Dynasonics DDFXD Doppler Ultrasonic Flow Meter - Manual (Page 43)

06-DPP-UM-00147 02/12 43
4-20MA CALIBRATION
The 4-20 mA ISO-MOD is factory calibrated and should not require adjustment unless it is replaced.
NOTE: The CAL 4MA and CAL 20MA entries should not be used in
an attempt to set the 4-20 mA range. Utilize FLOW 4MA and FLOW
20MA, detailed above, for this purpose.
CAL 4MA (CHOICE)
The 4-20CAL? entry allows fine adjustments to be
made to the “zero” and span of the 4-20 mA output.
Select YES to access adjustment. To adjust the 4 mA
output, a milliammeter or reliable reference must be
connected to the 4-20 mA output.
PROCEDURE:
1) Disconnect one side of the current loop and
connect the milliammeter in series (disconnect
either wire at the terminals labeled +/- on the
ISO-MOD 4-20 mA module) see Figure 4.2.
2) Using the arrow keys, increase the numerical
value to increase the current in the loop to 4
mA. Decrease the value to decrease the cur-
rent in the loop to 4 mA. Typical values range
between 40-80 counts.
3) Re-connect the 4-20 mA output circuitry as
required.
CAL 20MA (VALUE)
Calibration of the 20 mA setting is conducted much
the same way as the 4 mA adjustments.
PROCEDURE:
1) Disconnect one side of the current loop and connect the milliammeter in series (disconnect either
wire at the terminals labeled +/- on the ISO-MOD 4-20 mA module) see Figure 4.2.
2) Using the arrow keys, increase the numerical value to increase the current in the loop to 20 mA.
Decrease the value to decrease the current in the loop to 20 mA. Typical values range between
3700-3900 counts.
3) Re-connect the 4-20 mA output circuitry as required.
10A MAX
FUSED 400mA
FUSED
CAT III
1000V
HOLD MIN MAX REL
Hz % ms RANGE
AutoHOLD FAST MIN MX LOGGING YES
CANCEL SAVE NO
SETUP
—A
mA
A
W
V
TEMPERATURE
COM
OFF
nS
W
VIEW MEM
CLEAR MEM
V
dB
mV
dB
ac+dc
V
ac+dc
A
mA
mV
ac+dc
mA
A
—A
ac+dc
—A
°C
°F
MEM 51000
AUTO MANUAL
0 0
OUT (-)
IN (+)
I/O: 4-20 mA
P.N. D020-1045-100
ISO-MOD
JP2
JP1
INT PWR EXT PWR
FIGURE 4.2 - 4-20 mA CALIBRATION SETUP