TPS WP-90 User manual

Congratulations !
You have purchased the latest in Handheld Specific Ion-pH-mV-Temperature
instrumentation. We trust that your new WP-90 will give you many years of
reliable service.
The WP-90 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 WP-90. It also contains a full listing of all of the items that you should
have received with your WP-90. 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 WP-90,
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
E-mail : [email protected]
Web Site : www.tps.com.au Model WP-90
Specific Ion, pH,
mV, & Temp. Meter
Handbook Version : 1.1
Date : 07 Jun 01
Author : MS

Page 2Contents
1. Introduction.....................................................................................4
1.1 WP-90 Display and Controls.............................................................................4
1.2 Unpacking Information.....................................................................................6
1.3 Specifications....................................................................................................7
2. WP-90 Menu Structure ...................................................................9
3. Specific Ion Mode.........................................................................11
3.1 Selecting ppM or ppK Mode ...........................................................................11
3.2 Selecting Exponential Mode (e.g. Molar)........................................................13
4. Specific Ion Calibration................................................................15
4.1 Calibration Procedure .....................................................................................15
4.2 Calibration Notes............................................................................................17
4.3 Calibration Messages......................................................................................17
5. pH Calibration...............................................................................18
5.1 Calibration Procedure .....................................................................................18
5.2 Calibration Notes............................................................................................19
5.3 Calibration Messages......................................................................................19
6. mV Calibration ..............................................................................20
7. Relative mV Calibration................................................................20
7.1 Notes ..............................................................................................................20
8. Temperature Calibration ..............................................................21
8.1 Calibration Procedure .....................................................................................21
8.2 Calibration Notes............................................................................................22
8.3 Calibration Messages......................................................................................22
8.4 Manual Temperature Setting...........................................................................22
9. Good Laboratory Practices (GLP)...............................................23
9.1 To recall GLP information on the display........................................................23
9.2 Failed Calibration...........................................................................................25
9.3 Printing GLP Information to the RS232 Port...................................................25
9.4 Instrument Serial Number...............................................................................26
9.5 Additional GLP Features.................................................................................26
10. Notepad Function......................................................................27
10.1 Recording Readings into the Notepad .........................................................27
10.2 Recalling Records from the Notepad...........................................................27
10.3 Erasing Records from the Notepad..............................................................28
10.4 Printing Records from the Notepad to the RS232 Port.................................28

Page 3
11. Automatic Datalogging .............................................................29
12. RS232 Port................................................................................. 31
12.1 Setting the Baud Rate .................................................................................31
12.2 Sending Readings to the RS232 Port...........................................................31
12.3 RS232 Configuration..................................................................................31
12.4 Communication and Statistical Software.....................................................31
12.5 Commands..................................................................................................32
12.6 Data Format................................................................................................33
12.7 GLP Data Format........................................................................................34
13. Battery Saver Function.............................................................35
14. Recharging the Battery.............................................................35
15. Clock Function.......................................................................... 36
15.1 Setting the Clock ........................................................................................36
15.2 Displaying or Hiding the Clock...................................................................36
16. Selecting Buffers for Auto Buffer Recognition .......................37
17. Initialising the WP-90 ................................................................38
18. Instrument firmware version number.......................................38
19. Troubleshooting........................................................................39
19.1 General Errors............................................................................................39
19.2 Specific Ion, pH and mV Troubleshooting...................................................40
19.3 Temperature Troubleshooting.....................................................................41
20. pH Sensor Fundamentals......................................................... 43
20.1 Asymmetry of a pH Sensor..........................................................................43
20.2 Slope of a pH Sensor...................................................................................44
20.3 pH Temperature Compensation...................................................................45
20.4 Checking the reference junction of a pH sensor...........................................45
20.5 Determining if a pH meter or a sensor is faulty ...........................................46
21. Warranty ....................................................................................47

