TPS WP-90 User manual

Congratulations !
You have purchased the latest in Handheld Specific Ion-pH-ORP-
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.
Model WP
-
90
Specific Ion, pH,
ORP & Temp. Meter
Version: 2.0
Date: 1-Jul-2012

Page
2
TPS Pty Ltd
6 / 253 Leitchs Road
Brendale
QLD 4500
Australia
Phone : [phone]
International : 61 7 32 058 027
Fax : [phone]
International : 61 7 3808 4871
Email : [email protected].au
Web : www.tps.com.au

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3
Contents
1. Introduction .....................................................................................5
1.1 WP-90 Display and Controls.................................................................. 5
1.2 Unpacking Information ........................................................................... 7
1.3 Specifications......................................................................................... 8
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 ................................................................................. 16
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/ORP Calibration ......................................................................20
7. Relative mV/ORP 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 ................................................................................. 24
9.3 Printing GLP Information to the RS232 Port........................................ 24
9.4 Instrument Serial Number.................................................................... 25
9.5 Additional GLP Features...................................................................... 25
10. Notepad Function ......................................................................26
10.1 Recording Readings into the Notepad................................................. 26
10.2 Recalling Records from the Notepad................................................... 26
10.3 Erasing Records from the Notepad ..................................................... 27
10.4 Printing Records from the Notepad to the RS232 Port........................ 27
11. Automatic Data logging.............................................................28

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4
12. RS232 Port................................................................................. 30
12.1 Setting the Baud Rate.......................................................................... 30
12.2 Sending Readings to the RS232 Port.................................................. 30
12.3 RS232 Configuration............................................................................ 30
12.4 Communication and Statistical Software ............................................. 30
12.5 Commands........................................................................................... 31
12.6 Data Format ......................................................................................... 32
12.7 GLP Data Format ................................................................................. 33
13. Battery Saver Function ............................................................. 34
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/ORP Troubleshooting................................... 40
19.3 Temperature Troubleshooting .............................................................. 42
20. Appendices: pH Sensor Theory .............................................. 43
20.1 Asymmetry of a pH Sensor .................................................................. 43
20.2 Slope of a pH Sensor ........................................................................... 44
20.3 pH Temperature Compensation........................................................... 45
21. Warranty .................................................................................... 46

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5
1. Introduction
1.1 WP-90 Display and Controls

Page
6
Press to record readings into memory. See section 10.1.
Also used at turn-on to select pH7.00 or pH6.86 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 RS232 port. See section 12.2.
Press to zero Relative mV/ORP, when Relative mV/ORP mode is
selected (section 7).
Press to access the user-friendly menu system which makes the WP-
90 easy to operate.
and
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.
Switches the WP-90 on and off.
Display 32 character alpha-numeric display with user-friendly menu
and prompting system. Shows Specific Ion/pH/ORP and Temperature
simultaneously. Date and time can also be displayed.

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7
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-ORP-Temp Instrument...................... 121191
2. Temperature/ATC Sensor...................................................... 121247
3. Battery charger ...................................................................... 130037
4. Manual
Options that may have been ordered with your WP-90:
1. Your choice of a complete range of Ion Selective, Reference, pH and
ORP sensors. (see cable label for part No)
2. Extended cable...................................................................... 130040
3. RS232 Serial Interface Cable................................................. 130041
4. Communication software for Windows 95 and later ............... 130086
5. USB to Serial Adaptor (requires 130041 also) ....................... 130087
6. Hard Carry Case.................................................................... 130059
7. Battery charger lead for 12V cigarette lighter socket.............. 130046
8. Battery charger lead for 12V DC, with battery clips ................ 130052
9. Solar Panel............................................................................ 130012

