TPS WP-91 User manual

Congratulations !
You have purchased the latest in Handheld Dissolved Oxygen-pH-mV-
Temperature instrumentation. We trust that your new WP-91 will give
you many years of reliable service.
The WP-91 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-91. It also contains a full listing of all of the items
that you should have received with your WP-91. 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-91, 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-91
Dissolved Oxygen –
pH –mV –Temp Meter
Version : 1.2
Date : 31-Oct-2003
Author : MS

Page 2Contents
1. Introduction ..............................................................................................4
1.1 WP-91 Display and Controls ...............................................................4
1.2 Unpacking Information ........................................................................6
1.3 Specifications......................................................................................7
2. WP-91 Menu Structure............................................................................10
3. Oxygen Operating Modes ......................................................................11
4. Dissolved Oxygen Calibration ...............................................................13
4.1 Calibration Procedure........................................................................13
4.2 Measurement Notes:.........................................................................15
4.3 Calibration Notes...............................................................................15
4.4 Calibration Messages........................................................................16
5. pH Calibration.........................................................................................17
5.1 Calibration Procedure........................................................................17
5.2 Calibration Notes...............................................................................19
6. mV Calibration........................................................................................19
7. Temperature Calibration ........................................................................20
7.1 Calibration Procedure........................................................................20
7.2 Calibration Notes...............................................................................20
7.3 Calibration Messages........................................................................21
8. Salinity Correction..................................................................................22
9. Altitude or Atmospheric Pressure Correction.......................................23
9.1 Selecting Altitude or Pressure Correction ..........................................23
9.2 Changing the Altitude or Pressure Correction value...........................24
9.3 Notes ................................................................................................25
10. Good Laboratory Practices (GLP)......................................................26
10.1 To recall GLP information on the display.......................................26
10.2 Failed Calibration..........................................................................28
10.3 Printing GLP Information to the RS232 Port..................................29
10.4 Instrument Serial Number..............................................................30
10.5 Additional GLP Features ...............................................................30
11. Notepad Function...............................................................................31
11.1 Recording Readings into the Notepad............................................31
11.2 Recalling Records from the Notepad.............................................31
11.3 Erasing Records from the Notepad................................................32
11.4 Printing Records from the Notepad to the RS232 Port...................33
12. Automatic Datalogging.......................................................................34

Page 3
13. RS232 Port...........................................................................................36
13.1 Setting the Baud Rate ...................................................................36
13.2 Sending Readings to the RS232 Port ............................................36
13.3 RS232 Configuration.....................................................................36
13.4 Communication and Statistical Software........................................36
13.5 Commands....................................................................................38
13.6 Data Format..................................................................................39
13.7 GLP Data Format..........................................................................40
13.8 Importing Data into Microsoft Excel...............................................41
14. Battery Saver Function.......................................................................43
15. Recharging the Battery.......................................................................44
16. Clock Function....................................................................................45
16.1 Setting the Clock...........................................................................45
16.2 Displaying or Hiding the Clock.......................................................45
17. Selecting pH6.88 or pH7.00 as the Primary Buffer............................46
18. Initialising the WP-91..........................................................................47
19. Instrument firmware version number. ...............................................47
20. Troubleshooting.................................................................................48
20.1 General Errors...............................................................................48
20.2 Dissolved Oxygen Troubleshooting ...............................................49
20.3 pH and mV Troubleshooting..........................................................50
20.4 Temperature Troubleshooting........................................................51
21. Dissolved Oxygen Sensor Fundamentals.........................................52
21.1 Operating Principle........................................................................52
21.2 Maintenance Of The Membrane....................................................53
21.3 Probe Storage...............................................................................53
21.4 Notes On Units Of Dissolved Oxygen............................................54
21.5 Equilibrium Conditions...................................................................55
21.6 Velocity Past The Membrane.........................................................56
22. pH Sensor Fundamentals...................................................................57
22.1 Asymmetry of a pH Sensor............................................................57
22.2 Slope of a pH Sensor ....................................................................58
22.3 pH Temperature Compensation.....................................................59
22.4 Checking the reference junction of a pH sensor.............................59
22.5 Determining if a pH meter or an sensor is faulty............................60
23. Warranty..............................................................................................61

Page 4
1. Introduction
1.1 WP-91 Display and Controls

Page 5
Press to record readings into memory. See section 11.1. Also used
to switch the Altitude or Atmospheric Pressure Correction system on
or off. See section 9.1.
Press to alternate temperature, date/time, and manual
Salinity/Altitude/ Pressure values on the display. See section 16.2.
Also used to select pH6.88 or pH7.00 as the primary pH buffer
(section 17).
Press to start or stop automatic logging. See section 12.
Alternatively, press to transmit current reading plus date and time to
the RS232 port (optional) See section 13.2.
Only used within the menu system on the WP-91.
Press to access the user-friendly menu system which makes the
WP-91 easy to operate.
and
The and keys are used for calibrating temperature readout
(section 7.1), setting the clock (section 16.1), setting the automatic
logging period (section 12), and displaying GLP information (section
10.1). The key is also used to initialise the WP-91 at turn-on. See
section 18.
Switches the WP-91 on and off.
Display
32 character alpha-numeric display with user-friendly menu and
prompting system. Shows Dissolved Oxygen, pH/mV and
Temperature simultaneously. Date, time, manual salinity value,
altitude or pressure can also be displayed.