Page 4
1. Introduction
1.1 WP-90 Display and Controls

Page 5
¬
Press to record readings into memory. See section 10.1.
Also used at turn-on to select pH6.88 or pH7.00 as the primary pH buffer
(section 16).
-
Press to show or hide the date and time. See section 15.2.
®
Press to start or stop automatic logging. See section 11.
Alternatively, press to transmit current reading plus date and time to the
optional RS232 port. See section 12.2.
¯
Press to zero Relative mV, when Relative mV mode is selected (section 7).
°
Press to access the user-friendly menu system which makes the WP-90 easy
to operate.
±and ³
The and keys are used for calibrating temperature readout (section
8.1), setting the clock (section 15.1), setting the automatic logging period
(section 11), and displaying GLP information (section 9.1).
The key is also used to initialise the WP-90 at turn-on. See section 17.
²
Switches the WP-90 on and off.
´Display
32 character alpha-numeric display with user-friendly menu and prompting
system. Shows Specific Ion/pH/mV and Temperature simultaneously. Date
and time can also be displayed.

Page 6
1.2 Unpacking Information
Before using your new WP-90, please check that the following accessories have
been included…
Part No
1. WP-90 Specific Ion-pH-mV-Temp Instrument ...............121191
2. Temperature/ATC Sensor..............................................121247
3. Battery charger..............................................................130037
4. WP-90 Handbook..........................................................130050
Options that may have been ordered with your WP-90…
1. RS232 Serial Interface Option .......................................130039
(includes cable and communication software for DOS)
2. Communication software for Windows 3.1, 95 & NT.....130086
3. Hard Carry Case............................................................130059
4. Battery charger lead for 12V cigarette lighter socket.......130046
5. Solar Panel....................................................................130012
6. RS232 Printer................................................................130031
Sensors…
Your choice of a complete range of Ion Selective, Reference, pH and Redox
sensors.
Other spares…
1. 6V NiCad Battery ............................................................130038
2. RS232 Interface Cable .....................................................130041

Page 7
1.3 Specifications
Mode Ranges Resolution Accuracy
Specific Ions Auto-ranging, in
units of ppM, ppK
and Exponential
Notation
3 significant
digits ± least significant digit
pH 0 to 14.00 pH 0.01 pH ±0.01 pH
mV & Relative mV 0 to +/-500.0 mV
0 to ±1500 mV 0.15 mV 1 mV ±0.3 mV ±1 mV
Temperature -10.0 to 120.0 OC±0.1 OC±0.2 OC
Specific Ion Specifications
Input Impedance :>3 x 1012 Ω
Asymmetry Range :Auto detection
Slope Range :50.0 to 110.0 %
Temperature Compensation :Automatic, 0 to 100 OC
Calibration :Automatic calibration in user-definable
standards.
pH Specifications
Input Impedance :>3 x 1012 Ω
Asymmetry Range :-1.00 to 1.00 pH
Slope Range :85.0 to 105.0 %
Temperature Compensation :Automatic, 0 to 100 OC
Calibration :Automatic calibration in pH4.00, pH6.88,
pH7.00, pH9.23 or pH10.00 buffers.
Temperature Specifications
Temp. Sensor Offset Range :-10.0oC to +10.0oC

Page 8
General Specifications
Memory :150 readings including date and time
Automatic Logging :User-set for one reading every 1 to 90
seconds, minutes or hours.
RS232 Output (optional) :300, 1200 & 9600 baud.
8 bits, no parity, 1 stop bit, XON/XOFF
Protocol.
Clock :Calendar clock displays date, month, hours,
minutes & seconds.
Year is recorded in memory and transmitted
to optional RS232 port, but is not displayed.
Battery Saver :On :Auto switch-off after 5 minutes
Off :Continuous use
Bar Graph display of battery charge level.
Readout of battery voltage available for
troubleshooting.
Good Laboratory Practices :Date, Time and results of last Specific Ion,
pH and Temperature calibration are stored in
memory. This information can be recalled or
sent to the optional RS232 port at any time.
Power :6V NiMH Rechargeable Battery for approx
75 hours operation.
Dimensions :187 x 110 x 51 mm
Mass :Instrument only :Approx 440g
Full Kit :Approx 2.0 kg
Environment Temperature :0 to 45 OC
Humidity :0 to 90 % R.H.

