Thermo Scientific AquaSensors AquaTrace User manual

Thermo Scientific
AquaSensors™ AquaTrace™
Trace DO System
User Guide

ROSS and the COIL trade dress are trademarks of Thermo Fisher Scientific Inc. U.S. patent 6,793,787.
Alconox® is the registered trademark of Alconox, Inc, Glenview, NY.
Dawn® is the registered trademark of Procter & Gamble, Cincinnati, OH.

Thermo Scientific AquaSensors™ AquaTrace™ Trace DO System User Guide 1
Preface
This instruction manual serves to explain the use of the Thermo Scientific
AquaTrace™ Trace Dissolved Oxygen Measurement System and is written to cover
as many applications as possible. Please do not hesitate to contact Thermo Fisher
Scientific or an authorized representative with questions or concerns.
The information presented in this instruction manual is subject to change without notice
as improvements are made, and does not represent any commitment whatsoever on the
part of Thermo Fisher Scientific.
Thermo Fisher Scientific cannot accept any responsibility for damage or malfunction
of the sensor due to improper use.
Contact Information
To contact Thermo Scientific AquaSensors Technical
Support:
Within the United States call 1.800.225.1480 or fax
978-232-6015.
Outside the United States call 978.232.6000 or fax
978.232.6031.
In Europe, the Middle East, Asia, and Africa, contact your
local authorized dealer.
Visit us on the web at: www.thermofisher.com/processwater

Safety Information
Thermo Scientific AquaSensors™ AquaTrace™ Trace DO System User Guide 2
The Thermo Scientific AquaSensors AquaTrace™
Dissolved Oxygen Measurement System shall be installed
and operated only in the manner specified. Only a skilled,
trained or authorized person should carry out installation,
setup and operation of the sensor system.
Before using the system, make sure that is connected as
specified. Failure to do so may result in permanent
damage to the system of its components.
Protection against electric shock will be achieved only by
observance of the corresponding installation rules.

Thermo Scientific AquaSensors™ AquaTrace™ Trace DO System User Guide 3
Table of Contents
1. INTRODUCTION ............................................................................................................................................ 4
1.1 General Information...................................................................................................................................... 4
1.2 Intended use........................................................................................................................................... 4
1.3 Safety Instructions....................................................................................................................................... 5
1.4 Removal from Service / Correct Disposal of the Trace DO Measurement System......................................... 5
2. PRODUCTDESCRIPTION................................................................................................................................. 6
2.1 System Description........................................................................................................................................ 6
2.2 Sensor Description........................................................................................................................................ 7
2.3 AV38 Remote Display.................................................................................................................................... 9
3. INSTALLATION............................................................................................................................................... 10
3.1 System Mounting and Installation.................................................................................................................. 10
3.2 Wiring......................................................................................................................................................... 12
4. SYSTEM OPERATION AND MAINTENANCE.................................................................................................... 13
4.1 Sensor Startup............................................................................................................................................ 13
4.2 System Shut-Down and Sensor Storage........................................................................................................ 14
4.3 System Maintenance – Cleaning................................................................................................................... 14
4.4 Sensor Maintenance – Replacing the Membrane Cap and Electrolyte.............................................................. 15
4.5 Sensor Maintenance – Trace DO System Troubleshooting.............................................................................. 16
5. SENSOR CALIBRATION.................................................................................................................................. 17
5.1 Temperature Calibration............................................................................................................................... 17
5.2 Dissolved Oxygen Calibration – Air Calibration............................................................................................... 19
5.3 Dissolved Oxygen Calibration – Zero Calibration............................................................................................ 22
5.4 Dissolved Oxygen Calibration – 1-Point Calibration ........................................................................................ 23
6. AquaTrace System Order Matrix and Accessories............................................................................................ 25
6.1 AquaTrace Trace DO System Configuration Options ...................................................................................... 25
6.2 AquaTrace System Replacement Electrolyte and Membrane Caps.................................................................. 25
6.3 AquaTrace Trace DO Specifications.............................................................................................................. 26
7. Terms and Conditions ....................................................................................................................................... 27
7.2 Terms and Conditions of Sale Continued...................................................................................................... 28

