ABB 9438 User Manual

Low and High Level

Dissolved Oxygen Monitor

9438

User Guide

IM/9438_6

ABB

The Company

We are an established world force in the design and manufacture of instrumentation for industrial
process control, flow measurement, gas and liquid analysis and environmental applications.

As a part of ABB, a world leader in process automation technology, we offer customers
application expertise, service and support worldwide.

We are committed to teamwork, high quality manufacturing, advanced technology and unrivalled
service and support.

The quality, accuracy and performance of the Company’s products result from over 100 years
experience, combined with a continuous program of innovative design and development to
incorporate the latest technology.

The UKAS Calibration Laboratory No. 0255 is just one of the ten flow calibration plants operated
by the Company and is indicative of our dedication to quality and accuracy.

Health and Safety

To ensure that our products are safe and without risk to health, the following points must be noted:

1. The relevant sections of these instructions must be read carefully before proceeding.

2. Warning labels on containers and packages must be observed.

3. Installation, operation, maintenance and servicing must only be carried out by suitably trained personnel and in accordance with the
information given.

4. Normal safety precautions must be taken to avoid the possibility of an accident occurring when operating in conditions of high pressure and/
or temperature.

5. Chemicals must be stored away from heat, protected from temperature extremes and powders kept dry. Normal safe handling procedures
must be used.

6. When disposing of chemicals ensure that no two chemicals are mixed.

Safety advice concerning the use of the equipment described in this manual or any relevant hazard data sheets (where applicable) may be
obtained from the Company address on the back cover, together with servicing and spares information.

EN ISO 9001:2000

Cert. No. Q 05907

R

E

G

I

S

T

E

R

E

D

EN 29001 (ISO 9001)

Lenno, Italy – Cert. No. 9/90A

0255

Stonehouse, U.K.

Warning – Refer to the manual for instructions

Caution – Risk of electric shock

Protective earth (ground) terminal

Earth (ground) terminal

Direct current supply only

Alternating current supply only

Both direct and alternating current supply

The equipment is protected
through double insulation

Electrical Safety

This equipment complies with the requirements of CEI/IEC 61010-1:2001-2 "Safety requirements for electrical equipment for
measurement, control, and laboratory use". If the equipment is used in a manner NOT specified by the Company, the protection
provided by the equipment may be impaired.

Symbols

One or more of the following symbols may appear on the equipment labelling:

Information in this manual is intended only to assist our customers in the efficient operation of our equipment. Use of this manual for
any other purpose is specifically prohibited and its contents are not to be reproduced in full or part without prior approval of the
Technical Publications Department.

1

1 INTRODUCTION ........................................................... 2

2 MECHANICAL INSTALLATION .................................... 3

2.1 Siting Requirements ............................................ 3

2.1.1 Instruments ...........................................3

2.1.2 Dissolved Oxygen Flowcell .................... 3

2.2 Mounting the Instrument ..................................... 3

2.2.1 Wall-mounted Instrument ...................... 3

2.2.2 Panel-mounted Instrument .................... 4

2.3 Installing the Dissolved Oxygen Flowcell ............. 5

2.3.1 Flowcell Dimensions (Overall)7 .............. 5

2.3.2 Enclosure Dimensions (Optional) ........... 5

2.3.3 Connecting the Sample Lines ................ 5

3 ELECTRICAL CONNECTIONS .....................................6

3.1 Access to Terminals ............................................ 6

3.1.1 Wall-mounted Instruments .................... 6

3.1.2 Panel-mounted Instruments .................. 6

3.2 Connections, General ......................................... 7

3.2.1 Relay Contact Protection

and Interference Suppression ................ 7

3.2.2 System Wiring Schematic ..................... 8

3.3 Wall-mounted Instrument Connections ............... 8

3.4 Panel-mounted Instrument Connections .............9

3.5 Selecting the Mains Voltage .............................. 10

3.5.1 Wall-mounted Instrument .................... 10

3.5.2 Panel-mounted Instrument .................. 10

3.6 Flowcell Solenoid Valve Connections ................ 11

4 SETTING UP ............................................................... 12

4.1 Fitting the Dissolved Oxygen Sensor ................. 12

4.2 Connecting the Flowcell .................................... 13

4.3 Checking Sample Flow ..................................... 13

5 CONTROLS AND DISPLAYS ..................................... 14

5.1 Displays ............................................................ 14

5.2 Switch Familiarization ........................................ 14

6START UP AND OPERATION ..................................... 15

6.1 Instrument Start-up........................................... 16

6.2 Operation – Dissolved Oxygen

Measurement Mode.......................................... 16

6.2.1 Operation Page ................................... 16

6.2.2 Calibration Page .................................. 17

7 PROGRAMMING AND ELECTRICAL CALIBRATION 18

7.1 Access to Secure Parameters........................... 18

7.2 Language Page ................................................ 18

7.3 Set Up Parameters Page .................................. 18

7.4 Set Up Alarm Page ........................................... 19

7.5 Set Up Retransmission Page ............................ 21

7.6 Electrical Calibration ......................................... 24

7.6.1 Equipment Required ........................... 24

7.6.2 Preparation ......................................... 24

7.7 Factory Settings Page....................................... 25

8 MAINTENANCE .......................................................... 28

8.1 Introduction ...................................................... 28

8.2 Cleaning/Changing the Sensor ......................... 28

8.2.1 Cleaning .............................................. 28

8.2.2 Changing the Sensor .......................... 28

9 SIMPLE FAULT FINDING ........................................... 29

9.1 Diagnostic Messages ........................................ 29

9.2 Low Sensor Efficiency/Slow Sensor Cal.

or no Response to D.O. Changes ..................... 30

9.3 Checking the Temperature Input .......................30

9.4 High Sample Readings ..................................... 30

10 SPECIFICATION ......................................................... 31

11 SPARES ...................................................................... 32

11.1 Strategic Spares ...............................................32

APPENDIX A – 9438 080 24 V DC

POWER SUPPLY UNIT (OPTIONAL).......................... 34

A.1 Description ....................................................... 34

A.2 PSU Dimensions ............................................... 34

A.3 Accessing PSU Terminals ................................. 34

A.4 PSU Connections ............................................. 35

A.5 Wiring Schematic .............................................. 35

A.6 Specification .....................................................35

APPENDIX B – CALIBRATION DIAGNOSTICS ................... 36

B.1 During Calibration ............................................. 36

B.2 Low Sensor Efficiency....................................... 36

CONTENTS

2

1 INTRODUCTION

Model 9438

Panel-Mounted Transmitter

9438 080

24 V DC P.S.U.

(optional)

Dissolved Oxygen 9438

Sensor mounted in
optional enclosure

Model 9438

Wall-Mounted Transmitter

4

6

0

0

ABB

4600

AB

B

D

.O

.



g/

kg

18 . 1

A

1

A

2

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,

1

/4 DIN-sized instrument.
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.

Fig. 1.1 System Elements

3

68

(2.68)

42

(1.65)

Fixing Centers

160 (6.3)

69 (2.72)

Fixing Centers

Allowance for
Cable Bends

200 (7.9)

61 (23/8) o.d.
Vertical Post

214

(8.43)

232

(9.13)

Three holes Ø6.3
suitable for M6
fasteners

Dimensions in mm (in)

250

(9.84)

Maximum distance

30 metres

C – Within Environmental Limits

55 C
Max.

–20 C

Min.

B – Within Temperature Limits

A – Maximum Distance of Instrument to Unit

Locate to suit

IP66

IP65

IP54

Environmental cover

Dissolved Oxygen 9438

IP65

Liquid handling panel

Mark fixing centers

(see Fig. 2.3)

Drill suitable

holes

Fix instrument to wall using

suitable fixings

1

2

3

2.1.2 Dissolved Oxygen Flowcell – Fig 2.7

Allow sufficient clearance (200 mm all around) for easy removal
of the flowcell assembly for maintenance when not installed in
the optional enclosure – see Section 2.3.1 for overall dimensions
of units.

Note. To eliminate the risk of bubbles accumulating at the
sensor, and hence giving erroneous readings, the flowcell
assembly must be mounted vertically.

2.2 Mounting the Instrument

2.2.1 Wall-mounted Instrument – Figs 2.2 to 2.4

Fig. 2.1 Siting Requirements – Instrument/Sensor

Fig. 2.2 Overall Dimensions

Fig. 2.3 Wall Mounting

2 MECHANICAL INSTALLATION

2.1 Siting Requirements

2.1.1 Instruments – Fig. 2.1

Caution.

• Mount instruments in a location free from excessive
vibration.

• Mount away from harmful vapours and/or dripping fluids.

Information. It is preferable to mount the transmitter at eye
level thus allowing an unrestricted view of the front panel
displays and controls.

