TPS Aqua-D User manual

Congratulations !
You have purchased the latest in Handheld, Waterproof Dissolved
Oxygen - Temperature instrumentation. This manual is for both the
Aqua-D, which uses the TPS ED1 sensor, and for the Aqua-DY, which
uses the YSI Dissolved Oxygen sensor. For simplicity, we refer only to
“Aqua-D” throughout the manual.
The Aqua-D is a breeze to operate. This manual has been designed to
help you get started, and also contains some handy application tips. If at
any stage you require assistance, please contact either your local TPS
representative or the TPS factory in Brisbane.
The manual is divided into the following sections:
1. Table of Contents
Each major section of the handbook is clearly listed. Sub-sections
have also been included to enable you to find the information you
need at a glance.
2. Introduction
The introduction has a diagram and explanation of the display and
controls of the Aqua-D. It also contains a full listing of all of the items
that you should have received with your Aqua-D. Please take the
time to read this section, as it explains some of items that are
mentioned in subsequent sections.
3. Main Section
The main section of the handbook provides complete details of the
Aqua-D, including operating modes, calibration, troubleshooting,
specifications, and warranty terms.
4. Appendices
Appendices containing background information and application notes
are provided at the back of this manual.
TPS Pty Ltd
4 Jamberoo Street
Springwood, Brisbane,
Australia, 4127
Phone : [phone]
International : 61 7 32 900 400
Fax : [phone]
International : 61 7 3808 4871
Email : [email protected]
Web : www.tps.com.au
Aqua-D & Aqua-DY
Dissolved Oxygen -
Temp. Meter
Version : 1.0
Date : 27/02/2002
Author : MS

Page 1
Contents
1. Introduction ..............................................................................................2
1.1 Aqua-D Display and Controls............................................................................. 2
1.2 Unpacking Information ...................................................................................... 4
1.3 Specifications ................................................................................................... 6
2. Operating Modes ......................................................................................8
3. Dissolved Oxygen Calibration................................................................10
3.1 Calibration.......................................................................................................10
3.2 Dissolved Oxygen Calibration Notes.................................................................11
3.3 Dissolved Oxygen Calibration Messages ..........................................................12
4. Temperature Calibration.........................................................................13
4.1 Calibration.......................................................................................................13
4.2 Calibration Notes .............................................................................................14
4.3 Calibration Messages.......................................................................................14
5. Setting the Salinity Correction Value.....................................................15
6. Battery Saver Function...........................................................................16
7. Initialising the Aqua-D............................................................................17
8. Instrument software version number.....................................................17
9. Troubleshooting .....................................................................................18
9.1 General Error Messages ..................................................................................18
9.2 Dissolved Oxygen Troubleshooting...................................................................19
9.3 Temperature Troubleshooting...........................................................................20
10. Dissolved Oxygen Sensor Fundamentals..........................................21
10.1 Operating Principle ......................................................................................21
10.2 Maintenance Of The Membrane ...................................................................22
10.3 Probe Storage .............................................................................................22
10.4 Notes On Units Of Dissolved Oxygen ...........................................................23
10.5 Equilibrium Conditions .................................................................................24
10.6 Velocity Past The Membrane........................................................................25
11. Warranty..............................................................................................26

Page 2
1. Introduction
1.1 Aqua-D Display and Controls

Page 3
¬Display
24 character alpha-numeric display. Can show any of the following
combinations of readouts (see section 2).
% Saturation +
Temperature Salinity-corrected ppM (mg/L) + Temperature
Salinity Correction
Value (in ppK) Temperature only
A unique “Large Digit” mode nearly doubles the size of the digits
(section 2).
User-friendly prompts and error messages are also provided.
-Used to calibrate all parameters. See sections 3, 4and 5.
®Used to select % Saturation, ppM, Manual Salinity or Temperature
modes. See section 2.
¯Switches the Aqua-D on and off.
Hold this key for 3 seconds to invoke Battery Saver mode. See
section 6.
°and ±
These keys toggle the Aqua-D between Large Display mode and
Dual Display mode. See section 2.
NOTE: The digits in Large Display mode are made by combining the
two rows of the display. This results in a small gap
approximately half way up the digits.

