12)
(H - L)
mA = -------------- x 16 + 4 = 15.43
(96 - 12)
Example: L = 12” (30.5 cm) from the bottom of the tank
H1 = 72” (183 cm) from the bottom of the tank
The correct loop current is 15.43mA.
H = 96” (244 cm) from the bottom of the tank
Depress SPAN S-UP or S-DW buttons as required to obtain
(72-12)
a meter reading of 16.80mA. If 16.80mA reading has been
mA = -------------- x 16 + 4 = 15.43
obtained, the calibration is complete.
(96 - 12)
The correct loop current is 15.43mA.
If a 16.80mA value cannot be reached, then perform OFFSET
AND RESET functions and re-start the
Depress SPAN S-UP or S-DW buttons as required to obtain
calibration.
a meter reading of 15.43mA. If 15.43mA reading has been
obtained, the calibration is complete.
If a 15.43mA value cannot be reached, then perform OFFSET
CALIBRATION PROCEDURE L1-H1
AND RESET functions and re-start the calibration Loop.
The ZERO, tank in L (Low) state, MUST always be calibrated
first.
Turn the DAMP ADJ pot to max CW (neg.) direction.
1. Fill the tank to its L1, some point below 100% level and
record this level as L1. See Fig. 4. To determine the loop
current at L1 level use the following formula:
(L1 - L)
mA = ------------- x 16 + 4
(H - L)
Example: L = 12” (30.5 cm) from the bottom of the tank
L1 = 24” (61 cm) from the bottom of the tank
H = 96” (244 cm) from the bottom of the tank