4

…2 MECHANICAL INSTALLATION

Position ‘U’ bolts on pipe

Position plates over ‘U’ bolts

Secure transmitter to mounting plate

Secure plates

1

2

3

4

191 (7.52)

12 (0.47)

Panel Cut-out

96 (3.78)

96

(3.78)

+0.8
–0

92

(3.62 )

+0.03
–0

+0.8
–0

92 (3.62 )

+0.03
–0

Dimensions in mm (in)

Cut a hole in the panel (see Fig. 2.5 for dimensions).
Instruments may be close stacked to DIN 43835.

Insert the instrument into the
panel cut-out.

Refit the panel clamps to the case, ensuring
that the panel clamp anchors are located
correctly in their slot.

Secure the instrument by
tightening the panel clamp
retaining screws.

Loosen the retaining screw
on each panel clamp.

Remove the panel clamp and
anchors from the instrument case.

4

5

6

1

3

2

3

2.2.2 Panel-mounted Instrument – Figs 2.5 and 2.6

Fig. 2.4 Pipe Mounting

Fig. 2.5 Overall Dimensions

Fig. 2.6 Panel Mounting

…2.2.1 Wall-mounted Instrument – Fig 2.4

5

2MECHANICAL INSTALLATION

Dissolved Oxygen 9438

Ø 8.5
for M8 fastener in
four positions

Dimensions in mm.

25

25

25

160 mm space required below sensor

panel, to allow for the opening of the

optional environmental cover.

160

440

200

325

Secure the enclosure to a
vertical surface using the four
fixing holes and suitable
screws/bolts.

100

85

175

190

116

approximately

140

310

142

approximately

Ø 5.5
for M5 fastener in
four positions

Dimensions in mm.

Flow Gauge

(ml/min)

Needle

Valve

(to set flow

rate)

Solenoid

Sample

Outlet

Solenoid-

operated

Valve

Sample

Drain

User supplied

10 mm i.d.

rubber tubing

User supplied

10 mm i.d.

rubber tubing

1 m maximum

Drain – see

Note

Sample

Outlet

Sample inlet via
shut off valve if
required.

Sample drain during
automatic calibration

2.3 Installing the Dissolved Oxygen Flowcell

2.3.1 Flowcell Dimensions (Overall) – Fig. 2.7

2.3.2 Enclosure Dimensions (Optional) – Fig. 2.8

2.3.3 Connecting the Sample Lines – Fig. 2.9

Mount the flowcell vertically (with or without the enclosure) as
shown in Figs 2.7 and 2.8. Connect the sample inlet and outlet
tubes as shown in Fig. 2.9.

Note.

• The sample flowrate must be between 100 and

400 ml min

–1

.

• The Company recommends that stainless steel tubing is
used for sample inlet lines.

• All sample drains should be kept as short as possible and
be vertical to allow the sample to drain freely.

Fig. 2.7 Flowcell Dimensions

Fig. 2.8 Enclosure Dimensions

Fig. 2.9 Connecting the Sample Lines

Note. Drain tubes must be straight and

vertical to allow the sample to flow freely.

6

3 ELECTRICAL CONNECTIONS

1

2

3

4

2

Earth Studs

slide
down

Pull out
slightly. . .

. . . and
slide off

Remove
protection
cover

Slacken
captive
screws

Remove nuts and
protection cover

Remove
mains cover

Mains
Cover

Earth Stud

1

2

Warning.

• Before making any connections, ensure that the power supply, any high voltage-operated control circuits and high common
mode voltage are switched off.

• Although certain instruments are fitted with internal fuse protection, a suitably rated external protection device, e.g. fuse or
miniature circuit breaker (m.c.b.), must also be fitted by the installer.

3.1 Access to Terminals

3.1.1 Wall-mounted Instruments – Fig. 3.1

3.1.2 Panel-mounted Instruments – Fig. 3.2

Fig. 3.1 Access to Terminals –

Wall-mounted Instrument

Fig. 3.2 Access to Terminals – Panel-mounted

Instrument (Rear View)

7

3 ELECTRICAL CONNECTIONS…

NC C NO

External

DC Supply

+–

Relay Contacts

Load

Diode

NC C NO

External

AC Supply

LN

Relay Contacts

C

R

Load

A – AC Applications B – DC Applications

3.2 Connections, General

Information.

• Earthing (grounding) – stud terminals are fitted to the transmitter case for bus-bar earth (ground) connection – see Fig. 3.1 or

3.2.

• Cable lengths – The cable length between the flowcell and the electronics unit is provided as ordered, and suitably terminated

at both ends.

• Cable routing – always route the signal cable and mains-carrying/relay cables separately, ideally in earthed metal conduit.

Ensure that the cables enter the transmitter through the glands nearest the appropriate screw terminals and are short and
direct. Do not tuck excess cable into the terminal compartment.

• Cable glands & conduit fittings – ensure a moisture-tight fit when using cable glands, conduit fittings and blanking plugs/

bungs (M20 holes). The M16 glands ready-fitted to wall-mounted instruments accept cable of between 4 and 7 mm diameter.

• Alarm Relay –the relay contacts are voltage-free and must be appropriately connected in series with the power supply and the

alarm/control device which they are to actuate. Ensure that the contact rating is not exceeded. Refer also to Section 3.2.1 for
relay contact protection details when the relays are to be used for switching loads.

• Retransmission output – Do not exceed the maximum load specification for the selected current retransmission range – see

Section 7.

Since the retransmission output is isolated the –ve terminal must be connected to earth (ground) if connecting to the isolated
input of another device.

3.2.1 Relay Contact Protection and Interference Suppression – Fig. 3.3

If the relays are used to switch loads on and off, the relay contacts can become eroded due to arcing. Arcing also generates radio
frequency interference (RFI) which can result in instrument malfunction and incorrect readings. To minimize the effects of RFI, arc
suppression components are required; resistor/capacitor networks for AC applications or diodes for DC applications. These
components can be connected either across the load or directly across the relay contacts. On 4600 Series instruments the RFI
components must be fitted to the relay terminal block along with the supply and load wires – see Fig. 3.3.

For AC applications the value of the resistor/capacitor network depends on the load current and inductance that is switched. Initially,
fit a 100R/0.022 µF RC suppressor unit (part no. B9303) as shown in Fig. 3.3A. If the instrument malfunctions (incorrect readings) or
resets (display shows 88888) the value of the RC network is too low for suppression – an alternative value must be used. If the correct
value cannot be obtained, contact the manufacturer of the switched device for details on the RC unit required.

For DC applications fit a diode as shown in Fig. 3.3B. For general applications use an IN5406 type ( 600 V peak inverse voltage at
3A – part no. B7363)

Note. For reliable switching the minimum voltage must be greater than 12 V and the minimum current greater than 100 mA.

Fig. 3.3 Relay Contact Protection

8

…3 ELECTRICAL CONNECTIONS

Power

Supply

Retransmission

Relay 1
Relay 2

Serial

Power
Supply

Retrans.

Relay 1
Relay 2

12 34567 +– N L

Serial

(If fitted)

12 3

45 6

12 3

45 6

1
2
3
4
5
6

4
5

–
–
–
–
–
–

–
–

Rx+
Rx–
Tx+
Tx–
0V

Retrans.
Output

Relays

1
2
3
5
6

–
–
–
–
–

NC
C
NO
C
NO

Relay 1

Solenoid
valve
Calibration
Relay

Mains Supply

NL––Neutral

Line

–

Earth

Output

RS422/
RS485

Earth Stud (on case) –
see Fig. 3.1

NC
C
NO

Normally Closed
Common
Normally Open

=

=

Channel 2Channel 1

13––+ve (Red)

–ve (Black)
Braid

D.O. Sensor

Earth Stud (on case)
– see Fig. 3.1

Channel 2Channel 1

PT1000

Temperature Compensator

5
6

7

–
–

–

White
Green
Link

+

Retrans 2 Output (if fitted)

-ve
+ve

3.2.2 System Wiring Schematic – Fig. 3.4

The wiring of a single solenoid/sensor system from a user­supplied 24 V DC supply is shown in Fig. 3.4.

If the 9438 080 power supply unit is employed, refer to
Appendix A for wiring details.

3.3 Wall-mounted Instrument Connections – Fig. 3.5

Note. Refer to Fig. 3.1 for access to terminals.

Caution. Slacken terminal screws fully before making

connections.

Warning. The power supply earth (ground) must be connected to ensure safety to personnel, reduction of the effects of
RFI and correct operation of the power supply interference filter.

