Thermo Scientific Alpha DO 500 User manual

Alpha DO 500
Transmitter
Dissolved Oxygen

ROSS and the COIL trade dress are trademarks of Thermo Fisher Scientific Inc. U.S. patent
6,793,787.
AQUAfast, Cahn, ionplus, KNIpHE, No Cal, ORION, perpHect, PerpHecT, PerpHecTion,
pHISA, pHuture, Pure Water, Sage, Sensing the Future, SensorLink, ROSS, ROSS Ultra,
Sure-Flow, Titrator PLUS and TURBO2 are registered trademarks of Thermo Fisher.
1-888-pHAX-ION, A+, All in One, Aplus, AQUAsnap, AssuredAccuracy, AUTO-BAR, AUTO-
CAL, AUTO DISPENSER, Auto-ID, AUTO-LOG, AUTO-READ, AUTO-STIR, Auto-Test, BOD
AutoEZ, Cable-Free, CERTI-CAL, CISA, DataCOLLECT, DataPLUS, digital LogR, DirectCal,
DuraProbe, Environmental Product Authority, Extra Easy/Extra Value, FAST QC, GAP,
GLPcal, GLPcheck, GLPdoc, ISEasy, KAP, LabConnect, LogR, Low Maintenance Triode,
Minimum Stir Requirement, MSR, NISS, One-Touch, One-Touch Calibration, One-Touch
Measurement, Optimum Results, Orion Star, Pentrode, pHuture MMS, pHuture Pentrode,
pHuture Quatrode, pHuture Triode, Quatrode, QuiKcheK, rf link, ROSS Resolution, SAOB,
SMART AVERAGING, Smart CheK, SMART STABILITY, Stacked, Star Navigator 21, Stat
Face, The Enhanced Lab, ThermaSense, Triode, TRIUMpH, Unbreakable pH, Universal
Access are trademarks of Thermo Fisher.
Guaranteed Success and The Technical Edge are service marks of Thermo Fisher.
PerpHecT meters are protected by U.S. patent 6,168,707. PerpHecT ROSS electrodes are
protected by U.S. patent 6,168,707. ORION Series A meters and 900A printer are protected
by U.S. patents 5,198,093, D334,208 and D346,753.ionplus electrodes and Optimum Results
solutions are protected by U.S. patent 5,830,338.ROSS Ultra electrodes are protected by
U.S. patent 6,793,787.ORP standard is protected by U.S. patent 6,350,367. No Cal
electrodes are protected by U.S. patent 7,276,142.© 2009 Thermo Fisher Scientific Inc. All
rights reserved. All trademarks are the property of Thermo Fisher Scientific Inc. and its
subsidiaries.The specifications, descriptions, drawings, ordering information and part
numbers within this document are subject to change without notice.This publication
supersedes all previous publications on this subject.

Preface
This manual serves to explain the use of the Alpha DO 500 transmitter. It functions in
two ways, firstly as a step by step guide to help you to operate the transmitter.
Secondly, it serves as a handy reference guide. It is written to cover as many
anticipated applications of the transmitter as possible. If there are doubts in the use
of the transmitter, please do not hesitate to contact the nearest Authorized
Distributor.
Thermo Scientific will not accept any responsibility for damage or malfunction to the
transmitter caused by improper use of the instrument.
Remember to fill in the guarantee card and mail it back to your authorized distributor.
The information presented in this manual is subject to change without notice as
improvements are made, and does not represent a commitment on the part of
Thermo Scientific.
Copyright 2009 All rights reserved.