Page 9
2. WP-90 Menu Structure
A detailed breakdown of the menu system of the WP-90 is shown below. This
diagram provides a quick reference for the menu functions available for the
WP-90.
Press the function keys in normal display mode, to perform the following tasks:
:Press to record current data plus date and time into memory.
:Press to show or hide date and time.
:Press to start and stop automatic logging.
If logging period is set to zero, press to transmit current reading plus
date and time to the RS232 port.
:Press to zero Relative mV, when Relative mV mode is selected.
:Press to access the user-friendly menu system, as detailed over the page.

Page 10
WP-90 Menu Structure
Menu →F1:Cal. →F1:Ion Pri (only in Ion mode)
or F1:pH (only in pH mode)
F2:Temp (in all modes)
F3:Ion Sec (only in Ion mode)
→F2:Notepad →F1:Recall
F2:Erase
F3:Print *
F4:Prog. →F1:Min
F2:Sec
F3:Hr
↑↓:Period
→F3:Mode →F1:Ion
F2:pH
F3:mV
F4:Rel mV
→F4:Setup →F1:Batt →F1:OFF
F2:ON
F2:Clock
F3:GLP →F1:Recall
F3:Print *
F4:Baud * →F1:300
F2:1200
F3:9600
* These functions available when RS232 option is fitted.

Page 11
3. Specific Ion Mode
Before taking Specific Ion measurements, it is necessary to set up this mode for
the Specific Ion to be measured. To set up the Specific Ion mode, follow these
simple steps…
3.1 Selecting ppM or ppK Mode
1. Select Specific Ion mode ( →→ F3:Mode →→ F1:Ion).
2. Select ppM/ppK as the unit of measurement.
Select Ion Mode
F1:ppM/ppK F2:Exp
Press to select readout in ppM (parts per million) and ppK (parts per
thousand). The WP-90 will automatically select the range that provides the
best resolution for the sample being measured.
3. Select the type of Specific Ion to be measured.
F1:+Mono F2:-Mono
F3:++Di F4:--Di
Press for Monovalent Cation (e.g. Na+).
Press for Monovalent Anion (e.g. F–).
Press for Divalent Cation (e.g. Cu2+).
Press for Divalent Anion (e.g. S2–).

Page 12
4. Enter the value of the Primary Standard to be used for calibration.
1.000ppM Pri Std
F1:←← F2:→→ ↑↑↓↓:Set
Use the and keys to set the first digit. The numbers scroll from 0
to 9 plus the decimal point.
Press to move to the next digit, then use the and keys to set
it.
Continue moving from digit to digit until the value of the Primary Standard
has been correctly set. Up to 4 digits plus a decimal point can be entered.
After the last digit has been entered, will move the cursor to the units.
Use the and keys to select ppM or ppK.
Press to save the Primary Standard.
5. Enter the value of the Secondary Standard to be used for calibration.
The Secondary Standard must be at least 2 to 100 times higher or lower than
the Primary Standard.
10.00ppM Sec Std
F1:←← F2:→→ ↑↑↓↓:Set
Use the and keys to set the first digit. The numbers scroll from 0
to 9 plus the decimal point.
Press to move to the next digit, then use the and keys to set
it.
Continue moving from digit to digit until the value of the Secondary Standard
has been correctly set.
Up to 4 digits plus a decimal point can be entered.
After the last digit has been entered, will move the cursor to the units.
Use the and keys to select ppM or ppK.
Press to save the Secondary Standard.
6. The WP-90 will now return to normal measurement mode.
7. A “ * ” will be shown is place of the decimal point if the Specific Ion mode is
not calibrated, or if calibration has failed.

