Xylem MULTI-3500i User Manual

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Multi 3500i

Operating manual

STO

ESC

pH / ISE / DO / conductivity measuring instrument

ba75689e01 01/2007

Accuracy when

going to press

Currentness of firmware The process of consistently improving our products includes the

The use of advanced technology and the high quality standard of our instruments are the result of a continuous development. This may result in differences between this operating manual and your instrument. Also, we cannot guarantee that there are absolutely no errors in this manual. Therefore, we are sure you will understand that we cannot accept any legal claims resulting from the data, figures or descriptions.

continuous further development of instrument firmware. The current Multi 3500i firmware is available on the Internet. It can easily be downloaded on your meter using the enclosed AK 340/B cable and a PC. For more detailed information, refer to the appendix of this operating manual or to the Internet under http://www.WTW.com

Reproduction in whole - or even in part - is prohibited without the express written permission of WTW GmbH, Weilheim. Printed in Germany.

Multi 3500i Contents

1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

1.1 General features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

1.2 SETs of equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

1.3 Keypad . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

1.4 Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

1.5 Socket field . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

2 Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

2.1 Authorized use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

2.2 General safety instructions . . . . . . . . . . . . . . . . . . . . . . . 10

3 Commissioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

3.1 Scope of delivery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

3.2 Power supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

3.3 Initial commissioning . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

4 Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

4.1 Switching on the measuring instrument . . . . . . . . . . . . . 13

4.2 General operating principles . . . . . . . . . . . . . . . . . . . . . 14

4.2.1 Operating modes . . . . . . . . . . . . . . . . . . . . . . . . 14

4.2.2 Navigation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

4.2.3 Example 1 on navigation: Setting the language 17

4.2.4 Example 2 on navigation: Setting the date and

time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

4.3 System settings (system menu) . . . . . . . . . . . . . . . . . . . 21

4.3.1 Data storage . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

4.3.2 Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

4.3.3 System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

4.4 pH value / ORP voltage . . . . . . . . . . . . . . . . . . . . . . . . . 25

4.4.1 General information . . . . . . . . . . . . . . . . . . . . . . 25

4.4.2 Measuring the pH value . . . . . . . . . . . . . . . . . . 27

4.4.3 Measuring the ORP voltage . . . . . . . . . . . . . . . 28

4.4.4 Settings for pH and ORP measurements . . . . . 29

4.4.5 pH calibration . . . . . . . . . . . . . . . . . . . . . . . . . . 30

4.4.6 Carrying out the TEC and NIST/DIN calibration 34

4.4.7 Carrying out a ConCal calibration . . . . . . . . . . . 38

4.5 Ion concentration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

4.5.1 General information . . . . . . . . . . . . . . . . . . . . . . 41

4.5.2 Measuring the ion concentration . . . . . . . . . . . . 42

4.5.3 Settings for ISE measurements . . . . . . . . . . . . 43

4.5.4 Calibrating for ISE measurements . . . . . . . . . . 43

4.6 Dissolved oxygen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

4.6.1 General information . . . . . . . . . . . . . . . . . . . . . . 49

4.6.2 Measuring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

4.6.3 Settings for DO sensors . . . . . . . . . . . . . . . . . . 51

4.6.4 DO calibration . . . . . . . . . . . . . . . . . . . . . . . . . . 53

Contents Multi 3500i

4.7 Conductivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

4.7.1 General information . . . . . . . . . . . . . . . . . . . . . . 58

4.7.2 Measuring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

4.7.3 Temperature compensation . . . . . . . . . . . . . . . . 60

4.7.4 Settings for conductivity measuring cells . . . . . . 61

4.7.5 Determining the cell constant (calibration in the

control standard) . . . . . . . . . . . . . . . . . . . . . . . . 63

4.8 Data storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66

4.8.1 Manual data storage . . . . . . . . . . . . . . . . . . . . . 67

4.8.2 Automatic data storage at intervals . . . . . . . . . . 68

4.8.3 Editing the measured value storage . . . . . . . . . 70

4.8.4 Erasing the measured value storage . . . . . . . . . 73

4.8.5 Displaying and outputting calibration records . . 74

4.9 Transmitting data (RS 232 interface) . . . . . . . . . . . . . . . 76

4.9.1 Options for data transmission . . . . . . . . . . . . . . 76

4.9.2 Connecting a PC/external printer . . . . . . . . . . . . 77

4.9.3 Operation with MultiLab pilot . . . . . . . . . . . . . . . 77

4.10 Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78

4.10.1 Resetting the sensor settings . . . . . . . . . . . . . . 78

4.10.2 Resetting the system settings . . . . . . . . . . . . . . 79

5 Maintenance, cleaning, disposal . . . . . . . . . . . . . . . . .81

5.1 Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81

5.2 Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81

5.3 Disposal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81

6 What to do if... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83

6.1 pH and ORP measurement . . . . . . . . . . . . . . . . . . . . . . 83

6.2 ISE measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85

6.3 DO measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86

6.4 Conductivity measurement . . . . . . . . . . . . . . . . . . . . . . . 87

6.5 General errors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88

7 Technical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .89

7.1 General data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89

7.2 Measuring ranges, resolution, accuracy . . . . . . . . . . . . . 91

7.2.1 pH/ORP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91

7.2.2 ISE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91

7.2.3 Dissolved oxygen . . . . . . . . . . . . . . . . . . . . . . . . 92

7.2.4 Conductivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93

8 Lists . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .95

9 Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .101

Appendix: Firmware Update . . . . . . . . . . . . . . . . . . . . . . .103

Multi 3500i Overview

1Overview

1.1 General features

The Multi 3500i compact precision handheld meter enables you to carry out pH measurements, ISE measurements, dissolved oxygen (DO) measurements and conductivity measurements quickly and reliably. The Multi 3500i handheld meter provides the maximum degree of operating comfort, reliability and measuring certainty for all applications.

The proven MultiCal cedures to determine/set up the cell constant support you in your work with the meter. The special AutoRead function enables precise measurements.

and OxiCal® calibration procedures and the pro-

STO

ESC

1 Keypad

2 Display

3 Socket field

Note

If you need further information or application notes, you can obtain the following material from WTW:

z Application reports

z Primers

z Safety datasheets.

You will find information on available literature in the WTW catalog or via the Internet.

Overview Multi 3500i

1.2 SETs of equipment

The measuring instrument is also available as part of individual SETs of equipment. You will find additional information on this and other accessories in the WTW catalog or via the Internet.

Multi 3500i Overview

Set (sample configuration):

1 Multi 3500i measuring instrument, carrying strap with 2 carrying

clips, armoring

2 Cond/Oxi beaker with beaker clip

3 pH beaker

4 Stand

5 Plastic beaker, 50 ml

6 Storing solution for pH electrodes

7 50 ml pH buffer solution, STP 4

8 50 ml pH buffer solution, STP 7

9 Calibration and control standard for conductivity measuring

cells, 50 ml

10 50 ml ELY/G electrolyte solution for DO sensors

11 50 ml RL/G cleaning solution for DO sensors

12 Exchange membrane caps for DO sensors (3 pieces)

13 SF 300 polishing strip for the maintenance of DO sensors

14 Conductivity measuring cell

15 pH combination electrode

16 DO sensor

17 Operating manual + short operating manual

18 Equipment case

19 Plug-in power supply unit

MultiLab pilot CD-ROM

Overview Multi 3500i

1.3 Keypad

PRTM

ESCSTOCAL

ENTER

Key functions

PRT

CAL

STO

ESC

Select the measured variable <M>:

– pH value / ORP / ion concentration

– DO concentration / DO saturation / DO partial

pressure

– Conductivity / specific resistance / salinity /

TDS

Output display contents to RS232 interface (e.g. print)

<PRT>

Switch the measuring instrument on/off

Calibrate the currently selected measured vari-

able

<CAL>

Store a measured value

<STO>

Switch to the next higher menu level / cancel input

<ESC>

Set values <▲>, <▼>

ENTER

Open a menu / confirm input

Multi 3500i Overview

1.4 Display

The graphical display can indicate up to three measuring windows at the same time. The illumination enables to read the display even in the darkness. You can modify the display to meet your requirements in multiple ways.

Measured variable

Measured value (with unit)

[SAL]

[nLF][Tr25]

6.949

7.29

731

mg/l

µS/cm

05.09.03 09:25

1.5 Socket field

24.0

°C

Temperature display

Sensor symbol

Status line

123

1 DO sensor or conductivity measuring cell or combined con-

ductivity / DO sensor

2 pH electrode or ISE combination electrode

3 pH temperature sensor

4 Plug-in power supply unit

5 RS232 serial interface

Overview Multi 3500i

Multi 3500i Safety

2 Safety

This operating manual contains basic instructions that you must follow during the commissioning, operation and maintenance of the measuring instrument. Consequently, all responsible personnel must read this operating manual before working with the measuring system. The operating manual must always be available within the vicinity of the measuring system.

Target group The measuring instrument was developed for work in the field and in

the laboratory. Thus, we assume that, as a result of their professional training and experience, the operators will know the necessary safety precautions to take when handling chemicals.

Safety instructions The individual chapters of this operating manual use the following safe-

ty instruction to indicate various types of danger:

Caution

indicates instructions that must be followed precisely in order to avoid the possibility of slight injuries or damage to the instrument or the environment.

Further notes

Note

indicates notes that draw your attention to special features.

Note

indicates cross-references to other documents, e.g. operating manuals.

2.1 Authorized use

The authorized use of the measuring instrument consists exclusively of the:

z pH and ORP measurement

z ISE measurement

z measurement of dissolved oxygen (DO) and

z conductivity measurement

in the field and laboratory.

The technical specifications as given in chapter 7 T be observed. Only the operation and running of the measuring instrument according to the instructions given in this operating manual is authorized. Any other use is considered to be unauthorized.

ECHNICAL DATA must

Safety Multi 3500i

2.2 General safety instructions

This instrument is built and inspected according to the relevant guidelines and norms for electronic measuring instruments (see chapter 7T

ECHNICAL DATA).

It left the factory in a safe and secure technical condition.

Function and operating

safety

Safe operation If safe operation is no longer possible, the instrument must be taken out

The smooth functioning and operational safety of the measuring instrument can only be guaranteed if the generally applicable safety measures and the specific safety instructions in this operating manual are followed during operation.

The smooth functioning and operational safety of the measuring instrument can only be guaranteed under the environmental conditions that are specified in chapter 7 T

ECHNICAL DATA.

If the instrument was transported from a cold environment to a warm environment, the formation of condensate can lead to the faulty functioning of the instrument. In this event, wait until the temperature of the instrument reaches room temperature before putting the instrument back into operation.

of service and secured against inadvertent operation! Safe operation is no longer possible if the measuring instrument:

z has been damaged in transport

z has been stored under adverse conditions for a lengthy period of

time

Obligations of the

purchaser

z is visibly damaged

z no longer operates as described in this manual.

If you are in any doubt, please contact the supplier of the instrument.

The purchaser of this measuring instrument must ensure that the following laws and guidelines are observed when using dangerous substances:

z EEC directives for protective labor legislation

z National protective labor legislation

z Safety regulations

z Safety datasheets of the chemical manufacturers.

Multi 3500i Commissioning

3 Commissioning

3.1 Scope of delivery

z Multi 3500i handheld measuring instrument with 4 rechargeable bat-

teries, 1.2 V type AA in the instrument

z Plug-in power supply with Euro plug,

exchange plugs for USA, UK, and Australia are enclosed

z Operating manual and short operating manual

z MultiLab pilot CD-ROM

3.2 Power supply

Mains operation and

charging the batteries

Charging time of the

batteries

You can operate the measuring instrument either with the built-in rechargeable batteries or with the plug-in power supply. The plug-in power supply supplies the measuring instrument with low voltage (9 V DC). At the same time, the rechargeable batteries are charged. The batteries are charged even when the instrument is switched off.

approx. 36 hours. The LoBat display indicator appears when the batteries are nearly empty and have to be charged as soon as possible.

Caution

The line voltage at the operating site must lie within the input voltage range of the original plug-in power supply (see chapter 7T

ECHNICAL DATA).

Caution

Use original plug-in power supplies only (see chapter 7 T

Note

The batteries should not be completely discharged. If you do not operate the instrument for a longer period of time you should charge the batteries every six months.

