Xylem CG 843 User Manual

Laboratory pH Meter

CG 843

Operating Manual

ba12243e_2 09/99

Accuracy when

going to press

All details contained in this operating manual are valid data at the time of going to press. However, SCHOTT may add details for both technical and commercial reasons, or in order to fulfil legal requirements of different countries. This does not affect the characteristics described.

Warranty

declaration

The designated instrument is covered by a warranty of three years from the date of purchase. The instrument warranty extends to manufacturing faults that are determined within the period of warranty. The warranty excludes components that are replaced during maintenance such as batteries, etc.

The warranty claim extends to restoring the instrument to readiness for use but not, however, to any further claim for damages. Improper handling or unauthorized opening of the instrument invalidates any warranty claim.

To ascertain the warranty liability, return the instrument and proof of purchase together with the date of purchase freight paid or prepaid.

Reprinting - even as excerpts - is only allowed with the explicit written authorization of SCHOTT Geräte GmbH, Hofheim. Printed in Germany.

List of contents

1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73

1.1 Keypad . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .74

1.2 Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .75

1.3 Sockets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .75

1.4 Declaration of conformity . . . . . . . . . . . . . . . . . .76

1.5 Technical data . . . . . . . . . . . . . . . . . . . . . . . . . .77

2 Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81

2.1 Authorized use . . . . . . . . . . . . . . . . . . . . . . . . .82

2.2 General safety instructions . . . . . . . . . . . . . . . .82

3 Commissioning . . . . . . . . . . . . . . . . . . . . . . . . 85

4 Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87

4.1 Switch on the instrument . . . . . . . . . . . . . . . . . .87

4.2 Measuring . . . . . . . . . . . . . . . . . . . . . . . . . . . . .88

4.2.1 Measuring the pH value . . . . . . . . . . . . .90

4.2.2 Measuring the Redox voltage . . . . . . . . .91

4.2.3 Transmitting measured values . . . . . . .92

4.3 Calibrating . . . . . . . . . . . . . . . . . . . . . . . . . . . . .93

4.3.1 Calibration interval (Int 3) . . . . . . . . . . . .96

4.3.2 AutoCal TEC . . . . . . . . . . . . . . . . . . . . .97

4.3.3 AutoCal DIN . . . . . . . . . . . . . . . . . . . . .100

4.3.4 ConCal . . . . . . . . . . . . . . . . . . . . . . . . .103

4.4 Storing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .106

4.4.1 Manual storage . . . . . . . . . . . . . . . . . . .106

4.4.2 Switching on AutoStore (Int 1) . . . . . . .108

4.4.3 Outputting the data storage . . . . . . . . .110

4.4.4 Clearing the storage . . . . . . . . . . . . . . .113

4.5 Data transmission . . . . . . . . . . . . . . . . . . . . . .114

4.5.1 Data transmission interval (Int 2) . . . . .114

4.5.2 Recorder (analog output) . . . . . . . . . . .116

4.5.3 PC/external printer (RS232 interface) .117

4.6 Configuration . . . . . . . . . . . . . . . . . . . . . . . . . .118

4.7 Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .122

List of contents

5 Maintenance, cleaning, disposal . . . . . . . . . 125

5.1 Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . .125

5.2 Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . .126

5.3 Disposal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .126

6 What to do if... . . . . . . . . . . . . . . . . . . . . . . . . 127

7 Lists . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131

1Overview

Overview

The compact pH measurements rapidly and reliably. The vides the highest degree of operating comfort, reliability and measuring safety for all applications.

The proven calibration procedures and special

AutoRead

CG 843

function support your work with the pH meter.

precision pH meter lets you perform

CG 843

pro-

1 Keypad 2 Display 3 Sockets

Note

The measuring instrument can also be delivered as part of a set. Information on this and other accessories is available in the SCHOTT general catalog.

Overview

1.1 Keypad

Switch measuring instrument on or off

Select measuring mode

<pH>

Call up calibration procedure

<CAL>

Activate/deactivate AutoRead

Store measured value

<STO>

Display/transmit measured values

<RCL>

Reduce values, scroll

▼>

Confirm inputs, start AutoRead

Increase values, scroll

▲>

1.2 Display

1.3 Sockets

Overview

Status line

Measured value display

Function and temperature displ a y

12345

1 Socket according to DIN 19262/BNC 2 PT 1000/NTC30 connection for pH combined electro-

de with temperature probe

3 Reference electrode connection 4 RS 232 interface/analog output 5 Connection for plug-in power supply (optional)

Caution

Only connect probes to the instrument that cannot feed excessive voltages or currents (> SELV and > circuit with current limiter).

Nearly all commercial electrodes – especially SCHOTT electrodes – meet these requirements.

