Xylem MULTI-3500i User Manual

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

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