6/08 ST 3000 Release 300 and SFC Model STS103 User’s Manual 185

10.3 Calibrating Analog Output Signal

Background You can calibrate the transmitter’s analog output circuit at its 0 and

100% levels by using the transmitter in its constant-current source

mode. It is not necessary to remove the transmitter from service.

Procedure The procedure in Table 57 shows the steps for calibrating the output

signal for a transmitter in the analog mode. Note that the procedure is

similar for a transmitter in the DE mode, but the SFC must be used to

read the output in percent in place of the milliammeter or voltmeter

readings.

Table 57 Calibrating Output Signal for Transmitter in Analog Mode

Step Press Key Read Display or Action Description

1 Connect SFC across loop wiring and
turn it on. Connect a precision
milliammeter or voltmeter ( 0.02%
accuracy or better) in loop to check
readings.
See Figure 38 for sample test
equipment hookup.
ATTENTION Be sure the
accuracy of the resistor is 0.01% or
better for current measurements
made by voltage drop.
2 DE READ
A
ID
TA ON.G
?TRIPS SECURED?
Be sure any switches that may trip
alarms or interlocks associated with
analog loop are secured or turned
off.
3 NON-VOL
ENTER
(Yes)
TA ON.G
SFC WORKING.. .
LIN AG NO.DP T
PT3Ø11
Confirm that “TRIPS” are secured
and establish communications with
sample transmitter PT 3011
4 INPUTJ
OUT-
PUT
PTOUT 30111P
FC WOSING.RK . .
PTOU T
%
30111
3.24
P
Ø
Display shows current transmitter
output level and it will update every
six seconds. Be sure to time your
next key press with an updated
display.
5 Z
0
PTOU T
%
30111
Ø_
P
Key in 0 (zero) as desired output
signal level in percent.
6 NON-VOL
ENTER
(Yes)
PTOUT 30111P
FC WOSING.RK . .
%.Ø
PTOUT 30111P
ØØ
#
Put transmitter into constant-current
source mode as noted by “#” sign in
display and set output to 0%.
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