Fig. 3.4 Wiring Schematic

(see Appendix A for wiring using optional PSU)

Fig. 3.5 Wall-mounted Instrument Connections

9438 Transmitter

Customer 24 V DC supply

Relay 2

C NO

Solenoid Valve

Solenoid valve powered from
user supplied 24 V DC source

+ve

–ve

9

3 ELECTRICAL CONNECTIONS…

+

–

Normally Closed

Common

Normally Open

Common

Normally Open

Neutral

Live

Earth

TBA

Relay 1

Solenoid Valve

Calibration

Relay

1
2
3
4
5
6

8
9
E
N
L

1
2
3
4
5
6
7
8

10
12

Mains Supply

Retransmission

Output

0V
Rx–
Rx+
Tx–
Tx+
Link
Green
White

–ve (Black)

+ve (Red)

TBB

RS422/RS485
Serial Interface
(if fitted)

D.O. Sensor

1
2
3
4
5
6
7
8
9
E
N
L

1
2
3
4
5
6
7
8
9
10
11
12

Earth Stud

Earth Stud (on case)

Earth Stud (on case)

Pt1000
Temperature
compensator

Braid

Retrans 2
Output (if fitted)

–ve
+ve

4
5

3.4 Panel-mounted Instrument Connections – Fig. 3.6

Note. Refer to Fig. 3.2 for Access to Terminals.

Caution. Slacken terminal screws fully before making connections.

Warning. The power supply earth (ground) must be connected to ensure safety to personnel, reduction of the effects of

RFI and correct operation of the power supply interference filter.

Fig. 3.6 Panel-mounted Instrument Connections

10

…3 ELECTRICAL CONNECTIONS

Remove cover (see Fig. 3.1)

Remove front
panel screws

Remove front

panel

Remove cap
and screw

Slacken
captive
screws and
remove
protection
cover

240 V AC

110 V AC

230

or

1

3

4

3

5

2

5

Undo captive
screw

Slide instrument
out of case

240 V AC

110 V AC

230

or

3

4

1

2

3.5 Selecting the Mains Voltage

3.5.1 Wall-mounted Instrument – Fig. 3.7

3.5.2 Panel-mounted Instrument – Fig. 3.8

Information. Use a small, flat-

blade screwdriver to remove the
screw caps from the case.

Fig. 3.7 Selecting the Mains Voltage –

Wall-mounted Instrument

Fig. 3.8 Selecting the Mains Voltage –

Panel-mounted Instrument

Note. Some versions are fitted

with a switch in place of links. The
applied voltage should be as
indicated on the switch, when
positioned.

Note. Some versions are
fitted with a switch in place
of links. The applied voltage
should be as indicated on
the switch, when positioned.

11

3 ELECTRICAL CONNECTIONS

Specification to BS 6500

Cross sectional area = 0.5 mm

2

Minimum current rating = 3 A
Construction = 16/0.2 mm
Nominal diameter = 5.4 mm (minimum 5.0 mm)

Remove cover to expose terminals
and thread the cable through the cable
gland.

Connect the wires as shown. Ensure
that the diode remains in the position
indicated (cathode to terminal 1 and
anode to terminal 2).

Fit the cover and tighten the cable
gland.

Solenoid

Valve

1

2

3

+24 V DC via N/O of relay
in 9438 transmitter
(see Fig. 3.4)

0 V

Cable Gland

Diode

See Appendix A if
9438 080 PSU is
supplied.

Customer supplied cable to transmitter or PSU

2

1

3

3

2

1

3.6 Flowcell Solenoid Valve Connections – Fig. 3.9

Fig. 3.9 Solenoid Connections

Note.

Use 2 core cable with 9438 080 PSU
(ABB part number 0233 731).

Use 3 core cable with customer supplied 24 V DC supply.

12

4 SETTING UP

1

2

3

4

5

7

Optional enclosure not shown for clarity

Slip the connector nut over
the connector body and screw
on to the oxygen sensor firmly.

Insert the complete assembly into
the flowcell ensuring that the O­ring is in place.

Remove the top from the oxygen sensor
container.

Unscrew the protective cap from the rear of the
oxygen sensor

Use the clamping screw to secure the
assembly. Screw in firmly using finger
pressure only.

Slide the thrust washer over
the connector body.

Place an O-ring (provided) as shown and
locate the connector body
on the oxygen sensor.

Flowcell

O-ring

Oxygen
Sensor

Connector

Body

O-ring

Clamping

Screw

Thrust
Washer

Connector

Nut

6

4.1 Fitting the Dissolved Oxygen Sensor – Fig. 4.1

Caution.

• Only install the oxygen sensor immediately prior to use, otherwise leave it
stored in its protective container. The sensor has a limited shelf life and should
NOT be stored longer than about 6 months. Store under cool conditions.

•Take special care to line up the two pins in the oxygen sensor with their
respective sockets before making the connection and tightening.

•Take care not to damage the delicate membrane on the end of the oxygen
sensor.

• Ensure that the mating surfaces (carrying the electrical connection) of the
oxygen sensor and connector body are clean and completely dry.

Caution. Do not overtighten the clamping screw.

Fig. 4.1 Fitting the Dissolved Oxygen Sensor

13

4 SETTING UP

Flow during normal
operation

Solenoid
Operated
Valve – Closed

Flow
Regulating
Valve

Sensor

Flow Indicator

Drain

Sample
In

Flow during calibration or
thermal overload condition

Solenoid
Operated
Valve – Open

Sample
In

Drain

Line up the red spots and
push the plug on firmly until
the locking ring engages.

Push the sensor connector on
firmly and tighten ONE TURN
clockwise.

4.2 Connecting the Flowcell – Fig. 4.2

4.3 Checking Sample Flow – Fig. 4.3

Note.

• The plug is a latching type to prevent it's
accidental removal. To remove, hold the
plug at its widest point and pull out.

• The plug is protected against spillage
and corrosion by a sleeve which slides
over it.

Fig. 4.2 Electrical Connections at the Flowcell

Fig. 4.3 Sample Flow Schematic

Check that the sample flows correctly in
both normal operation and during a
calibration or thermal overload.
To simulate a calibration manually, open the
valve – see Section 6.2.1 Operating Page
Carefully remove the dissolved oxygen
sensor and check that the flowcell is empty.
If sample still flows, check that the
installation complies with Section 2.3.3.

14

5 CONTROLS AND DISPLAYS

18.1

D.O. g/kg

Alarm
LEDs

Upper

Display Line

Lower

Display Line

Membrane Switches

A – Advancing to Next Page

Parameter 1
Parameter 2
Parameter 3
Parameter 4

Page 1

Parameter 1
Parameter 2
Parameter 3

Page 2

Advance to

next page

For majority

of parameters

or

B – Moving Between Parameters

C – Adjusting and Storing a Parameter Value

New value is
automatically stored

Parameter Value

Adjust

D – Selecting and Storing a Parameter Choice

Parameter X

Y
Z

Select

Parameter 1

Parameter 2
Parameter 3

Page X

Parameter 4

Advance to

next parameter

or

New value is
automatically stored

or

5.1 Displays – Fig. 5.1

The display comprises a 5-digit, 7-segment digital upper display
line and a 16-character dot-matrix lower display line. The upper
display line shows numerical values of dissolved oxygen
concentration, temperature, alarm set points or programmable
parameters. The lower display line shows the associated units or
programming information.

5.2 Switch Familiarization

Fig. 5.1 Location of Controls and Displays

Fig. 5.2 Membrane Switch Functions

15

6START UP AND OPERATION

Operating parameters.

Available only when 2

nd

retransmission output is fitted.

Secure parameters.

Linear

FACTORY SETTINGS

–––––

uA Zero

XXXX

FACTORY SET CODE

0 0 0 0 0

ELECTRICAL CAL

–––––

Calibrate YES

NO

–––––

uA Span

XXXX

Temp Zero (1k0)

XXXX

Temp Span (1k5)

XXXX

Adjust RTX Span

–––––

Cal Time 1 (min)

2

Cal Time 2 (min)

30

Alter Fact. Code

0 0 0 0 0

Adjust RTX Zero

–––––

Factory Settings Page

Section 7.6

D.O. g/kg

18 1

.

Calibrate YES

NO

–––––

Calibrating Air

879

.

SET UP PARAMETER

–––––

Pressure mmHg

760

Salinity ppt

0

Temp. Units (

C)

–––––

Disp. Units ug/kg

ug/l

ppb

–––––

SET UP ALARM

–––––

High Spt ug/kg

150.

–––––

A1 Action Hi/Lo

High

Low

A1 Type Status

Temp

DO

Off

–––––

Low Spt ug/kg

50.

Alter Sec. Code

0 0 0 0 0

Alter Cal. Code

0 0 0 0 0

SET UP RETRANS

–––––

SET UP RETRANS 1

–––––

200.

RTX Span mg/kg

20.

RTX Zero mg/kg

100.

Enter Input %

500.

