Metrohm 781 User Manual
780 pH Meter / 781 pH/Ion Meter
Manual
8.781.8002EN / 2014-07-31
Metrohm AG
CH-9100 Herisau
Switzerland
Phone +41 71 353 85 85
Fax +41 71 353 89 01
info@metrohm.com
www.metrohm.com
780 pH Meter / 781 pH/Ion Meter
Program Version 5.780.0020 und 5.781.0020
8.781.8002EN / 2014-07-31
Manual
jb/ebe
Teachware
Metrohm AG
CH-9100 Herisau
teachware@metrohm.com
This documentation is protected by copyright. All rights reserved.
Although all the information given in this documentation has been
checked with great care, errors cannot be entirely excluded. Should you
notice any mistakes please send us your comments using the address
given above.
Documentation in additional languages can be found on
http://documents.metrohm.com.
Contents
780/781 pH/Ion Meter, Manual
Table of contents
1 Introduction .......................................................... 1
1.1 Instrument description ................................................................................. 1
1.2 Parts and controls ........................................................................................ 3
1.3 Information about this Manual ..................................................................... 5
1.3.1 Notation and pictograms ......................................................................... 5
1.4 Safety information ........................................................................................ 6
1.4.1 Electrical safety ........................................................................................ 6
1.4.2 General handling rules ............................................................................. 6
2 Installation ........................................................... 7
2.1 Instrument setup .......................................................................................... 7
2.1.1 Packaging ................................................................................................. 7
2.1.2 Checks ...................................................................................................... 7
2.1.3 Location .................................................................................................... 7
2.2 Connecting the accessories ........................................................................ 8
2.3 Connecting optional devices ....................................................................... 9
2.3.1 Connecting the 801 Magnetic Stirrer ....................................................... 9
2.3.2 Connecting the 802 Rod Stirrer ..............................................................10
2.3.3 Connecting a Dosimat Plus (only 781) ..................................................11
2.3.4 Connecting a sample changer ...............................................................12
2.3.5 Connecting a printer ...............................................................................13
2.3.6 Connecting a computer .........................................................................15
2.4 Connecting the electrodes and sensors ................................................... 16
2.5 Mains connection ....................................................................................... 17
2.6 Switch on .................................................................................................... 17
2.7 Initial configuration .................................................................................... 18
3 Short operating tutorial ..................................... 19
3.1 pH measurement ........................................................................................ 19
3.1.1 Requirements .........................................................................................19
3.1.2 Preparations ...........................................................................................19
3.1.3 pH calibration .........................................................................................20
3.1.4 pH measurement ....................................................................................22
3.2 Determination of an ion concentration (only 781: Conc mode) ............... 23
3.2.1 Requirements .........................................................................................23
3.2.2 Preparations ...........................................................................................23
3.2.3 Calibrating the fluoride ISE .....................................................................24
3.2.4 Direct measurement of fluoride ..............................................................28
4 Operation ........................................................... 31
4.1 The keypad ................................................................................................. 31
4.2 Operating concept ..................................................................................... 32
4.3 All key functions at a glance ...................................................................... 33
4.4 Operating principles .................................................................................. 38
4.4.1 Configuration and method parameters .................................................38
4.4.2 Editing menu entries ..............................................................................38
4.4.3 Entering text ............................................................................................39
I
Contents
780/781 pH/Ion Meter, Manual
5 Configuration ..................................................... 41
5.1 Report ......................................................................................................... 42
5.2 Printing out measured values .................................................................... 44
5.3 Storing measured values ........................................................................... 47
5.4 Auxiliaries ................................................................................................... 48
5.5 Monitoring .................................................................................................. 51
5.6 Peripheral units .......................................................................................... 52
5.7 RS232 settings ........................................................................................... 54
6 Methods / Parameters ........................................ 55
6.1 Method management ................................................................................. 55
6.2 pH measurement (pH mode) ..................................................................... 56
6.2.1 Measuring parameters ........................................................................... 56
6.2.2 Calibration parameters........................................................................... 58
6.2.3 Limits pH ................................................................................................ 62
6.2.4 Limits T ................................................................................................... 62