ECHNICAL DATA).

Automatic switchoff The instrument has an automatic switchoff function in order to save the

batteries (see section 4.3.3).

Display illumination

with battery operation

During battery operation, the measuring instrument automatically switches off the display illumination if no key has been pressed for 15 seconds. The illumination is switched on with the next keystroke again. The display illumination can be switched off completely.

Commissioning Multi 3500i

1 If necessary, replace the Euro plug (1) on the plug-in power

supply unit (2) by the country-specific plug suitable for your country.

2 Connect the plug (3) to the socket (4) of the measuring instru-

ment.

3 Connect the plug-in power supply unit to an easily accessible

mains socket.

3.3 Initial commissioning

Perform the following activities:

z For mains operation and charging the batteries: Connect the plug-in

power supply unit (see section 3.2 P

z Switch on the measuring instrument (see section 4.1)

z Set the language (see section 4.2.3)

z Set the date and time (see section 4.2.4)

Note

When you set the language, date and time according to the mentioned sections of this operating manual you will quickly be familiar with the simple operation of the Multi 3500i.

OWER SUPPLY).

Multi 3500i Operation

4 Operation

4.1 Switching on the measuring instrument

Switching on Press the <ON/OFF> key.

The measured value display appears.

6.949

25.0

Switching off Press the <ON/OFF> key.

Automatic switchoff The instrument has an automatic switchoff function in order to save the

batteries (see section 4.3.3). The automatic switchoff switches off the measuring instrument if no key is pressed for an adjustable period.

The automatic switchoff is not active

z if the power is supplied by the plug-in power supply unit,

z if the Automatic data storage function is active, or with automatic

data transmission

z if the communication cable and a PC with a running communication

program are connected,

z if the printer cable is connected (for external printers).

Display illumination

with battery operation

°C

Operation Multi 3500i

4.2 General operating principles

This section contains basic information of the operation of the Multi 3500i.

Operating elements,

display

Operating modes,

navigation

An overview of the operating elements and the display is given in section 1.3 and section 1.4.

An overview of the operating modes and navigation of the Multi 3500i is given in section 4.2.1 and section 4.2.2.

4.2.1 Operating modes

The instrument has the following operating modes:

z Measuring

The measuring data of one to three sensors is displayed in the measured value display

z Calibration

The course of a calibration with calibration information, functions and settings is displayed

z Data storage

The measuring instrument stores measuring data automatically or manually

z Transmitting data

The measuring instrument transmits measuring data and calibration records to the serial interface automatically or manually.

z Setting

The system menu or a sensor menu with submenus, settings and functions is displayed

Multi 3500i Operation

4.2.2 Navigation

Measured value display In the measured value display, you can

z select a measuring window with <▲><▼> and

open the relevant measuring menu by shortly

pressing

<MENU/ENTER>.

z open the system menu with the sensor-independent settings by

pressing <MENU/ENTER> for a long

time (approx. 1 s).

z change the display in the selected measuring window

(e. g. pH < − > mV) by pressing <M>.

Menus and dialogs The menus for settings and dialogs in courses contain further sub-

menus. The selection is made with the <▲><▼> keys. The current se- lection is displayed in reverse video.

z Submenus

The name of the submenu is displayed at the upper edge of the frame. Submenus are opened by confirming with <MENU/ENTER>. Example:

System

General

Interface Clock function Reset

z Settings

Settings are indicated by a colon. The current setting is displayed on the right-hand side. The setting mode is opened with

<MENU/ENTER>. Subsequently, the setting can be changed with <▲><▼> and <MENU/ENTER>.

Example:

System

Language: Deutsch

Beep

: Off

Illumination: On Contrast: 48 % Temperature unit Switchoff time: 30 min

: °C

Operation Multi 3500i

z Functions

Functions are designated by the name of the function. They are immediately carried out by confirming with <MENU/ENTER>. Example: Display the Calibration record function.

Calibration type: TEC Calibration interval Unit for slope: mV/pH

Calibration record

i 2.00 4.01 7.00 10.01

: 7 d

Messages Information or operating instructions are designated by the i symbol.

They cannot be selected. Example:

i Buffer recognition TEC i Immerse sensor in buffer 1

Set temperature: 25 °C

Continue

Note

The principles of navigation are explained in the two following sections by reference of examples:

z Set the language (see section 4.2.3)

z Set the date and time (see section 4.2.4).

Multi 3500i Operation

4.2.3 Example 1 on navigation: Setting the language

1 Press the <ON/OFF> key.

The measured value display appears. The instrument is in the measuring ode.

7.00

25.0

°C

2 Open the system menu by pressing <MENU/ENTER> for a

long

time (approx. 1 s).

The instrument is in the setting mode.

Storage & config

Data storage

Display System

3 Select the System submenu with <▲><▼>.

The current selection is displayed in reverse video.

4 Open the System

submenu with <MENU/ENTER>.

System

General

Interface Clock function Reset

5 Select the General submenu with <▲><▼>.

The current selection is displayed in reverse video.

Operation Multi 3500i

6 Open the General submenu with <MENU/ENTER>.

System

Language: Deutsch

Beep

: Off

Illumination: On Contrast: 48 % Temperature unit Switchoff time: 30 min

: °C

7 Open the setting mode for the Language with

<MENU/ENTER>.

System

Language: Deutsch Beep: Off Illumination: On Contrast Temperature unit: °C Switchoff time: 30 min

: 48 %

8 Select the required language with <▲><▼>.

9 Confirm the setting with <MENU/ENTER>.

The setting becomes active the next time the system menu is called up.

10 To make further settings, switch to the next higher menu level

with <ESC>. or Switch to the measured value display with <M>. The instrument is in the measuring ode.

Multi 3500i Operation

4.2.4 Example 2 on navigation: Setting the date and time

The measuring instrument has a clock with a date function. The date and time are indicated in the status line of the measured value display. The indication can be switched off. When storing measured values and calibrating, the current date and time are automatically stored as well.

The correct setting of the date and time and date format is important for the following functions and displays:

z Current date and time

z Calibration date

z Identification of stored measured values.

Therefore, check the time at regular intervals.

Note

After a fall of the supply voltage (empty batteries), the date and time are reset to 01.01.2003, 00:00 hours.

Setting the date, time

and date format

The data format can be switched from the display of day, month, year (dd.mm.yy) to the display of month, day, year (mm/dd/yy or mm.dd.yy).

1 In the measured value display:

Open the system menu by pressing <MENU/ENTER> for a long

time (approx. 1 s).

The instrument is in the setting operating mode.

2 Select and confirm the System / Clock function menu with

<▲><▼> and <MENU/ENTER>. The setting menu for the date and time opens up.

3 Select and confirm the Time menu with <▲><▼> and

<MENU/ENTER>. The seconds are highlighted.

System

Time: 14:53:40 Date

: 30.10.03

Date format: dd.mm.yy

4 Change and confirm the setting with <▲><▼> and <MENU/

ENTER>.

The minutes are highlighted.

Operation Multi 3500i

5 Change and confirm the setting with <▲><▼> and <MENU/

ENTER>.

The hours are highlighted.

6 Change and confirm the setting with <▲><▼> and <MENU/

ENTER>. The time is set.

7 If necessary, set the Date and Date format. The setting is made

similarly to that of the time.

8 If necessary, select and set the Date with <▲><▼> and

<MENU/ENTER>.

9 To make further settings, switch to the next higher menu level

with <ESC>. or Switch to the measured value display with <M>. The instrument is in the measuring operating mode.

Multi 3500i Operation

4.3 System settings (system menu)

The system menu comprises the following settings:

z Data storage (see section 4.3.1)

z Display (see section 4.3.2)

z System (see section 4.3.3).

4.3.1 Data storage

This menu contains all functions to display, edit and erase stored measured values and calibration records.

Note

Detailed information on the data storage functions of the Multi 3500i is given in section 4.8.

4.3.2 Display

With the aid of Display submenu, you can modify the measured value display to meet your requirements. When doing so, you can display or hide the following elements:

z pH/ISE measuring window

z DO measuring window

z Conductivity measuring window

z Date indication in the status line

z Time indication in the status line

Note

When several sensors or multiple sensors (e.g. ConOx) are connected, all available measured variables are automatically displayed. If you do not wish to have all measured values displayed, you can hide measured values of individual sensors.

Operation Multi 3500i

Settings To open the system menu in the measured value display, press the

<MENU/ENTER> key for approx. 1 s

. After completing the settings,

switch to the measured value display with <M>.

Menu item Setting Description

Display / Time On

Off

Display / Date On

Off

Display / pH On

Off

Display / O2 On

Off

Display / Cond On

Off

Display of the time in the system status line

Display of the date in the system status line

Display of the pH/ISE measuring window. This menu item is only visible if the electrode and an additional sensor are connected.

Display of the DO measuring window. This menu item is only visible if a DO sensor is connected.

Display of the conductivity measuring window. This menu item is only visible if a conductivity measuring cell is connected.

Multi 3500i Operation

4.3.3 System

Overview The following sensor-independent instrument features can be adjusted

in the system menu/System and its submenus:

z Menu language

z Beep on keystroke

z Display illumination

z Display contrast

z Unit of the temperature display

z Interval of the automatic switchoff

z Data interface

z Clock and date function

z Function to reset all sensor-independent system settings to the de-

fault condition

Settings To open the system menu in the measured value display, press the

<MENU/ENTER> key for approx. 1 s

. After completing the settings,

switch to the measured value display with <M>.

Menu item Setting Description

System / General / Language

Deutsch English

Select the menu language

(further)

System / General / Beep

System / General / Illumination

System / General / Contrast

System / General / Temperature unit

On Off

Switch on/off the beep on keystroke

Switching the display illumination on/off

0 ... 100 % Changing the display con-

trast

°C °F

Temperature unit, degrees Celsius or degrees Fahrenheit. All temperatures are displayed with the selected unit.

System / General / Switchoff time

10, 20, 30, 40, 50 min, 1 2 3 4 5 10 15 20 24 h

The automatic switchoff automatically switches the measuring instrument off if no entry is made for a specified period of time (switchoff interval). This saves the batteries.

Operation Multi 3500i

Menu item Setting Description

System / Interface / Baud rate

1200, 2400, 4800, 9600,

Baud rate of the data interface

19200

System / Interface / Output format

ASCII CSV

Output format for data transmission For details, see section 4.9

System / Interface / Header

Yes No

Option for output in csv format. "Yes" creates a header in the table.

System / Clock function

Time Date

Settings of time and date. For details, see section 4.2.4

Date format

System / Reset - Resets the system settings to

the default values. For details, see section 4.10.2

Multi 3500i Operation

4.4 pH value / ORP voltage

4.4.1 General information

You can measure the following variables:

z pH value [ ]

z ORP [mV]

Caution

When connecting an earthed PC/printer, measurements cannot be performed in earthed media as incorrect values would result. The RS232 interface is not galvanically isolated.

Temperature

measurement

For reproducible pH measurements, it is essential to measure the temperature of the test sample. You have the following possibilities of measuring the temperature:

z Automatic measurement of the temperature by the temperature sen-

sor (NTC30 or Pt 1000) integrated in electrode.

z Measurement of the temperature by the integrated temperature sen-

sor of a simultaneously connected DO sensor or conductivity measuring cell in the test sample.

z Manual determination and input of the temperature.

The measuring instrument recognizes whether a suitable sensor is connected and automatically switches on the temperature measurement.

Operation Multi 3500i

The display of the temperature indicates the active temperature measuring mode:

Temperature

sensor

Resolution of the temp.

Mode

display

pH Cond or

Oxi

yes - 0.1 °C Automatic with pH tem-

yes yes 0.1 °C

perature sensor

-- 1°C Manual

-yes0.1 °C,

measured temperature value flashes

The temperature value of the second sensor (Cond or Oxi) in the same test sample is taken over for pH measurement*

* If you do not wish that, you can:

– either disconnect the 2nd sensor and use the manual temperature

input or

– use an electrode with a temperature sensor.

Preparatory activities Perform the following preparatory activities when you want to measure:

1 Connect a pH or ORP electrode to the measuring instrument.

The pH/ISE measuring window is displayed.

2 If necessary, select the pH or mV display with <M>.

3 Adjust the temperature of the solutions and measure the cur-

rent temperature if the measurement is made without a temperature sensor.