Enter Output %

–––––

RTX Type 4-20

0-20

0-10

RTX. Log

Bi-Linear

Linear

–––––

Diagnostics YES

NO

SET UP RETRANS 2

–––––

Cal. Time s

30

Fail M.time s

30

Fail S.time s

30

RTX. Log

Bi-Linear

Linear

–––––

RTX O/P Temp

D.O.

–––––

200.

RTX Span mg/kg

o

C

20.

RTX Zero mg/kg

o

C

–––––

RTX Type 4-20

0-20

0-10

Bi-Linear

Bi-Linear

Linear

100.

Enter Input %

500.

Enter Output %

Cal. Time s

30

Fail M.time s

30

Fail S.time s

30

Test Retrans. (%)

00

Autocal Off

4Weeks

1Week

1Day

–––––

Temperature (

o

C)

200

.

Sensor O/P (

A)

–––––

Sensor Eff



–––––

High Set

g/kg

150

.

Low Set

g/kg

50

.

Operation Page

Section 6.2.1

Calibration Page

Section 6.2.2

Diagnostics YES

NO

Set Up Retransmission Page

Section 7.5

Set Up Parameters Page

Section 7.3

Set Up Alarm Page

Section 7.4

SECURITY CODE

00000

Access to Secure Parameters

Section 7.1

Secure Parameters

ENGLISH

–––––

Language Page

Section 7.2

Open Valve NO

YES

–––––

To Set up Retrans 2

If NO Retrans 2

Reset Cal. NO

YES

–––––

SENSOR CAL.

–––––

00000

Cal. User Code

Cal. Aborted

–––––

–––––

Sensor Eff

Recovery Period

520.

–––––

Slow Sensor Cal.

Fig. 6.1 Overall Programming Chart

Note. The values shown on the pages in this

illustration are the factory default values.

16

…6 START UP AND OPERATION

D.O. g/kg

Temperature ( C)

SENSOR CAL.

–––––

18 1

200

.

High Set g/kg

150

Open Valve NO

YES

.

°

.

Sensor Eff

–––––

Low Set g/kg

50

.

–––––

Sensor O/P (A)

–––––

6.1 Instrument Start-up – Fig. 6.1

Ensure all electrical connections have been made and switch on the power supply. If the instrument is being commissioned for the
first time, calibration and programming of parameters is required.

The overall operating and programming chart is shown in Fig. 6.1.

6.2 Operation – Dissolved Oxygen Measurement Mode

Operation in the Dissolved Oxygen measurement mode comprises an Operating Page and a Calibration Page. The Operating Page is
a general use page in which parameters are viewed only and cannot be altered. To alter or program a parameter, refer to the
programming pages in Section 7. The Calibration Page allows a calibration to be carried out. A 5-digit calibration code is used to
prevent unauthorized access to the sensor calibration page. The value is preset at 00000 to allow access during commissioning, but
should be altered to a unique value, known only to authorized operators, in the

Set Up Alarm page – see Section 7.2

6.2.1 Operation Page

Measured Dissolved Oxygen

The measured dissolved oxygen is displayed in µg/l, mg/l, ppb, ppm, mg/kg or µg/kg.
Auto ranging: 0.0 to 99.9 µg kg

–1

100 to 999 µg kg

–1

1.00 to 9.99 mg kg

–1

10.0 to 20.0 mg kg

–1

Press to advance to next parameter or press to advance to Calibration Page,
Section 6.2.2.

Sample Temperature

The sample temperature is displayed in either °C or °F – see Section 7.1.

Sensor Output

Raw current signal (µA) generated by the sensor.

Sensor Efficiency

Bar graph indication of the sensor performance, based on last calibration – see Section

6.2.2.

High Setpoint

The

High alarm setpoint value is only visible if the alarm is programmed for either D.O. or

Temperature and is set to

High or High/Low.

Low Setpoint

The

Low alarm setpoint value is only visible if the alarm is programmed for either D.O. or

Temperature and is set to

Low or High/Low.

Open Valve

Manually open the calibration valve to drain the flowcell prior to accessing the sensor. The
reading displayed when the valve is open does not represent the dissolved oxygen
content of air-saturated water at the prevailing ambient temperature.

Advance to Calibration Page, Section 6.2.2.

17

6START UP AND OPERATION

YES

NO

Abort

for 2 secs

Calibrating Air

879

.

SENSOR CAL.

–––––

00000

Cal. User Code

Cal. Aborted

–––––

–––––

Sensor Eff

Recovery Period

520.

D.O. g/kg

18.1

Calibrate YES

NO

–––––

–––––

Slow Sensor Cal.

OR

Press to advance to next parameter

or
Press to return to Operation Page, Section 6.1

Calibration Access

Enter the required calibration code number, between 00000 and 19999. If an incorrect
value is entered, access to calibration is prevented and

Calibration Page is displayed.

Select YES to enable manual calibration and press to start the calibration sequence.

Calibrating in Air

The calibration valve opens exposing the sensor to air. A flashing dot indicates that a
calibration is in progress and the displayed value is the sensor reading based on the LAST
calibration. See timings below.
Wait Period Where the sensor is exposed to air before the stability of the sensor is

checked. This is preset at 2 minutes (Cal Time 1).

Stability Period The readings are monitored for between 1 and 5 minutes until a stable

response is achieved.
When stability has been achieved the calibration valve closes allowing sample to flow
past the sensor.

Abort Calibration

Pressing

during Calibrating in Air aborts the calibration and the Cal. Aborted message
is displayed for 2 seconds. The calibration valve closes allowing the sample to flow past
the sensor again.
Note that the

A2 LED continues to indicate that a calibration is in progress, and will do so

for the duration of the programmed recovery period.

Sensor Efficiency

A five-bar display provides an indication of the sensor's performance.

 >85% efficiency
 >70% "
 >60% "

Pass

 >50% "
 >40% "
 <40% " Low sensor efficiency

Slow Sensor Response

If the output from the sensor does not stabilize during the 1 to 5 minute stability period the
calibration will not be accepted and Slow Cal. will be desplayed.

Recovery Period

Shows the sample reading as the sensor recovers at the lower sample value. The
Recovery Period is preset at 30 minutes (Cal Time 2).

The display automatically returns to the Operating Page at the end of this period.

6.2.2 Calibration Page

Calibration involves standardizing the instrument and the sensor by exposing the sensor to air.
During a calibration, retransmission and alarm outputs are automatically held to prevent inadvertent operation of ancillary equipment.

18

7 PROGRAMMING AND ELECTRICAL CALIBRATION

SECURITY CODE

00000

Espanol

–––––

SET UP PARAMETER

–––––

Pressure mmHg

760

Salinity ppt

0

Temp. Units (C)

–––––

Disp. Units ug/kg

ug/l

ppb

–––––

Autocal 4 Weeks

1 Week

1 Day

Off

–––––

SET UP ALARM

–––––

Reset Cal. NO
YES

–––––

_____

SET UP PARAMETER

–––––

Francais

Espanol

˜

7.1 Access to Secure Parameters

A 5-digit security code is used to prevent tampering with the secure parameters.

Security Code

Enter the required code number between 00000 and 19999 to gain access to the secure
parameters. If an incorrect value is entered, access to subsequent programming pages
is prevented and the display reverts to the

Operation Page.

Advance to Language Page, Section 7.2.

7.2 Language Page

Language Page
Select the language to be displayed on all subsequent pages: Español, Francais,
Deutsch or English.

Advance to Set Up Parameters Page, Section 7.3

7.3 Set Up Parameters Page

Press to advance to next parameter
or

Press to advance to Set Up Alarm Page, Section 7.4.
These two switches are used to advance to all subsequent parameters and pages. If a
parameter is changed it is automatically stored on operation of either switch.

Display Units

Select the required display units:

µg/kg, µg/l, or ppb.

Barometric Pressure Correction

Set the local barometric pressure in mm Hg (between 500 and 800).
If the local barometric pressure is unknown the default value, which is the standard sea­level value of 760 mm Hg, should not be changed.

Salinity Correction

Required when monitoring sea water or other waters containing high concentrations of
dissolved salts.
Enter the appropriate value between 0 and 80 parts per thousand (ppt).
Leave at the default value of 0 ppt if correction is not required.

Temperature Units

Select either °C or °F.

Auto Calibration

Select the frequency of automatic calibrations: 1 Day, 1 Week or 4 Weeks. Select Off to
disable automatic calibrations. Only manual calibrations may be carried out.

Reset Auto Calibration

Select

YES to reset the timing for automatic calibrations. To fix the calibration to a specific

time of day select

YES at the correct time of day. (This will be automatically reset following

a power failure.)

Advance to Set Up Alarm Page, Section 7.4.

19

7 PROGRAMMING AND ELECTRICAL CALIBRATION…

SET UP ALARM

–––––

High Spt ug/kg

150.