6.2.5 Plot parameters ...................................................................................... 63
6.2.6 Preselections .......................................................................................... 63
6.2.7 Electrode test ......................................................................................... 64
6.3 Temperature measurement (T mode) ........................................................ 65
6.3.1 Measuring parameters ........................................................................... 65
6.3.2 Limits T ................................................................................................... 66
6.3.3 Plot parameters ...................................................................................... 67
6.3.4 Preselections .......................................................................................... 67
6.4 Potential measurement (U mode) .............................................................. 68
6.4.1 Measuring parameters ........................................................................... 68
6.4.2 Limits U................................................................................................... 69
6.4.3 Plot parameters ...................................................................................... 70
6.4.4 Preselections .......................................................................................... 70
6.5 Direct ion measurement (781 only: Conc mode) ...................................... 71
6.5.1 Type of measurement ............................................................................ 71
6.5.2 Ion parameters ....................................................................................... 71
6.5.3 Measuring parameters ........................................................................... 72
6.5.4 Calculation parameters .......................................................................... 74
6.5.5 Calibration parameters........................................................................... 75
6.5.6 Limits Conc ............................................................................................ 77
6.5.7 Limits T ................................................................................................... 78
6.5.8 Plot parameters ...................................................................................... 78
6.5.9 Preselections .......................................................................................... 79
6.6 Standard and sample addition (781 only: Conc mode) ............................ 80
6.6.1 Standard / Sample addition ................................................................... 80
6.6.2 Preselections .......................................................................................... 83
7 Various functions ............................................... 85
7.1 Calibration and addition/subtraction data ................................................ 85
7.1.1 pH calibration data ................................................................................. 85
7.1.2 Conc calibration data (781 pH/Ion Meter only) ..................................... 89
7.1.3 Addition/Subtraction data (781 pH/Ion Meter only) ............................... 93
7.2 Reports ....................................................................................................... 96
II
Contents
780/781 pH/Ion Meter, Manual
7.2.1 Arrangement of a report .........................................................................98
7.2.2 Report identification ...............................................................................99
7.2.3 Measuring point report ...........................................................................99
7.2.4 Calibration report ..................................................................................101
7.2.5 Result report (781 pH/Ion Meter only) ..................................................102
7.2.6 Configuration report .............................................................................103
7.2.7 Parameter report ..................................................................................104
7.2.8 Measured values memory report .........................................................105
7.2.9 User method report ..............................................................................106
7.3 Measured values memory ........................................................................ 107
7.3.1 Save measured values .........................................................................107
7.3.2 Print measured values ..........................................................................107
7.3.3 Show measured values ........................................................................108
7.4 Limit monitoring ....................................................................................... 109
7.4.1 Uses ......................................................................................................109
7.4.2 How it functions ....................................................................................110
7.5 Setup ........................................................................................................ 111
7.5.1 Locking .................................................................................................111
7.5.2 Input assignment ..................................................................................112
7.5.3 Graphics ...............................................................................................112
8 Troubleshooting – Messages – Maintenance .. 113
8.1 Troubleshooting ....................................................................................... 113
8.2 Messages ................................................................................................. 115
8.3 QM support............................................................................................... 120
8.4 Validation .................................................................................................. 122
8.4.1 Electronic tests .....................................................................................122
8.4.2 Wet tests ...............................................................................................123
8.4.3 pH/Ion Meter maintenance...................................................................123
8.5 Diagnosis .................................................................................................. 124
8.6 pH electrode test ...................................................................................... 126
8.6.1 Preparations .........................................................................................126
8.6.2 Procedure .............................................................................................127
8.6.3 Results ..................................................................................................129
