Emerson Process Management OXYMITTER 4000 Section Description and Specifications, System Overview

	Instruction Manual
Hazardous Area Oxymitter 4000	IB-106-340C Rev. 4.1
	July 2004
		1

SECTION 1

DESCRIPTION AND SPECIFICATIONS

1-1 COMPONENT CHECKLIST OF TYPICAL

SYSTEM (PACKAGE CONTENTS)

A typical Rosemount Hazardous Area Oxymitter 4000 Oxygen Transmitter should contain the items shown in Figure 1-1.Record the part number, serial number, and order number for each component of your system in the table located on the first page of this manual.

The Oxymitter 4000 is offered in both hazardous area and general purpose configurations. The hazardous area version has special markings on the approval label. The general purpose version does not. If you received the general purpose version, ensure you do not install it in a potentially explo- sive atmosphere.

Also, use the product matrix in Table 1-1at the end of this section to compare your order num- ber against your unit. The first part of the matrix defines the model. The last part defines the various options and features of the Hazardous Area Oxymitter 4000. Ensure the features and options specified by your order number are on or included with the unit.

1-2 SYSTEM OVERVIEW

a.Scope

This Instruction Bulletin provides the infor- mation needed to install, start up, operate, and maintain the Hazardous Area Oxymitter 4000. Signal conditioning electronics out- puts a 4-20 mA signal representing an O2 value and provides a membrane keypad or full function Local Operator Interface (LOI) for setup, calibration, and diagnostics. This same information, plus additional details, can be accessed with the

HART Model 275/375 handheld communi- cator or Asset Management Solutions (AMS) software.

b.System Description

The Hazardous Area Oxymitter 4000 is designed to measure the net concentration of oxygen in an industrial process; i.e., the oxygen remaining after all fuels have been oxidized. The probe is permanently posi- tioned within an exhaust duct or stack and performs its task without the use of a sampling system.

The equipment measures oxygen percent- age by reading the voltage developed across a heated electrochemical cell, which consists of a small yttria-stabilized, zirconia disc. Both sides of the disc are coated with porous metal electrodes. When operated at the proper temperature, the millivolt output voltage of the cell is given by the following Nernst equation:

EMF = KT log10(P1/P2) + C

Where:

1.P2 is the partial pressure of the oxy- gen in the measured gas on one side of the cell.

2.P1 is the partial pressure of the oxy- gen in the reference air on the oppo- site side of the cell.

3.T is the absolute temperature.

4.C is the cell constant.

5.K is an arithmetic constant.

NOTE

For best results, use clean, dry, instru- ment air (20.95% oxygen) as the refer- ence air.

Rosemount Analytical Inc. A Division of Emerson Process Management Description and Specifications 1-1