–––––

–––––

A1 Action Hi/Lo

High

Low

A1 Type Status

Temp

DO

Off

To Alter Sec. Code

7.4 Set Up Alarm Page

Press to advance to next parameter
or
Press to advance to Set Up Retrans Page, Section 7.5.

Alarm Type

Select the type of alarm required. For Status, Temp and DO alarm types, the alarm
l.e.d. is off and the relay energized during normal conditions. In a fail condition, the l.e.d.
is on and the relay de-energized.

Status The instrument alerts the operator to a power failure, a condition that causes

any of the error messages listed in Table 9.1 to be displayed, or the status of
a calibration.

Calibration Fail will cause the Relay and LED to pulse every second.

Temp The instrument alerts the operator if the temperature of the process fluid

exceeds or drops below the set point value parameter, depending on the type
of Alarm Action selected below.

D.O. The instrument alerts the operator if the Dissolved Oxygen value of the sample

exceeds or drops below the set point value parameter, depending on the type
of Alarm Action selected below.

Off If selected, no alarm is set and the alarm l.e.d. is off and the relay de-energized

at all times.

Alarm Action

For 'Fail-safe' alarm operation the relay's alarm state must be the same as the power­down state, i.e. the relay is de-energized.

For High alarm operation the relay must be energized below the alarm set point.

For Low alarm operation the relay must be energized above the alarm set point.

The alarm LEDs are illuminated in the alarm condition.

Hi/Lo Alarm activates above the

High Set Point or below the Low Set Point.

High Alarm activates above the

High Set Point.

Low Alarm activates below the Low Set Point.

The set point band is defined as the actual value of the set point plus or minus the
hysteresis value. The hysteresis value is ±1% of the

Alarm 1 Set Point. Alarm action

occurs if the input value is above or below the set point band. If the input moves within
the set point band, the last alarm action is maintained.

Continued on next page…

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20

…7 PROGRAMMING AND ELECTRICAL CALIBRATION

High Spt ug/kg

150.

Low Spt ug/kg

50.

Alter Sec. Code

0 0 0 0 0

Alter Cal. Code

0 0 0 0 0

SET UP RETRANS

–––––

...Continued from A1 Action

High Set Point

The

High set point can be set to any value within the full measurement range, with the

units automatically changing.
The set point value is subject to hysteresis as detailed above.

Set the alarm set point to the required value.

Displayed only if

Alarm Action is set to High or Hi/Lo.

Low Set Point

The

Low set point can be set to any value within the full measurement range, with the

units automatically changing.
The set point value is subject to hysteresis as detailed above.

Set the alarm set point to the required value.

Displayed only if

Alarm Action is set to High or Hi/Lo.

Alter Secure Parameters Security Code

Set the secure parameters security code to a value between 00000 and 19999.

IMPORTANT – YOU MUST MEMORIZE THE NEWLY SET SECURITY CODE. If it is
forgotten contact the Company for advice.

Alter D.O. Sensor Calibration Security Code

Set the pH calibration security code to a value between 00000 and 19999.

IMPORTANT – YOU MUST MEMORIZE THE NEWLY SET SECURITY CODE. If it is
forgotten contact the Company for advice.

Advance to Set Up Retransmission Page, Section 7.5.

…7.4 Set Up Alarm Page

21

7 PROGRAMMING AND ELECTRICAL CALIBRATION…

SET UP RETRANS

–––––

–––––

SET UP RETRANS 1

–––––

Log

Bi-Linear

Yes

Linear

RTX Type 4-20

0-20

0-10

RTX. Log

Bi-Linear

Linear

–––––

200.

RTX Span mg/kg

20.

RTX Zero mg/kg

100.

Enter Input %

500.

Enter Output %

Diagnostics YES

NO

No

7.5 Set Up Retransmission Page

In this section the actual values denoted by 'xxxxx' are unimportant and are used to determine display reading stability when carrying
out the electrical calibration procedure.

Press

to advance to next parameter

or

Press

to advance to Factory Settings Page, Section 7.7.

Set Up Retransmission 1

Retransmission 1 Output Range

The retransmission 1 output can be selected from three mA current ranges to ensure
compatibility with the peripheral device connected.
Select the current range required for retransmission 1 output.

Retransmission 1 Output Scale

Select the retransmission output scale required.

Log (logarithmic) – see Fig. 7.2.
Bi-Linear – see Fig. 7.1.
Linear

Note for Bi-linear and log scales. The accuracy specification of the instrument should
always be given consideration when setting the scale limits to avoid impractical
discrimination on the retransmission output.

Retransmission 1 Span

The span current output can be set to any value between:

Linear 20 mg kg–1 and 20 mg kg

–1

Bi-Linear 20 mg kg–1 and 20 mg kg

–1

Log 100 mg kg–1 and 20 mg kg

–1

Retransmission 1 Zero

The zero current output can be set to any value between 1.0 mg kg

–1

and 200 mg kg–1. This

is available only for logarithmic output.

Note. For linear output, the zero value is always 0 mg kg

–1

Enter Input %

Set the percentage of the display span at which the breakpoint occurs: 1.0 to 100% in

0.1% increments. This is point A on Fig. 7.1.

Enter Output %

Set the percentage output at which the breakpoint occurs: 0.0 to 100% in 0.1% steps.
This is point B on Fig. 7.1.

Diagnostics

Select whether the current output diagnostics are required. See Appendix B.

Continued on next page…

22

…7 PROGRAMMING AND ELECTRICAL CALIBRATION

SET UP RETRANS 2

–––––

Cal. Time s

30

Fail M.time s

30

Fail S.time s

30

–––––

Log

Bi-Linear

Linear

RTX Type 4-20

0-20

0-10

RTX. Log

Bi-Linear

Linear

–––––

RTX O/P Temp

D.O.

–––––

Te mp

D.O.

200.

RTX Span mg/kg

o

C

20.

RTX Zero mg/kg

o

C

Yes

No

If NO Retrans 2, go to Test Retrans (%)

…7.5 Set Up Retransmission Page

Calibration Pulse time

Set the frequency of the calibration pulse signal. Programmable frequency of 15, 30, 45
seconds, 1, 2, 3, 4, 5 minutes.
See Appendix B.

Calibration Fail Mark Time

Set the mark time period for the current output to be driven hard upscale. Programmable
period of 30 seconds, 1, 2, 3, 4, 5,…,10 minutes.
See Appendix B.

Calibration Fail Space Time

Set the space time period for the current output to be driven to 0%. Programmable
period of 30 seconds, 1, 2, 3, 4, 5, …,10 minutes.
See Appendix B.

Set Up Retransmission 2 – see also Table 7.1.

Note. Available only on 9438 800 series instruments.

Retransmission 2 Output Range

The retransmission 2 output can be selected from three mA current ranges to ensure
compatibility with the peripheral device connected.
Select the current range required for retransmission 2 output.

Retransmission 2 Output Assignment

Select the Retransmission output required:

Temp – Temperature
D.O. – Dissolved Oxygen

Retransmission 2 Output Scale

Select the retransmission output scale required. Only available if D.O. selected.

Log (Logarithmic) – see Fig. 7.2.
Bi-Linear – see Fig. 7.1.
Linear

Note for Bi-linear and log scales. The accuracy specification of the instrument should
always be given consideration when setting the scale limits to avoid impractical
discrimination on the retransmission output.

Retransmission 2 Span

Set the span to the required value. See Table 7.1 for details.

Retransmission 2 Zero

Set the zero to the required value. See Table 7.1 for details.

Continued on next page…

23

7 PROGRAMMING AND ELECTRICAL CALIBRATION…

Yes

100.

Enter Input %

500.

Enter Output %

Diagnostics YES

NO

FACTORY SETTINGS

–––––

Bi-linear

Linear

Cal. Time s

30

Fail M.time s

30

Fail S.time s

30

Test Retrans. (%)

00

Return to
SET UP RETRANS

No Retrans 2

No

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Enter Input %

Set the percentage of the display span at which the breakpoint occurs: 1.0 to 100% in

0.1% increments. This is point A on Fig. 7.1.

Enter Output %

Set the percentage output at which the breakpoint occurs: 0.0 to 100% in 0.1% steps.
This is point B on Fig. 7.1.

Diagnostics

Select whether the current output diagnostics are required. See Appendix B.

Calibration Pulse Time

Set the frequency of the calibration pulse signal. Programmable frequency of 15, 30, 45
seconds, 1, 2, 3, 4, 5 minutes.
See Appendix B.

Calibration Fail Mark Time

Set the mark time period for the current output to be driven hard upscale. Programmable
period of 30 seconds, 1, 2, 3, 4, 5, …,10 minutes.
See Appendix B.