8.6.4 Messages and measures .....................................................................131
8.6.5 Care and maintenance of pH glass electrodes ...................................132
9 Annex ................................................................ 135
9.1 Technical data .......................................................................................... 135
9.1.1 Measuring modes ................................................................................135
9.1.2 Measuring inputs ..................................................................................135
9.1.3 Measuring input specifications ............................................................136
9.1.4 Interfaces ..............................................................................................136
9.1.5 Power supply ........................................................................................136
9.1.6 Safety specifications ............................................................................137
9.1.7 Electromagnetic compatibility (EMC) ..................................................137
9.1.8 Ambient temperature ............................................................................137
9.1.9 Reference conditions ...........................................................................137
9.1.10 Dimensions ...........................................................................................137
9.2 Evaluation ................................................................................................. 138
III
Contents
780/781 pH/Ion Meter, Manual
9.2.1 pH calibration ....................................................................................... 138
9.2.2 Calibration for ion measurements ........................................................ 142
9.2.3 Addition method ................................................................................... 143
9.3 Menu structures ....................................................................................... 144
9.3.1 Instrument configuration ...................................................................... 144
9.3.2 Method parameters in the pH mode ................................................... 146
9.3.3 Method parameters in the T mode ...................................................... 147
9.3.4 Method parameters in the U mode...................................................... 147
9.3.5 Method parameter in the Conc mode ................................................. 148
9.4 Stored buffer series ................................................................................. 150
9.5 Remote box .............................................................................................. 156
9.5.1 Pin occupancy of the remote connection of the Remote box ............. 156
9.5.2 Functions of the individual remote lines .............................................. 157
9.6 Accessories .............................................................................................. 158
9.7 Warranty (guarantee) ............................................................................... 160
10 Index ................................................................. 163
IV
Contents
780/781 pH/Ion Meter, Manual
List of illustrations
Fig. 1: 781 pH/Ion Meter connected to 801Magnetic Stirrer .................................................... 1
Fig. 2: Front view of the 780 pH Meter or 781 pH/Ion Meter .................................................... 3
Fig. 3: Rear view of the 780 pH Meter or 781 pH/Ion Meter ..................................................... 4
Fig. 4: Possible arrangements for mounting the base plate .................................................... 8
Fig. 5: Attaching the support rod and base plate..................................................................... 8
Fig. 6: Ready-mounted pH/ISE measuring system .................................................................. 9
Fig. 7: 780 pH Meter / 781 pH/Ion Meter – 801 Magnetic stirrer .............................................. 9
Fig. 8: 780 pH Meter / 781 pH/Ion Meter – 802 Rod stirrer .................................................... 10
Fig. 9: 781 pH/Ion Meter – Dosimat Plus ................................................................................ 11
Fig. 10: 781 pH/Ion Meter – Dosimat Plus – Sample changer ............................................... 12
Fig. 11: 780 pH Meter / 781 pH/Ion Meter – Printer ............................................................... 13
Fig. 12: Connecting sensors ................................................................................................... 16
Fig. 13: Remote outputs in limit monitoring .......................................................................... 110
Fig. 14: Diagram showing changes in potential during an electrode test ........................... 129
Fig. 15: Theoretical U/pH relationship ................................................................................ 138
Fig. 16: 3-Point pH calibration .............................................................................................. 139
Fig. 17: Connections of the optional 6.2148.010 Remote box ............................................. 156
Fig. 18: Pin occupancy at remote interface .......................................................................... 156
V
1 Introduction
780/781 pH/Ion Meter, Manual
780 pH Meter
781
pH/Ion Meter
Electrodes in Potentiometry
Application Notes
Application
Bulletins
781 pH/Ion Meter
780 pH Meter,
781 pH/Ion Meter
780 pH Meter
Conc
mode
1 Introduction
This Manual provides you with a comprehensive overview of the installation, working principles and operation of the
measuring modes of the 780 pH Meter are concerned (pH, temperature
and potential) and their operation in these modes is also identical, the
Manuals for both have been incorporated in a single document. The
special measuring mode of the 781 pH/Ion Meter – the measurement of
concentration – is, like the other measuring modes, described in separate sections. These sections, which apply only to the operation of the
781 pH/Ion Meter, are marked accordingly.
Information about the use of Metrohm pH or ion-selective electrodes
can be found in the appropriate leaflet and the ISE Manual that is included with the electrode.
Additional theoretical principles can be found in the Metrohm Monograph "
. As these two instruments are identical as far as the three
".
and
You can also request our descriptions of applications involving pH and
ISE measurements in the form of
Internet under
from your local Metrohm agency or download them from the
www.metrohm.com.
Fig. 1: 781 pH/Ion Meter connected to 801Magnetic Stirrer
1.1 Instrument description
and
Both instrument versions, the
are used for measuring pH, temperature and potential reliably and at
high resolution. The
having an additional operating mode for the potentiometric determination of the concentration by using ion-selective electrodes (
).
