Process Technology DQ15D - 4-20 Ma Output Option

M-34-01
Revision - Date: 01 - 04/23/08
DQ15D Manual
16
Warning!
Calibration procedures require the
removal of the rear cover of the control.
It also requires that power is ON,
exposing the technician to potentially
lethal voltages. Exercise EXTREME
CARE and wear tested electrician’s
gloves whenever power is on.
Equipment needed
• PCN 5416 or 5419 board.
• An NIST traceable sensor
simulator (calibrator), a precision
20 mA or higher calibrator/tester,
or a precision DMM for
verification.
Calibration Procedure
1 Turn OFF all power.
2 Remove rear cover.
3 Remove sensor leads.
4 Install appropriate sensor
calibrator, i.e. resistors or thermo-
couple simulator.
5 Remove ONE lead of the 4-20
mA output wire and install the
DMM or tester in series with the
external loop and this terminal.
OBSERVE POLARITY.
6 Restore power to control.
7 Verify basic instrument sensor
input accuracy by simulating various
sensor inputs and observing the
display values. If out of tolerance,
perform appropriate sensor calibration
before proceeding.
8 Simultaneously press and hold
and for approximately 6 sec. The
screen displays
AC.0 . While the 0 is
flashing, use
to enter 33. The
screen changes to display L followed
by the current lower process limit,
i.e. 0°, -20°, 0V, etc.
9 Use or to alter the lower
display value. Press
SET to store the
new value. The display will then
read hexadecimal 2AAA or 4.0mA,
verify that this is the value displayed
on your 4-20 mA calibrator/tester
or DMM.
4-20mA Output Option
The DQ15D is available with an
optional 4-20 mA output signal
proportional to the measured
(displayed) temperature. This
option is useful for source
transmitting the measured
temperature to a current loop-
sensing device such as a PLC,
remote intelligent display or chart
recorder. Use Terminals #2 and #3
for 2 wire 1000 ohm RTD.
Factory calibration is verified using
an intelligent NIST traceable 4 digit
DMM, a NIST traceable sensor
calibrator, and an intelligent display.
The factory range setting is 0-500°
F vs. 4-20 mA. Custom ranges can
be accommodated if specified at
time of order. Field calibration can
use a similar arrangement or a 4-20
mA calibrator for verification.
Since calibration is an involved
operation, it is suggested that it be
performed only after determining
that the measured values differ
from factory settings, or if the
output range is to be altered.
Use Terminals #2 and #3 for 2
wire 1000ohm RTD.
4-20mA Output Option
4-20 mA Output Option