4 Calibrate or check the measuring instrument with the elec-

trode.

Multi 3500i Operation

4.4.2 Measuring the pH value

1 Perform the preparatory activities according to section 4.6.1.

2 Immerse the pH electrode in the test sample.

6.949

AutoRead

(Drift control)

Criteria With identical measurement conditions, the following applies:

24.8

3 Select the pH or mV display with <M>.

The AutoRead function (drift control) continually checks the stability of the measurement signal. The stability has a considerable impact on the reproducibility of measured values. The display of the measured variable flashes until a stable measured value is available.

Measured variable

pH value Better than 0.01 > 30 seconds

°C

Reproducibility Response time

Operation Multi 3500i

4.4.3 Measuring the ORP voltage

Note

ORP electrodes are not calibrated. However, you can check ORP electrodes using a test solution.

1 Perform the preparatory activities according to section 4.6.1.

2 Submerse the ORP electrode in the sample.

AutoRead

(drift control)

Criteria With identical measurement conditions, the following applies:

157.0

24.8

3 Select the mV display with <M>.

Measured variable Reproducibility Response time

ORP voltage better than 0.6 mV > 30 seconds

°C

Multi 3500i Operation

4.4.4 Settings for pH and ORP measurements

Overview The following settings are possible for pH and ORP measurements:

z Resolution

z Calibration interval

z Buffers for calibration

z Unit for slope

z Calibration record (display)

Settings The settings are made in the measuring menu of the pH/ORP measure-

ment. To open the settings, activate the relevant measuring window in the measured value display and press the <MENU/ENTER> key shortly. After completing the settings, switch to the measured value display with <M>.

Menu item Possible

setting

Calibration /

1 ... 999 d Calibration interval for the pH elec- Calibration interval

Calibration / Calibration type

TEC

NIST/DIN

ConCal

Calibration / Unit for slope

Calibration /

mV/pH

- Displays the calibration record of Calibration record

Man. temperature

-20 ...

+130 °C

Description

trode (in days). The measuring instrument reminds you to calibrate regularly by the flashing sensor symbol in the measuring window.

Buffer sets to be used for pH calibration. For details, see section 4.4.5.

Unit of the slope. The % display refers to the Nernst slope of

-59.16 mV/pH (100 x determined slope/Nernst slope).

the last calibration.

Entry of the manually determined temperature. For measurements without temperature sensor only.

Reset - Resets all sensor settings to the

delivery condition (see section 4.10.1).

High resolution On

Off

Resolution of the pH display:

On = 0.001 Off = 0.01

Operation Multi 3500i

4.4.5 pH calibration

Why calibrate? pH electrodes age. This changes the asymmetry (zero point) and slope

of the pH electrode. As a result, an inexact measured value is displayed. Calibration determines the current values of the asymmetry and slope of the electrode and stores them in the measuring instrument. Thus, you should calibrate at regular intervals.

When to calibrate? z After connecting another electrode

z When the sensor symbol flashes:

– after the calibration interval has expired

– after a voltage interruption (empty batteries)

Buffer sets for

calibration

You can use the buffer sets quoted in the table for an automatic calibration. The pH values are valid for the specified temperature values. The temperature dependence of the pH values is taken into account during calibration.

Buffer set Name on the

display

pH values at 25 °C

Technical buffer solutions TEC 2.00

4.01

7.00

10.01

NIST/DIN buffer solutions NIST/DIN 1.679

4.006

6.865

9.180

12.454

(user-defined single-point or twopoint calibration)

ConCal pH 7.0 ± 0.5

and any other buffer solution

Note

The buffers are selected in the sensor menu (setting, Calibration type, see section 4.4.4).

Multi 3500i Operation

Calibration points Calibration can be performed using one, two or three buffer solutions in

any order (single-point, two-point or three-point calibration). The measuring instrument determines the following values and calculates the calibration line as follows:

Determined

Displayed calibration data

values

1-point ASY z Asymmetry = ASY

z Slope = Nernst slope

(-59.16 mV/pH at 25 °C)

2-point ASY

SLO

3-point ASY

SLO

z Asymmetry = ASY

z Slope = SLO

z Asymmetry = ASY

z Slope = SLO

The calibration line is calculated by linear regression.

Note

You can display the slope in the units, mV/pH or % (see section 4.3.3).

AutoRead In calibration, the AutoRead function is automatically activated.

The current AutoRead measurement can be terminated at any time (accepting the current value).

Calibration record When finishing a calibration, the new calibration values are displayed

as an informative message (

i symbol) first. Then you can decide

whether you want to take over these values of the new calibration or whether you want to continue measuring with the old calibration data. After accepting the new calibration values the calibration record is displayed.

Operation Multi 3500i

Display calibration data

and output to interface

You can have the data of the last calibration displayed (see section 4.8.5). Subsequently, you can transmit the displayed calibration data to the interface, e. g. to a printer or PC, with the <PRT> key.

Note

The calibration record is automatically transmitted to the interface after calibrating.

Sample record:

03.11.03 07:14

CALIBRATION pH

03.11.03 07:10:45

Multi 3500i ser. no. 12345678

Cal. interval 7 d

AutoCal TEC

Buffer 1 4.01

Buffer 2 7.00

Buffer 3 10.01

Voltage 1 184.0 mV 24.0 °C

Voltage 2 0.0 mV 24.0 °C

Voltage 3 -177.0 mV 24.0 °C

Slope -60.2 mV/pH

Asymmetry 3.0 mV

Sensor +++

Multi 3500i Operation

Calibration evaluation After calibrating, the measuring instrument automatically evaluates the

calibration. The asymmetry and slope are evaluated separately. The worse evaluation of both is taken into account. The evaluation appears on the display and in the calibration record.

Display Calibration

record

+++ -15 ... +15 -60.5 ... -58

++ -20 ... +20 -58 ... -57

+ -25 ... +25 -61 ... -60.5

- -30 ... + 30 -62 ... -61

Clean the electrode according to the electrode operating manual

Error Error

Perform error elimination according to chapter 6 W

DO IF...

HAT TO

Asymmetry [mV]

< -30 or > 30

Slope [mV/pH]

-57 ... -56

-56 ... -50

< -62 or > -50

Preparatory activities Perform the following preparatory activities when you want to calibrate:

1 Connect the pH electrode to the measuring instrument.

The pH/ISE measuring window is displayed.

2 Keep the buffer solutions ready. Adjust the temperature of the

buffer solutions, or measure the current temperature, if you measure without a temperature sensor.

Operation Multi 3500i

4.4.6 Carrying out the TEC and NIST/DIN calibration

The two calibration procedures only differ in the usage of different buffer sets (see section 4.4.5). Make sure that the Calibration type is correctly set in the sensor menu (see section 4.4.4).

For this procedure, use any one, two or three WTW technical buffer solutions in ascending or descending order.

The TEC calibration is described below. With the NIST/DIN calibration, the NIST/DIN buffer recognition and different nominal buffer values are displayed. Apart from that, the procedure is identical.

Note

The TEC calibration for pH 10.01 is optimized for the WTW technical buffer solution TEP 10 Trace or TPL 10 Trace. Other buffer solutions can lead to an erroneous calibration. The correct buffer solutions are given in the WTW catalog or in the Internet.

1 In the measured value display, select the pH or mV measuring

window with <▲><▼> and <M>.

2 Start the calibration with <CAL>.

The calibration display appears.

pH <CAL>

i Buffer recognition TEC i Immerse sensor in buffer 1

Continue

3 Immerse the electrode in buffer solution 1.

4 If the Set temperature menu item appears, measure and enter

the temperature of the buffer manually (measurement without temperature sensor).

5 Select Continue with <▲><▼> and press <MENU/ENTER>.

The buffer is measured. The measured value is checked for stability (AutoRead).

Multi 3500i Operation

pH <CAL>

i Buffer value = 7.000 i U = 3.0 mV i Temperature =

24.8 °C

Displayed:

– Recognized nominal buffer

value (referring to 25 °C)

– current electrode voltage

– current temperature value

Terminate AutoRead

6 Wait for the end of the AutoRead measurement or accept the

calibration value with <MENU/ENTER>. The calibration display for the next buffer appears.

pH <CAL>

i Buffer recognition TEC i Immerse sensor in buffer 2

Exit with one point calibration

Continue

7 For single-point calibration, select Exit with one point calibra-

tion with <▲><▼> and confirm with <MENU/ENTER> .

The calibration is completed as a single-point calibration. The new calibration values are displayed as a message (

i).

You have the following options: z Accept the new calibration values with <MENU/ENTER>.

Subsequently, the calibration record is displayed and output to the interface at the same time.

z To switch to the measured value display without

accepting

the new calibration values, press <M> or <ESC>.

Note

For single-point calibration, the instrument uses the Nernst slope (-59.16 mV/pH at 25 °C) and determines the asymmetry of the electrode.

Operation Multi 3500i

Continuing for two-point

calibration

(Calibration type TEC)

8 Thoroughly rinse the electrode with distilled water.

9 Immerse the electrode in buffer solution 2.

10 If the Set temperature menu item appears, measure and enter

the temperature of the buffer manually (measurement without temperature sensor).

11 Select Continue with <▲><▼> and press <MENU/ENTER>.

The buffer is measured. The measured value is checked for stability (AutoRead).

pH <CAL>

i Buffer value = 10.011 i U = -177.0 mV i Temperature = 24.8 °C

Terminate AutoRead

12 Wait for the end of the AutoRead measurement or Terminate

AutoRead and accept the calibration value with

<MENU/ENTER>. The calibration display for the next buffer appears.

pH <CAL>

i Buffer recognition TEC i Immerse sensor in buffer 3

Exit with 2 point calibration

Continue

13 For two-point calibration, select Exit with 2 point calibration with

<▲><▼> and confirm with <MENU/ENTER>. The calibration is completed as a two-point calibration. The new calibration values are displayed as a message (

i).

You have the following options: z Accept the new calibration values with <MENU/ENTER>.

Subsequently, the calibration record is displayed and output to the interface at the same time.

z To switch to the measured value display without

accepting

the new calibration values, press <M> or <ESC>.

Multi 3500i Operation

Continuing for three-

point calibration

(Calibration type TEC)

14 Thoroughly rinse the electrode with distilled water.

15 Immerse the electrode in buffer solution 3.

16 If necessary, measure the temperature of buffer 3 manually,

then enter and confirm it with <▲><▼> and <MENU/ENTER> in the Set temperature setting.

17 Select Continue with <▲><▼> and press <MENU/ENTER>.

The buffer is measured. The measured value is checked for stability (AutoRead).

pH <CAL>

i Buffer value = 4.010 i U = 184.0 mV i Temperature = 24.8 °C

Terminate AutoRead

18 Wait for the end of the AutoRead measurement or Terminate

AutoRead and accept the calibration value with

<MENU/ENTER>. The new calibration values are displayed as a message (

i).

You have the following options: z Accept the new calibration values with <MENU/ENTER>.

Subsequently, the calibration record is displayed and output to the interface at the same time.

z To switch to the measured value display without

the new calibration values, press <M> or <ESC>.

accepting

Operation Multi 3500i

4.4.7 Carrying out a ConCal calibration

Single-point calibration Use any buffer solution for this rapid method.

The calibration will be the more exact the nearer the pH value of the buffer solution is to that of the test sample.

Two-point calibration Use two buffer solutions for this procedure:

z first buffer solution: pH 7.0 ± 0.5

z any other buffer solution

For this calibration, Calibration type ConCal must be set in the sensor menu (see section 4.4.4).

1 In the measured value display, select the pH or mV measuring

window with <▲><▼> and <M>.

2 Start the calibration with <CAL>.

The calibration display appears.

pH <CAL>

i Immerse sensor in buffer 1 i Temperature = 24.8 °C

Set buffer: 7.00

Continue

3 Thoroughly rinse the electrode with distilled water.

4 Immerse the electrode in buffer solution 1.

5 Set the nominal buffer value for the measured temperature with

<MENU/ENTER> and <▲><▼>. Then confirm the value with <MENU/ENTER>.

6 If the Set temperature menu item appears, measure and enter

the temperature of the buffer manually (measurement without temperature sensor).

7 Select Continue with <▲><▼> and press <MENU/ENTER>.

The buffer is measured. The measured value is checked for stability (AutoRead).

