Operator Manual

748223-K June 2002

Model 7003M

1-4 CONDITIONS AFFECTING MEASUREMENT

Oxygen measurement is affected by the following:

•Composition of the sampled gas

•Sample and calibration gas pressures

•Environment of sensor, cable and analyzer

Each must be considered when calibrating and operating the analyzer to obtain accurate measurements.

a.Gas Composition

Any substance in the sample that significantly interferes or "poisons" the sensor oxygen reading should be removed by a chemical and/or mechanical sample handling system (see Section 5-2 on page 5-1). If ambient air is not used as the span gas, the composition of calibration gases should also be representative of the sample.

The sample and calibration gases must meet certain specifications (see Specifications in Preface) to ensure accurate measurement. Physical parameters that affect measurement include:

b.Sample and Cal Gas Pressures

The sample and calibration gases may be at different pressures as long as the pressure of each remains constant. Any variation in the pressure of either gas will result in an incorrect output reading of the same proportion.

Two methods of sample calibration are recommended:

1.Calibrate at the sample pressure, or

2.Calibrated at a different pressure, and enter the two pressure in the analyzer (Section 4-2c on page 4-4)

Refer to Section 5-2 on page 5-1 for a more detailed discussion of the relationship between gas pressures and apparent oxygen concentration.

c.Environmental Factors

If radio frequency interference (RFI) normally occurs in the operating environment, the sensor cable should be electrically shielded during installation.

•Pressure

•Humidity

•Temperature

•Gas composition

Also refer to Section 5-2 on page 5-1 for additional information about how gas conditions affect the oxygen measurement.

1-2 Description and Specifications

Rosemount Analytical Inc. A Division of Emerson Process Management