Page 4
1.2 Unpacking Information
Before using your new Aqua-D, please check that the following
accessories have been included:
1.2.1 Aqua-D
Standard Kit includes… Part No
1. Aqua-D Dissolved Oxygen-Temperature Instrument.............123143
2. 9V Battery .............................................................................130026
3. Aqua-D Handbook................................................................130050
Sensor and cables…
1. ED1 Dissolved Oxygen sensor, (no cable) ............................123400
(includes sensor protector and membrane kit)
2. 1m detachable cable for ED1 Dissolved Oxygen sensor .......123228
3. 3m detachable cable for ED1 Dissolved Oxygen sensor .......123230
4. 5m detachable cable for ED1 Dissolved Oxygen sensor .......123232
5. Extended cable (ordered by the metre)..................................130040
Options that may have been ordered with your Aqua-D:
1. Hard Plastic Carry Case........................................................130057
2. Adaptor to fit sensor into standard BOD bottle.......................123201
Other spares:
1. Membrane kit ........................................................................123301
(includes Filling Solution, Sodium Sulphite and Membrane Sheet)
2. Filling Solution, 45mL............................................................123303
3. Sodium Sulphite for Zero Calibration, 50g.............................123302

Page 5
1.2.2 Aqua-DY
Standard Kit includes… Part No
1. Aqua-DY Dissolved Oxygen-Temperature Instrument...........123144
2. 9V Battery .............................................................................130026
3. Aqua-D Handbook................................................................130050
Sensor and cables…
1. YSI Field Dissolved Oxygen sensor, (no cable).....................123204
(includes integral protector and membrane kit)
2. 1m detachable cable for YSI Dissolved Oxygen sensor.........123212
3. 3m detachable cable for YSI Dissolved Oxygen sensor.........123221
4. 5m detachable cable for YSI Dissolved Oxygen sensor.........123222
5. Extended cable (ordered by the metre)..................................130040
6. YSI non-stirring BOD bottle sensor........................................123214
7. YSI self-stirring BOD bottle sensor........................................123213
Options that may have been ordered with your Aqua-DY:
1. Hard Plastic Carry Case........................................................130057
Other spares:
1. Membrane kit ........................................................................123300
(includes Filling Solution, Sodium Sulphite, 2 Membrane Envelopes
and 2 O-Rings)
2. Filling Solution, 45mL............................................................123303
3. Sodium Sulphite for Zero Calibration, 50g.............................123302

Page 6
1.3 Specifications
Range Resolution Accuracy
% Saturation 0 to 250.0 % Sat’n 0.1 % Sat’n ±0.3 % Sat’n
ppM (mg/L) 0 to 25.0 ppM 0.1 ppM ±0.1 ppM
Salinity 0 to 50.0 ppK
(Manually set) 0.1 ppK Not Applicable
Temperature -10.0 to 120.0 OC
(dissolved oxygen sensor
limited to 45 OC)
0.1 OC±0.2 OC
Additional Dissolved Oxygen Specifications
Temperature Compensation.............. Dual automatic system for:
1. Membrane permeability
2. Solubility in ppM mode
Sensor Zero Range........................... 0 to 7%
Sensor Span Range.......................... 70.0 to 135.0%
Calibration......................................... One-touch automatic calibration in
Zero and in Air.
Additional Temperature Specifications
Temperature Sensor Offset Range.... -10.0oC to +10.0oC

Page 7
General Specifications
Display.............................................. 24 Character alphanumeric LCD,
with full text prompts and error
messages.
Power................................................ 9V Alkaline Battery for 100+ hours
operation.
Battery Saver .................................... On :Auto switch-off after 5
minutes
Off : Continuous use
Dimensions ....................................... 157 x 78 x 35 mm
Mass ................................................. Instrument only :Approx 200g
Full Kit :Approx 1.5kg
Environment...................................... Temperature :0 to 45 OC
Humidity :0 to 90 % R.H.