Both instruments have comprehensive monitoring functions (for calibration, validation and service intervals), diagnostic functions and an au-
differs from the
and the
by
1
1.1 Instrument description
780/781 pH/Ion Meter, Manual
781 pH/Ion Meter
Conc mode
calibration
standard addition
tomatic pH electrode test. Up to 100 values can be stored in the
memory together with the most important additional data; these can be
viewed and outputted as a report. All the parameter settings for a
measuring mode can be permanently stored as a method.
All stored information (measured values, configuration, parameters,
etc.) can be transmitted via the RS 232 interface to a printer or computer for output as a report.
Both instruments have the following features:
• Dot-matrix display for both the continuous display of the measured
value and for showing the user dialog.
• High-impedance measuring input for pH, redox or ISE sensors, a
connection for a separate reference electrode and an input for temperature sensors (Pt1000 or NTC).
• MSB connection (Metrohm Serial Bus) for a stirrer and for a
Dosimat Plus.
• RS 232 connection for a serial printer or a computer.
• A connection for an external keyboard or a barcode reader.
The
has an additional
which allows the
measurement of the concentration by using ion-selective electrodes, either directly after calibration or by standard or sample addition methods. Such a
or
can be carried out either
manually or automatically. In the latter method a standard solution is
added automatically by a Dosimat Plus included in the system. The calibration concentrations or the standard additions are calculated automatically according to the given conditions and these are added with
great accuracy.
2
1 Introduction
780/781 pH/Ion Meter, Manual
1 LCD display
3 Main function keys
2 On/Off key
4 Input, navigation and
function keys
1.2 Parts and controls
Fig. 2: Front view of the 780 pH Meter or 781 pH/Ion Meter
Key for switching the instrument on and
off
Each key has several functions;
the particular function depends on the
work status of the instrument
3
1.2 Parts and controls
780/781 pH/Ion Meter, Manual
5 Connection for potentiometric electrodes
10
RS232 interface
6 Connection for separate reference
electrode
11
Barcode reader/
Keyboard connection
7 Serial number
12
12V power connection
8 Connection for temperature sensor
13
Grounding connection
9
MSB connection
, directly or via
Fig. 3: Rear view of the 780 pH Meter or 781 pH/Ion Meter
pH, ISE, redox or silver electrodes
Connection for printer or PC
with built-in or separate reference electrode; socket type F
4 mm socket type B
Pt1000 or NTC, for connection with two 2
mm B-plugs; 6.2103.130 and 6.2103.140
Adapters are included for use with 4 mm
banana plugs
(Metrohm Serial Bus) for connecting a
stirrer and/or Dosimat Plus
the optional Remote Box (6.2148.010)
For measurements in grounded solu-
tions, grounding of the instrument
may be advantageous to avoid inter-
ferences; 4 mm socket type B
4
1 Introduction
780/781 pH/Ion Meter, Manual
Menu item, parameter or input value
<MODE>
Key
12
Operating element
Danger
Warning
Attention
Information
TIP !
TIP
1.3 Information about this Manual
Please study this Manual carefully before you start to use the instrument. The Manual contains information and warnings that must be observed by the user in order to guarantee the safe use of the instrument.
1.3.1 Notation and pictograms
The following notations and pictograms (symbols) are used in this
Manual:
Range
This symbol indicates a possible risk of death
or injury if the given information is not properly
observed.
This symbol indicates a possible risk of damage to the instrument or its components if the
given information is not properly observed.
This symbol indicates important information.
Please read it carefully before you continue.
This symbol indicates additional information
and tips.
This symbol indicates information that may be
of particular use to you.
5
1.4 Safety information
780/781 pH/Ion Meter, Manual
Warning!
ng with water or other solutions in the immediate vicinity of
1.4 Safety information
This instrument should only be used in accordance with the information given in this Manual.
1.4.1 Electrical safety
Please observe the following guidelines:
• Only qualified Metrohm technicians should carry out service work
on electronic components.
• Do not open the pH/Ion Meter housing. This could destroy the
pH/Ion Meter. Inside the housing there are no components that the
user can service or exchange.
Electrical safety when handling the 780 pH Meter and the 781 pH/Ion
Meter is guaranteed within the framework of the IEC 61010 Standard.
The following points must be observed:
Please make sure that the external power supply is always kept dry.
Protect it against direct liquid contact .
