Xylem FDO 925 User Manual

FDO

Operating manual

®

925

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Optical D.O. sensor

FDO®925

Note

The latest version of the present operating manual can be found on the
Internet under www.WTW.com.

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Copyright © Weilheim 2010, WTW GmbH

Reprinting - even as excerpts - is only allowed with the explicit written
authorization of WTW GmbH, Weilheim.
Printed in Germany.

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FDO®925 Contents

Contents

1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

1.1 Structure and function . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

1.2 Recommended fields of application . . . . . . . . . . . . . . . . 22

2 Measuring / Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

2.1 General information on the handling of the sensor cap . 23

2.2 Commissioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

2.3 Measuring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

2.4 Function check and user calibration . . . . . . . . . . . . . . . . 24

2.5 Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

3 Maintenance, cleaning, replacement . . . . . . . . . . . . . . . . 25

3.1 General maintenance instructions . . . . . . . . . . . . . . . . . . 25

3.2 Exchanging the sensor cap . . . . . . . . . . . . . . . . . . . . . . . 26

3.3 Cleaning the sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

3.4 Checking the zero point of the sensor . . . . . . . . . . . . . . . 28

4 What to do if... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

5 Technical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

6 Wear parts and accessories . . . . . . . . . . . . . . . . . . . . . . . 32

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Contents FDO®925

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FDO®925 Overview

12

5

7

3106984

1 Overview

1.1 Structure and function

Structure

Sensor cap with

memory chip

Intelligent mem-

brane (IQMC tech-

nology)

1 Shaft

2 Connection head

3 Fixing ring

4 Sensor membrane

5 SC-FDO

®

925 sensor cap with memory chip

6 Gold-plated contacts for the memory chip of the sensor cap

7 Locking device

8 Measurement window

9 O-ring

10 Thermistor enclosure with temperature sensor

A memory chip is integrated in the sensor cap. The following data are stored
on the memory chip:

z Type designation of the sensor cap

z Series number

z Data of the factory calibration or user calibration

For each membrane, the individual calibration values are determined by a
factory calibration process and stored to the memory chip of the sensor cap,
ensuring maximum accuracy over the whole lifetime of the sensor.

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