Page 8
2. Operating Modes
Press the key to select the desired operating mode. The sequence is
shown in the following table…
% Saturation Mode 100.0%S
25.0oc
Dissolved Oxygen data in % Saturation units is shown on the top line and
Temperature data is shown on the bottom line.
Select this mode to calibrate the % Saturation readout.
Press or to toggle between dual readout or large digit readout.
↓↓
ppM Mode 8.24ppMS
25.0oc
Dissolved Oxygen data in ppM (mg/L) units is shown on the top line and
Temperature data is shown on the bottom line.
Select this mode to calibrate the ppM readout.
The “S” is shown after the “ppM” units when the Salinity correction value is
set to greater than 0.0ppK (see section 5).
Press or to toggle between dual readout or large digit readout.
↓↓
Salinity Mode 36.0ppK
The Salinity correction value only is shown on the top line.
Select this mode to set the Salinity correction value.
Press or to toggle between regular readout or large digit readout.
↓↓
Continued over the page…

Page 9
Operating modes, continued…
Temperature Mode 25.0oc
Temperature data only is shown on the top line.
Select this mode to calibrate Temperature.
Press or to toggle between regular readout or large digit readout.
↓↓
Back to % Saturation mode
Note: The decimal point is replaced by a ” ∗∗ “ if a Dissolved Oxygen or
Temperature calibration has failed (see sections 3and 4), if the unit is
initialised (see section 7), or if the unit has lost its factory calibration (see
section 9.1).

Page 10
3. Dissolved Oxygen Calibration
A “ ∗” in place of the decimal point indicates that the Dissolved Oxygen
readout is not calibrated, or a past calibration has failed. The “ ∗” will be
removed once an Air calibration has been successfully performed.
3.1 Calibration
1. Switch the Aqua-D on.
2. Select the desired % Saturation or ppM Mode (see section 2). Each
mode should be calibrated separately for optimum accuracy.
3. Plug the Dissolved Oxygen sensor into the sensor socket.
4. Ensure that temperature has already been calibrated (see section 4).
NOTE: If the decimal point in the temperature reading is replaced by
a “ ∗“, then the temperature readout is not calibrated.
5. Rinse the Dissolved Oxygen sensor in distilled water and blot dry.
6. Zero Calibration
(a) Place the sensor into an oxygen-free solution. This solution may
be prepared by dissolving 2g of Sodium Sulphite in 100mL of
distilled water. A 50g bottle of Sodium Sulphite powder is
supplied with a new Dissolved Oxygen sensor for this purpose
(part number 123302).
(b) Allow the reading to stabilise at or near zero. This may take 2-3
minutes.
(c) Press and hold the key for 2 seconds to calibrate.
(d) Discard the oxygen-free solution after use.
(e) A “ ∗“ will not be removed from the display after a Zero
Calibration.
7. Rinse the Dissolved Oxygen sensor in distilled water and blot dry.

Page
11
8. Air Calibration
(a) Hang the Dissolved Oxygen sensor in air. The tip of the sensor
should be pointing downwards.
(b) Allow the reading to stabilise. After a zero calibration, this may
take up to 5 minutes.
(c) Press and hold the key for 2 seconds to calibrate.
(d) A ∗in the display will be replaced by a decimal point after a
successful air calibration.
9. The Aqua-D is now calibrated for Dissolved Oxygen and is ready for
use in the mode that was selected during calibration.
NOTES:
When taking sample measurements, always ensure that there is
adequate flow of solution past the membrane for accurate, stable
readings. See section 10.6.
If salinity-corrected ppM Dissolved Oxygen readings are required, set
the salinity correction value before taking sample measurements.
See section 5.
3.2 Dissolved Oxygen Calibration Notes
1. A zero calibration should be performed at least monthly. In
applications where there is a low level of dissolved oxygen, a zero
calibration may have to be done weekly.
2. An air calibration should be performed at least weekly. Of course,
more frequent calibration will result in greater confidence in results.
3. All calibration information is retained in memory when the Aqua-D is
switched off, even when the battery is removed.
4. The salinity correction value is ignored during zero and air calibration.
There is therefore no need to re-set the salinity correction value when
calibrating Dissolved Oxygen.