1. INTRODUCTION
1.1 General Information
The product is designed for continuous use in industrial process applications and complies with safety
regulations currently in force. Improper use could lead to hazards for the user or a third-party, and/or
adverse effects to the plant or other equipment.
Thermo FisherScientificdoes not accept any liability for damage that may arise if informationin this
manual is not followed. Therefore,the operatinginstructionsand specifications must be read and
understoodby all personsinvolved in installation and operation of this equipment.
This manual identifies safety instructions and additional information by means of the following symbols:
This symbol draws attention to safety instructionsand warnings of potential danger,
which if neglected, could result in injury to persons and/or damage to property.
This symbol identifies additional informationand instructions,which if neglected, could
lead to inefficient operation and possible loss of production.
It is recommended that this manual be made accessible to everyone who may need it as a
reference. Please contact Thermo Fisher Scientific or an authorized representative with any
questions.
1.2 Intended use
The Thermo Scientific AquaSensors AquaTrace DO System is capable of continuous monitoring of
dissolved oxygen in applications between 20 ppm and 0.1 ppb. The system also measures water
temperature.
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:
Observing the instructions, notes and requirements set out in this instruction manual.
Observing all local safety regulations.
Thermo Scientific AquaSensors™ AquaTrace™ Trace DO System User Guide 4

Observing all warnings and cautions in the documentation regarding all products used in this
measurement system, including the sensor, mounting hardware, AV38 electronics and
cabling.
Observing the prescribed environmental and operational conditions.
Observing chemical compatibility with all wetted materials.
1.3 Safety Instructions
The Trace DO Measurement System should be installed and operated only
by personnel familiar with the sensor and qualified for such work.
A defective Trace DO Measurement System should be returned to Thermo
Fisher Scientific for repair or replacement. Contact Thermo Fisher Scientific to
obtain a Return Material Authorization (RMA) number.
No modifications to the Trace DO Measurement System are allowed. The
manufacturer/supplier accepts no responsibility for damage caused by unauthorized
modifications. The risk is borne entirely by the user.
1.4 Removal from Service / Correct Disposal of the Trace DO Measurement System
Removal from Service
1. Shut off the process sample connection to the AquaTrace system.
2. Disconnect the power supply to the AquaTrace system.
3. Disconnect any cable wiring from the AquaTrace analyzer’s outputs.
4. Disconnect the process connections to the AquaTrace system.
5. Remove the sensor from the flow chamber.
6. Rinse the sensor head with clean water and replace the storage cap on the end of the AquaTrace sensor.
7. Rinse the inside of the flow chamber with clean water and allow it to dry.
8. Replace the sensor inside the flow chamber.
Correct Disposal of Unit
When the Trace DO Measurement System is taken out of service, observe the local environmental
regulations for correct disposal.
Thermo Scientific AquaSensors™ AquaTrace™ Trace DO System User Guide 5

2. PRODUCTDESCRIPTION
2.1 System Description
The Thermo Scientific AquaSensors AquaTrace DO system is used for continuous measurement of dissolved oxygen. The
system is capable of measuring dissolved oxygen where the oxygen concentration is below 20 ppm but it is intended for
service in applications below 1000 ppb. The system also measures the sample temperature across its rated range.
The AquaTrace DO is a complete system that includes all components necessary for the low-level oxygen measurement. The
system consists of a low-level oxygen sensor head, a DataStick sensor body with a communication adapter, and a sample
chamber mounted to a back panel for easy installation. The system includes an AV38 remote display either mounted to the
back panel or ready for mounting at a remote location depending on how the system is configured.
The sample chamber secures the sensor in the process. It directs the sample flow onto the sensing face of the probe and
directs the outlet flow away from the sensor tip while also eliminating entrapped bubbles. This improves the sensor’s
response to changing process conditions and maximizes the accuracy of the dissolved oxygen measurement. The sample
chamber uses a union-style locking ring to secure the sensor, allowing the sensor to be inserted and removed without
twisting the sensor cable.
The AquaTrace system includes an AV38 local display that allows the operator to interface with the sensor. The AV38 allows
the operator to display the system’s measurement values, to calibrate the sensor, and to configure the sensor’s various
measurement options. The AV38 can be configured with relays and analog outputs for use in control systems and can
include host communications for network communications using one of several standard protocols. The images below
indicate panel dimensions.
AquaTrace Trace DO Measurement System
Thermo Scientific AquaSensors™ AquaTrace™ Trace DO System User Guide 6

