7.1
95-8533
5-2
CALIBRATION AND ADJUSTMENTS
To ensure optimum performance, calibration must be
performed on a regularly scheduled basis. Since
each application is different, the length of time
between regularly scheduled recalibrations can vary
from one installation to the next. In general, the more
frequently a system is checked, the greater the
reliability.
IMPORTANT!
4 to 20 ma devices not manufactured by Det-
Tronics must be pre-calibrated. To ensure
adequate protection, calibration must be
performed on a regularly scheduled basis.
NOTE
If the calibration procedure is not completed
within 12 minutes, the detector will revert back to
the previous calibration values. The red LED will
blink. The calibration will be logged as aborted.
NOTE
The “Sensor Replacement” calibration procedure
must be used for the initial calibration of a new
sensor. The “Routine Calibration” procedure can
be used for all subsequent calibrations.
NOTE
Some calibration procedures require the
operator to activate the reed switch located on a
circuit board inside the junction box. See Figure
5-1 for reed switch location. To activate the
switch, hold the calibration magnet against the
side of the junction box near the switch location
approximately one inch above the mounting
surface. (Do not open the junction box.) Hold
the calibration magnet in place for approximately
4 seconds to initiate the calibration procedure.
CALIBRATION ALGORITHM A
FOR MANUAL CALIBRATION OF UNIVERSAL DCU
Normal Calibration
1. Activate the reed switch. (The red LED blinks
while the reed switch is closed.)
2. After the reed switch has been closed for 3
seconds, the calibrate LED blinks, indicating it is
ready for the zero input.
3. Enter the zero input (4 ma).
4. Activate the reed switch. (The red LED blinks
while the switch is closed.)
5. After the reed switch has been closed for 3
seconds, the communication module records the
uncalibrated value in the calibration log and
calibrates the zero value. (The calibrate LED
stays on steady.)
6. Apply the calibration gas.
7. The calibrate LED blinks as the input increases.
8. Activate the reed switch. (The red LED blinks
while the reed switch is closed.)
9. The communication module records the
uncalibrated value in the calibration log and
calibrates the span value after the reed switch is
on for 3 seconds.
10. The calibrate LED stays on steady.
GND
9
10
7
8
5
6
3
4
1
2
13
14
11
12
A1881
MAGNETIC REED SWITCH
*
*
TO ACTIVATE THE MAGNETIC REED SWITCH,
HOLD THE CALIBRATION MAGNET AGAINST THE SIDE OF THE ENCLOSURE
AT THE LOCATION OF THE REED SWITCH,
APPROXIMATELY ONE INCH ABOVE THE MOUNTING SURFACE.
SW1
Figure 5-1—DCU Terminal Wiring Board Mounted in Six-Port
Junction Box
Summary of Contents for DET-TRONICS 95-8533
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