Multi 3500i Operation

pH <CAL>

i Buffer value = 6.80 i U = 12.0 mV i Temperature =

Terminate AutoRead

24.8 °C

8 Wait for the end of the AutoRead measurement or Terminate

AutoRead and accept the calibration value with <MENU/ENTER>. The calibration display for the next buffer appears.

pH <CAL>

i Immerse sensor in buffer 2 i Temperature = 24.8 °C

Exit with one point calibration

Set buffer: 8.27

Continue

9 For single-point calibration, select Exit with one point calibra-

tion with <▲><▼> and confirm with <MENU/ENTER>.

The calibration is completed as a single-point calibration. The new calibration values are displayed as a message (

i).

You have the following options: z Accept the new calibration values with <MENU/ENTER>.

Subsequently, the calibration record is displayed and output to the interface at the same time.

z To switch to the measured value display without

accepting

the new calibration values, press <M> or <ESC>.

Note

For single-point calibration, the instrument uses the Nernst slope (-59.16 mV/pH at 25 °C) and determines the asymmetry of the electrode.

Operation Multi 3500i

Continuing for two-point

calibration

(Calibration type

ConCal)

10 Thoroughly rinse the electrode with distilled water.

11 Immerse the electrode in buffer solution 2.

12 Set the nominal buffer value with <MENU/ENTER> and

<▲><▼>. Then confirm the value with <MENU/ENTER>.

13 If the Set temperature menu item appears, measure and enter

the temperature of the buffer manually (measurement without temperature sensor).

14 Select Continue with <▲><▼> and press <MENU/ENTER>.

The buffer is measured. The measured value is checked for stability (AutoRead).

pH <CAL>

i Buffer value = 8.85 i U = -102.0 mV i Temperature =

Terminate AutoRead

24 °C

15 Wait for the end of the AutoRead measurement or Terminate

AutoRead and accept the calibration value with <MENU/ENTER>. The new calibration values are displayed as a message (

i).

You have the following options: z Accept the new calibration values with <MENU/ENTER>.

Subsequently, the calibration record is displayed and output to the interface at the same time.

z To switch to the measured value display without

accepting

the new calibration values, press <M> or <ESC>.

Multi 3500i Operation

4.5 Ion concentration

4.5.1 General information

Note

Incorrect calibration of ion sensitive electrodes will result in incorrect measured values. Calibrate regularly before measuring.

Caution

When connecting an earthed PC/printer, measurements cannot be performed in earthed media as incorrect values would result. The RS232 interface is not galvanically isolated.

Temperature

measurement in ISE

measurements

For reproducible measurements of the ion concentration, it is essential to measure the temperature of the test sample. You have the following possibilities of measuring the temperature:

z Measurement of the temperature by the integrated temperature sen-

sor of a simultaneously connected DO sensor or conductivity measuring cell in the test sample.

z Manual determination and input of the temperature.

The measuring instrument recognizes whether a suitable sensor is connected and automatically switches on the temperature measurement.

The display of the temperature indicates the active temperature measuring mode:

Temperature

sensor,

Cond or Oxi

- 1°C Manual

yes 0.1 °C,

Resolution of the temp. display

measured temperature value flashes

Mode

The temperature value of the second sensor (Cond or Oxi) in the same test sample is taken over for measurement*

* If this is not required you can unplug the second sensor and enter the temperature manually.

Operation Multi 3500i

Preparatory activities Perform the following preparatory activities when you want to measure:

1 Connect the ISE combination electrode to the measuring in-

strument. The pH/ISE measuring window is displayed.

2 If necessary, select the ISE display (unit, mg/l) with <M>.

3 Measure the temperature of the test sample using a thermom-

eter.

4 Calibrate or check the measuring instrument with the elec-

trode.

Note

While no valid calibration is available, e.g. in the delivery condition, "Error" appears in the measured value display.

AutoRead

(drift control)

Criteria With identical measurement conditions, the following applies:

4.5.2 Measuring the ion concentration

1 Perform the preparatory activities according to section 4.5.1.

2 Immerse the electrode in the test sample.

ISE

0.157

mg/l

°C

Temperature while cali-

brating and measuring

Measuring signal Reproducibility Response time

Electrode voltage

For precise ISE measurements the temperature difference between measurement and calibration should not be greater that 2 K. Therefore,

better than 0.1 mV > 30 seconds

Multi 3500i Operation

adjust the temperature of the standard and measuring solutions accordingly. If the temperature difference is greater the [TempErr] warning appears in the measured value display.

4.5.3 Settings for ISE measurements

Overview The following settings are possible for ISE measurements:

z Calibration record (display)

Settings The settings are made in the measuring menu of the ISE measure-

Menu item Possible

Description

setting

Calibration / Calibra- tion record

- Displays the calibration

record of the last calibration.

Man. temperature -20 ... +130 °C Entry of the manually de-

termined temperature. For measurements without temperature sensor only.

4.5.4 Calibrating for ISE measurements

Why calibrate? Ion-selective electrodes age and are temperature-dependent. This

changes the slope. As a result, an inexact measured value is displayed. Calibration determines the current value of the slope of the electrode and stores it in the instrument.

Thus, you should calibrate before each measurement and at regular intervals.

When to calibrate? z Before any measurement if possible

z After connecting another ISE electrode

z When the sensor symbol flashes, e.g. after a voltage interruption

(empty batteries)

Operation Multi 3500i

Standard solutions Use two or three different standard solutions. For three-point calibra-

tion, the standard solutions have to be selected in either increasing or decreasing order.

Temperature while cali-

brating and measuring

ISE Cal This is the conventional two-point or three-point calibration proce-

Standard

Values [mg/l]

solution

Std 1 0.01; 0.02; 0.05; 0.1; 0.2; 0.5; 1; 2; 5; 10; 20; 50; 100;

Std 2

Std 3

200; 500; 1000 If Std 2 If Std 2

> Std 1, Std 3 must be > Std 2 < Std 1, Std 3 must be < Std 2

The calibration line is calculated by linear regression.

Note

The measurement precision is also dependent on the selected standard solutions. Therefore, the selected standard solutions should cover the expected value range of the subsequent concentration measurement.

For precise ISE measurements the temperature difference between measurement and calibration should not be greater that 2 K. Therefore, adjust the temperature of the standard and measuring solutions accordingly. If the temperature difference is greater the [TempErr] warning appears in the measured value display.

dure that uses 2 or 3 freely selectable standard solutions. The concentration expected in the measurement determines the concentration of the calibration standards.

AutoRead In calibration, the AutoRead function is automatically activated.

Calibration record When finishing a calibration, the new calibration values are displayed

Display calibration data

and output to interface

The current AutoRead measurement can be terminated at any time (accepting the current value).

as an informative message (

i symbol) first. Then you can decide

Multi 3500i Operation

Note

The calibration record is automatically transmitted to the interface after calibrating.

Sample record:

03.11.03 07:14

CALIBRATION ISE

03.11.03 07:12:01

Multi 3500i ser. no. 12345678

Standard 1 0.010 mg/l

Standard 2 0.020 mg/l

Voltage 1 0.0 mV 24.0 °C

Voltage 2 9.0 mV 24.0 °C

Slope 29.9 mV

Sensor +++

Calibration evaluation After calibrating, the measuring instrument automatically evaluates the

calibration.

Display Calibration

Magnitude of the slope [mV]

record

+++ 50.0 ... 70.0 or 25.0 ... 35.0

Error Error

Perform error elimination according to chapter 6 W

DO IF...

HAT TO

< 50 or > 70 or < 25 or > 35

Operation Multi 3500i

Preparatory activities Perform the following preparatory activities when you want to calibrate:

1 Connect the ISE combination electrode to the measuring in-

strument. The pH/mV/ISE measuring window is displayed.

2 Keep the standard solutions ready.

3 Measure the temperature of the standard solutions using a

thermometer.

Carrying out an

ISE calibration

Proceed as follows to calibrate the instrument:

1 In the measured value display, select the ISE measuring win-

dow with <▲><▼> and <M>.

2 Start the calibration with <CAL>.

The calibration display appears.

ISE <CAL>

i Immerse sensor in std. 1

Set temperature:24 °C Continue

Set standard: 0.010 mg/l

3 Thoroughly rinse the electrode with distilled water.

4 Immerse the electrode in standard solution 1.

5 Select the Set standard setting with <▲><▼> and press

<MENU/ENTER>.

6 Set the concentration of the standard solution with <▲><▼>

and press <MENU/ENTER>.

7 Measure the temperature of the standard solution using a ther-

mometer.

8 Select the Set temperature setting with <▲><▼> and press

<MENU/ENTER>.

9 Set the temperature with <▲><▼> and press

<MENU/ENTER>.

10 Select Continue with <▲><▼> and press <MENU/ENTER>.

The standard solution is measured. The measured value is checked for stability (AutoRead).

Multi 3500i Operation

ISE <CAL>

i Standard = 0.010 mg/l i U = 0.5 mV

Terminate AutoRead

11 Wait for the end of the AutoRead measurement or accept the

calibration value with <MENU/ENTER>. The calibration display for the next standard solution appears.

ISE <CAL>

i #1 0.010 mg/l 24 °C i Immerse sensor in std. 2

Set temperature:24 °C Continue

Set standard: 0.020 mg/l

Continuing for two-point

calibration

12 Thoroughly rinse the electrode with distilled water.

13 Immerse the electrode in standard solution 2.

14 Select the Set standard setting with <▲><▼> and press

<MENU/ENTER>.

15 Set the concentration of the standard solution with <▲><▼>

and press <MENU/ENTER>.

16 Measure the temperature of the standard solution using a ther-

mometer.

17 Select the Set temperature setting with <▲><▼> and press

<MENU/ENTER>.

18 Set the temperature with <▲><▼> and press

<MENU/ENTER>.

19 Select Continue with <▲><▼> and press <MENU/ENTER>.

The standard solution is measured. The measured value is checked for stability (AutoRead).

Operation Multi 3500i

ISE <CAL>

i Standard = 0.020 mg/l i U = 8.4 mV

Terminate AutoRead

20 Wait for the end of the AutoRead measurement or accept the

calibration value with <MENU/ENTER>. The calibration display for the next standard solution appears.

ISE <CAL>

i #2 0.020 mg/l 24 °C i Immerse sensor in std. 3

Set temperature:24 °C Continue Exit with 2 point calibration

Set standard: 0.050 mg/l

Continuing for three-

point calibration

21 For two-point calibration, select Exit with 2 point calibration with

<▲><▼> and confirm with <MENU/ENTER> . The calibration is completed as a two-point calibration. The new calibration values are displayed as a message (

i).

You have the following options: z Accept the new calibration values with <MENU/ENTER>.

Subsequently, the calibration record is displayed and output to the interface at the same time.

z To switch to the measured value display without

accepting

the new calibration values, press <M> or <ESC>.

Repeat the steps 12 to 20 in the same way for the third standard solution. After finishing the last calibration step, the new calibration values are displayed as a message (

i).

You have the following options:

z Accept the new calibration values with <MENU/ENTER>. Subse-

quently, the calibration record is displayed and output to the interface at the same time.

z To switch to the measured value display without

accepting the new

calibration values, press <M> or <ESC>.

Multi 3500i Operation

4.6 Dissolved oxygen

4.6.1 General information

You can measure the following variables:

z DO concentration

z DO saturation index ("DO saturation")

z DO partial pressure

DO measurements with the Multi 3500i can be carried out using a ConOx, CellOx 325, DurOx 325 or StirrOx G DO sensor. The stirrer of the StirrOx G DO sensor has to be supplied with voltage separately using the NT/pH Mix 540 power supply. The measuring instrument automatically recognizes the type of the connected DO sensor.

The measuring instrument is supplied with the following functions:

z AutoRange (automatic switchover of the measurement range), If a

measuring range is exceeded, AutoRange causes the measuring instrument to automatically change to the next higher measuring range and back again. Therefore, the instrument always measures in the measuring range with the highest possible resolution.

z The AutoRead function (drift control) for checking the stability of the

measurement signal. This ensures the reproducibility of the measuring signal. The display of the measured variable flashes until a stable measured value is available.

Note

Incorrect calibration of DO sensors will result in incorrect measured values. Calibrate at regular intervals.