Thermo Scientific AquaSensors™ AquaTrace™ Trace DO System User Guide 7
System Specifications:
Wetted Materials.........................Sample Chamber –Acrylic, Viton, 316 Stainless Steel
Sensor – PEEK, 316 Stainless Steel, Viton, FEP
Operating Temperature..............5 to 50°C (40 to 120°F)
Maximum Pressure.....................60 psi supply
Sample Flow Rate......................50 to 400 mL/min (0.8 to 6.3 gal/hr)
Measuring Range.......................0.1 ppb to 20 ppm
Resolution ..................................0.1 ppb / 0.01 ppm
2.2 Sensor Description
The Thermo Scientific AquaSensors Trace DO sensor uses the amperometric measurement technique
to maximize lifetime in continuous industrial applications. The sensor is easily maintained and
reconditioned by replacing the convenient pre-tensioned membrane cap and electrolyte. The sensor
includes an integral temperature element that is closely coupled to the process sample to insure an
accurate measurement.
The sensor head is pre-calibrated for span and the zero is factor set. The integral electronics in the
sensor head retain calibration data and the sensor does not require a new calibration when the system
is installed, although it is recommended that a sample calibration be performed at the typical service
range to maximize accuracy during operation.
The Trace DO sensor uses the DataStick sensor system. The DataStick consists of a standard sensor
body, an interchangeable sensor head, and a communications adapter. The sensor head threads into
the front of the DataStick sensor body. The DataStick body’s internal electronics work with the sensor
head to calculate the measurement values. The communications adapter assembles into the back end
of the DataStick body and transmits the measurement data using one of several standard
communication protocols.
The sensor is designed for continuous use and has 1-inch NPT mounting threads for installation into
the sample chamber adapter. The parts of the sensor system are shown here:

Communications Adapter (MODBUS RTU supplied) plugs
into sensor body and is secured with a retaining ring
Universal DataStick Sensor Body automatically calculates
measurements based on the sensor head
1-inch NPT threads for connection to sample chamber adapter
Trace DO Sensor Head plugs into sensor body and is secured
with a retaining ring
Screw-on membrane cap
Sensor Highlights:
0.1 ppb to 20 ppm Measurement Ranges
Calibration stored in Sensor (Does not require recalibration after connection to
Analyzer/Controller)
0.1 ppb Resolution
Fast Response
Simple membrane and electrolyte replacement
Provides measurement, calibration, configuration and diagnostic functions without
Analyzer/Controller
Works with AV38 for local display, current output data reporting, and relay control
Thermo Scientific AquaSensors™ AquaTrace™ Trace DO System User Guide 8


Temperature measurement included
Can be connected to MODBUS, DeviceNET, Ethernet, USB,RS-232and CANopen networks.
2.3 AV38 Remote Display
For detailed information on configuration of AV38current outputs, relays, host communications,
please refer to the AV38 manual. This manual will describe basic calibration, configuration and
dissolved oxygen compensation functions directly related to dissolved oxygen measurements
The AV38 is a universal display interface for DataStick sensor systems that includes dissolved oxygen
measurement. The enclosure has ¼ DIN dimensions for easy mounting and is rated NEMA4X for
outdoor use. It uses a liquid crystal display (LCD)with a high contrast backlight for best readability and
is powered with 24 volts DC or optionally with line power(90 VAC to 240 VAC).
The AV38 automatically recognizes the type of DataStick connected to the
system and provides the appropriate calibration, configuration and diagnostic
menus. It has options for two 4-20 current outputs, twoalarm/control/wash
relays and network communications to a host computer. In addition, the AV38
can address up to 247 DataStick sensors.
Thermo Scientific AquaSensors™ AquaTrace™ Trace DO System User Guide 9