Page 13
3.2 Selecting Exponential Mode (e.g. Molar)
1. Select Specific Ion mode ( →→ F3:Mode →→ F1:Ion).
2. Select Exponential mode as the unit of measurement. This mode is designed
specifically for units such as Molar.
Select Ion Mode
F1:ppM/ppK F2:Exp
Press to select Exponential readout (e.g. Molar). The WP-90 will
automatically select the range that provides the best resolution for the sample
being measured.
3. Select the type of Specific Ion to be measured.
F1:+Mono F2:-Mono
F3:++Di F4:--Di
Press for Monovalent Cation (e.g. Na+).
Press for Monovalent Anion (e.g. F–).
Press for Divalent Cation (e.g. Cu2+).
Press for Divalent Anion (e.g. S2–).
4. Enter the value of the Primary Standard to be used for calibration.
1.0010+00 Pri Std
F1:←← F2:→→ ↑↑↓↓:Set
Use the and keys to set the first digit. The numbers scroll from 0
to 9.
Press to move to the next 2 digits, then use the and keys to
set each in turn (the decimal point is fixed in the second position).
Press to move the 10+, then use the and keys to set it as 10+
or 10–.
Press to move to the next 2 digits, then use the and keys to
set each in turn.

Page 14
For example…
1.0010+01 is 1.00 x 101in units of the operator’s choice (e.g. Molar).
1.0010–01 is 1.00 x 10–1 in units of the operator’s choice (e.g. Molar).
Press to save the Primary Standard.
5. Enter the value of the Secondary Standard to be used for calibration.
The Secondary Standard must be at least 2 to 100 times higher or lower than
the Primary Standard.
1.0010+00 Sec Std
F1:←← F2:→→ ↑↑↓↓:Set
Use the and keys to set the first digit. The numbers scroll from 0
to 9.
Press to move to the next 2 digits, then use the and keys to
set each in turn (the decimal point is fixed in the second position).
Press to move the 10+, then use the and keys to set it as 10+
or 10–.
Press to move to the next 2 digits, then use the and keys to
set each in turn.
For example…
1.0010+01 is 1.00 x 101in units of the operator’s choice (e.g. Molar).
1.0010–01 is 1.00 x 10–1 in units of the operator’s choice (e.g. Molar).
Press to save the Secondary Standard.
6. The WP-90 will now return to normal measurement mode.
7. A “ * ” will be shown is place of the decimal point if the Specific Ion mode is
not calibrated, or if calibration has failed.

Page 15
4. Specific Ion Calibration
4.1 Calibration Procedure
1. Plug the Ion Selective Electrode into the Sensor socket.
If a separate Reference Electrode is being used, plus this into the separate
4mm Reference socket provided.
2. Switch the meter on.
3. Select and set up Ion mode, as detailed in section 3.
For the purposes of this handbook, the WP-90 has been set up for 1.000ppM
as the Primary Standard and 0.100ppM as the Secondary Standard.
4. Ensure that temperature has already been calibrated (see section 8.1).
NOTE: A “ ∗” in place of the decimal point in the temperature readout
indicates that temperature is not calibrated.
5. Rinse the Ion Selective, Reference and Temperature sensors in distilled water
and blot dry.
Primary Calibration
6. Place the Ion Selective, Reference and Temperature sensors into the Primary
Standard.
Ensure that any Ionic Strength Adjusting Buffer (ISAB) that may be required
has been added (see the Ion Selective Electrode’s handbook).
A magnetic stirrer providing constant, gentle stirring generally improves
stability.
7. Select Primary Calibration ( →→ F1:Cal →→ F1:Ion Pri).
The following message should be displayed. The current reading is displayed
on the top left. A “∗” in the reading indicates that the WP-90 is currently not
calibrated.
1*234ppM 25.0Oc
F1:Cal at1.000ppM
When the reading has stabilised, press to perform a Primary
Calibration.
A “∗” will not be removed from the display after a 1-point Asymmetry
Calibration.