Table of Contents
1. Introduction ...........................................................................................................1
1.1 Before You Begin ................................................................................................................... 1
1.2 Intended Use .......................................................................................................................... 1
1.3 Safety Instructions.................................................................................................................. 2
1.4 Taking Out of Service / Correct Disposal of the Unit ............................................................. 2
2. Getting Started ......................................................................................................3
2.1 Description of Instrument .......................................................................................................3
Power Supply Requirements (SL2 Position) ................................................................................... 3
2.2 Measurement and Control System......................................................................................... 4
2.3 Connecting Peripherals..........................................................................................................5
2.3.1 Connection Terminals.................................................................................................... 5
2.3.2 Connecting Dissolved Oxygen Electrode ...................................................................... 6
2.3.3 Connecting Temperature Probe .................................................................................... 6
2.4 Installation .............................................................................................................................. 7
2.4.1 Mechanical Dimensions................................................................................................. 7
2.4.2 Wall Mount..................................................................................................................... 7
2.4.3 Panel Mount................................................................................................................... 8
2.5 Display & Keypad ................................................................................................................... 9
2.5.1 Display Overview........................................................................................................... 9
2.5.2 Key Functions.............................................................................................................. 10
3. Normal Operation ................................................................................................11
3.1 Measurement mode ............................................................................................................. 11
3.2 Menu Overview .................................................................................................................... 12
4. Calibration Mode .................................................................................................13
4.1 Entering Calibration Mode.................................................................................................... 13
4.2 Calibration in mg/l or ppm of Oxygen................................................................................... 14
4.2.1 1-Point Calibration ....................................................................................................... 14
4.2.2 2-Point Calibration ....................................................................................................... 15
4.3 Calibration in% Saturation of Oxygen .................................................................................. 17
4.3.1 1-Point Calibration ....................................................................................................... 17
4.3.2 2-Point Calibration: ...................................................................................................... 18
5. Setup Mode ..........................................................................................................20
5.1 Enter Setup mode ................................................................................................................20
5.2 Configuration Settings..........................................................................................................21
5.3 Offset Settings...................................................................................................................... 23
5.4 Temperature Settings........................................................................................................... 25
5.5 Range Settings..................................................................................................................... 27
5.6 Hold Settings ........................................................................................................................ 28
5.7 Out of Range Settings .......................................................................................................... 29
5.8 Viewing Calibration Point ..................................................................................................... 30
5.9 Viewing Electrode Condition ................................................................................................ 31
5.10 Resetting .............................................................................................................................. 32
6. Technical Specifications.....................................................................................33
7. List of Accessories .............................................................................................35
7.1 Thermo Scientific.................................................................................................................. 35
7.2 Eutech Instruments ..............................................................................................................36

8. Troubleshooting ..................................................................................................37
9. General Information ............................................................................................38
9.1 Warranty............................................................................................................................... 38
9.2 Return of Goods ................................................................................................................... 38
9.3 Guidelines for Returning Unit for Repair .............................................................................. 38
9.4 Maintenance and Cleaning .................................................................................................. 38
10. Appendices .......................................................................................................39
10.1 Appendix 1 – Salinity vs. Temperature (@ 760mmHg)........................................................ 39
10.2 Appendix 2 – Abbreviations Used in LCD............................................................................ 40

Instruction Manual Alpha DO 500
1
1. Introduction
1.1 Before You Begin
We thank you for purchasing the Alpha DO 500 Transmitter.
The construction of the Alpha DO 500 Transmitter employs leading edge
technology and complies with safety regulations currently in force.
Notwithstanding this, improper use could lead to hazards for the user or a
third-party, and/or adverse effects on the plant or other equipment. Therefore,
the operating instructions must be read and understood by the persons
involved before work is started with the Alpha DO 500 Transmitter.
The instruction manual must always be stored close at hand, in a place
accessible to all people working with the Alpha DO 500 Transmitter.
If you have questions, which are not or insufficiently answered in this
instruction manual, please contact your authorized supplier. They will be glad
to assist you.
1.2 Intended Use
Alpha DO 500 Transmitters are intended solely for dissolved oxygen (DO)
and temperature measurement, as described in this instruction manual.
Any other use, or use not mentioned here, that is incompatible with the
technical specifications is deemed inappropriate. The operator is solely
responsible for any damage arising from such use.
Other prerequisites for appropriate use include:
–Comply with the instructions, notes and requirements set out in this
instruction manual.
–Comply with all local safety regulations concerning safety at work.
–Comply with all information and warnings in the documentation dealing
with the products used together with the Alpha DO 500 Transmitter
(housings, sensors, etc.).
–Comply with local environmental and operational conditions.

