Recommended Configuration - Emerson Rosemount Oxymitter 4000 Instruction Manual

Oxymitter 4000
Recommended
Configuration
2-6
Calibration Handshake Signal
If using an optional IMPS 4000 or SPS 4001B, the logic I/O must be
configured for calibration handshaking. Of the ten modes in Table 2-1, only
modes 8 and 9 are configured for calibration handshaking. For an Oxymitter
4000 with an IMPS 4000 or an SPS 4001B, the factory sets the default to
mode 8. In this mode, the logic I/O will be used to communicate between the
Oxymitter 4000 and sequencer and to signal the sequencer when a
CALIBRATION RECOMMENDATION indication occurs.
4-20 mA Signal Upon Critical Alarm
Emerson recommends that the factory default be utilized. The 4-20 mA signal
will go to the 3.5 mA level upon any critical alarm which will cause the O
reading to be unusable. Customer can also select
21.6 mA as the failure setting if normal operations cause O
below the zero % O (3.5 mA) level.
2
If the O measurement is being utilized as part of an automatic control loop,
2
the loop should be placed into manual upon this failure event or other
appropriate action should be taken.
Calibration
Emerson recommends utilizing an autocalibration system, actuated by the
"calibration recommended" diagnostic. New O
than a year, but older cells may require recalibration every few weeks as
they near the end of their life. This strategy ensures that the O
always accurate, and eliminates many unnecessary calibrations based on
calendar days or weeks since previous calibration.
When utilizing the SPS 4001B or IMPS 4000, consider wiring some or all
associated alarm contacts.
1. CALIBRATION INITIATE. Contact from the control room to an
SPS 4001B or IMPS 4000 (one per probe) provides the ability to
manually initiate a calibration at any time from the control room. Note
that calibrations can also be initiated from a HART handheld
communicator, from Asset Management Solutions software, or from the
keypad on the Oxymitter 4000.
2. IN CALIBRATION. One contact per probe provides notification to the
control room that the "calibration recommended" diagnostic has initiated
an automatic calibration through the SPS 4001B or IMPS 4000. If the O
signal is being utilized in an automatic control loop, this contact should
be utilized to place the control loop into manual during calibration.
3. CALIBRATION FAILED. One contact per probe from an SPS 4001B or
IMPS 4000 to the control room for notification that the calibration
procedure failed. Grouped with this alarm is an output from a pressure
switch which indicates when the calibration gas bottles are empty.
4. 4-20 mA SIGNAL DURING CALIBRATION. The 4-20 mA signal can be
configured to respond normally during any calibration, or it can be
configured to hold the last O
factory default is for the 4-20 mA signal to operate normally throughout
calibration. Holding the last O
being averaged for the purpose of automatic control. Unless several
probes are being averaged, always place control loops that are using
the O signal into the manual mode prior to starting the calibration.
2
Instruction Manual
IM-106-340, Rev. 4.3
cells may operate for more
2
value upon the initiation of calibration. The
2
value may be useful if several probes are
2
July 2017
2
readings to go
2
reading is
2
2