Page 16
8. Rinse the Sensors in distilled water and blot dry.
Secondary Calibration
9. Place the Ion Selective, Reference and Temperature sensors into the
Secondary Standard.
Ensure that any Ionic Strength Adjusting Buffer (ISAB) that may be required
has been added (see the Ion Selective Electrode’s handbook).
A magnetic stirrer providing constant, gentle stirring generally improves
stability.
10. Select Secondary Calibration ( →→ F1:Cal →→ F3:Ion Sec).
The following message should be displayed. The current reading is displayed
on the top left. A “∗” in the reading indicates that the WP-90 is currently not
calibrated.
0*123ppM 25.0Oc
F1:Cal at0.100ppM
When the reading has stabilised, press to perform a Secondary
Calibration.
A “∗” in the display will be replaced by a decimal point after a successful 2-
point Slope calibration.
11. The WP-90 is now calibrated ready for Specific Ion measurements.

Page 17
4.2 Calibration Notes
1. A Primary Calibration should be performed at least weekly. In applications
where the reference electrode junction can become blocked, such as dairy
products, mining slurries etc, a Primary Calibration may have to be done
daily.
2. A full Primary and Secondary Calibration should be performed at least
monthly. Of course, more frequent calibration will result in greater
confidence in results.
3. All calibration information is retained in memory when the WP-90 is
switched off, even when the battery is removed. This information can be
recalled or printed later using the GLP function (see section 9).
4. The WP-90 displays the value of the standard to which it will attempt to
calibrate. Ensure that the standard value displayed corresponds to the
standard that you are using. Alter the set-up if necessary (see section 3)
4.3 Calibration Messages
1. If a Primary Calibration has been successfully performed, the WP-90 will
display the following message, and the offset value of the sensor. For
example…
Primary Cal. OK
Offset= 1.0mV
2. If a Secondary Calibration has been successfully performed, the WP-90 will
display the following message, and the slope value of the sensor. For
example…
Sec Cal. OK
Slope= 99.0%
3. If a Secondary Calibration has failed, the WP-90 will display the following
message, and the failed span value of the sensor. For example…
Sec Cal. Failed
Slope= 49.0%
Notes
1. The Offset range is unlimited, as long as the reading is not over-ranged. This
is to allow for the large variety of Ion Selective Electrodes available.
2. The allowable Slope range is 50.0% to 110.0%. This range is ample to allow
for correctly functioning Ion Selective Electrodes.

Page 18
5. pH Calibration
5.1 Calibration Procedure
1. Plug the pH sensor into the Sensor socket.
2. Switch the meter on.
3. Ensure that you are using buffers which have been selected for automatic
buffer recognition. See section 16 for a detailed explanation.
4. Select pH Mode ( →→ F3:Mode →→ F2:pH).
5. Ensure that temperature has already been calibrated, or manually set (see
sections 8.1 and 8.4). NOTE: If the decimal point in the temperature reading
is shown by a ∗, then the temperature readout is not calibrated.
6. Remove the wetting cap from the pH sensor.
7. Rinse the pH and Temperature sensors in distilled water and blot them dry.
8. Ensure that you are using the primary buffer for which the WP-90 has been
set (see section 16).
Place both sensors into a small sample of pH6.88 (or pH7.00) buffer, so that
the bulb and reference junction are both covered.
DO NOT place the sensors directly into the buffer bottle.
9. Select pH Calibration ( →→ F1:Cal. →→ F1:pH).
10. When the reading has stabilised, press the key to calibrate. If a 1 point
calibration has been performed, the ∗will not be removed until a full 2 point
calibration has been performed.
11. Rinse the pH and Temperature sensors in distilled water and blot them dry.
12. Place both sensors into a small sample of pH4.00, pH9.23 or pH10.00
Buffer, so that the bulb and reference junction are both covered. DO NOT
place the sensors directly into the buffer bottle.
NOTE: pH9.23 buffer is highly unstable. Avoid using this buffer if
possible. Discard immediately after use.
13. Select pH Calibration ( →→ F1:Cal. →→ F1:pH).
14. When the reading has stabilised, press the key to calibrate. The ∗will
now be replaced by a decimal point, if calibration was successful.
15. The WP-90 is now calibrated for pH and is ready for use. Discard the used
samples of buffer.

