Rosemount 755R, Инструкция по эксплуатации

Страница: 19 / 80

I
NSTALLATION
748213-P Rosemount Analytical June 1997 2-3
Model 755R Oxygen Analyzer
2.2.1 Z
ERO
S
TANDARD
G
AS
In the preferred calibration method, described in Section 3.4.1, a suitable zero
standard gas is used to establish a calibration point at or near the lower range limit.
Composition of the zero standard normally requires an oxygen-free zero gas, typically
nitrogen.
2.2.2 S
PAN
S
TANDARD
G
AS
A suitable span standard gas is required to establish a calibration point at or near the
upper range limit. If this range limit is 21% or 25% oxygen, the usual span standard
gas is air (20.93% oxygen).
2.3 SAMPLE HANDLING
Basic requirements for sample handling are:
1. A 2-micron particulate filter, inserted into the sample line immediately upstream
from the analyzer inlet.
2. Provision for pressurizing the sample gas to provide flow through the analyzer.
3. Provision for selecting sample, zero standard, or span standard gas for admission
to the analyzer, and for measuring the flow of the selected gas.
F
IGURE
2-1. I
NTERCONNECTION OF
T
YPICAL
G
AS
M
ANIFOLD TO
M
ODEL
755R
Zero
Standard
Gas
Span
Standard
Gas
Sample In
Needle
Valves
Flowmeter
Two Micron
Filter
Model 755R
Oxygen Analyzer
To Vent