Instruction Manual Alpha DO 500
2
1.3 Safety Instructions
- The Alpha DO 500 Transmitter should be installed and operated
only by personnel familiar with the instrument and who are
qualified for such work.
- A defective Transmitter must neither be installed nor put into
service.
- The Alpha DO 500 Transmitter must only be operated under the
specified operating conditions (see section 5.9).
- The Alpha DO 500 Transmitter must not be repaired by the
customer.
- No modifications to the Alpha DO 500 Transmitter are allowed. The
manufacturer/supplier accepts no responsibility for damage
caused by unauthorized modifications. The risk is borne entirely
by the user.
1.4 Taking Out of Service / Correct Disposal of the Unit
Taking out of Service
xFirst disconnect the unit from the power supply and then undo all electrical
connections.
xRemove the unit from the wall / panel.
Correct Disposal of the Instrument
When the DO Transmitter is permanently taken out of service, obey the local
environmental regulations for correct disposal or send the instrument to your
local distributor, they will take care of proper disposal.

Instruction Manual Alpha DO 500
3
2. Getting Started
2.1 Description of Instrument
The Thermo Scientific Alpha DO 500 Transmitter is used for measuring
dissolved oxygen and temperature values. The dissolved oxygen values can
be measured using industrial dissolved oxygen sensors. The temperature
values can be measured using 2-wire or 3-wire Pt100 sensors. The DO
Transmitter can be used for applications such as water treatment and
monitoring, galvanic-decontamination, chemical processing, food processing,
clean or wastewater control and neutralization processes.
The Alpha DO 500 Transmitter has many user-friendly and safety features
which include:
xPush-button keypad for calibration and setup
xBuilt-in non-volatile memory to ensure that calibration and other
information are not erased if power supply fails
xMenu-driven program that simplifies setup
xAutomatic temperature compensation (ATC)
xManual temperature compensation setting without the ATC probe, with
independent setting for calibration and process temperature
xLarge dual display LCD for easy reading with clear multiple
annunciators, operational mode indicators and error indicators.
xGalvanically isolated current output of 4 to 20mA
xHold function to freeze output current (22mA)
xOut of range current indication (3.8mA)
xProtection against electromagnetic interference
Power Supply Requirements (SL2 Position)
This transmitter requires a 12 to 24V DC power supply. Other Transmitters
and/or a chart recorder may be connected in series.
1. Insert positive loop wire from power supply to pin 1, tighten screw.
2. Insert negative loop wire to pin 2, tighten screw. This wire may be linked to a
chart recorder or to negative terminal of power supply.
Alpha pH500 Power Supply
Chart recorder
1
2

Instruction Manual Alpha DO 500
4
2.2 Measurement and Control System
A typical measurement system consists of:
xA Alpha DO 500 Transmitter
xA dissolved oxygen sensor with integrated or separate Pt100
temperature sensor
xAn appropriate measurement cable
xAn immersion, flow or process assembly
xA chart recorder
Power Adaptor
(12 to 24 V DC)
4 - 20 mA
Measurement Cable
Housing and
Sensors
Chart Recorder
Alpha DO500 Transmitter
ENT
ESC
2-wire Dissolved Oxygen Transmitter
Alpha DO500
CAL

Instruction Manual Alpha DO 500
5
2.3 Connecting Peripherals
2.3.1 Connection Terminals
Remove Back Cover:
Remove the screws from the four corners at the back of the DO Transmitter.
Remove the back cover. The connectors are exposed on the back PCBA as
shown in the Figure 1 below.
Connectors:
xSL2 – 12 to 24 V DC power
xSL1 – Dissolved Oxygen electrode & Temperature probe connections
(wiring has to be done in the detachable connector
SL1
SL2
Figure 1: Outer Side of Back PCBA
SL1 Connections SL 2 Connections
1. DO Input, +ve terminal 1. DC Power Supply +ve
terminal
2. DO Input, -ve terminal 2. DC Power Supply –ve
terminal
3. No Connection 3. No Connection
4. No Connection
5. PT100 Compensate
(Short to pin 6 for 2-wire
RTD)
6. PT100 Sense
7. PT100 Ground
8. No Connection