DataStick sensors connected to the AV38 communicate via MODBUS
RTU. As such, the AV38can be used to select any two of the DataStick
sensors on the bus for display, current output reporting and relay alarms by
selecting the desired station addresses. When there is no DataStick
sensor connected at the selected network address, the measure screen
will indicate “DataStick Absent”.
There are seven keys for menu navigation. The MENU key is used to toggle between the menu
and the measure screen. Pressing the Menu key provides options for calibration, configuration,
communications, outputs and relays. Refer to the AV38Manual for Details.
3. INSTALLATION
3.1 System Mounting and Installation
The AquaTrace measurement system is mounted on a 12 inch X 12 inch panel with four ¼” mounting
holes. Use ¼ inch bolts with washers to mount the panel to a wall.
The sample supply is connected to the fitting at the bottom of the flow chamber. The sample supply
should be regulated to control pressure and flow. The sample pressure should not exceed 60 psi. The
sample flow rate should be regulated between 50 mL/min and 400 mL/min. The sensor will operate
properly across this range, however rapid variations in flow can cause temporary measurement
fluctuations. To insure a stable measurement, the sample supply should be regulated to provide a
consistent flow rate to the sample chamber.
The outlet fitting on the sample chamber must be connected to a vented drain. Excessive tubing length
or pipe restrictions that result in back pressure to the outlet are not allowed.
The inlet and outlet port on the sample chamber are supplied with compression fittings for use with ¼
inch OD tubing. When the inlet and outlet are to be directly plumbed, remove the compression fittings
and connect to the flow chamber with 1/8 inch NPT fittings
Note that the tubing and plumbing used to install the AquaTrace system must not be gas measuring the
process. Verify that all plumbing permeable. Stainless steel, Kynar PVDF and polypropylene are
relatively impermeable to oxygen. Other materials such as silicone are gas permeable and allow oxygen
contamination that will prevent the system from accurately components are suitable for use with a low
oxygen process.
Thermo Scientific AquaSensors™ AquaTrace™ Trace DO System User Guide 10

Tools and Equipment required for installation:
½ inch drill with drill bits for appropriate wall anchor
Four ¼ inch diameter bolts – 1.5 inches long
Four ¼ inch flat washers
Adjustable wrench
¼ inch tubing
Pressure / flow regulating valve
Shut-off valve
Standard screw driver
Panel Mounting Instructions:
1. Place the 12 inch x 12 inch pane on the wall where it is to be mounted and mark the placement
of the upper left hole.
2. Drill a mounting hole for the upper left corner with a masonry drill bit and install a wall anchor.
3. Mount the AquaTrace panel with the upper left mounting bolt.
4. Using a level, rotate the panel until the top edge is level, then mark the remaining three
mounting holes.
5. Rotate the AquaTrace panel out of the way, drill the three mounting holes and install wall
anchors.
6. Secure the panel with all four bolts and washers and tighten.
Thermo Scientific AquaSensors™ AquaTrace™ Trace DO System User Guide 11

