Emerson Process Management 3000 - Manual (Page 62)

Instruction Manual
IB-106-300NH Rev. 4.2
July 2002
4-2 Calibration Rosemount Analytical Inc. A Division of Emerson Process Management
World Class 3000
2. Calibration Methods
There are three calibration methods:
manual (semiautomatic), manually ini-
tiated automatic, and fully automatic.
Manual (semiautomatic) calibration is
done without an MPS unit. Calibration
gases are switched on and off by the
operator and the IFT is sequenced
through the calibration procedure by
the operator with the front panel key-
board. The IFT prompts the operator
for the correct action. Manually initiated
automatic calibration is done with an
MPS. The operator manually initiates
the calibration at the IFT or through a
remote switch, and the IFT controls the
operation of the MPS unit and the cali-
bration sequencing. Fully automatic
calibration requires no action from the
operator. The setup is the same as
semiautomatic except the IFT auto-
matically initiates the calibration at a
fixed calibration interval. In this mode
the operator can also manually initiate
calibrations between the intervals in
the same manner as semiautomatic
calibrations.
c. Manual (Semiautomatic) Calibration
1. Calibration Gases For Manual
(Semiautomatic) Calibration
There are two options for supplying
calibration gases to the probe during
semiautomatic calibration. The first "A"
uses refillable bottles and adjustable 2-
stage pressure regulators; the second
"B" uses disposable bottles and a fixed
single stage regulator to provide a
mixed flow. Normally, the first (method
"A") will have a higher cost and not be
portable. The second ("B") is less
costly, portable, and weighs about 10
lbs (4.5 kg).
Test Method "A" Fixed Tanks and
Manifolds
(a) Required Equipment
Do not use 100% nitrogen as a zero
gas. It is suggested that gas for the
zero be between 0.4% and 2.0% O
2
. Do
not use gases with hydrocarbon con-
centrations of more than 40 parts per
million. Failure to use proper gases
will result in erroneous readings.
NOTE
Ambient air is not recommended for
use as high calibration gas. An 8% O
2
balance in nitrogen is recommended
for high calibration gas.
1 Two tanks of precision cali-
bration gas mixtures. Rec-
ommended calibration gases
are nominally 0.4% and 8.0%
oxygen in nitrogen.
Two sources of calibrated gas
mixtures are:
LIQUID CARBONIC GAS
CORP.
SPECIALTY GAS
LABORATORIES
700 South Alameda Street
Los Angeles, California
90058
213/585-2154
767 Industrial Road
San Carlos, California 94070
415/592-7303
9950 Chemical Road
Pasadena, Texas 77507
713/474-4141
12054 S.W. Doty Avenue
Chicago, Illinois 60628
312/568-8840
603 Bergen Street
Harrison, New Jersey 07029
201/485-1995