Electronic components are sensitive to electrostatic charges and can
be destroyed by a discharge. Always switch off the pH/Ion Meter before making or breaking electrical connections on the rear panel of the
instrument.
1.4.2 General handling rules
Handling solutions
When worki
the pH/Ion Meter please avoid excessive liquid splashes on the instrument housing or power supply. Any such splashes must be removed as quickly as possible in order to prevent the liquid from entering the instrument or the power supply.
6
2 Installation
780/781 pH/Ion Meter, Manual
2 Installation
2.1 Instrument setup
2.1.1 Packaging
The 780/781 pH/Ion Meter and its specially packed accessories are
supplied in very protective special packaging made of shock absorbing
polypropylene foam. Please store this packaging in a safe place; it is
the only way in which the safe transport of the instrument can be guaranteed. Should you wish to dispose of it please consider suitable disposal or recycling processes.
2.1.2 Checks
Please check that the delivery is complete and undamaged immediately on receipt (compare with delivery note and list of accessories given in
Section 9.6).
2.1.3 Location
Place the instrument on a suitable vibration-free laboratory bench, protected from corrosive atmospheres and contact with chemicals.
7
2.2 Connecting the accessories
780/781 pH/Ion Meter, Manual
stand base
C
2.2 Connecting the accessories
Both the stand for attaching the stirrer, clamping ring and electrode
holder as well as the pH/Ion Meter itself can be mounted on the supplied
You can chose between the arrangements shown in Fig. 4 to suit your
own particular working preference.
.
Fig. 4: Possible arrangements for mounting the base plate
Versions A and B are intended for mounting an 801 Magnetic stirrer on
the left- and right-hand side of the pH/Ion Meter respectively. If you frequently work without such a permanently attached stirrer then you can
mount the base plate so that you have space for the sample vessel directly in front of the support rod (versions
Attach the base plate with the screws provided as shown in Fig. 5. The
rubber feet included prevent the system from slipping about on the
work bench and should therefore be stuck on to the base plate.
and D).
Fig. 5: Attaching the support rod and base plate
8
2 Installation
780/781 pH/Ion Meter, Manual
9
801 Magnetic Stirrer
802 Rod Stirrer
804 Ti-Stand
Dosimat Plus
801 Magnetic Stirrer
2.3 Connecting optional devices
Devices which are to be remotely controlled from the pH/Ion Meter (e.g.
Metrohm stirrers or Dosimat Plus devices) are connected to MSB connection
6.2148.010 Remote Box (e.g.
2.3.1 Connecting the 801 Magnetic Stirrer
Mount the magnetic stirrer on the support rod before attaching the
clamping ring (6.2013.010) and the electrode holder (6.2021.020). Further details are given in the corresponding Manual.
For example, the ready-mounted system could look like this:
. This can be carried out either directly (
with
) or via the optionally available
).
or
Fig. 6: Ready-mounted pH/ISE measuring system
The
is connected to it directly:
Fig. 7: 780 pH Meter / 781 pH/Ion Meter – 801 Magnetic stirrer
is controlled via MSB connection 9. The stirrer
9
2.3 Connecting optional devices
780/781 pH/Ion Meter, Manual
802 Rod Stirrer
804 Ti Stand,
9
2.3.2 Connecting the 802 Rod Stirrer
The
connected directly to the pH/Ion Meter. This is done by plugging the
MSB connection cable of the 804 Ti Stand into MSB connection
pH/Ion Meter:
Fig. 8: 780 pH Meter / 781 pH/Ion Meter – 802 Rod stirrer
, in combination with the
can also be
of the
10
2 Installation
780/781 pH/Ion Meter, Manual
Controlled addition of standard or sample solutions
781 pH/Ion Meter
865
876
DOS
Furthermore, the Dosimat Plus
“HOLD”
“HOLD”
“HOLD”
2.3.3 Connecting a Dosimat Plus (only 781)
For automatic calibration as well as for the addition of standard or
samples in the Conc mode with the
and
available 6.2148.010 Remote Box. Control is carried out via the
6.2141.350 cable:
Dosimat Plus devices can be connected via the separately
the Metrohm
Fig. 9: 781 pH/Ion Meter – Dosimat Plus
If a Dosimat Plus is used then a stirrer is normally also required. This is
then connected directly with the MSB connection of the 6.2148.010
Remote Box (stirrer: 801 or 802+804).