Calibration Fail Space Time

Set the space time period for the current output to be driven to 0%. Programmable
period of 30 seconds, 1, 2, 3, 4, 5, …,10 minutes.
See Appendix B.

Test Retransmission Output

The instrument automatically transmits a test signal of 0, 25, 50, 75 or 100% of the
retransmission range selected above. The % test signal selected is shown on the upper
display.

Example – for a selected range of 0 to 20 mA and 50% retransmission test signal, 10 mA

is transmitted.

Select the required retransmission test signal.

Advance to Factory Settings Page, Section 7.7.

…7.5 Set Up Retransmission Page

Table 7.1 Retransmission 2

24

…7 PROGRAMMING AND ELECTRICAL CALIBRATION

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7.6 Electrical Calibration

Note. The instrument is calibrated by the company prior to despatch and an electrical calibration should be carried out only if
the accuracy of the instrument is suspect and suitably calibrated test equipment is available.

7.6.1 Equipment Required

a) Current source: 0 to +100 µA.

b) Decade resistance box (temperature input simulator): 0 to 1k5 .

c) Digital milliammeter (current output measurement): 0 to 20 mA.

Note. Resistance boxes have an inherent residual resistance which may range from a few milliohms up to 1 ohm. This value must
be taken into account when simulating input levels, as should the overall tolerance of the resistors within the boxes.

7.6.2 Preparation

a) Switch off the supply and disconnect the sensor, temperature compensator and current output from the electronics unit terminal

block – see Fig. 3.5 or Fig. 3.6.

b) Connect the current source / resistance box to the appropriate terminals – see Table 7.2.

Connect the milliammeter to the retransmission output terminals – see Fig. 3.5 or 3.6.

c) Switch on the supply and allow ten minutes for the circuits to stabilize.

d) Select the

Factory Settings Page and carry out the procedure in Section 7.7.

Table 7.2 Transmitter Terminal Functions

25

7 PROGRAMMING AND ELECTRICAL CALIBRATION…

FACTORY SETTINGS

–––––



A Zero (0A)

XXXX

FACTORY SET CODE

0 0 0 0 0

ELECTRICAL CAL

–––––

Calibrate YES

NO

–––––



A Span (100A)

XXXX

Temp Zero (1k0)

XXXX

YESNO

Temp Span (1k5)

XXXX

Adjust RTX Zero

–––––

7.7 Factory Settings Page

When carrying out the electrical calibration procedure, the actual values denoted by xxxxx are unimportant and are used only
to determine display reading stability.

Press

to advance to next parameter

or

Press

to return to Operating Page, Section 6.2.1.

Parameters in these pages are factory set and should not normally require adjustment.
They can be set up only if the necessary equipment is available.

Factory Settings Access Code

Enter the required code number. If an incorrect value is entered, access to subsequent
parameters is prevented and the display reverts to the top of the page.

Select YES to access the electrical calibration sequence. Select NO to advance to

Cal Time 1.

Caution. Do not select YES unless instrument calibration is required.

Microamp Zero

Set the current source to 0 µA and allow the instrument display to stabilize.

Microamp Span

Set the current source to +100 µA and allow the instrument display to stabilize.

Calibrate Temperature Zero

Set the temperature simulator resistance box to 1000 and allow the instrument display
to stabilise.

Calibrate Temperature Span

Set the temperature simulator resistance box to 1500 and allow the instrument display
to stabilise.

Adjust Retransmission Zero

Set the milliammeter reading to 4.00 mA.

Note. Retransmission signal span is calibrated using 20.00 mA. The correct value
transmitted depends on the range selected in the

Set Up Outputs Page.

Continued on next page…

26

…7 PROGRAMMING AND ELECTRICAL CALIBRATION

Adjust RTX Span

–––––

Cal Time 1 (min)

2

Cal Time 2 (min)

30

Alter Fact. Code

0 0 0 0 0

D.O. g/kg

18.1

Adjust RTX Zero 2

–––––

Adjust RTX Span 2

–––––

…7.7 Factory Settings Page

Adjust Retransmission Span

Set the milliammeter reading to 20.00 mA.

Note. Retransmission signal span is calibrated using 20.00 mA. The correct value
transmitted depends on the range selected in the

Set Up Outputs Page.

Adjust Retransmission Zero 2

See

Adjust Retransmission Zero.

Adjust Retransmission Span 2

See

Adjust Retransmission Span.

Calibration Time 1

Wait period before the stability of the sensor is checked during the calibration sequence.
Programmable from 1 to 10 minutes (default = 2 minutes). See Section 7.5.

Calibration Time 2

Recovery period where the sample is allowed to flow and the instrument settles on
reading, before the instrument is brought back on-line (default = 30 minutes).
See Section 7.5.

Alter Factory Setting Security Code

Set the security code to a value between 00000 and 19999.

Return to Operating Page, Section 6.2.1.

27

7 PROGRAMMING AND ELECTRICAL CALIBRATION

Dissolved Oxygen Measurement – shown as % of Display Span

% Retransmission Output

0

10

20

30

40

50

60

70

80

90

100

0102030405060708090100

A

B

Dissolved Oxygen Measurement – shown as % of Display Span

% Retransmission Output

1% 100%10%

0

10

20

30

40

50

60

70

80

90

100

Fig. 7.1 Bi-Linear Scaling

Fig. 7.2 Logarithmic Scaling (two decades example)

28

8.1 Introduction

No routine maintenance is required for this instrument other than
periodic calibration – see Section 6.2.2. However, if following a
calibration the sensor output shows one flashing bar, the sensor
capsule has therefore become exhausted and needs replacing
immediately.
If the output shows two bars, replace the sensor capsule in the
near future.

Storage

DO:
— use sensors in date rotation to prevent them being

stored longer than necessary.
— at all times, store sensors in a dry and cool environment.
— store sensors in a refrigerator to extend their life, but DO

NOT allow them to freeze.
DO NOT:
— allow sensors to dry out, either in storage or in use.
— leave sensors in vehicles where they are likely to freeze

or be exposed to high temperatures.
— leave sensors on-site without protection from direct sun

or high temperatures.
— use the sensor if it's sealed environment has dried out.

A dirty membrane may also be the cause of the low sensor
output. To clean the sensor proceed with the following.

Caution.

• Only install the oxygen sensor immediately prior to use,
otherwise leave it stored in its protective container.

•Take special care to line up the two pins in the oxygen
sensor with their respective sockets before making the
connection and tightening.

•Take care not to damage the delicate membrane on the
end of the oxygen sensor.

• Ensure that the mating surfaces (carrying the electrical
connection) of the oxygen sensor and connector body are
clean and

completely dry.

8.2 Cleaning/Changing the Sensor

8.2.1 Cleaning

1) Drain the flowcell, by manually opening the solenoid valve ­Select YES to 'Open Valve' on the main operating page of
the transmitter. See Section 6.2.1.

2) Unscrew the clamping screw and carefully remove the
sensor assembly from the flowcell. Check that O-ring does
not fall out.

8 MAINTENANCE

3) Inspect the sensor. If the membrane is clean, refit the sensor
as in 5) below.

If deposits are visible on the membrane, remove by gently
wiping the membrane with a moist paper tissue; for oily or
greasy deposits, the tissue may be moistened with a mild
detergent or, if necessary with iso-propyl alcohol (propan-2­ol). After cleaning, dry the interior of the flowcell with a paper
tissue or soft cloth, ensure that the O-ring is correctly
positioned.

4) Insert the sensor assembly into the flowcell.

5) Use the clamp screw to secure the assembly. Screw in firmly
using finger pressure only.

Caution. Do not overtighten the clamping screw.

6) Close the solenoid valve – Select NO to 'Open Valve' on the
main operating page of the transmitter. See Section 6.2.1.

7) Carry out a calibration – see Section 6.2.2. If a low sensor
efficiency is displayed, see Section 9.2.

8.2.2 Changing the Sensor

1) Drain the flowcell, by manually opening the solenoid valve –
Select YES to 'Open Valve' on the main operating page of
the transmitter. See Section 6.2.1.

2) Unscrew the clamping screw and remove the sensor
assembly from the flowcell.

3) Disconnect the sensor capsule and discard both the sensor
and sealing washer.

4) Take out the O-ring from the flowcell; dry the interior of the
flowcell with a tissue or soft cloth and insert the new O-ring
supplied with the replacement capsule. Ensure that the O­ring is correctly located on the shoulder near the end of the
cavity.

5) Remove the new sensor from its container, taking care not to
damage the membrane. Unscrew the protective cap from
the rear of the sensor.

6) Fit the new sealing washer (supplied) as shown in Fig 4.1 and
locate and secure the connector body on the sensor.

7) Insert the complete assembly into the flowcell.