Caution

When connecting an earthed PC/printer, measurements cannot be performed in earthed media as incorrect values would result. The RS232 interface is not galvanically isolated.

Temperature sensor The DO sensor has an integrated temperature sensor that always mea-

sures the current temperature of the test sample.

Operation Multi 3500i

Preparatory activities Perform the following preparatory activities when you want to measure:

1 Connect the DO sensor to the measuring instrument.

The DO measuring window is displayed.

2 Calibrate or check the measuring instrument with the sensor.

4.6.2 Measuring

1 Perform the preparatory activities according to section 4.6.1.

2 Immerse the DO sensor in the test sample.

7.29

25.0

Selecting the

displayed

measured variable

Salinity correction When measuring the concentration of solutions with a salt content of

You can switch between the following displays with <M>:

z DO concentration [mg/l]

z DO saturation [%]

z DO partial pressure [mbar].

more than 1 g/l, a salinity correction is required. For this, you have to measure and input the salinity of the measured medium first. When the salinity correction is switched on, the [SAL] indicator is displayed in the measuring window.

Note

The salinity correction is switched on or off and the salinity is entered in the measuring menu of the DO measurement (see section 4.6.3).

mg/l

°C

Multi 3500i Operation

Note

The ConOx double sensor can perform the salinity correction automatically. The conductivity module of the sensor measures the salt content of the test sample simultaneously with the DO. The measuring instrument takes the measured value into account.

AutoRead

(drift control)

Criteria With identical measurement conditions, the following applies:

Measuring mode Reproducibility Response time

DO concentration better than 0.05 mg/l > 10 seconds

DO saturation in-

better than 0.6 % > 10 seconds

dex

DO partial pres-

Better than 1.2 mbar > 10 seconds

sure

4.6.3 Settings for DO sensors

Overview The following settings are possible for DO sensors:

z Salinity correction

z Salinity (salinity equivalent)

z Calibration interval

z Comparison measurement

Operation Multi 3500i

Settings The settings are made in the measuring menu of the DO measurement.

To open the settings, activate the relevant measuring window in the measured value display and press the <MENU/ENTER> key shortly

After completing the settings, switch to the measured value display with

<M>.

Menu item Possible

Description

setting

Calibration / Calibration interval

1 ... 999 d Calibration interval for the DO

sensor (in days). The measuring instrument reminds you to calibrate regularly by the flashing sensor symbol in the measuring window.

Calibration / Comparison meas.

On Off

Enables to adjust the measured value with the aid of a comparison measurement, e.g. Winkler titration. For details, see section 4.6.4.

Calibration / Calibration record

- Displays the calibration

record of the last calibration.

Reset - Resets all sensor settings to

the delivery condition (see section 4.10.1).

Sal automatic On

Off

Automatic salt content correction for concentration measurements.

Note:

This function is available with the ConOx double sensor only

Sal correction On

Off

Manual salt content correction for concentration measurements.

Salinity 0.0 ... 70.0 Salinity or salinity equivalent

for the salt content correction. This function is only available if the manual salt content correction is switched on.

Multi 3500i Operation

4.6.4 DO calibration

Why calibrate? DO sensors age. This changes the slope of the DO sensor. Calibration

determines the current slope of the sensor and stores this value in the instrument.

When to calibrate? z After connecting another DO sensor

z When the sensor symbol flashes (after the calibration interval has

expired).

Calibration datasets The Multi 3500i administrates three sets of calibration data:

z Set 1 for the type, "CellOx": – CellOx 325, or

– StirrOx G

z Set 2 for the type, "DurOx": – DurOx 325

z Set 3 for the type, "ConOx": – ConOx

Sensors of different types can be calibrated separately from each other. When a sensor of one type is calibrated, the calibration data of the other types remain stored. The Multi 3500i recognizes the type of the connected sensor and automatically uses the correct calibration data.

Calibration procedure The Multi 3500i provides 2 calibration procedures:

z Calibration in water vapor-saturated air.

Use an OxiCal

air calibration vessel for the calibration.

z Calibration via a comparison measurement (e.g. Winkler titration ac-

cording to DIN EN 25813 or ISO 5813). At the same time, the relative slope is adapted to the comparison measurement by a correction factor. When the correction factor is active, the [Factor] in- dicator appears in the measuring window.

AutoRead The calibration procedure automatically activates the AutoRead func-

tion.

Display calibration data

and output to interface

Note

The calibration record is automatically transmitted to the interface after calibrating.

Operation Multi 3500i

Sample record:

03.11.03 07:14

CALIBRATION ConOx

03.11.03 07:12:58

Multi 3500i ser. no. 12345678

Cal. interval 14 d

Relative slope 0.97

Sensor +++

Calibration evaluation After the calibration, the measuring instrument evaluates the current

status of the sensor against the relative slope. The evaluation appears on the display and in the calibration record. The relative slope has no effect on the measuring accuracy. Low values indicate that the electrolyte will soon be depleted and the sensor will have to be regenerated.

Display Calibration

record

+++ S = 0.8 ... 1.25

++ S = 0.7 ... 0.8

+ S = 0.6 ... 0.7

Error Error

Perform error elimination according to chapter 6 W

DO IF...

HAT TO

Relative slope

S < 0.6 or S > 1.25

Multi 3500i Operation

Calibration in

water vapor

saturated air

(air calibration vessel)

For this calibration procedure, the Comparison meas. setting must be set to Off in the measuring menu.

Proceed as follows to calibrate the instrument:

Note

The sponge in the air calibration vessel must be moist (not wet). Leave the sensor in the air calibration vessel for a time long enough to adjust.

1 Put the DO sensor into the air calibration vessel.

2 Connect the DO sensor to the measuring instrument.

3 In the measured value display, select the DO measuring win-

dow with <▲><▼> and <M>.

4 Start the calibration with <CAL>.

The calibration display for the relevant sensor type appears.

ConOx <CAL>

i Relative slope = 1.00 i Use air calibration vessel

Continue

5 Put the DO sensor into the air calibration vessel.

6 Press <MENU/ENTER>.

The AutoRead measurement to determine the relative slope starts.

ConOx <CAL>

i Relative slope = 1.00 i Temperature = 24.8 °C

Terminate AutoRead

7 Wait for the end of the AutoRead measurement or accept the

calibration value with <MENU/ENTER>. The determined relative slope is displayed as a message (

i).

Operation Multi 3500i

ConOx <CAL>

i Relative slope = 0.98 i Sensor+++

8 You have the following options:

z Accept the new calibration values with <MENU/ENTER>.

Subsequently, the calibration record is displayed and output to the interface at the same time.

Calibration via a

Comparison meas.

z To switch to the measured value display without

accepting

the new calibration values, press <M> or <ESC>.

For this calibration procedure, the Comparison meas. setting must be set to On in the measuring menu.

Note

Before calibrating via a comparison measurement, the sensor should be calibrated in the air calibration vessel.

Proceed as follows to calibrate the instrument:

1 Connect the DO sensor to the measuring instrument.

2 Immerse the DO sensor in the reference solution.

3 In the measured value display, select the DO measuring win-

dow with <▲><▼> and <M>.

4 Start the calibration with <CAL>.

The calibration display appears.

ConOx <CAL>

i Immerse sensor in ref. sol.

Continue

Multi 3500i Operation

5 Press <MENU/ENTER>.

The AutoRead measurement to determine the DO concentration starts.

ConOx <CAL>

i Concentration = 8.5 mg/l i Temperature = 24.8 °C

Terminate AutoRead

6 Wait for the end of the AutoRead measurement or accept the

measured value with <MENU/ENTER>. The determined DO content is displayed as a message (

i).

ConOx <CAL>

i Concentration = 8.49 mg/l i Temperature =

Set factor: 1.000

24.8 °C

7 Press <MENU/ENTER>.

8 Using <▲> <▼>, set the correction factor to adjust the dis-

played concentration value to the nominal value (value of the comparison measurement). Subsequently, accept the correction factor with <MENU/ENTER>.

9 Select Accept with <▲><▼> and press <MENU/ENTER>.

The measuring instrument switches to the measured value display. The [Factor] indicator appears in the measuring window.

Operation Multi 3500i

4.7 Conductivity

4.7.1 General information

You can measure the following variables:

z Conductivity

z Specific resistance

z Salinity

z Total dissolved solids (TDS)

The measuring instrument is supplied with the following functions:

z AutoRange (automatic switchover of the measurement range). If a

z AutoRead drift control) for checking the stability of the measurement

signal. This ensures the reproducibility of the measuring signal. The display of the measured variable flashes until a stable measured value is available.

Temperature

measurement

The TetraCon 325, ConOx, LR 325/01 and LR 325/001 conductivity measuring cells have an integrated temperature sensor.

Caution

When connecting an earthed PC/printer, measurements cannot be performed in earthed media as incorrect values would result. The RS232 interface is not galvanically isolated.

Preparatory activities Perform the following preparatory activities when you want to measure:

1 Connect a conductivity measuring cell to the measuring instru-

ment. The conductivity measuring window is displayed.

2 Check whether the Measuring cell and cell constant settings

are suitable for the connected conductivity measuring cell. If necessary, correct the settings.

Note

The selection of the measuring cell and setting of the cell constant is made in the conductivity measuring menu (see section 4.7.4). The cell constant to be set must either be taken from the operating manual of the measuring cell or is printed on the measuring cell.

Multi 3500i Operation

4.7.2 Measuring

You can carry out conductivity measurements as follows:

1 Perform the preparatory activities according to section 4.7.1.

2 Immerse the conductivity measuring cell in the test sample.

731

24.8

Selecting the

displayed

measured variable

AutoRead criterion The measuring instrument checks the stability of the measured value

You can switch between the following displays with <M>:

z Conductivity [µS/cm] / [mS/cm]

z Specific resistance [k

z Salinity SaL [ ]

z Total dissolved solids TDS [mg/l]

The factor to calculate the total dissolved solids is set to 1.00 in the factory. You can adjust this factor to meet your requirements in the range of 0.40 to 1.00. The factor can be set in the TDS measuring menu.

on the basis of the temperature measurement. For identical measurement conditions, the following applies:

µS/cm

°C

Ω

·cm] / [MΩ·cm]

Measured variable

Temperature better than 0.02 °C > 10 seconds

Reproducibility Response time

Operation Multi 3500i

4.7.3 Temperature compensation

The calculation of the temperature compensation is based on the preset reference temperature, 20 °C or 25 °C. It appears on the display as Tr20 or Tr25.

You can select one of the following temperature compensation methods:

z Nonlinear temperature compensation (nLF)

according to EN 27 888

z Linear temperature compensation (Lin)

with selectable coefficients of 0.000 ... 3.000 %

z No temperature compensation (off)

Note

The reference temperature and temperature compensation are set in the conductivity measuring menu (see section 4.7.4).

Application tips Select the following temperature compensations given in the table ac-

cording to the respective test sample:

Test sample Temperature compensation Display

indicator

Natural water (ground water, surface

nLF according to EN 27 888

nLF

water, drinking water)

Ultrapure water nLF

nLF

according to EN 27 888

4.7.4 Settings for conductivity measuring cells

Overview The following settings are possible for conductivity measuring cells:

z Measured variable

z Reference temperature

z Temperature compensation

z TDS factor

z Calibration interval

z Measuring cell/cell constant

Settings The settings are made in the measuring menu of the conductivity mea-

surement. To open the settings, activate the relevant measuring window in the measured value display and press the <MENU/ENTER> key shortly

. After completing the settings, switch to the measured value dis-

play with <M>.

Menu item Possible

Description

setting

Calibration / Calibra- tion interval

1 ... 999 d Calibration interval for the

measuring cell (in days). The measuring instrument reminds you to calibrate regularly by the flashing sensor symbol in the measuring window.

Calibration / Calibra- tion record

- Displays the calibration

record of the last calibration.

Reset - Resets all sensor settings to

the delivery condition (see section 4.10.1).

Temp. comp. (TC) / Reference temp.

20 °C 25 °C

Reference temperature

This setting is only available when the Conductivity or

Spec. resist. display is set.

Temp. comp. (TC) / Compensation

nLF lin Off

Procedure for temperature compensation (see section 4.7.3).

This setting is only available when the Conductivity or Spec. resist. display is set.

Operation Multi 3500i

Menu item Possible

Description

setting

Temp. comp. (TC) / Linear coeff.