Overview

1.4 Declaration of conformity

29.03.99

SCHOTT Geräte GmbH

Im Langgewann 5

D 65719 Hofheim am Taunus

Deutschland, Germany, Allemagne

29. März, March 29rd, 29, Mars, 1999

AGQSF0000-A058-00/990329

Ambient

temperature

Overview

1.5 Technical data

Storage temperature - 25 °C ... + 65 °C Operating temp. 0 °C ... + 55 °C

Measuring ranges

and resolution

Measuring

accuracy (± 1 digit)

Allowable relative humidity

Annual mean: < 75 % 30 days/year: 95 % Other days: 85 %

pH - 2.000 ... + 16.000

- 2.00 ... + 16.00

resolution selectable

U [mV] - 999.9 ... + 999.9

- 1999 ... + 1999 T [°C] - 5.0 ... + 100.0 T [°F] + 23.0 ... + 212.0

Given as measuring uncertainty at a confidence level of 95%. All accuracies additionally depend on the accuracies of the measuring probes.

pH (± 2 pH units around

± 0.005 at + 15 °C ... + 35 °C ± 0.01

the calibration point) U [mV] ± 0.4 at + 15 °C ... + 35 °C

± 1

T [°C] NTC 30: ± 0.1

PT 1000: ± 0.5 at 0 °C ... 15 °C ± 0.1 at 15 °C ... 35 °C ± 1 at 35 °C ... 55 °C

T [°F] NTC 30: ± 0.2

PT 1000: ± 0.9 at 32 °F ... 59 °F ± 0.2 at 59 °F ... 95 °F ± 1.8 at 95 °F ... 131 °F

Overview

Housing

EMC and

VDE norms

Length [mm] 230 Width [mm] 210 Height [mm] 70 Weight [kg] Approx. 1.3

(without plug-in power supply unit)

Material ABS

Interference emission (generic standard)

EN 50081-1 FCC class A

Interference immunity (generic standard)

Protective class 3, EN61010-1 Climatic class 2, VDI/VDE 3540

Test marks

Display

TÜV GS, UL/CUL, CE

Multifunctional LCD

Keypad Foil keypad (Polyester)

EN 50082-1

Power supply

Overview

Batteries 4 x 1.5 V AA type alkaline manganese

batteries Runtime Approx. 3000 operating hours Mains power

supply (option)

Plug-in power supply unit:

Connection max. overvoltage category II

Plug-in power supply (Euro plug):

Type no.: Z851

Order no.: 28 520 4897

FRIWO FW3288, 11.8134

Friwo Part No. 1816492

Input: 230V ~ / 50 Hz / 23 VA

Output: 6 V = / 1,8 A /10,8 VA

Plug-in power supply (US plug):

Type no.: Z852

Order no.: 28 520 4901

FRIWO FW3288, 11.8451

Friwo Part No. 1816493

Input: 120V ~ / 60 Hz / 21,5 VA

Output: 6 V = / 1,8 A

Plug-in power supply (UK plug):

Type no.: Z849

Order no.: 28 520 4975

FRIWO FW3288, 11.8453

Friwo Part No. 1770896

Input: 230V ~ / 50 Hz / 23 VA

Output: 6 V = / 1,8 A

Data storage Ring store for 200 value pairs, pH/mV, temperature

Temperature

compensation

Automatic with Pt 1000/NTC (30 k

-5 ... 99.9 °C

Manual input -20 ... 130 °C resolution 1K

Overview

Connectors

Input amplifier

Calibration modes

Electrodes Socket acc. to DIN 19 262 or BNC

4-mm socket for reference electode Temp. probe 4-mm socket for temperature probe Interface/

analog output

Bidirectional RS 232 interface or ana-

log output with autom. recognition of

the PC, printer, or recorder connected Plug-in power

2 pole special Friwo supply (option)

-12

Input impedance  10 Offset current 

AutoCal TEC With Technical buffers, pH values

2.00; 4.00; 7.00; 10.00 at 25 °C;

buffers are temperature compensa-

ted in the range 0 ... 90 °C AutoCal DIN With standard buffers according to

DIN 19 266/NIST, pH values:

1.68; 4.01; 6.87; 9.18 at 25 °C;

buffers are temperature compensa-

ted in the range 0 ... 90 °C ConCal With any buffers; one and two-point

calibration, manual acceptance of

measured values and temp. input

Safety

2 Safety

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

Target group This measuring instrument was developed for use in the lab-

oratory. 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.

Symbols used

Caution

indicates instructions that have to be followed to prevent damage to your instrument.

Warning

indicates instructions that have to be followed to protect yourself and the instrument from dangerous electrical voltage.