8) Use the clamping screw to secure the assembly. Screw in
firmly using finger pressure only.

Caution. Do not overtighten the clamping screw.

9) Close the solenoid valve – Select NO to 'Open Valve' on the
main operating page of the transmitter. See section 6.2.1.

10) Carry out a calibration – see Section 6.2.2. If a low sensor
efficiency is displayed, see Section 9.2.

29

9 SIMPLE FAULT FINDING

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9.1 Diagnostic Messages

If erroneous or unexpected results are obtained the fault may be indicated by an error message.
If Alarm A1 has been selected as a STATUS alarm, then the LED and relay operation can be seen in Table 9.1.
The STATUS alarm operates as a FAILSAFE alarm (during an alarm condition the relay state is the same as the power-down state, i.e.
de-energized).

Table 9.1 Diagnostic Messages

30

…9 SIMPLE FAULT FINDING

erutarepmeT

( )C

ecnatsiseRtupnI

()

00.0001

010.9301

023.9701

037.6111

044.5511

050.4911

064.2321

077.0721

089.8031

090.7431

0010.5831

5.0310.0051

9.2 Low Sensor Efficiency/Slow Sensor Cal. or no
Response to D.O. Changes

a) Check that the sample drains fully from flowcell. If the sample

does NOT drain fully check:
i) Operation of solenoid valve.
ii) Sample inlet flow rate does not exceed 400 ml min

–1

maximum.

iii) Sample fluid paths are free flowing and clear of partial

blockages.

iv) Solenoid valve drain tube is not kinked, blocked,

excessively long, does no rise along its length.

v) Flow gauge is not blocked or dirty.

b) Replace the sensor (see Section 8.2.2) as an initial check. It

is also important that all program parameters have been set
correctly and have not been altered inadvertently – see
Section 7.

If the fault persists:
c) Carry out an electrical calibration as detailed in Section 7.6

and check that the instrument responds correctly to the
current input.

Failure to respond to the input usually indicates a fault with
the transmitter, which must be returned to the Company for
repair.

d) If the response in a) is correct, select the

Operating Page and

set the current source to a value which gives an on-scale
D.O. reading on the transmitter. Make a note of the current
source setting and the D.O. reading. Reconnect the sensor
cable and connect the current source to the sensor end of
the cable. Set the same current value on the source and
check that the transmitter displays the noted reading in this
configuration.

If check a) is correct but check b) fails, check the cable
connections and condition. If the response for both checks is
correct, fit a new sensor and calibrate it.

9.3 Checking the Temperature Input

Check that the instrument responds to a temperature input.
Disconnect the PT1000 leads and connect a suitable resistance
box directly to the transmitter inputs – see Section 7.6. Check
that the transmitter displays the correct values as set on the
resistance box – see Table 9.2.

Incorrect readings usually indicate an electrical calibration
problem. Recalibrate the instrument – see Section 7.6.

9.4 High Sample Readings

If the sample reading is higher than expected, the most likely
reason is air ingress into the main sample line.
Check and tighten ALL sample connections as it is possible to
have an air leak into the sample without sample leaking.

Table 9.2 Temperature Readings for Resistance Inputs

31

10 SPECIFICATION

System

Measuring ranges

Programmable within the ranges 0 to 20.0 µg kg

–1

and 0 to

20 mg kg

–1

Scaling

µg kg

–1

, mg kg–1 or ppb, ppm

Accuracy

±5% of reading or ±1 µg kg

–1

, whichever is the greater

Response time

90% of a step change in 1 minute

Resolution

0.1 µg kg

–1

Stability

±5% of reading or ±1 µg kg

–1

per week, whichever is the
greater
Not applicable when autocalibration is in operation

Temperature compensation

5 to 55°C (41 to 131°F) automatic using Pt1000 resistance
thermometer

Salinity correction

Preset within the range 0 to 80 ppt

Barometric pressure correction

Preset within the range 500 to 800 mm Hg

Sample flow

100 to 400 ml min

–1

Sample pressure

Maximum 2 bar

Sample temperature

5 to 55°C (41 to 131°F)

Sensor ambient temperature

0 to 55°C (32 to 131°F)

Environmental Data

Operating temperature limits

–20 to 55°C (–4 to 131°F)

Operating humidity limits

Up to 95% RH non-condensing

Storage temperature limits

Liquid handling panel: –25 to 70°C (–13 to 158°F)
Sensor: 0 to 55°C (32 to 131°F)
Transmitter: –25 to 70°C (–13 to 158°F)
Solenoid valve power
supply (optional): –25 to 70°C (–13 to 158°F)

Protection

Liquid handling panel

IP65
IP54 – Liquid handling panel enclosure
Solenoid valve power supply
(optional): IP65 (optional)

Transmitter

Panel-mounting, IP66/NEMA4X
Wall-mounting, IP66/NEMA4X front

Power Requirements

System

Power consumption, <21 VA

Transmitter

Power supply, 100 to 130 V or 200 to 260 V 50/60 Hz
Power consumption, <10 VA

Error due to power supply variations

Less than ±2% for +6% –20% variation from nominal
supply voltage

Insulation, mains to earth

2 kV r.m.s.

Solenoid valve

Power supply, 90 to 132 V or 180 to 264 V 47/63 Hz
Power consumption, <11 VA

Mechanical Data

Mounting

Transmitter, Wall- or Panel-mounting
Liquid handling panel/enclosure, Wall-mounting
Solenoid valve power supply, Wall-mounting

Overall dimensions

Liquid handling panel

without unions and without
environmental enclosure: 100 approx. x 310 x 118 mm

(3.94 approx. x 12.2 x 4.65 in.)
with environmental
enclosure: 250 x 440 x 160 mm

(9.84 x 17.32 x 6.3 in.)

Transmitter

Wall-mounting: 160 x 214 x 68 mm

(6.29 x 8.43 x 2.68 in.)
Panel-mounting: 96 x 96 x 191 mm

(3.78 x 3.78 x 7.52 in.)
Panel cutout: 92 x 92 mm

(3.62 x 3.62 in.)

Weights

Liquid handling panel

With sensor fitted, without
environmental enclosure: 1.3 kg (2.86 lb)
With sensor fitted and with
environmental enclosure: 3.9 kg (8.58 lb)

Transmitter

Wall-mounting: 2 kg (4.41 lb)
Panel-mounting: 1.5 kg (3.31 lb)
Solenoid valve
power supply: 0.7 kg (1.54 lb)

Sample connections

Compression fitting to accept either 6 mm or

1

/4 in. O.D.

tubing – to be specified when ordering

32

…10 SPECIFICATION 11 SPARES

Specification – Transmitter

Transmitter Display

Measured value

5-digit x 7-segment back-lit l.c.d.

Information

16-character, single line, dot matrix, back-lit l.c.d.

Insulation, contacts to earth

2kVr.m.s.

Set Point and Relay

No. of set points

One

Set point adjustment

Programmable as a concentration or diagnostics alarm

Set point hysteresis

±1% of f.s.d. (fixed)

Local set point annunciation

Red l.e.d.

Number of relays

One

Relay contacts

Single pole changeover
Rating: 250 V AC 250 V DC maximum

3AAC 3 A DC maximum

Loading: (non-inductive) 750 VA 30 W maximum

(inductive) 75 VA 3 W maximum

Retransmission

Number of retransmission signals

One, fully isolated

Optional second current output

Output current
0 to 10, 0 to 20 or 4 to 20 mA programmable

Maximum load resistance

500 (20 mA maximum)

Serial communication

RS422/RS485 (optional, with one current output signal)

Normal, replacement spares are shown in Fig. 11.1. Strategic
spares are listed below.

11.1 Strategic Spares

Part No. Description ................................................ Qty

9438 080 24V Power Supply Unit ................................... 1

0234 037 Solenoid Valve assembly................................. 1

0216 574 Flow Gauge assembly ..................................... 1

0216 575 Needle Valve Cartridge assembly .................... 1

PCB Assemblies, Wall Mounted

9438 070 Complete Main PCB assembly, for

single current o/p .......................................... 1

9438 071 Complete Main PCB assembly, for

single current o/p + Serial/Modbus ............... 1

9438 072 Complete Main PCB assembly, for

2 current o/p version ..................................... 1

4600 0295 Display PCB assembly .................................... 1

4600 0335 Low Level D.O. Module assembly ................... 1

4600 0405 2nd Retransmission output module

assembly ....................................................... 1

PCB Assemblies, Panel Mounted

9438 075 Complete Main PCB assembly (cropped),

for single current o/p ..................................... 1

9438 076 Complete Main PCB assembly

(cropped), for single current o/p +

Serial/Modbus ............................................... 1

9438 077 Complete Main PCB assembly (cropped),

for 2 current o/p version ............................... 1

4600 0246 Power supply PCB assembly (cropped) .......... 1

4600 0285 Mother PCB assembly .................................... 1

4600 0335 Low Level D.O. Module assembly ................... 1

4600 0405 2nd Retransmission output module

assembly ....................................................... 1

Test Equipment

9439 950 Dissolved Oxygen Test Simulator .................... 1

9439 035 Test Simulator lead.......................................... 1

33

11 SPARES

Replacement Seals Pack (9437016)

comprising:

2 x large O-rings
2 x small O-rings
2 x nylon seals
2 x end caps*
1 x protective cover

*The end cap is used to blank off
this connector when the plug is not
fitted.