0.000 ...

3.000 %/K

Coefficient of the linear temperature compensation.

This setting is only available when the linear temperature compensation is set.

Measuring cell Measuring cell used

Cal Measuring cells the cell con-

stant of which is determined by calibration in the KCL control standard solution. Calibration ranges:

0.450 to 0.500 cm

0.800 to 1.200 cm

-1

The currently valid cell constant is displayed in the status line.

LR325/001 LR 325/001 measuring cell,

nominal cell constant

0.010 cm

-1

. The cell constant is permanently set.

and

LR325/01 LR 325/01 measuring cell,

man Any measuring cells with free-

Cell constant 0.090 to

0.110 cm

Man. cell const. 0.250 to

25.000 cm

nominal cell constant

0.100 cm

-1

. The cell constant can be adjusted in the range from 0.090 to 0.110 cm

-1

ly adjustable cell constants in the range from 0.250 to

25.000 cm

-1

Display and setting option of

-1

the cell constant of the LR 325/01 measuring cell.

Display and setting option of

-1

the cell constant of any measuring cells (man).

Multi 3500i Operation

4.7.5 Determining the cell constant (calibration in the control standard)

Why determine the cell

constant?

Procedure You can determine the actual cell constant of the conductivity measur-

AutoRead The calibration procedure automatically activates the AutoRead func-

Aging slightly changes the cell constant, e. g. by coatings. As a result, an inexact measured value is displayed. The original characteristics of the cell can often be restored by cleaning the cell. Calibration determines the current value of the cell constant and stores this value in the instrument. Thus, you should calibrate at regular intervals (we recommend: every 6 months).

ing cell by calibrating with the control standard in the following ranges:

z 0.450 ... 0.500 cm

-1

(e.g. TetraCon 325, nominal cell constant 0.475)

z 0.800 ... 1.200 cm

-1

(cells with a cell constant of approx. 1)

The cell constant is determined in the control standard, 0.01 mol/l KCl. Cell constants outside the ranges quoted above cannot be calibrated.

In the delivery condition, the calibrated cell constant of the measuring instruments is set to 0.475 cm

-1

(conductivity measuring cells,

TetraCon 325 and ConOx).

tion.

Display calibration data

and output to interface

Note

The calibration record is automatically transmitted to the interface after calibrating.

Sample record:

3.11.03 07:14

CALIBRATION Cond

03.11.03 07:13:22

Multi 3500i ser. no. 12345678

Cal. interval 14 d

Cell constant 0.975 1/cm 25.0 °C

Sensor +++

Operation Multi 3500i

Calibration evaluation After the calibration, the measuring instrument automatically evaluates

the current status of the calibration. The evaluation appears on the display and in the calibration record.

-1

Display Calibration

Cell constant [cm

]

record

Determining the

cell constant

+++ within the ranges

0.450 ... 0.500 cm

-1

Error Error

Perform error elimination according to chapter 6 W

DO IF...

HAT TO

0.800 ... 1.200 cm

outside the ranges

0.450 ... 0.500 cm or

0.800 ... 1.200 cm

For this calibration procedure, the Measuring cell setting must be set to cal in the measuring menu. Proceed as follows to determine the cell constant:

1 Connect a conductivity measuring cell to the measuring instru-

ment.

2 In the measured value display, select the conductivity measur-

ing window with <▲><▼> and <M>.

3 Start the calibration with <CAL>.

The calibration display appears.

<CAL>

i Cell constant = 0.475 1/cm i Immerse sensor in solution

Continue

4 Immerse the conductivity measuring cell in the control standard

solution, 0.01 mol/l KCI.

Multi 3500i Operation

5 Press <MENU/ENTER>.

The AutoRead measurement to determine the cell constant starts.

<CAL>

i Cell constant = 0.481 1/cm i Temperature = 24.8 °C

Terminate AutoRead

6 Wait for the end of the AutoRead measurement or accept the

calibration value with <MENU/ENTER>. The determined cell constant is displayed as a message (

<CAL>

i Cell constant = 0.481 1/cm i Sensor+++

i).

7 You have the following options:

z Accept the new calibration values with <MENU/ENTER>.

Subsequently, the calibration record is displayed and output to the interface at the same time.

z To switch to the measured value display without

the new calibration values, press <M> or <ESC>.

accepting

Operation Multi 3500i

4.8 Data storage

You can transmit measured values (data records) to the data storage in two ways:

z Manual data storage (see section 4.8.1)

z Automatic data storage at intervals (see section 4.8.2)

Each storage process transmits the current dataset to the interface at the same time.

Measurement dataset A complete dataset consists of:

z Date/time

z Instrument designation with series number

z ID number

z Measured values of the connected sensors

z Temperature values of the sensors connected

z AutoRead info: AR appears with the measured value if the Auto-

Read criterion was met while storing (stable measured value). Otherwise, the AR display is missing.

z Measurement conditions (salt content correction, cell constant, ref-

erence temperature, temperature compensation, TDS factor).

Storage locations The measuring instrument has separate data storages for manually

stored measured values and automatically stored measured values.

Storage Maximum number of datasets

Manual data storage 504

Automatic data storage 1800

Multi 3500i Operation

4.8.1 Manual data storage

Proceed as follows to transmit to the data data storage and simultaneously output to the interface a measurement dataset:

1 Press the <STO> key shortly.

The menu for manual data storage appears.

<STO> 1 of 504

- 30.10.2003 11:24:16

- pH 7.000 24.8 °CAR

- Oxi 7.27 mg/l 25.0 °CAR

- TDS 689 mg/l 25.0 °CAR

Store with ID no.:1

Continue

2 If necessary, change and confirm the ID number (1 ... 999) with

<▲><▼> and <MENU/ENTER>. The dataset is stored. The instrument switches to the measured value display.

If the data storage is full The following window appears if all 504 storage locations are occupied:

Warning

Data storage full. Erase?

Yes

You have the following options:

z To erase the entire data storage, confirm Yes.

z To cancel the data storage process and switch to the measured val-

ue display, confirm No. Then you can, e.g. transmit the stored data to a PC (see section 4.8.3) and subsequently erase the data storage (see section 4.8.4).

Operation Multi 3500i

4.8.2 Automatic data storage at intervals

The storage interval (Interval) determines the chronological interval between automatic storage processes. Each storage process transmits the current dataset to the interface at the same time.

Configuring the auto-

matic data storage func-

tion

Settings You can configure the automatic data storage function with the follow-

1 Press the <STO> key for a long time.

The menu for automatic data storage appears.

<STO_>

Store with ID no. 1 Interval 30 s Duration 180 min Continue

00d03h00min 00d15h

34 min

ing settings:

Menu item Possible

Description

setting

Store with ID no. 1 ... 999 ID number for the dataset

series.

Interval 5 s, 10 s, 30 s,

Storage interval.

1 min, 5 min, 10 min, 15 min, 30 min, 60 min

The lower limit of the storage interval can be restricted by the number of free storage locations. The upper limit is restricted by the storage duration.

Duration 1 min ... x min Storage duration

Specifies after which time the automatic data storage should be terminated.

The lower limit of the storage duration is restricted by the storage interval. The upper limit is restricted by the number of free storage locations.

Multi 3500i Operation

Data storage adminis-

tration

Starting the automatic

data storage function

The two lower display lines indicate the use of the data storage calculated in advance for the selected settings:

<STO_>

Store with ID no. 1 Interval 30 s Duration 180 min Continue

00d03h00min 00d15h

34min

To start the automatic data storage function, select Continue with <▲><▼> and confirm with <MENU/ENTER>. The measuring instru- ment switches to the measured value display.

Adjusted storage duration for the entire dataset series

Maximum usable storage duration

Graphical display of the storage use

6.949

24.8

The active automatic data storage function can be recognized from the progress bar in the status line. The progress bar indicates how much of the adjusted storage duration has already expired.

Note

The automatic data storage function is interrupted if you start other functions, e.g. output the data storage. After the other function has been finished, the automatic data storage function is continued. Note that this causes chronological gaps in the dataset series.

°C

Operation Multi 3500i

Terminating the auto-

matic data storage func-

tion prematurely

Proceed as follows to switch off the automatic data storage function before the adjusted storage duration has expired:

1 Press the <STO> key for a long time.

The following window appears.

Warning

Stop automatic storage?

Yes

2 Select and confirm Yes with <▲><▼> and <MENU/ENTER>.

The measuring instrument switches to the measured value display. The automatic data storage function is terminated.

4.8.3 Editing the measured value storage

You can select the contents of the manual or automatic measured value storage by means of different filter criterions and

z read them out on the display, and

z output them to the interface.

Each measured value storage has a separate erasure function for the entire contents, independent of the filter settings.

Editing the data storage The storage can be edited in the system menu, submenu Data storage.

To open the system menu in the measured value display, press the <MENU/ENTER> key for approx. 1 s

Note

The settings are explained here using the manual data storage as an example. The same settings and functions are available for the automatic data storage.

Multi 3500i Operation

Settings

Menu item Setting/

function

Data storage /

- Displays in pages all mea-

Manual data storage / Display

Data storage /

- Outputs to the interface all

Manual data storage / Output to RS232

Description

suring datasets that correspond to the filter settings.

Further options: z Scroll through the

datasets with <▲><▼>.

z Output the displayed

dataset to the interface with <PRT>.

z Quit the display with

<ESC>.

measuring datasets that correspond to the filter settings. The output takes place in ascending order of the ID number. The process can take several minutes. To terminate the process prematurely, press <ESC>.

Data storage / Manual data storage / Data filter

Data storage / Manual data storage / Erase

-> see explanations below this table

Allows to set certain filter criteria in order to display and output them to the interface datasets.

- Erases the entire contents of the selected measuring data storage, independent of the filter settings.

Note: All calibration data remains stored when performing this action.

Operation Multi 3500i

Data filter

Display presentation

of a dataset

Menu item Setting/

Description

function

Filter Filter criteria:

No filter Data filter switched off

Date & ID number

Selection according to period and ID number

ID number Selection according to ID

number

Date Selection according to pe-

riod

From TT.MM.JJ Selects all datasets within

the specified period.

Until TT.MM.JJ

With ID 0 ... 999 Selects all datasets with

the specified ID number.

30.10.2003 11:24:16 (1) ID number 1

- pH 7.000 24.8 °CAR

- Oxi 7.27 mg/l 25.0 °CAR

- TDS 689 mg/l 25.0 °CAR

Multi 3500i Operation

Sample printout

3.11.03 15:48:08 Multi 3500i ser. no. 12345678 ID number: 1 ISE 0.316 mg/l 22 °C , AR Oxi 6.32 mg/l 24.8 °C , AR Sal = 0.7 Cond 1413 uS/cm 24.8 °C C = 0.975 1/cm, Tref25, Lin, TC = 2.000 %/K ________________________________________

03.11.03 09:56:20 Multi 3500i ser. no. 12345678 ID number: 1 pH 6.12 24.8 °C , AR Oxi 7.46 mg/l 24.8 °C Sal = 0.0 Res 69.0 kOhm*cm 24.8 °C , AR C = 0.010 1/cm, Tref25, Lin, TC = 2.000 %/K ________________________________________

03.11.03 09:27:24 Multi 3500i ser. no. 12345678 ID number: 1 pH 7.13 24.8 °C Cond-TP, AR Oxi 5.95 mg/l 24.8 °C , AR Sal = 0.7 Res 0.708 kOhm*cm 24.8 °C , AR C = 0.975 1/cm, Tref25, Lin, TC = 2.000 %/K ________________________________________

etc...

Quitting the display To quit the display of stored measuring datasets, you have the follow-

ing options:

z Switch directly to the measured value display with <M>.

z Quit the display and move to the next higher menu level with <ESC>

or <MENU/ENTER>.

4.8.4 Erasing the measured value storage

How to erase the measured value storage is described in section 4.8.3 E

DITING THE MEASURED VALUE STORAGE.

Operation Multi 3500i

4.8.5 Displaying and outputting calibration records

You can display the calibration data

z of one selected sensor, or

z of all sensors connected

and then output them to the interface.