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8
1.3 Specifications
Specific Ions
Range ..................................Auto-ranging, in units of ppM, ppK and
Exponential Notation
Resolution ............................3 significant digits
Accuracy ..............................± least significant digit
pH
Range ..................................0 to 14.00 pH
Resolution ............................0.01 pH
Accuracy ..............................±0.01 pH
mV/ORP
Range ..................................0 to ±500.0 and 0 to ±1500 mV (auto-
ranging)
Resolution ............................0.15 and 1 mV
Accuracy ..............................±0.3 and ±1 mV
Temperature
Range ..................................-10.0 to +120.0
O
C
Resolution ............................0.1
O
C
Accuracy ..............................±0.2
O
C
General Specifications
Temperature Compensation:
pH & Ion (only, not for mV/ORP). Automatic 0 to 100
o
C
Manual 0 to 100
o
C
Calibration:
pH ........................................Auto Standard Recognition in pH4.01,
pH6.86, pH7.00, pH9.18 or pH10.01
buffers.
pH Sensor Asymmetry Range -1.00 to +1.00 pH
pH Sensor Slope Range.......85.0 to 105%
Input Impedance ..................>3 x 10
12
Ω

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9
Specific Ion.......................... Calibration in user-definable standards.
mV/ORP .............................. Sensor calibration not available.
Temperature........................ Use a reference thermometer.
Temperature Sensor Offset . -10.0
o
C to +10.0
o
C
Memory.................................... 3600 readings including date and time
Automatic Logging.................... User-set for one reading every 1 to 90
seconds, 1 to 90 minutes, or 1 to 24 hours.
RS232 Output .......................... 300, 1200, 9600 & 19200 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 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 Value of last Specific Ion,
pH and Temperature calibration are
stored, and can be recalled or sent to the
RS232 port at any time.
Power....................................... 6V NiMH Rechargeable Battery for
approx 50 hours operation.
Dimensions .............................. 195 x 110 x 55 mm
Mass ........................................ Instrument only : Approx 520g
Full Kit : Approx 2.5kg
Environment............................. Temperature : 0 to 45
O
C
Humidity : 0 to 95 % R.H.

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10
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 WP-90 menu functions.
→
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/ORP
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
F4:19200

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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. Cu
2+
).
Press for Divalent Anion (e.g. S
2–
).

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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.

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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. Cu
2+
).
Press for Divalent Anion (e.g. S
2–
).
4. Enter the value of the Primary Standard to be used for calibration.
1.00 10
+
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.

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14
For example…
1.00 10+ 01 is 1.00 x 10
1
in units of the operator’s choice (e.g. Molar).
1.00 10– 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.
1.00 10
+
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…
1.00 10+ 01 is 1.00 x 10
1
in units of the operator’s choice (e.g. Molar).
1.00 10– 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.

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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, plug 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 Electrode, (Reference Electrode if using) and
Temperature sensors in distilled water and blot dry.
Primary Calibration
6. Place the Ion Selective Electrode, (Reference Electrode if using) 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 25.0
O
c
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.
8. Rinse the Sensors in distilled water and blot dry.

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16
Secondary Calibration
9. Place the Ion Selective Electrode, (Reference Electrode if using) 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 25.0
O
c
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.
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)

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17
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.

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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 pH7.00 (or pH6.86) 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 pH4.01, pH9.18 or
pH10.01 Buffer, so that the bulb and reference junction are both
covered. DO NOT place the sensors directly into the buffer bottle.
pH9.18 and pH10.01 buffers are unstable once the bottles have
been opened. 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.

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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. 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%.

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20
6. mV/ORP Calibration
The mV/ORP section is factory calibrated. There is no sensor calibration
using a calibration standard for this mode.
7. Relative mV/ORP Calibration
Select Relative mV/ORP mode when measurements relative to a
calibration standard are required. Calibration of the Relative mV/ORP
mode is simply a matter of zeroing the reading when the sensor is in the
calibration standard.
1. Plug the ORP sensor into the Sensor socket. Temperature
compensation is not applied in Relative mV/ORP mode, so the
temperature sensor does not need to be connected.
2. Switch the meter on.
3. Select Relative mV/ORP 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 25.0
O
c
500mV F4:Zeros
or: 1000mVR 25.0
O
c
31/12 12:00:00
Press to alternate between absolute mV/ORP or the clock on the
bottom line.
4. Remove the wetting cap from the ORP sensor.
5. Rinse the sensor in distilled water and blot dry.
6. Place the ORP sensor into a sample of the calibration 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 25.0
O
c
500mV F4:Zeros
or: 0mVR 25.0
O
c
31/12 12:00:00
7. The WP-90 Relative mV/ORP 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.