Emerson Process Management 3000 - Manual (Page 137)

Instruction Manual
Appendix D Rev. 2.4
July 1998
Rosemount Analytical Inc. A Division of Emerson Process Management Appendices D-1
World Class 3000
APPENDIX D, REV 2.4
MPS 3000 MULTIPROBE CALIBRATION GAS SEQUENCER
DESCRIPTION
Read the “Safety instructions for the
wiring and installation of this appara-
tus” at the front of this Instruction
Bulletin. Failure to follow the safety
instructions could result in serious
injury or death.
D-1 DESCRIPTION
The Rosemount MPS 3000 Multiprobe Calibra-
tion Gas Sequencer provides automatic calibra-
tion gas sequencing for up to four probes. The
MPS routes calibration gas to the selected
probe under control of the CRE, IFT, or digital
electronics package. The electronics package
can be preprogrammed by the user for auto-
matic periodic recalibration, or manually initiated
calibration through the keypad on the front of
the electronics package. The calibration pa-
rameters held in the electronics package can be
selected to automatically update after each
calibration.
The MPS is housed in a NEMA 4X (IP56) non-
hazardous enclosure, Figure D-1.
NOTE
A single multichannel MPS cannot be
shared among a number of CRE
electronics.
The MPS, Figure D-2, consists of: an air pres-
sure regulator, a terminal board, a flowmeter
assembly (one for each probe, up to four per
MPS), HI GAS solenoid, LO GAS solenoid, a
manifold, and a power supply. Each flowmeter
assembly contains a probe solenoid.
An optional Z-purge arrangement is available for
hazardous area classification. See Application
Data Bulletin AD 106-300B.
16860013
Figure D-1. MPS 3000 Multiprobe Calibration Gas
Sequencer
D-2 THEORY OF OPERATION
A typical automatic calibration setup is shown in
Figure D-3. The MPS 3000 Multiprobe Calibra-
tion Gas Sequencer operates under the control
of the CRE, IFT, or digital electronics package.
When the electronics package initializes auto-
matic calibration, the solenoid controlling the
selected probe is energized. Next, the solenoid
controlling calibration gas 1 (high O
2
) energizes
allowing calibration gas 1 to flow to that probe.
After the probe measures the oxygen concen-
tration of calibration gas 1, the gas solenoid is
deenergized. An operator selected time delay
allows the gas to clear the system. Next, the
solenoid controlling calibration gas 2 (low O
2
)
energizes and allows calibration gas 2 to flow to
the probe. After the probe measures the oxygen
concentration of calibration gas 2, the gas and
probe solenoids deenergize. The automatic
calibration is now complete for the probe
selected.
D