Displaying the calibra-

tion record of a selected

sensor

Displaying the calibra-

tion records of all

sensors connected

The calibration record of the last calibration can be found under the Calibration / Calibration record menu item in the respective measuring

menu. To open the settings, activate the relevant measuring window in the measured value display and press the <MENU/ENTER> key shortly

The calibration records of the last calibration can be found under the Data storage / Calibration data storage menu item in the system menu. To open the system menu in the measured value display, press the

<MENU/ENTER> key for approx. 1 s

Menu item Setting/

Description

function

Data storage / Cali- bration data storage / Display

- Displays in pages all calibration records of all sensors.

Further options: z Scroll through the cali-

bration records with

<▲><▼>.

Data storage / Cali- bration data storage / Output to RS232

z Output the displayed

calibration record to the interface with <PRT>.

z Quit the display with

<ESC> or <MENU/ENTER>.

z Switch directly to the

measured value display with <M>.

- Outputs to the interface the calibration records of all sensors.

Multi 3500i Operation

Sample printout

03.11.03 07:14

CALIBRATION pH

03.11.03 07:10:45

Multi 3500i ser. no. 12345678

Cal. interval 7 d

AutoCal TEC

Buffer 1 4.01

Buffer 2 7.00

Buffer 3 10.01

Voltage 1 184.0 mV 24.0 °C

Voltage 2 0.0 mV 24.0 °C

Voltage 3 -177.0 mV 24.0 °C

Slope -60.2 mV/pH

Asymmetry 3.0 mV

Sensor +++

03.11.03 07:14

CALIBRATION ISE

03.11.03 07:12:01

Multi 3500i ser. no. 12345678

Standard 1 0.010 mg/l

Standard 2 0.020 mg/l

Voltage 1 0.0 mV 24.0 °C

Voltage 2 9.0 mV 24.0 °C

Slope 29.9 mV

Sensor +++

etc...

Operation Multi 3500i

4.9 Transmitting data (RS 232 interface)

4.9.1 Options for data transmission

Via the RS 232 interface, you can transmit data to a PC or an external printer. The following table shows which data are transmitted to the interface in which way:

Data Control Operation / description

Current measured values of all connected sensors

Stored measured values

Manual z By pressing <PRT> short-

ly.

z Simultaneously with every

manual data storage process (see section 4.8.1).

Automatic, at intervals

z By pressing <PRT> for a

long time. Then you can set the transmission interval.

z Simultaneously with every

automatic data storage process (see section 4.8.2).

Manual z Displayed dataset with

<PRT> after calling up from the data storage.

z All datasets according to

the filter criteria via the Output to RS232 function.

For details, see section 4.8.3.

Calibration records Manual z Calibration record of a sen-

sor with <PRT> (after calling up from the data storage or at the end of a calibration).

z All calibration records after

calling up from the data storage via the Output to RS232 function.

For details, see section 4.8.5

Automatic z For the respective sensor

at the end of a calibration.

Note

The following rule applies: With the exception of the menus, shortly pressing the <PRT> key generally outputs the display contents to the

Multi 3500i Operation

CTS

interface (displayed measured values, measuring datasets, calibration records).

4.9.2 Connecting a PC/external printer

Use the AK340/B (PC) or AK325/S (ext. printer) cable to connect the interface to the devices.

Caution

The RS232 interface is not galvanically isolated. When connecting an earthed PC/printer, measurements cannot be performed in earthed media as incorrect values would result.

Set up the following transmission data on the PC/printer:

Baud rate selectable between:

1200, 2400, 4800, 9600, 19200

Handshake RTS/CTS

Socket assignment

PC only:

Parity none

Data bits 8

Stop bits 2

1 2 RxD

RS 232

REC

4.9.3 Operation with MultiLab pilot

With the aid of the MultiLab pilot software, you can record and evaluate measuring data with a PC. The data is transmitted after the measuring instrument is connected to the RS232 serial interface (COM interface) of a PC.

3 Ground 4TxD

Note

More detailed information can be found in the MultiLab pilot operating manual.

Operation Multi 3500i

4.10 Reset

You can reset (initialize) all sensor settings and sensor-independent settings separately from each other.

4.10.1 Resetting the sensor settings

Note

The calibration data are reset to the default settings together with the measuring parameters. Recalibrate after performing a reset.

pH The following settings for pH measurements are reset to the default

settings with the Reset function:

Setting Default settings

Calibration type TEC

Cal. interval 7 d

Unit for slope mV/pH

Measured variable pH

High resolution On

Asymmetry 0 mV

Slope -59.16 mV

Temperature, manual 25 °C

Oxi The following settings for DO measurements are reset to the default

settings with the Reset function:

Setting Default settings

Cal. interval 14 d

Comparison meas. Off

Measured variable DO concentration

Relative slope (S

)1.00

Rel

Salinity (value) 0.0

Salinity (function) Off

Multi 3500i Operation

Cond The following settings for conductivity measurements are reset to the

default settings with the Reset function:

Setting Default settings

Cal. interval 150 d

Measured variable

-1

Cell constant (c) 0.475 cm

0.475 cm

(calibrated)

-1

(set up)

Temperature compensation nLF

Reference temperature 25 °C

Temperature coefficient (TC) of

2.000 %/K the linear temperature compensation

TDS factor 1.00

The sensor settings are reset under the Reset menu item in the respective measuring menu. To open the settings, activate the relevant measuring window in the measured value display and press the <MENU/ENTER> key shortly

4.10.2 Resetting the system settings

The following system settings can be reset to the delivery status:

Setting Default settings

Language English

Temperature unit °C

Beep On

Baud rate 4800 Baud

Output format ASCII

Contrast 48 %

Illumination On

Switchoff time 30 min

The system settings are reset under the System / Reset menu item in the system menu. To open the system menu in the measured value display, press the <MENU/ENTER> key for approx. 1 s

Operation Multi 3500i

Multi 3500i Maintenance, cleaning, disposal

5 Maintenance, cleaning, disposal

5.1 Maintenance

The measuring instrument is maintenance-free.

5.2 Cleaning

Occasionally wipe the outside of the measuring instrument with a damp, lint-free cloth. Disinfect the housing with isopropanol as required.

Caution

The housing components are made out of synthetic materials (polyurethane, ABS and PMMA). Thus, avoid contact with acetone and similar detergents that contain solvents. Remove any splashes immediately.

5.3 Disposal

Packing This measuring instrument is sent out in a protective transport packing.

We recommend: Keep the packing material. The original packing protects the measuring instrument from transport damages.

Rechargeable batteries Remove the rechargeable battery from the instrument and dispose of it

at a suitable facility according to local legal requirements. It is illegal to dispose of the rechargeable batteries with household refuse. Proceed as follows to disassemble the rechargeable batteries:

NiMH

Maintenance, cleaning, disposal Multi 3500i

1 Open the housing:

– Undo the four screws on the underside of the instrument

– Open the lower cover (1).

2 Take the four batteries (2) out of the battery compartment.

Measuring instrument Dispose of the measuring instrument without the rechargeable batter-

ies as electronic waste at an appropriate collection point.

Multi 3500i What to do if...

6 What to do if...

6.1 pH and ORP measurement

Error message,

OFL or UFL

(measuring range

exceeded or undercut)

Error message, Error

(calibration error)

Cause Remedy

Electrode:

– Air bubble in front of the

diaphragm

– Air in the diaphragm – Extract air or

– Gel electrolyte dried out – Replace electrode

Test sample

– The pH value lies outside the

measuring range

Cause Remedy

Electrode:

– Diaphragm contaminated – Clean diaphragm

– Membrane contaminated – Clean membrane

– Remove air bubble

moisten diaphragm

– not possible

– Moisture in the plug – Dry plug

– Not enough electrolyte – Top up electrolyte

– Electrode obsolete – Replace electrode

– Electrode broken – Replace electrode

– Socket damp – Dry socket

Calibration procedure:

– Incorrect solution temperature

(without temperature sensor)

– Incorrect buffer solutions – Select buffer solutions

– Buffer solutions too old – Use only once.

– Set up correct temperature

suitable for the calibration procedure

Note the shelf life

What to do if... Multi 3500i

No stable measured

Cause Remedy

value

pH electrode:

– Diaphragm contaminated – Clean diaphragm

– Membrane contaminated – Clean membrane

Test sample

– pH value not stable – Measure with air excluded if

necessary

– Temperature not stable – Adjust temperature if

necessary

Electrode + test sample:

– Conductivity too low – Use suitable electrode

– Temperature too high – Use suitable electrode

Obviously incorrect

measured values

Sensor symbol flashes

– Organic liquids – Use suitable electrode

Cause Remedy

pH electrode:

– Not connected – Connect electrode

– Cable broken – Replace electrode

– pH electrode unsuitable – Use suitable electrode

– Temperature difference

between buffer and test

– Adjust temperature of buffer

or sample solutions

sample too high

– Measurement procedure not

– Follow special procedure

suitable

Cause Remedy

– Calibration interval expired – Recalibrate the measuring

system

Multi 3500i What to do if...

6.2 ISE measurement

Error message OFL

Obviously incorrect

measured values

Error message, Error

(invalid

calibration)

Cause Remedy

– Measuring range exceeded – Dilute test sample

Cause Remedy

– Electrode not connected – Connect electrode

– Cable broken – Replace electrode

Cause Remedy

Ion-sensitive electrode:

– Moisture in the plug – Dry plug

– Electrode obsolete – Replace electrode

– Electrode unsuitable for the

– Use a suitable electrode

range to be measured

– Socket damp – Dry socket

Warning [TempErr]

Warning [ISEErr]

Calibration procedure:

– Wrong sequence of standards

– Select correct sequence

for three point calibration

– Calibration standards do not

have the correct temperature (max.

± 2 °C temperature

– Adjust the temperature of

the calibration standards

difference)

Cause Remedy

– Temperature difference

between measurement and

– Adjust the temperature of

the test sample

calibration greater than 2 K.

Cause Remedy

– Electrode voltage outside

– Recalibrate

calibrated range

What to do if... Multi 3500i

6.3 DO measurement

DO sensor was not

recognized

Error message OFL

Error message, Error

(invalid calibration)

Cause Remedy

– Sensor not connected – Connect sensor

– Cable broken – Replace sensor

Cause Remedy

– Measuring range exceeded – not possible

Cause Remedy

DO sensor:

– Electrolyte solution depleted – Regenerate sensor

– Membrane contaminated – Clean membrane

– Electrode system poisoned – Regenerate sensor

Error message, LEAK

Measured value flashes

for a long time

(No stable measured

value)

Measured value too low

Cause Remedy

DO sensor:

– Membrane damaged – Exchange the membrane cap

– Membrane head screwed on

– Screw membrane head tight

not tight enough

Cause Remedy

DO sensor:

– Membrane contaminated – Clean membrane

Cause Remedy

DO sensor:

– Insufficient flow – Provide flow to the sensor

Multi 3500i What to do if...

Measured value too

high

Sensor symbol flashes

Conductivity

measuring cell

was not recognized

Cause Remedy

– High amount of dissolved

substances

– Air bubbles bump on the

membrane with high velocity

– The carbon dioxide pressure is

– Correct solubility function

using the salinity equivalent

– Avoid direct flow to the

membrane

– Measuring not possible

too high (> 1 bar)

Cause Remedy

– Calibration interval expired – Recalibrate the measuring

system

6.4 Conductivity measurement

Cause Remedy

– Measuring cell not connected – Connect measuring cell

– Cable broken – Replace measuring cell

Error message, Error

(invalid

calibration)

Sensor symbol flashes

Cause Remedy

– Measuring cell contaminated – Clean cell and replace it if

necessary

– Unsuitable control standard – Use control standard,

0.01 mol/l KCl

Cause Remedy

– Calibration interval expired – Recalibrate the measuring

system

What to do if... Multi 3500i

6.5 General errors

Display, LoBat

Instrument does not

react to keystroke

Cause Remedy

– Batteries almost empty – Charge the batteries (see

section 3.2)

Cause Remedy

– Operating condition undefined

or EMC load unallowed

– Processor reset:

Press the <ON/OFF> and

<CAL> key simultaneously.