Instruction Manual Alpha DO 500
6
2.3.2 Connecting Dissolved Oxygen Electrode
Refer the instruction sheet that comes with your Dissolve Oxygen electrode
to identify polarity (+ve and –ve) of DO wires.
1. Connect DO +ve wire to Pin 1 of SL1 connector
2. Connect DO -ve wire to Pin 2 of SL1 connector
2.3.3 Connecting Temperature Probe
For Automatic Temperature Compensated (ATC) readings, a 100:Pt RTD
temperature probe (2-wire or 3-wire) can be connected to the Transmitter.
3-Wire Probe:
1. Connect PT100 compensate wire to Pin 5 of SL1 connector
2. Connect PT100 sense wire to Pin 6 of SL1 connector
3. Connect PT100 GND wire to Pin 7 of SL1 connector
2-Wire Probe:
1. Short Pin 5 & 6 of SL1 connector using a small piece of wire.
2. Connect PT100 sense wire to Pin 6 of SL1 connector
3. Connect PT100 GND wire to Pin 7 of SL1 connector

Instruction Manual Alpha DO 500
7
2.4 Installation
2.4.1 Mechanical Dimensions
ENT
ESC
2-wire Dissolved Oxygen Transmitter
Alpha DO 500
CAL
2.4.2 Wall Mount
Pierce through holes at
both sides
11
Cover the catch slots at
both sides with overlays
2

Instruction Manual Alpha DO 500
8
2.4.3 Panel Mount
Panel
Gasket
Prepare panel cut-out of
92.0 mm X 92.0 mm
Remove back cover of
DO Transmitter and slide it
through panel cut-out
Attach catch to both sides
of DO Transmitter
Insert threaded rods through catch
until DO Transmitter is held against panel
2
3
4
1
1
Panel

Instruction Manual Alpha DO 500
9
2.5 Display & Keypad
2.5.1 Display Overview
The Liquid Crystal Display (LCD) of the Alpha DO 500 Transmitter has two
alpha-numerical displays (Upper and a Lower).
xUpper display: Measured dissolved oxygen reading (in % saturation or
ppm or mg/l) is displayed when the Transmitter is in normal operation
(measurement) mode.
xLower display: Measured temperature value is displayed when the
Transmitter is in normal operation (measurement) mode. In Calibration
mode, calibration points are displayed here.
The two displays indicate function names, options & settings in Setup mode.
Refer ‘Appendix 2 – Abbreviations Used in LCD’ for more details.
The LCD also consists of various mode indicators, status annunciators and
unit of measurement indicators.
%
SETUP MEAS CAL
Upper Display
Lower Display
ERR
ATC
°C
READY
-
-
HOLD
ppm
mg/l
K=
Mode Indicators
MEAS Measurement mode (Refer Section 3.1)
SETUP Setup mode (Refer Section 5)
CAL Calibration mode (Refer Section 4)
Status Annunciators
READY Appears when the reading is stable
HOLD Appears in Setup mode and Calibration mode to indicate that the relay function
is frozen
ATC Appears when Automatic Temperature Compensation (ATC) is enabled.
Not visible when Manual Temperature Compensation (MTC) is enabled.
Flashes if the temperature probe is faulty in its ATC mode. (Refer Section 5.4)
ERR Appears when an error occurs
Buffer annunciator. Appears in calibration mode or viewing calibrated point
Electrode annunciator. Appears when viewing electrode properties or during
calibration error

Instruction Manual Alpha DO 500
10
2.5.2 Key Functions
ENT
ESC
2-wire Dissolved Oxygen Transmitter
lpha DO500
CAL
Key Description
CAL
Enter Calibration mode
ENT
Enter Setup mode.
Access sub screens (parameters) within a group of settings in Setup
mode.
Confirm (save) setup parameters and numerical values
Start/Confirm calibration in Calibration mode.
Select a group of settings in Setup mode.
Select parameters and increment/decrement numerical values in Setup
and Calibration modes.
(When pressed continuously, speed of values increment/decrement
increases)
Returns to Measurement mode when both keys are pressed
simultaneously.
Units of Measurement Indicators
% Dissolved Oxygen in Percentage Saturation
ppm Dissolved Oxygen in Parts Per Million
mg/l Dissolved Oxygen in milligram per liter
ºC Temperature in Celsius (Refer Section5.4)