Please note that for the standard addition the mode “
the Dosimat Plus. The activation pulse must be activated on the pH
Meter as well as the Dosimat Plus.
must be in the status
pressing the “Go” key once (check: the display of the Dosimat Plus
shows
in the top right-hand corner).
. You can set the status to
” is set on
by
11
2.3 Connecting optional devices
780/781 pH/Ion Meter, Manual
Compact Sample Changer 869
2.3.4 Connecting a sample changer
For simple automated measurement of several samples and standards
with the pH/Ion Meter the Metrohm
be connected. Communication takes place via the 6.2148.010 Remote
Box, i.e. the measurements are triggered by the sample changer and
their completion is also transmitted by the pH/Ion Meter via the remote
connection. The individual steps for processing a series of samples or
standards are defined as a method in the sample changer.
Please note that when work is carried out in this way that no sample data is transferred between the sample changer and the pH/Ion Meter.
This means that the assignment of the report outputs is only possible
by using the consecutive run number (see Section 5.4).
The connection of a Compact Sample Changer 869 and a Dosimat Plus
865 for automatic calibration with standard addition is described here
as an example. A detailed description of how to program a method in
the Compact Sample Changer 869 is given in the corresponding Manual of the instrument.
can
Fig. 10: 781 pH/Ion Meter – Dosimat Plus – Sample changer
12
2 Installation
780/781 pH/Ion Meter, Manual
2.3.5 Connecting a printer
A printer with a serial or parallel interface can be connected to the
RS232 interface for printing out reports.
The connection of the 40-character Custom DP40-S4N printer
(Metrohm ordering number: 2.140.0200) with the serial 6.2134.110 Cable is described as an example:
Fig. 11: 780 pH Meter / 781 pH/Ion Meter – Printer
The transmission parameters for the pH/Ion Meter and the printer must
be the same. On the pH/Ion Meter these are set under
CONFIG/peripheral units/character set: (see Section 5.6)
and under
CONFIG/RS232 settings (see Section 5.7).
These settings and other possible printer connections are given in the
following table. If you wish to connect a printer which is not mentioned
here then make sure that it emulates the Epson mode or uses the international character set according to IBM Standard Table 437 and IBMcompatible graphics control characters.
Please observe the paper feed settings after each report printout (see
Section 5.1).
The settings for graph sizes in the printer output are accessible in the
setup of the pH/Ion Meter and are described in Section 7.5.3. This can
particularly be necessary for single sheet printers (i.e. HP Desk Jet).
13
2.3 Connecting optional devices
780/781 pH/Ion Meter, Manual
IDP-560 EMULATION
GERMANY also for Swedish.
Seiko
6.2134.110
Character Set: Seiko
Handshake: HWs
none
Handshake: HWs
Character Set: Epson
Handshake: HWs
HP Desk Jet
2.145.0330
Character Set: HP
see Printer Manual
ON
1 2 3 4 5 6 7 8 9
10
SSW1
2
1 2 3 4 5 6 7
8
B:
A4 Paper
A:
Printer Cable 780/781 settings Printer settings
Custom
DP40-S4N
DPU-414
Citizen
iDP562 RS
6.2134.110 Character Set: Citizen
Baud Rate: 9600
Data Bit: 8
Stop Bit: 1
Parity: none
Handshake: HWs
Baud Rate: 9600
Data Bit: 8
Stop Bit: 1
Parity: none
6.2134.050 Character Set: Citizen
Baud Rate: 9600
Data Bit: 8
Stop Bit: 1
Parity: none
FONT MAP = ENGLAND *
PRINT = REVERSE
LITTLE
CR CODE = VOID
CR AFTER B. FULL = VOID
CR ON B. EMPTY = VALID
BUFFER 1K BYTE
BAUD RATE = 9600
PROTOCOL = 8,N,1
FLOW CONTROL CTS-RTS
(*) FRANCE also for Italian, Spanish
and Portuguese,
Epson LX300+
HP Desk Jet
with serial
interface
with parallel
interface
6.2134.050 As above, but
6.2134.050 Character Set: HP
Baud Rate: 9600
Data Bit: 8
Stop Bit: 1
Parity: none
RS232/
Parallel
Converter
Baud Rate: 9600
Data Bit: 8
Stop Bit: 1
Parity: none
Handshake: HWs
see Printer Manual
14
2 Installation
780/781 pH/Ion Meter, Manual
Settings
switched on. When the Vesuv program is started it automatically
checks the configuration of the connected instrument and makes the
corresponding settings for the report output so that data acquisition
2.3.6 Connecting a computer
The report output via the RS232 interface can be made to either a printer or a PC. With the program Metrodata Vesuv 3.0 for Windows it is
possible to implement automatic data acquisition and evaluation.