Thermo Scientific AquaSensors™ AquaTrace™ Trace DO System User Guide 12
General System Installation Instructions:
1. Connect the sample chamber outlet to a vented drain.
2. Connect the process supply to the sample chamber inlet. The sample supply flow rate must be
between 50 and 400 mL/min and the sample pressure must not exceed 60 psi. Use an
appropriate flow or pressure valve to obtain consistent flow.
3. Connect the appropriate power to the AV38 Remote Display. Route the power line through the
cord grip in the AV38 housing and connect the leads to the appropriate terminals. Follow local
codes and regulations governing the power supply. Refer to the AV38 User Guide for details on
connecting power.
4. The Trace DO sensor is supplied with the sensor cable connected to the AV38 Remote Display.
If the sensor has been disconnected for any reason, reconnect it to the appropriate terminals.
Follow the connection guide on the AV38 terminals or refer to the sensor set-up section in this
user guide.
5. Unscrew the sample chamber retaining ring and remove the Trace DO sensor.
6. Carefully remove the protective cap from the sensor head. Refer to Section 4.1 of this user
guide, the sensor set-up, for detailed information on handling and setting up the sensor.
7. Insert the sensor back into the sample chamber and tighten the retaining ring.
8. Open process flow to the sample chamber. Observe the chamber and verify that it purges any
trapped gas and drains properly.
9. Power up the AV38 Remote Display.
10. The AV38 Remote Display includes optional host communications, relays and analog outputs
that can be used with various control systems. Refer to the AV38 user guide for detailed
instructions to configure these options.
3.2 Wiring A DataStick sensor can be configured to operate using one of several standard communications
protocols. A label at the end of the sensor cable identifies the specific communication protocol used by
that sensor. The sensor supplied with the AquaTrace DO system uses the MODBUS RTU protocol
enabling it to communicate with the AV38 Remote Display.
There are two different methods to make the electrical connection between the Trace DO sensor and
the AV38 Remote Display. The sensor can be wired directly to the Remote Display. In cases where the
AV38 Remote Display is mounted more than 30 feet from the AquaTrace panel, the sensor can be
connected using an interconnect cable and a junction box. The system is supplied with the sensor
directly wired to the Remote Display.
Direct Connection:
1. Insert the sensor cable through a watertight cord grip into the AV38 Remote Display. Conduit
holes are located on the base of the AV38 for this purpose.
2. Connect the sensor wires to the AV38 as shown on the AV38 wiring chart.
Indirect Connection (using extension cable and a junction box):
1. Insert the sensor cable and interconnect cable through watertight cord grips into the junction
box.

2. Connect the sensor cable lead wires and the interconnect cable lead wires to the terminal
strip in the junction box.
3. Insert the other end of the interconnect cable through a watertight cord grip into the AV38
Remote Display. Conduit holes are located on the base of the AV38 for this purpose.
4. Connect the interconnect lead wires to the AV38 as shown on the AV38 wiring chart
Be sure that the wire colors of the sensor cable match those of
the interconnect cable.
Route the interconnect cable through metal conduit to minimize
electrical noise that may interfere with the sensor signal.
4. SYSTEM OPERATION AND MAINTENANCE
Thermo Scientific AquaSensors™ AquaTrace™ Trace DO System User Guide 13
4.1 Sensor Startup
The sensor is shipped with a protective cap on the sensor head to keep the membrane wet and protect it
from damage. The cap should remain on the sensor head until the sensor is installed in the sample.
Remove the cap by pulling it straight off down the side of the sensor. Be careful not to damage the
sensor membrane. Save the protective cap and use it to keep the membrane moist whenever the sensor
is removed from service.
The membrane cap is screwed onto the front of the sensor and care should be taken not to unscrew it.
The cap contains dissolved oxygen electrolyte that will spill out if the cap is removed.
The sensor has been charged and tested prior to shipment. However, it requires time to stabilize when it
is initially installed. Depending on the oxygen level of the process, the sensor may need to run for up to
12 hours to stabilize after installation.
The sensor has been calibrated for span and offset prior to shipment. The span has been set using an
air calibration at approximately 8 ppm. The operator can redo either of these calibrations, although care
must be taken, particularly with the zero calibration, to insure accurate results. For maximum accuracy it
is recommended the operator perform a 1-point calibration at the high end of the application range. This
will update the span and optimize the sensor for the particular process application. The temperature
measurement can also be calibrated with a sample calibration. If the temperature measurement requires
calibration, it is advantageous to update it prior to calibrating the dissolved oxygen measurement
because the DO reading is temperature compensated. See Section 5 for instructions on performing the
various calibrations.