Page 12
3.3 Dissolved Oxygen Calibration Messages
1. If a zero calibration has been successfully performed, the Aqua-D will
display the following message, and then display the zero response of
the sensor.
Cal. OK
Zero= 1.0%
2. If a zero calibration has failed, the Aqua-D will display the following
message, then the failed zero value of the sensor.
Cal. Failed
Zero= 10.0%
3. If an air calibration has been successfully performed, the Aqua-D will
display the following message, and then the span value of the
sensor.
Cal. OK
Span=100.0%
4. If an air calibration has failed, the Aqua-D will display the following
message, and then the failed span value of the sensor.
Cal. Failed
Span= 70.0%

Page
13
4. Temperature Calibration
A “ ∗” in place of the decimal point indicates that the Temperature
readout is not calibrated, or a past calibration has failed. The “ ∗” will be
removed once Temperature has been successfully calibrated.
4.1 Calibration
1. Switch the Aqua-D on.
2. Select Temperature mode (see section 2).
3. Plug the Dissolved Oxygen sensor into the sensor socket
4. Place the sensor into a beaker of room temperature water, alongside
a good quality mercury thermometer. Stir the sensor and the
thermometer gently to ensure an even temperature throughout the
beaker.
5. When the reading has stabilised, press and hold the key for 2
seconds.
6. The reading from the sensor is now displayed on the top line, and the
value you are going to set is on the bottom line. For example…
Enter 25.0oc
Temp ↑↑ 26.0↓↓
7. Press the and keys until the bottom line shows the same
temperature as the mercury thermometer.
8. Press the key to calibrate the temperature readout.
Alternatively, press the key to abort temperature calibration.

Page 14
4.2 Calibration Notes
1. Temperature calibration information is stored in memory when the
meter is switched off, even if the battery is removed.
2. Temperature does not need to be re-calibrated unless the Dissolved
Oxygen sensor is replaced or the meter is initialised.
4.3 Calibration Messages
1. If a temperature calibration has been successfully performed, the
Aqua-D will display the offset value of the sensor. For example…
Cal. OK
Offset= 1.0oc
2. If a temperature calibration has failed, the Aqua-D will display the
failed offset value of the sensor.
Cal. Failed
Offset=10.5oc

Page
15
5. Setting the Salinity Correction Value
The salinity of the sample affects the Dissolved Oxygen reading in ppM
mode. As the salinity increases, the solubility of Oxygen decreases. The
Dissolved Oxygen sensor is not able to detect the salinity of the sample,
so the operator must enter this value manually for salinity-corrected ppM
Dissolved Oxygen readings.
To set the salinity correction value:
1. Measure the salinity of the sample solution. For best results, use a
good quality salinity meter, such as a TPS model Aqua-C or WP-84.
Note the reading.
2. Switch the Aqua-D on.
3. Press the key until the meter is in Salinity mode (see section 2).
The currently selected salinity correction value is displayed.
4. Press and hold the key for 2 seconds.
5. The display should now look like this:
Enter Man.
Sal ↑↑ 36.0↓↓
6. Press the and keys until the bottom line shows the salinity
value obtained in step 1.
7. Press the or key to set the salinity correction value.
NOTES:
1. For non salinity-corrected readings in ppM mode, simply set the
salinity correction value to 0.0 .
2. If the salinity correction value is set to above zero, an “S” is added to
the display in ppM mode, to signify that salinity correction is being
applied. For example…
8.24ppMS
25.0oc
3. The salinity correction value is ignored during zero and air calibration.
There is therefore no need to re-set the salinity correction value when
calibrating Dissolved Oxygen.

Page 16
6. Battery Saver Function
The Aqua-D is equipped with a battery saver function. If no button has
been pressed for five minutes, the unit beeps and flashes the display for
20 seconds, and then shuts off. This function can be disabled for
continuous use.
To enable or disable the battery saver function:
1. Switch the Aqua-D on.
2. With the meter already switched on, press and HOLD the key for
3 seconds.
3. The battery saver menu is now displayed. For example…
:ON ↑↑↓↓
9.00V
4. In this mode, use the or keys to toggle the battery saver
function on or off.
ON enables the battery saver function. The unit will turn itself off
after 5 minutes.
OFF disables the battery saver function. The unit will not switch itself
off.
NOTE: The display also shows the battery volts. This gives the
operator an idea of how much battery life is remaining. The
symbol flashes when the battery volts drops below 7.50
volts. At 6.00 volts the meter turns itself off.
5. When you have set the battery saver function to the desired position,
press the key to return to normal measurement mode.