This is done by connecting RS232 interface 10 of the pH/Ion Meter using the optionally available 6.2134.040 Cable (9-pin/9-pin) with a free
serial COM port on the PC. If only a 25-pin COM port is available then
the optionally available 6.2125.110 Cable (9-pin/25-pin) or a commercially available adapter must be used.
The RS232 interface must be configured with identical settings on both
the connected instruments (PC and pH/Ion Meter). You should select
the standard values for the pH/Ion Meter configuration under
FIG/RS232 settings
Baud Rate: 9600
Data Bit: 8
Stop Bit: 1
Parity: none
Handshake: HWs
Please note that, before starting the program 'Vesuv Datalogger', the
pH/Ion Meter must have been configured correctly, connected up and
CON-
(see Section 5.7):
functions properly.
As well as the data acquisition function described above, the 780/781
pH/Ion Meter also has numerous remote control possibilities that allow
the complete control of the instrument via the RS232 interface. However, as the utilization of this option only makes sense in very special situations, you can obtain detailed information about the remote control
language of the pH/Ion Meter from your local Metrohm agency in a
separate document (780/781 pH/Ion Meter Operation via RS232;
8.781.1113).
15
2.4 Connecting the electrodes and sensors
780/781 pH/Ion Meter, Manual
5
8
switched off
5
Connection for potentiometric electrodes
6
Connection for separate reference electrode
8
Connection for temperature sensor
2.4 Connecting the electrodes and sensors
On its rear panel the 780/781 pH/Ion Meter has connections for a potentiometric electrode
perature sensor
Connect your electrodes and sensors according to the following diagram to the
.
, a separate reference electrode 6 and a tem-
pH/Ion Meter:
Fig. 12: Connecting sensors
pH, ISE, redox or silver electrodes with built-in or separate
reference electrode; plug F
plug B, 4 mm
Pt1000 or NTC, connected via two 2 mm banana plugs, reducing adapters for 4 mm plug B may be necessary
(6.2103.130 / 6.2103.140). Please observe color classification
for shielding purposes.
To help you choose the optimal potentiometric electrode for your particular application Metrohm can provide you with a range of information
material:
Catalog: Metrosensor Electrodes
Product booklet: Electrodes for pH Measurement
Monograph 8.015.5003: Electrodes in Potentiometry
You can obtain these documents from your local Metrohm agency or
under www.metrohm.com.
16
2 Installation
780/781 pH/Ion Meter, Manual
12
Mains cable
e sure that the power supply is always kept dry. Protect it
<ON/OFF>
2.5 Mains connection
The pH/Ion Meter has an external power supply (6.2153.000) providing
12V (DC). This is connected to 12V mains connection
One of the following cables is supplied with the instrument
• 6.2154.000 Mains cable 2 Pol (C7) – EU (XVI)
• 6.2154.010 Mains cable 2 Pol (C7) – US (N1/15)
• 6.2154.020 Mains cable 2 Pol (C7) – GB (BS89/3)
• 6.2154.030 Mains cable 2 Pol (C7) – AUS (SAA/2)
and is connected to the external power supply.
Please mak
against direct liquid contact .
2.6 Switch on
.
ON/ OFF
After the selected accessories have been connected switch on the
pH/Ion Meter with the
strument will start in the last operating mode to have been used for
measuring pH, temperature, potential or concentration (781 only).
During the switch-on process an instrument checking routine is carried
out automatically. If an error message is displayed here ('
please contact your local Metrohm agency.
key (see also Section 4.3). The in-
Err x') then
17
2.7 Initial configuration
780/781 pH/Ion Meter, Manual
<CLEAR>
Dialog language: english
<ENTER>
Date and time
Temperature sensor and unit
2.7 Initial configuration
The pH/Ion Meter is delivered with standard settings for the configuration and method parameters. Many of these can be reset at any time by
pressing the
should ever be necessary to reset the configuration of the instrument to
its original condition then this can be carried out by a re-initialization of
the instrument memory (see Section 8.5).