Thermo Scientific AquaSensors™ AquaTrace™ Trace DO System User Guide 14
4.2 System Shut-Down and Sensor Storage
The sensor membrane must be kept wetted at all times. The sensor is shipped with a protective cover
over the membrane cap. This should be kept on the sensor until it is put into service. If the sensor is
going to be removed from service for any length of time, it should be stored as follows:
1. Rinse the sensor with clean water.
2. Clean the sensor head as necessary per the cleaning procedure in Section 4.3 of this user
guide.
3. Fill the protective vinyl cap with clean water.
4. Secure the protective cap on the end of the sensor.
If the entire system will be taken out of service for any prolonged period, prepare it for storage as
follows:
1. Shut off process flow to the sample chamber.
2. Remove the Trace DO sensor from the sample chamber.
3. Clean and cap the Trace DO sensor as noted above.
4. Drain the sample chamber and rinse it with clean water. If necessary, clean any deposits as
noted below.
5. Dry the interior of the sample chamber.
6. Place the capped Trace DO sensor back in the flow chamber for storage.
4.3 System Maintenance – Cleaning
In order to maintain an accurate measurement value, the sensor will need occasional maintenance. The
maintenance interval will be dictated by the process in which it is installed. The harsher the process, the
more often the sensor will require maintenance. Regular maintenance will yield a longer sensor life.
Clean the sensor as follows:
1. Remove the sensor from the sample chamber.
2. Rinse or spray the sensor with warm water to remove any heavy deposits.
3. If fine deposits are still present, soak the sensor in a container of warm detergent water for one
hour. Do not use detergents that contain oily skin softeners like aloe or lanolin that can coat the
membrane. Alconox® and Dawn® dishwashing liquid work well.
4. Rinse the sensor with clean warm water.
5. If deposits are still present on the membrane, repeat the soaking and rinsing steps.
Before returning the sensor to service, allow it to soak in water at ambient temperature for about an hour
to stabilize the DO membrane.
After cleaning the sensor, perform an air calibration per the instructions in Section 5.
Reinstall the sensor in the sample chamber and perform a 1-point calibration to adjust the sensor span
as necessary. See section 5 for instructions on performing a 1-point calibration.

The sample chamber should be kept clean as well. It should be inspected regularly for the formation of
deposits or films. Clean the inside of the sample chamber when required as follows:
1. Shut off process flow to the sample chamber.
2. Remove the sensor from the sample chamber.
3. Drain the sample chamber.
4. Rinse the chamber out with a soft brush and clean water. If necessary, use a mild detergent
such as Alconox or Dawn dishwashing liquid. Do not use chemical solvents or abrasive cleaners
on the sample chamber.
5. Rinse the chamber with clean water.
6. Insert the Trace DO sensor back into the flow chamber and secure it with the retaining ring.
7. Resume process flow through the sample chamber.
4.4 Sensor Maintenance – Replacing the Membrane Cap and Electrolyte
If the sensor head has been cleaned and the sensor will still
not calibrate properly, replace the membrane cap and
electrolyte solution per the following procedure:
Thermo Scientific AquaSensors™ AquaTrace™ Trace DO System User Guide 15
1. Hold the sensor firmly with the electrode tip facing
down. Remove the existing membrane cap by turning
it counterclockwise. Dispose of the old membrane cap
and electrolyte using an approved method.
2. Fill the new membrane cap with fresh DO electrolyte
and gently agitate it to remove trapped bubbles.
3. Place the sensor head into the new membrane cap
4. Slowly screw the new membrane cap clockwise onto
the sensor head until secure. Place a finger tip on the
outside surface of the membrane and apply slight
pressure to support it as you thread the cap onto the
sensor. Excess electrolyte will be expelled from the
cap as you assemble it.
Install slowly! Screwing the membrane cap
on quickly may cause pressurization of the
membrane.
Do not over tighten!
Maximum torque: 10 lbs·in (1.130 N·m)
5. Before returning the sensor to service, allow it to soak
in water at ambient temperature for about an hour to
stabilize the DO membrane.
6. After soaking the sensor, perform an air calibration per
the instructions in Section 5.
7. Reinstall the sensor in the sample chamber and
perform a 1-point calibration to adjust the sensor span