End Cap

O-ring

Protective

Cover

Flowcell

Connector

Body

O-ring
(

3

/4 in. I.D. x 0.070in cord)

Plug

Handle Assembly 9437025

which includes:

Connector Body
Sensor Connector Cable Assembly
Connector Nut
Thrust Washer
Clamping Screw
Plug

Clamping Screw

Thrust Washer

Connector Nut

Compression Coupling
(to suit 6 mm or

1

/4 in.

o.d. stainles steel pipe)

Sensor Connector
Cable Assembly:
9437 029/031/032/034

(1 m/5 m/10 m/30 m respectively)

Oxygen Sensor 9435 300

(including O-rings)

O-ring
(

7

/8 in. I.D. x 0.070 in. cord)

Note. Ensure that the correct O-rings are
fitted in the appropriate positions as
shown.
Fit new O-rings when a new sensor is
fitted.

Fig. 11.1 Replacement Spares

34

APPENDIX A – 9438 080 24 V DC POWER SUPPLY UNIT (OPTIONAL)

23

All dimensions in mm

Note. Make allowance for cable bends

160

63

CTRS

fixing

98

145 CTRS

136

62

M6 stud for

earth

bonding

Fixing screws M4

Slacken
captive
screws

A.1 Description

The 24 V DC switch mode power supply unit is capable of
powering up to four separate 9438 dissolved oxygen system
solenoids. The 24 V is switched to the solenoid when required by
the operation of the calibration relay in the main 9438
transmitter.

Fig. A.3 shows the connection details in the PSU.

Fig. A.4 shows the interconnection between the PSU and a
single 9438 transmitter.

A.2 PSU Dimensions – Fig. A.1

Warning.

• Before making any connections, ensure that the power
supply, any high voltage-operated control circuits and
high common mode voltage are switched off.

• Although certain instruments are fitted with internal fuse
protection, a suitably rated external protection device,
e.g. fuse or miniature circuit breaker (m.c.b.), must also
be fitted by the installer.

A.3 Accessing PSU Terminals – Fig. A.2

Fig. A.1 Power Supply Unit Dimensions

Fig. A.2 Access to PSU Terminals

35

APPENDIX A – 9438 080 24 V DC POWER SUPPLY UNIT (OPTIONAL)

Pre-wired to
terminal block

110/115 V AC
230/240 V AC
Mains cable in

To earth
terminal in lid

To 4641/4646 transmitter solenoid valve relay (maximum: 4)

To solenoid valve on flowcell assembly (maximum: 4 valves)

Earth bonding stud.
(Enclosure must be bonded
to earth via this stud)

TO RELAY 2 OF TRANSMITTERS

SWITCHED OUTPUT TO SOL VALVE

E N L

0V

+24V

0V

+24V

0V

+24V

0V

+24V

TX4 TX3 TX2 TX1

SOL 4 SOL 3 SOL 2 SOL 1

COM

N/O

COM

N/O

COM

N/O

COM

N/O

Solenoid Valve Powered Via Optional PSU

9438 Transmitter

Relay 2

C NO

Solenoid Valve

90 – 264 V a.c.
Mains. supply

Switch Mode PSU

(up to 4 D.O. Systems)

Switched Output to
Solenoid Valve

0V +24V

C N/O

A.4 PSU Connections – Fig. A.3

A.5 Wiring Schematic – Fig. A.4 A.6 Specification

Overall dimensions

160 x 98 x 62 mm
(6.3 x 3.86 x 2.44 in.)

Output power

24 V @ 2.5 A, 60 W maximum from all outputs

Holdup time

6 ms at full load 115/230 V AC

Line regulation

0.3% over operating range

Load regulation

0.5% from minimum load to full load

Power supply

Voltage requirements

90 to 264 V AC, 47 to 63 Hz

Fig. A.3 PSU Connections

Fig. A.4 Wiring Schematic

Important Note. PSU should be earth bonded.

Note. 0V is internally connected to earth.

36

APPENDIX B – CALIBRATION DIAGNOSTICS

Cal Pulse

Expose to Air

Recovery Period

Time

Output Current (%)

50

100

0

Mark

(30 s to 5 min)

Expose to Air

Output Current (%)

50

100

Space

(30 s to 5 min)

0

Time

Fig. B.1 During Calibration

Fig. B.2 Low Sensor Efficiency

The transmitter can be configured to enable the current output signal to indicate certain calibration diagnostic information.
If the option for diagnostics is selected within the Set Up Retransmission scrolls, then the current output will indicate when a
calibration is taking place, and also will indicate if the sensor is giving Low Sensor Efficiency.

B.1 During Calibration

The current output value will be maintained during a calibration, but the output will pulse from the maintained value to 0%, depending
upon a programmable Cal Pulse period.
The Calibration Pulse period can be programmed 15, 30, 45 seconds, 1, 2, 3, 4, 5 minutes.

This will continue for the full duration of the calibration, exposing the sensor to air, and the recovery period.
At the end of the recovery period, if the response is good, the instrument will go back on line and the current output will become live.

B.2 Low Sensor Efficiency

If the output from a sensor is found to be below a predetermined level during a calibration (i.e. Low Sensor Efficiency) the calibration
will not be accepted. The current output immediately goes above the full scale value, and will continue to pulse on a programmable
Mark/Space basis.
The time for the Mark and Space periods can be programmed separately to 30 seconds, 1, 2, 3…..10 minutes.

PRODUCTS & CUSTOMER SUPPORT

Products

Automation Systems

• for the following industries:

– Chemical & Pharmaceutical
– Food & Beverage
– Manufacturing
– Metals and Minerals
– Oil, Gas & Petrochemical
– Pulp and Paper

Drives and Motors

• AC and DC Drives, AC and DC Machines, AC motors to 1kV

• Drive systems

• Force Measurement

• Servo Drives

Controllers & Recorders

• Single and Multi-loop Controllers

• Circular Chart and Strip Chart and Recorders

• Paperless Recorders

• Process Indicators

Flexible Automation

• Industrial Robots and Robot Systems

Flow Measurement

• Electromagnetic Flowmeters

• Mass Flow Meters

• Turbine Flowmeters

• Flow Elements

Marine Systems & Turbochargers

• Electrical Systems

• Marine Equipment

• Offshore Retrofit and Refurbishment

Process Analytics

• Process Gas Analysis

• Systems Integration

Transmitters

• Pressure

• Temperature

• Level

• Interface Modules

Valves, Actuators and Positioners

• Control Valves

• Actuators

• Positioners

Water, Gas & Industrial Analytics Instrumentation

• pH, conductivity, and dissolved oxygen transmitters and sensors

• ammonia, nitrate, phosphate, silica, sodium, chloride, fluoride,
dissolved oxygen and hydrazine analyzers.

• Zirconia oxygen analyzers, katharometers, hydrogen purity and
purge-gas monitors, thermal conductivity.

Customer Support

We provide a comprehensive after sales service via a Worldwide
Service Organization. Contact one of the following offices for
details on your nearest Service and Repair Centre.

United Kingdom

ABB Limited
Tel: [phone]
Fax: [phone]

United States of America

ABB Inc.
Tel: [phone]
Fax: [phone]

Client Warranty

Prior to installation, the equipment referred to in this manual must
be stored in a clean, dry environment, in accordance with the
Company's published specification.

Periodic checks must be made on the equipment's condition. In
the event of a failure under warranty, the following documentation
must be provided as substantiation:

1. A listing evidencing process operation and alarm logs at time of
failure.

2. Copies of all storage, installation, operating and maintenance
records relating to the alleged faulty unit.

IM/9438 Issue 6

The Company’s policy is one of continuous product
improvement and the right is reserved to modify the

information contained herein without notice.

Printed in UK (05.05)

© ABB 2005

ABB Limited

Oldends Lane, Stonehouse
Gloucestershire
GL10 3TA
UK
Tel: [phone]
Fax: [phone]

ABB Inc.

Analytical Instruments
9716 S. Virginia St., Ste. E
Reno, Nevada 89521
USA
Tel: [phone]
Fax: [phone]

ABB has Sales & Customer Support
expertise in over 100 countries worldwide

www.abb.com