Multi 3500i Technical data

7 Technical data

7.1 General data

Dimensions approx. 172 x 80 x 37 mm

Weight approx. 0.3 kg (without plug-in power supply)

Mechanical structure Type of protection IP 66

Electrical safety Protective class III

Test certificates cETLus, CE

Ambient conditions Storage - 25 °C ... + 65 °C

Operation -10 °C ... + 55 °C

Climatic class 2

Power

supply

Serial

interface

Rechargeable batteries

Operational life up to 500 h with one battery charging

Plug-in power supply (charging device)

Connection of the cable AK 340/B or AK 325/S

Baud rate adjustable:

Type RS232, data output

Data bits 8

Stop bits 2

Parity None

Handshake RTS/CTS

Cable length Max. 15m

4 x 1.2 V nickel metal hydride (NiMH), type AA

FRIWO FW7555M/09, 15.1432.500-00 Friwo Part. No. 1883259 Input: 100 ... 240 V ~ / 50 ... 60 Hz / 400 mA Output: 9 V = / 1,5 A Connection max. overvoltage category II Primary plugs contained in the scope of delivery: Euro, US, UK and Australian.

1200, 2400, 4800, 9600, 19200 Baud

Technical data Multi 3500i

Guidelines

and norms used

EMC EC guideline 89/336/EEC

EN 61326-1:1998 EN 61000-3-2 A14:2000 EN 61000-3-3:1995 FCC Class A

Instrument safety E.C. guideline 73/23/EEC

EN 61010-1 A2:1995

Climatic class VDI/VDE 3540

IP protection EN 60529:1991

FCC Class A Equipment Statement

Note: This equipment has been tested and found to comply with the limits for a Class A digital device, pursuant to Part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference when the equipment is operated in a commercial environment. This equipment generates, uses, and can radiate radio frequency energy and, if not installed and used in accordance with the instruction manual, may cause harmful interference to radio communications. Operation of this equipment in a residential area is likely to cause harmful interference in which case the user will be required to correct the interference at his own expense.

Multi 3500i Technical data

7.2 Measuring ranges, resolution, accuracy

7.2.1 pH/ORP

Measuring ranges,

resolution

Variable Measuring range Resolution

pH - 2.000 ... + 20.000

- 2.00 ... + 20.00

U [mV] - 999.9 ... + 999.9

- 2000 ... + 2000

0.001

0.01

0.1 1

T [°C] - 5.0 ... + 105.0 0.1

Manual

temperature input

Variable Range Increment

[°C] - 20 ... + 130 1

manual

Accuracy (± 1 digit) Variable Accuracy Temperature of the test

sample

pH * ± 0.004 + 15 °C ... + 35 °C

U [mV] / range

- 999.9 ... + 999.9 ± 0.2 + 15 °C ... + 35 °C

- 2000 ... + 2000 ± 1 + 15 °C ... + 35 °C

T [°C] / temperature sensor

Measuring ranges,

resolution

Manual

temperature input

NTC 30 ± 0.2 0 °C ... + 55 °C

PT 1000 ± 0.3 0 °C ... + 55 °C

* when measuring in a range of ± 2 pH around a calibration point

7.2.2 ISE

Variable Measuring range Resolution

ISE [mg/l] 0.000 ... 10.000

0.00 ... 100.00

0.0 ... 100.0 0 ... 2000

0.001

0.01

0.1 1

Variable Range Increment

[°C] - 20 ... + 130 1

manual

Technical data Multi 3500i

7.2.3 Dissolved oxygen

Measuring ranges,

resolution

The values quoted in brackets apply especially for the

Note: DurOx 325 sensor.

Variable Measuring range Resolution

DO concentration [mg/l]

0 ... 20.00 (0 ... 20.0) 0 ... 90.0 (0 ... 90)

Saturation [%] 0 ... 200.0 (0 ... 200)

0 ... 600

partial pressure

[mbar]

0 ... 200.0 (0 ... 200) 0 ... 1250

T [°C] 0 ... 50.0 0.1

Accuracy (± 1 digit) Variable Accuracy

DO concentration [mg/l]

± 0.5 % of measured value at ambient temperature + 5 °C ... + 30 °C

Saturation [%] ± 0.5% of measured value

when measuring in the range of ± 10 K around the calibration temperature

partial pressure

[mbar]

± 0.5 % of measured value at ambient temperature + 5 °C ... + 30 °C

0.01 (0.1)

0.1 (1)

0.1 (1) 1

Correction functions Temperature

compensation

Salinity correction 0 ... 70.0 SAL

Air pressure correction

Accuracy better than 2 % at 0 ... + 40 °C

Automatic through integrated pressure sensor in the range of 500 ... 1100 mbar

Multi 3500i Technical data

7.2.4 Conductivity

Measuring ranges,

resolution

Variable Measuring range Resolution

[µS/cm] 0.000 ... 2.000*

0.00 ... 20.00**

0.0 ... 200.0 0 ... 2000

[mS/cm] 0.00 ... 20.00

0.0 ... 200.0 0 ... 2000

Specific resistance [kOhm*cm]

0.000 ... 2.000

0.00 ... 20.00

0.0 ... 200.0 0 ... 2000

Specific resistance [MOhm*cm]

0.00 ... 20.00

0.0 ... 200.0 0 ... 2000

SAL 0.0 ... 70.0

0.001

0.01

0.1 1

0.01

0.1 1

0.001

0.01

0.1 1

0.01

0.1 1

0.1 according to the IOT table

TDS [mg/l] 0 ... 2000

1 Factor can be set between 0.40 and 1.00

T [°C] - 5.0 ... + 105.0 0.1

* only possible with cells of the cell constant, 0.010 cm ** only possible with cells of the cell constant, 0.010 cm-1 or 0.090 ... 0.110 cm

Cell constants Cell constant C Values

Can be calibrated in the ranges

Adjustable 0.010 cm-1 (fixed)

Reference temperature Reference

temperature

Adjustable 20 °C (Tr20)

0.450 ... 0.500 cm

0.800 ... 1.200 cm

0.090 ... 0.110 cm

0.250 ... 25.000 cm

Values

25 °C (Tr25)

-1

Technical data Multi 3500i

Accuracy (± 1 digit) Variable Accuracy Temperature of the test

sample

/ Temperature compensation

None (Off) ± 0.5 %

Nonlinear (nLF) ± 0.5 % 0 °C ... + 35 °C

according to EN 27 888

± 0.5 % + 35 °C ... + 50 °C

Extended nLF function according to WTW measurements

Linear (lin) ± 0.5 % + 10 °C ... + 75 °C

SAL / range

0.0 ... 42.0 ± 0.1 + 5 °C ... + 25 °C

± 0.2 + 25 °C ... + 30 °C

TDS [mg/l]

± 1

T [°C] / temperature sensor

NTC 30 ± 0.2 0 °C ... + 55 °C

PT 1000 ± 0.3 0 °C ... + 55 °C

Multi 3500i Lists

8Lists

This chapter provides additional information and orientation aids.

Abbreviations The list of abbreviations explains the indicators and abbreviations that

appear on the display and in the manual.

Specialist terms The glossary briefly explains the meaning of the specialist terms. How-

ever, terms that should already be familiar to the target group are not described here.

Lists Multi 3500i

Abbreviations

Conductivity value (international γ)

ASY Asymmetry

Calibration type NIST/DIN

Calibration type TEC

C Cell constant [cm

Automatic pH calibration with buffer solutions prepared according to NIST or DIN 19 266

Automatic pH calibration with WTW technical buffer solutions according to DIN 19267

-1

] (internat. k)

°C Temperature unit, degrees Celsius

Cal Calibration

ConCal Conventional single-point or two-point calibration

for pH measurements

dDay

°F Temperature unit, degrees Fahrenheit

h Hour

j Year

Lin Linear temperature compensation

LoBat Batteries almost empty (Low battery)

mMonth

mV Voltage unit

mV/pH Unit of the electrode slope (internat. mV)

nLF Nonlinear temperature compensation

OFL Display range exceeded (Overflow)

OxiCal Automatic calibration for DO measurements

pH pH value

S Slope (internat. k)

SAL Salinity

SELV Safety Extra Low Voltage

SLO Slope setting on calibration

Multi 3500i Lists

TDS Total Dissolved Solids

Tr20 Reference temperature of 20 °C

Tr25 Reference temperature of 25 °C

UFL Display range undercut (underflow)

U Voltage

Lists Multi 3500i

Glossary

Adjusting To manipulate a measuring system so that the relevant value (e. g. the

displayed value) differs as little as possible from the correct value or a value that is regarded as correct, or that the difference remains within the tolerance.

Asymmetry Designation for the offset potential of a pH electrode. It is the measur-

able potential of a symmetrical electrode, the membrane of which is immersed in a solution with the pH of the nominal electrode zero point (WTW electrodes: pH = 7).

AutoRange Name of the automatic selection of the measuring range.

AutoRead WTW name for a function to check the stability of the measured value.

Calibration Comparing the value from a measuring system (e. g. the displayed

value) to the correct value or a value that is regarded as correct. Often, this expression is also used when the measuring system is adjusted at the same time (see adjusting).

Cell constant, k Characteristic quantity of a conductivity measuring cell, depending on

the geometry.

Conductivity Short form of the expression, specific electrical conductivity. It is a

measured value of the ability of a substance to conduct an electric current. In water analysis, the electrical conductivity is a dimension for the ionized substances in a solution.

Diaphragm The junction is a porous body in the housing wall of reference elec-

trodes or electrolyte bridges. It forms the electrical contact between two solutions and makes electrolyte exchange more difficult. The expression, junction, is also used for ground or junction-less transitions.

DO partial pressure Pressure caused by the oxygen in a gas mixture or liquid.

DO saturation Short name for the relative DO saturation.

Note: The DO saturation value of air-saturated water and the DO saturation value of oxygen-saturated water are different.

Electrode zero point The zero point of a pH electrode is the pH value at which the electro-

motive force of the pH electrode at a specified temperature is zero. Normally, this is at 25 °C.

Electromotive force of

an electrode

The electromotive force U of the electrode is the measurable electromotive force of an electrode in a solution. It equals the sum of all the galvanic voltages of the electrode. Its dependency on the pH results in the electrode function which is characterized by the parameters, slope and zero point.

Xylem MULTI-3500i User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

1Overview

1.1 General features

1.2 SETs of equipment

1.3 Keypad

1.4 Display

1.5 Socket field

2 Safety

2.1 Authorized use

2.2 General safety instructions

3 Commissioning

3.1 Scope of delivery

3.2 Power supply

3.3 Initial commissioning

4 Operation

4.1 Switching on the measuring instrument

4.2 General operating principles

4.2.1 Operating modes

4.2.2 Navigation

4.2.3 Example 1 on navigation: Setting the language

4.3 System settings (system menu)

4.3.1 Data storage

4.3.2 Display

4.3.3 System

4.4 pH value / ORP voltage

4.4.1 General information

4.4.2 Measuring the pH value

4.4.3 Measuring the ORP voltage

4.4.4 Settings for pH and ORP measurements

4.4.5 pH calibration

4.4.6 Carrying out the TEC and NIST/DIN calibration

4.4.7 Carrying out a ConCal calibration

4.5 Ion concentration

4.5.1 General information

4.5.2 Measuring the ion concentration

4.5.3 Settings for ISE measurements

4.5.4 Calibrating for ISE measurements

4.6 Dissolved oxygen

4.6.1 General information

4.6.2 Measuring

4.6.3 Settings for DO sensors

4.6.4 DO calibration

4.7 Conductivity

4.7.1 General information

4.7.2 Measuring

4.7.3 Temperature compensation

4.7.4 Settings for conductivity measuring cells

4.7.5 Determining the cell constant (calibration in the control standard)

4.8 Data storage

4.8.1 Manual data storage

4.8.2 Automatic data storage at intervals

4.8.3 Editing the measured value storage

4.8.4 Erasing the measured value storage

4.8.5 Displaying and outputting calibration records

4.9 Transmitting data (RS 232 interface)

4.9.1 Options for data transmission

4.9.2 Connecting a PC/external printer

4.9.3 Operation with MultiLab pilot

4.10 Reset

4.10.1 Resetting the sensor settings

4.10.2 Resetting the system settings

5 Maintenance, cleaning, disposal

5.1 Maintenance

5.2 Cleaning

5.3 Disposal

6 What to do if...

6.1 pH and ORP measurement

6.2 ISE measurement

6.3 DO measurement

6.4 Conductivity measurement

6.5 General errors

7 Technical data

7.1 General data

7.2 Measuring ranges, resolution, accuracy

7.2.1 pH/ORP

7.2.2 ISE

7.2.3 Dissolved oxygen