as necessary. See Section 5 for instructions on
performing a 1-point calibration.
4.5 Sensor Maintenance – Trace DO System Troubleshooting
If the sensor is not providing reasonable signals to the Remote Display, check the following:
Verify that process is flowing through the sample chamber. If flow is blocked, the sensor will
consume the available oxygen in the sample chamber and display a 0 ppb dissolved oxygen
measurement.
Inspect the integrity of the sensor membrane. If the membrane is torn or punctured, replace it
with a new membrane cap and fresh electrolyte.
Inspect the sensor cable for damage. Any cuts or kinks in the outer jacket may damage signal
connections.
Inspect the terminal block connections to be sure the wires are not corroded or loose.
Make sure all sensor wires are connected properly to the AV38 Remote Display terminal block.
Immerse the sensor in a solution of known dissolved oxygen value and check the displayed
measurement.
Verify that the AV38 Remote Display electronics are working correctly by connecting it to
another sensor if available.
Note: Any new sensor that has been in storage for more than a few days should be
soaked in clean water for at least 30 minutes before reviewing measurement
performance.
Note: The membrane of any DO sensor in storage must be kept moist at all times. The
protective cap should be filled with clean water and placed securely over the sensor
head.
Thermo Scientific AquaSensors™ AquaTrace™ Trace DO System User Guide 16

5. SENSOR CALIBRATION
5.1 Temperature Calibration
The AquaTrace system’s temperature measurement can be recalibrated using a 1-point sample
calibration. Use the following procedure to calibrate the temperature measurement:
1. Enter the calibration menu on the AV38 Remote Display (see the AV38 user guide for detailed
information on the various menus in the user interface).
2. Press the ENTERkey from the TEMPERATUREcalibration menu to initiate the calibration
process. When the temperature calibration procedure is started, the analog output is placed into
hold mode. The user is prompted to prepare the sensor. The sensor value is dynamically
updated during this step.
Thermo Scientific AquaSensors™ AquaTrace™ Trace DO System User Guide 17
▲
◄ ►
▼
≡ Calibrate
► Temperature
MENU ESC
ENTER
3. Remove the Trace DO sensor from sample chamber.
4. Place the Trace DO sensor in a beaker filled with clean water at the desired calibration
temperature.
5. Allow the sensor to stabilize in the calibration bath. The time required to stabilize will vary based
on the temperature difference between the process sample and the calibration bath. If the two
do not vary significantly, the temperature measurement should stabilize within five minutes. If
the variation is significant it may take up to fifteen minutes for the temperature measurement to
stabilize sufficiently for an accurate calibration.
6. Use a known reference sensor to determine the actual temperature of the calibration bath.
7. When the sensor is ready, press the ENTERkey is pressed and the user is presented with a
calibration value for editing.
25.3
°C
Sensor
ready?
▲
◄ ►
MENU ESC ENTER
▼

8. The AV38 will display the calibration value for editing. Use the arrow keys to edit the
temperature value to the known value of the calibration bath. When the value is correct, press
the ENTER key to continue.
Thermo Scientific AquaSensors™ AquaTrace™ Trace DO System User Guide 18
▲
◄ ►
▼
Temperature ?
( 25.0)
MENU ESC
ENTER
9. The AV38 will calibrate the temperature sensor to match the value entered. During this time, the
calibration procedure can be aborted by pressing the ESC key.
Temperature
Calibrating…
▲
◄ ►
MENU ESC ENTER
▼
10. After the calibration point has been stored, the AV38 will prompt the user to confirm that the
calibration procedure has been successful. Press the ENTER key to accept and continue.
Temperature
Confirm Cal OK
▲
◄ ►
MENU ESC ENTER
▼
11. When the enter key is pressed, the analog output is placed into active mode and the monitoring
of sensor and temperature values is resumed. This successfully completes the temperature
calibration procedure.
12. If an error occurs during calibration that causes the procedure to fail, the reason for the failure
will be shown.