Page 19
5.2 Calibration Notes
1. A 1-point calibration should be performed at least weekly. In applications
where the electrode junction can become blocked, such as dairy products,
mining slurries etc, a 1-point calibration may have to be done daily.
2. A full 2-point calibration should be performed at least monthly. Of course,
more frequent calibration will result in greater confidence in results.
3. All calibration information is retained in memory when the WP-90 is
switched off, even when the battery is removed. This information can be
recalled or printed later using the GLP function (see section 9).
4. The WP-90 displays the value of the pH buffer to which it will attempt to
calibrate. Ensure that the buffer value displayed corresponds to the buffer
that you are using.
5.3 Calibration Messages
1. If a 1-point Calibration has been successfully performed, the WP-90 will
display the following message, and the asymmetry value of the sensor. For
example…
1 Point Cal.OK
Asy=0.10pH
2. If a 1-Point Calibration has failed, the WP-90 will display the following
message, and the failed asymmetry value of the sensor. For example…
1 Point Cal.Fail
Asy=1.50pH
3. If a 2-Point Calibration has been successfully performed, the WP-90 will
display the following message, and the asymmetry and slope values of the
sensor. For example…
2 Point Cal.OK
Asy=0.10pH then: 2 Point Cal.OK
Slope= 99.0%
4. If a Secondary Calibration has failed, the WP-90 will display the following
message, and the failed slope value of the sensor. For example…
2 Point Cal.Fail
Slope= 70.0% or: 2 Point Cal.Fail
Slope=130.0%
Notes
1. The allowable Asymmetry range is –1.00pH to +1.00pH.
2. The allowable Slope range is 85.0% to 105.0%.

Page 20
6. mV Calibration
The mV section is factory calibrated. There is no user-calibration facility for this
mode.
7. Relative mV Calibration
Select Relative mV mode when measurements relative to a known standard are
required. Calibration of the Relative mV mode is simply a matter of zeroing the
reading when the sensor is in the known standard.
1. Plug the Redox sensor into the Sensor socket. Temperature compensation is
not applied in Relative mV mode, so the temperature sensor does not need to
be connected.
2. Switch the meter on.
3. Select Relative mV Mode ( →→ F3:Mode →→ F4:Rel mV).
The display should now be showing Relative mV on the top line with absolute
mV or date and time on the bottom line. For example…
1000mVR 25.0Oc
500mV F4:Zeros or: 1000mVR 25.0Oc
31/12 12:00:00
Press to alternate between absolute mV or the clock on the bottom line.
4. Remove the wetting cap from the Redox sensor.
5. Rinse the sensor in distilled water and blot dry.
6. Place the Redox sensor into a sample of the known standard. Ensure that the
platinum tip and reference junction are both covered.
When the reading has stabilised, press the key to zero the Relative mV
reading. The Relative mV reading will now be zero, and the absolute mV
reading will remain unchanged. For example…
0mVR 25.0Oc
500mV F4:Zeros or: 0mVR 25.0Oc
31/12 12:00:00
7. The WP-90 Relative mV mode is now zeroed and is ready for use. The
readout can be re-zeroed by pressing the key whenever required.
7.1 Notes
1. The Relative mV offset is retained in memory when the WP-90 is switched
off, even when the battery is removed.
2. The Relative mV zero is reset when leaving Relative mV mode.