Model MicroCEM

Instruction Manual

748467-A January 2002

2-3 GASES

NOTE

For external gas lines, the use of new tubing throughout is strongly recommended. The preferred type is teflon or stainless steel, sealed at both ends.

a.Connection

Besides sample gas, the MicroCEM re- quires other gases for operation. In most cases, one or more Calibration Standards must be provided. These should be cylin- ders of gas which closely resemble the expected sample, both in species and concentrations. These calibration gases are normally introduced into the system as an input to the Sample Conditioning Plate Option or sample conditioning may be provided by others.

Each gas cylinder should be equipped with a clean, hydrocarbon free two-stage pressure regulator with indicating gauges of approximately 0 to 3000 psig (0 to 20.7 bar) for cylinder pressure and 0 to 100 psig (0 to 6.7 bar) for delivery pressure. Pressure regulators should have a metal- lic as opposed to elastomeric diaphragm, and provide for ¼ inch compression fitting outlet and should be LOX clean.

NOTE

All connections specified in the Installation Drawing, in conjunction with the Application Data Sheet, should be made.

b.Conditioning

All gases must be supplied to the ana- lyzer as conditioned gases! When the

system is used with corrosive gases, it must be verified that there are no gas components which may damage the gas path components.

The gas conditioning must meet the following conditions:

•Free of condensable constituents

•Free of dust above 2 ∝m

•Free of aggressive constituents which may damage the gas paths

•Temperature and pressure in accor- dance with the specifications

When analyzing vapors, the dewpoint of the sample gas must be at least 10 °C below the ambient temperature in order to avoid the precipitation of condensate in the gas paths.

An optional barometric pressure compensation feature can be supplied. This requires a pressure sensor with a range of 800 – 1,100 hPa. The concentration values computer by the detectors will then be corrected to eliminate erroneous measurements due to changes in barometric pressure.

The gas flow rate must be in the range of

0.2l/min to a maximum of 1.5 l/min. A constant flow rate of 1 l/min is recom- mended.

NOTE

The maximum gas flow rate for paramagnetic oxygen detectors is 1.0 l/min!

Rosemount Analytical Inc. A Division of Emerson Process Management

Installation

2-3