Introduction - ABB 9438 User Manual

1 INTRODUCTION

This manual describes how to install and operate the 9438 Low
Level Dissolved Oxygen Monitoring system. Fig. 1.1 shows the
main elements of the system. Mechanical and electrical
installation details of the optional power supply unit are in
Appendix A.
The Dissolved Oxygen (D.O.) transmitters and associated
flowcell have been designed for continuous monitoring and
control of power station boiler feed water/steam condensate.
Calibration of the sensor can be manually initiated when
required, or set to automatic with the programmable
frequencies: 1 day, 1 week and 4 weeks.
System status can be assessed remotely using programmable
alarm and/or current output diagnostic functions.
The 9438 500 transmitter is a wall-mounted instrument and the
9438 501 model is a panel-mounted,
Both instruments have a single programmable D.O. input
channel, and a single temperature input channel. The sample
temperature is sensed by a Pt1000 resistance thermometer
incorporated in the flowcell.
Instrument operation and programming is via four tactile
membrane switches located on the front panel. Programs are
protected from unauthorized alteration by a five-digit security
code.
2
1
/ DIN-sized instrument.
4
Model 9438
Panel-Mounted Transmitter
Sensor mounted in
optional enclosure
Fig. 1.1 System Elements
Model 9438
Wall-Mounted Transmitter
9438 080
24 V DC P.S.U.
(optional)