Page 6
1.2 Unpacking Information
Before using your new WP-91, please check that the following
accessories have been included:
Part No
1. WP-91 Dissolved Oxygen-pH-Temp Instrument..................123150
2. pH6.88 Buffer, 200mL .........................................................121306
3. pH4.00 Buffer, 200mL .........................................................121381
4. Battery charger....................................................................130037
5. WP-91 Handbook ................................................................130050
Options that may have been ordered with your WP-91:
1. YSI Dissolved Oxygen-Temperature Sensor.......................123204
2. 3m Cable for DO2Sensor....................................................123221
3. Combination pH Sensor, 1m................................................121207
4. Combination Redox Sensor, 1m..........................................121262
5. Temperature Sensor, 1m.....................................................121253
(when Dissolved Oxygen sensor not in use)
6. RS232 Serial Interface Option (includes cable)...................130039
7. WinTPS Communication software for Windows 95 & Later.130086
8. Hard Carry Case..................................................................130059
9. Battery charger lead for 12V cigarette lighter socket...........130046
10. Solar Panel..........................................................................130012
11. RS232 Printer......................................................................130031
Other spares:
1. 6V NiCad Battery.................................................................130038
2. RS232 Interface Cable ........................................................130041
3. Membrane, Filling Solution & Zero DO2Kit..........................123300
4. Sodium Sulphite for Zero DO2calibration, 50g....................123302
5. Filling Solution for EDYSI Sensor, 45mL .............................123307

Page 7
1.3 Specifications
ModeRange* Resolution Accuracy
Dissolved Oxygen
ppM (mg/L) 0 to 20.00 ppM
20.0 to 40.0 ppM 0.01 ppM 0.1 ppM ±0.2% of full scale of selected
range
Dissolved Oxygen
% Saturation 0 to 240.0 % Sat
240 to 450 % Sat 0.1 % Sat 1 % Sat ±0.3% Saturation
% Gaseous Oxygen 0 to 45.0 % Gas
45 to 100 % Gas 0.1% Gas 1 % Gas ±0.1 % Gaseous
pH 0 to 14.00 pH 0.01 pH ±0.01 pH
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
*Oxygen ranges subject to sensor performance.
Additional Dissolved Oxygen Specifications
Salinity Correction.........................User-set, from 0 to 50.0 ppK NaCl
Barometric Pressure Correction...User-set, from 800 to 1100 HPa
Altitude Correction.........................User-set, from 0 to 5000m
Temperature Compensation .........Dual automatic temperature
compensation system.
DO2Sensor Span Range...............70 to 135%
DO2Sensor Zero Range................0 to 7.5%
Automatic Calibration....................Zero in Sodium Sulphite (Na2SO3)
Solution Span in Air.
Additional pH Specifications
Input Impedance............................>3 x 1012 Ω
Asymmetry Range..........................-1.00 to 1.00 pH
Slope Range...................................85.0 to 105.0 %

Page 8
Temperature Compensation .........Automatic, 0 to 100 OC

Page 9
Additional Temperature Specifications
Temp. Sensor Offset Range.....-10.0oC to +10.0oC
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 Value of last Dissolved
Oxygen, pH and Temperature
calibration are stored, along with
Altitude or Pressure setting at time of
calibration. This information can be
recalled or sent to the optional RS232
port at any time.
Power.........................................6V NiCad 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 10
2. WP-91 Menu Structure
A detailed breakdown of the menu system of the WP-91 is shown below.
This diagram provides a quick reference for the menu functions available
for the WP-91.
Menu →F1:Cal. →F1:Oxy
F2:Temp
F3:pH (not available in mV mode)
F4:Sal
or F4:Altitude
or F4:Pressure
or F4:Comp. →F1:Sal
(see sections 8& 9)F2:Altitude
or F2:Pressure
→F2:Notepad →F1:Recall
F2:Erase
F3:Print *
F4:Prog →F1:Min
F2:Sec
F3:Hr
↑↓:Set
→F3:Mode →F1:ppM →Man Sal Comp
F1:OFF
or F2:ON
F2:%Sat
F3:%Gas
F4:mV
or F4:pH
→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.