Before you start to make measurements please check the following
configuration settings and, if necessary, alter them according to your
own requirements. If you first want to make yourself familiar with the
operation of the pH/Ion Meter and the various editing possibilities then
please read Sections 4.1, 4.2 and 4.4. More detailed explanations of the
individual configuration settings are given in Section 5.
CONFIG/Verschiedenes/Dialog:english
key during input (see also Section 4.3). If it
After this choice has been confirmed with
guage changes immediately. For example, this item would then appear.
CONFIG/auxiliaries/dialog:english
Please switch the instrument off and on if this setting has been
changed.
CONFIG/auxiliaries/date
and /time
Please check that the date and time are correct.
CONFIG/auxiliaries/Temp.sensor
and /Temp.unit
Enter the type of temperature sensor that is connected. If no temperature sensor is connected and you always want to enter the measuring
temperature manually then you can ignore this setting.
the dialog lan-
18
3 Short operating tutorial
780/781 pH/Ion Meter, Manual
780 pH Meter (2.780.0010)
781 pH/Ion Meter (2.781.0010)
801 Magnetic Stirrer (2.801.0010)
pH electrode (enclosed)
Calibration buffers
3 Short operating tutorial
In this section the necessary steps for carrying out a simple pH and ion
measurement with calibration are described. The instructions are limited to those steps that are absolutely necessary and will enable you to
carry out your first measurements with the pH/Ion Meter directly. The
operating principles are described in Section 4.4.
3.1 pH measurement
3.1.1 Requirements
The following instruments, accessories and solutions are required for
carrying out the pH calibration and measurement described below:
•
•
Other stirrers can also be used (see Section 5.6).
•
Or another pH electrode with Pt1000 temperature sensor, e.g.:
6.0258.600 Unitrode, LL pH glass, with cable 6.2104.600, 2 mm
temp. plug
6.0257.000 Aquatrode Plus for ion-deficient water, 4 mm temp. plug
6.0228.000 Solitrode, LL pH glass, PP shaft, 4 mm temp. plug
or
•
Metrohm buffer solutions pH 4.00, 7.00 and 9.00 (6.2307.230)
3.1.2 Preparations
Before you start this short tutorial you must ensure that the instrument
and accessories have been correctly installed as described in Sec-
tion 2. The most important points concerning the installation are briefly
given again below (please refer to the Section mentioned for details). If
you are not certain whether all the settings (
pH
) correspond to the original conditions you can first reset any altera-
tions by initializing the memory (
tion 8.5).
The calibration parameters for the pH mode are set for a calibration using two Metrohm buffers as default (see Section 6.2.2). If you want to
use other buffers then the corresponding buffer type must be entered.
1 pH/Ion Meter installation
CONFIG and PARAMETER
RAM Initialization) (see Sec-
• Set up instrument Section 2.1
• Connect stirrer Section 2.3.1
• Connect electrode Section 2.4
• Mains connection Section 2.5
19
3.1 pH measurement
780/781 pH/Ion Meter, Manual
pH 7
<STIRRER>
<CAL>
ENTER>
pH 4
<ENTER>
the measurement display. This can also be done immediately
<ENTER>
ON/ OFF
2 Initial configuration
CONFI G
3.1.3 pH calibration
1 Start calibration with first buffer
CAL
2 Continue calibration with second buffer
ENT ER
• Switch on pH/Ion Meter Section 5.4
• Set dialog language Section 5.4
• Set date/time Section 5.4
• Set temperature sensor Section 5.4
• Immerse pH electrode in buffer solution
• Switch on stirrer with
• Start calibration with
• If no temperature sensor is connected:
enter the temperature and exit with
<
• Remove pH electrode from first buffer, rinse with water and
blot off gently with a lint-free tissue
• Immerse pH electrode in second buffer solution
continue calibration sequence with
and
ENT ER
3 Result
• Wait for potential measurement, result will be displayed:
• After 30 s the pH/Ion Meter will switch back automatically to
with
.
20
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