Instruction Manual Alpha DO 500
11
3. Normal Operation
3.1 Measurement mode
When the DO Transmitter is powered on, the display shows all the LCD
segments briefly, and then automatically enters into the Measurement mode.
%
MEAS
ATC
°C
READY
25.0
99.0
The mode indicator ‘MEAS’ at the top of the display indicates that the
Transmitter is in Measurement mode. The upper alpha-numerical display
shows the measured dissolved oxygen value, while the lower display shows
the temperature value. The indicator “%”, “ppm” or “mg/l” at the upper right
side of the display indicates the current measurement mode. (Refer section
5.2 for switching measurement modes)
NOTE: To guarantee accurate readings, the measuring system (the DO
Transmitter and the sensor) must be calibrated regularly.
From measurement mode you can access:
xCalibration mode (by pressing CAL key)
xSetup mode (by pressing ENT key)
For more details, refer section 4 for Calibration mode and section 5 for Setup
mode.)

Instruction Manual Alpha DO 500
12
3.2 Menu Overview
MEAS
%
°C
ATC
READY
ENT
SETUP
HOLD
SETUP
HOLD
ENT
SETUP
HOLD
SETUP
HOLD
SETUP
HOLD
SETUP
HOLD
ENT
ENT
ENT
ENT
ENT
ENT
ENT
SETUP
HOLD
CAL
ENT
ENT
ENT
ENT
ENT
ENT
ENT
ENT
SETUP
HOLD
SETUP
HOLD
ENT ENT
ENT ENT
CAL
HOLD

Instruction Manual Alpha DO 500
13
4. Calibration Mode
4.1 Entering Calibration Mode
While in measurement mode, press CAL key to access calibration mode.
LCD indicates ‘CAL dO’.
Calibration in or
Calibration in saturation
mg/l ppm
%
Calibration Mode
- See Section 4.3
- See Section 4.4
CAL
HOLD
CAL
&
To quit Calibration Mode
ENT
MEAS
%
°C
ATC
READY
NOTES:
xTo exit calibration mode at any time during calibration, press  and 
keys simultaneously (escape). The DO Transmitter returns to the
measurement mode and the old calibration values remain active.
xThe calibration is always carried out in the units of measurement (mg/l
or ppm or %) selected in setup mode.

Instruction Manual Alpha DO 500
14
4.2 Calibration in mg/l or ppm of Oxygen
The DO Transmitter is capable of calibration of up to 2 points for dissolved
oxygen. All new calibration values will automatically override existing
calibration data. Make sure the unit of measurement is set to mg/l or ppm.
(Refer Section 5.2 for switching unit of measurements).
If you wish to abort the DO calibration, press  and  keys simultaneously
and the DO Transmitter reverts to measurement mode.
4.2.1 1-Point Calibration
The 1-point calibration is done at high-point using 8.24 mg/l of dissolved
oxygen solution.
Measured value should be
within +/- 50 % of high-point
Calibration error occurs if measured value
is not within +/- 50% of high-point
during 1-point calibration
2
CAL
HOLD
1
ENTENTENT
CAL
HOLD
2
CAL
HOLD
2
CAL
HOLD
3
mg/l
MEAS
mg/l
°C
ATC
READY
4
CAL
HOLD mg/l
READY
ERR
+
11
From measurement mode press CAL key to enter calibration mode as
described in section 4.1. The LCD shows ‘CAL Do’. Press ENT key to
begin calibration.
2
Select 1-point calibration: The display shows ‘1Pt CAL’. If ‘2Pt CAL’ is
shown, press  or  key to select ‘1Pt CAL’.
Press ENT key to confirm the selection.
3
The buffer annunciator appears in LCD. The lower display shows ‘HI’,
indicating the high-point is being calibrated. Immerse the electrode in
8.24 mg/l dissolved oxygen solution. Immerse the temperature probe in
the solution if ATC is enabled. The upper display shows the measured
value of dissolved oxygen of the solution. Allow the reading to stabilize.
LCD shows ‘READY’ annunciator when the reading is stable.
Press  or  key to adjust the reading to 8.24 mg/l. The Transmitter
allows adjusting up to r50% of the measured value.
Press ENT key to confirm the reading.
NOTE: The transmitter does not accept the calibration and shows
calibration error if the displayed (measured) value is more than
r50% of the high-point value.
4
The calibration is completed. The DO Transmitter reverts to
measurement mode.