Emerson Process Management OXYMITTER 4000 - Manual (Page 83)

Instruction Manual
IB-106-340C Rev. 4.1
July 2004
Rosemount Analytical Inc. A Division of Emerson Process Management Startup and Operation with LOI 6-5
Hazardous Area Oxymitter 4000
7. Gas Time – How long should each cal
gas flow. Factory default is 300 sec-
onds, but the user may want to vary
this depending upon the length of cali-
bration gas tubing runs.
8. Purge Time – Used if the O
2
output is
selected to hold the last value during
calibration. After the second cal gas is
removed, how long until the sensor
comes back to the normal process
reading, and the 4-20 mA signal can
be released.
9. Auto Calib? – Select “Yes” if an SPS
or IMPS autocalibration system is part
of the system.
b. SYSTEM/Input/Output
1. Analog – Pertaining to the analog
4-20 mA signal representing O
2
.
(a) O2 Type – 4-20 mA signal may
be configured to increase with
increasing O
2
or the reverse.
(b) O2 Range – Upper O
2
range is
user selectable.
(c) O2 Alarm Level – User can config-
ure the digital output to alarm at a
given O
2
level.
(d) Do O2 Trim – Procedure for cali-
brating the 4-20 mA signal to a
precision mA source. Procedure
is intuitive.
2. Digital – A bi-directional logic signal
may be configured as an alarm, or as
a calibration handshake signal.
(a) Logic I/O Mode – One of 9 different
sets of conditions can be set for
the digital signal. See Table 8-2.
(b) Low O2 Alarm – If any of the con-
ditions noted above include a low
O
2
process alarm, set the value
here.
(c) Input State – Notes the current
condition of the bi-directional digital
signal.
(d) Force Output – Forces the output
state of the signal to either open or
closed. This is used primarily when
diagnosing potential problems with
this signal.
c. SYSTEM/Parameters
1. O2 Slope – O
2
slope is data regarding
the strength of the sensing cell output.
This information is automatically cal-
culated after a calibration, and the user
does not normally input this data.
2. O2 Constant – O
2
constant is the
amount of voltage a cell generates
with ambient air as the calibration gas.
Again, this is normally calculated as a
result of calibration, and is not normally
input by the user.
3. O2 T90 Time – Some users may feel
that the O
2
reading is too active for
certain processes. This feature permits
the user to dampen the O
2
signal. The
default value is zero seconds damp-
ening.
4. Auto Tune – The electronics detects
the line voltage powering the instru-
ment automatically, and picks proper
algorithms for heater control. User can
force a high voltage algorithm, or a low,
but Auto Tune is the default, and is
recommended.
5. Lockout Time – Keypad lockout time
default is 30 sec., but is user configur-
able. A “Z” keypad pattern will unlock
the keypad.
6. Revert Time – Once a user goes one
level deep into the menu structure, an
additional “revert time” is provided to
prevent nuisance lockouts. One hour is
the default, and it is user configurable.
7. Luminance – Gas florescence bright-
ness is user adjustable.
6