ABB 9438 User Manual

ABB 9438 User Manual Manual pdf 4 page image

21 INTRODUCTIONModel 9438Panel-Mounted Transmitter9438 08024 V DC P.S.U.(optional)Dissolved Oxygen 9438Sensor mounted inoptional enclosureModel 9438Wall-Mounted Transmitter4600ABB4600ABBD.O. g/kg18 . 1A1A2This manual describes how to install and operate the 9438 LowLevel Dissolved Oxygen Monitoring system. Fig. 1.1 shows themain elements of the system. Mechanical and electricalinstallation details of the optional power supply unit are inAppendix A.The Dissolved Oxygen (D.O.) transmitters and associatedflowcell have been designed for continuous monitoring andcontrol of power station boiler feed water/steam condensate.Calibration of the sensor can be manually initiated whenrequired, or set to automatic with the programmablefrequencies: 1 day, 1 week and 4 weeks.System status can be assessed remotely using programmablealarm and/or current output diagnostic functions.The 9438 500 transmitter is a wall-mounted instrument and the9438 501 model is a panel-mounted, 1 / 4 DIN-sized instrument.Both instruments have a single programmable D.O. inputchannel, and a single temperature input channel. The sampletemperature is sensed by a Pt1000 resistance thermometerincorporated in the flowcell.Instrument operation and programming is via four tactilemembrane switches located on the front panel. Programs areprotected from unauthorized alteration by a five-digit securitycode.Fig. 1.1 System Elements