Page
17
7. Initialising the Aqua-D
If the calibration settings of the Aqua-D exceed the allowable limits, and
the unit cannot be re-calibrated, then it may need to be initialised to
factory default values. This action may be required if a sensor is replaced.
To initialise the Aqua-D…
1. Switch the Aqua-D off.
2. Press AND HOLD the key while switching the Aqua-D on.
3. The following messages are now displayed…
Memory & Cal
Reset !
↓↓
You MUST
Re-Calibrate
↓↓
TPS AQUA-D
V1.0 S1234
4. The meter then displays % Saturation and Temperature. Note that
the decimal points have been replaced with a “ ∗“, to indicate that the
unit requires re-calibration.
8. Instrument software version number.
If you need to phone or fax TPS for any further technical assistance, the
version number of your Aqua-D firmware may of benefit to us. Please
obtain the version number before phoning or faxing.
The version number is displayed on the bottom left of the display when
the Aqua-D is switched on. For example…
TPS AQUA-D
V1.0 S1234
“V1.0” in this example is the firmware version number.
“S1234” in this example is the instrument’s serial number.

Page 18
9. Troubleshooting
9.1 General Error Messages
Error
Message Possible Causes Remedy
Factory
Cal. Fail
See
Handbook
The EEPROM chip which
contains the factory
calibration information has
failed.
The unit must be returned to
TPS for service.
Memory
Failed
Calib.
Lost
Memory
Reset !
You MUST
Re-Cal.
User calibration settings
have been lost or corrupted. Re-calibrate the instrument.
Both a Zero and an Air
calibration are required for
Dissolved Oxygen (section
3) and a 1 point calibration
for temperature (section 4).
Meter displays the
word OFF, and
switches off.
Battery is below 6.00 volts. Replace the battery.
Meter will not turn
on. Battery is exhausted. Replace the battery.
Flashing
symbol. Battery is below 7.50 volts. Replace the battery soon.
Note that the unit will switch
itself off when the battery
falls below 6.00 volts.

Page
19
9.2 Dissolved Oxygen Troubleshooting
Symptom Possible Causes Remedy
Unit fails to
calibrate, even
with new sensor.
Calibration settings outside
of allowable limits due to
previous failed calibration.
Initialise the unit. See section
7.
•Zero calibration
fails (Zero is
greater than
7.0%)
•Air calibration
fails (Span is
less than 70% or
greater than
135%).
•Unstable or
inaccurate
readings.
1. Membrane is leaking or
broken.
2. Gap between membrane
and gold cathode is dry.
3. Incorrectly fitted
membrane.
4. Sensor is empty.
5. Sensor is faulty.
Replace membrane and refill
sensor.
ED1 Undo the barrel 3 turns,
then re-tighten to re-
flush the filling solution.
YSI Gently pump the
pressure compensation
diaphragm several
times.
Membrane should be smooth
and convex with no wrinkles.
Re-fit membrane if
necessary.
Replace membrane and re-
fill sensor.
Return sensor to factory for
repair or replacement
Blackened Silver
anode Sensor has been exposed to sulphides or other chemical
poisoning.
Return to the TPS factory for
cleaning and service.
Tarnished or
scratched Gold
cathode.
Sensor has been chemically
poisoned or physically
damaged.
Return to the TPS factory for
cleaning and service.
Meter reads OVR
ppM or OVR%.1. Sensor has not yet polarised.
2. Sensor is faulty
Wait for 2-3 minutes for the
sensor to polarise after the
Aqua-D is switched on.
Return sensor to factory for
repair or replacement.
For complete details on the operation, care and maintenance of your
ED1 or YSI dissolved oxygen sensor, see the separate leaflet that is
supplied with the sensor.