Note

Indicates notes that draw your attention to special features.

Note

Indicates cross-references to other documents, e.g. application reports, operating manuals of electrodes, etc.

Safety

2.1 Authorized use

This instrument is authorized exclusively for pH and Redox measurements in the laboratory. The technical specifications as given in the section 1.5 T

ECHNICAL DATA must 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 unauthorized.

2.2 General safety instructions

This instrument is constructed and tested in compliance with the EN 61010-1 safety regulations for electronic measuring instruments. It left the factory in a safe and secure technical condition.

Function and opera-

tional safety

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

The smooth functioning and operational safety of the instrument can only be guaranteed under the climatic conditions specified in the section 1.5 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.

Caution

The instrument is only allowed to be opened by personnel authorized by SCHOTT.

Safety

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

be taken out of service and secured against inadvertent operation. Safe operation is no longer possible if:

l the instrument has been damaged in transport l the instrument has been stored under adverse conditions

for a lengthy period of time

l the instrument is visibly damaged l the instrument no longer operates as described in this

manual

If you are in doubt contact the supplier of the instrument.

Obligations of the

operator

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

l EEC directives for protective labor legislation l National protective labor legislation l Safety regulations l Safety datasheets of the chemical manufacturer.

Safety

Commissioning

3 Commissioning

Perform the following activities for the initial commissioning:

l Set the date and time l Connect the plug-in power supply.

Setting the date

and time

1 Press and hold down the <pH> key. 2 Press the <on/off> key.

The

display test

appears briefly on the display. The measuring instrument then switches automatically to the setting of the baud rate.

3 Press the <run/enter> key repeatedly until the date

flashes on the display.

4 Set today’s date by pressing <

▲> <▼>.

5 Confirm with <run/enter>.

The date (month) flashes on the display.

6 Set the current month by pressing <

▲> <▼>.

7 Confirm with <run/enter>.

The year appears on the display.

8 Set the current year by pressing <

▲> <▼>.

9 Confirm with <run/enter>.

The hour field flashes on the display.

10 Set the current time by pressing <

▲> <▼>

11 Confirm with <run/enter>.

The minutes field flashes on the display.

12 Set the current time by pressing <

▲> <▼>

13 Confirm with <run/enter>.

The measuring instrument then switches to the pH measuring mode automatically.

Commissioning

Connecting the

plug-in power

supply (optional)

The measuring instrument works battery-powered. It can, however, also be supplied by the plug-in power supply which is available as an accessory.

Warning

The line voltage on site must lie within the input voltage range of the original plug-in power supply unit (see section

ECHNICAL DATA).

1.5 T

Caution

Use original plug-in power supplies only (see section 1.5 T

ECHNICAL DATA).

2 1

1 Insert the plug (1) into the socket (2) of the pH meter. 2 Connect the original plug-in power supply (3) to an

easily accessible mains socket.

Note

You can also perform measurements without a plug-in power supply.

Operation

4Operation

4.1 Switch on the instrument

1 Place the instrument on a flat surface and protect it

against intense light and heat.

2 Press the <on/off> key.

display test

The The instrument then switches automatically to the previously selected measuring mode.

Note

The instrument has an energy saving feature to avoid unnecessary battery depletion. The energy saving feature switches the instrument off if no key has been pressed for an hour. The energy saving feature is not active:

appears briefly on the display.

l if the power is supplied by the plug-in power supply l if the l if the communication cable is connected l if the recorder cable is connected l if the printer cable is connected

AutoStore

function is active

(for external printers)

Operation

4.2 Measuring

Preparatory

activities

Perform the following preparatory activities when you want to measure:

1 Connect the electrode to the instrument. 2 Adjust the temperature of the buffer or test solutions

or measure the current temperature if the measurement is made without a temperature probe.

3 Calibrate or check the instrument with the electrode

according to section 4.3 C

ALIBRATING.

4 Select the measuring mode by pressing <pH>.

Note

Incorrect calibration of the pH electrode will result in incorrect measured values. Therefore, regularly perform calibration 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.

Operation

Temperature probe Measurements can be performed with and without a temper-

ature probe. A connected temperature probe is indicated by TP on the display.

Note

The pH meter automatically recognizes the type of the temperature probe used. As a result, you can connect electrodes with the NTC30 or Pt1000.

The temperature measurement is absolutely essential for a reproducible pH measurement. If the measurement is made without a temperature probe, proceed as follows:

1 Determine the current temperature using an external

thermometer.

2 Set up the temperature by pressing <

▲> <▼>.

Note

When calibrating without a temperature probe, set up the current temperature of the respective buffer solution manually by pressing the <

▲> <▼> keys.

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