Metrohm 751 User Manual

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751 GPD Titrino

Series 9...

Instructions for Use

8.751.1103

99.07 Ti

Table of contents

1 Overview...................................................................................................................1

2 Manual operation .....................................................................................................4

2.1 Keypad.......................................................................................................................... 4

2.2 Principle of data input................................................................................................... 5

2.3 Text input ...................................................................................................................... 6

2.4 Configuration, key <CONFIG>................................................................................... 7

2.5 Selection of the mode, key <MODE> ...................................................................... 14

2.6 Parameters, key <PARAM>...................................................................................... 15

2.6.1 Parameters for DET and MET ............................................................................. 15

2.6.2 Parameters for SET.............................................................................................. 25

2.6.3 Parameters for KFT.............................................................................................. 34

2.6 Parameters, key <PARAM>...................................................................................... 42

2.6.4 Parameters for STAT............................................................................................ 43

2.6.5 Parameters for DOS ............................................................................................ 55

2.6.6 Parameters for DOC ............................................................................................ 62

2.6.7 Parameters for MEAS .......................................................................................... 69

2.6.8 Parameters for CAL ............................................................................................. 71

2.6.9 Parameters for TIP ............................................................................................... 73

2.7 Result calculations ..................................................................................................... 74

2.8 Statistics calculation................................................................................................... 77

2.9 Common variables ..................................................................................................... 79

2.10 Data output ............................................................................................................... 80

2.10.1 Reports for the output at the end of a determination ....................................... 80

2.10.2 Display of titration curve .................................................................................... 83

2.11 User name, key <USER> ....................................................................................... 84

2.12 TIP, Titration procedure............................................................................................ 85

2.13 Method memory, keys <USER METH> and <CARD> ........................................ 89

2.13.1 Key <USER METH>......................................................................................... 89

2.13.2 Key <CARD>.................................................................................................... 91

2.14 Calibration data, key <CAL.DATA>........................................................................ 94

2.15 Current sample data, key<SMPL DATA> .............................................................. 95

2.16 Silo memory for sample data ................................................................................... 96

2.17 Storing results and silo calculations ........................................................................ 99

2.17.1 Storing determination results ............................................................................ 99

2.17.2 Silo calculations............................................................................................... 100

2.18 Manual dosing and preparation of titration burets................................................ 103

2.18.1 Manual dosing ................................................................................................. 103

2.18.2 Preparation of titration burets, key <PREP> ................................................. 103

751 GPD Titrino

Table of contents

3 Operation via RS232 Interface (green pages)......................................................105

3.1 General rules ............................................................................................................ 105

3.1.1 Call up of objects............................................................................................... 106

3.1.2 Triggers.............................................................................................................. 107

3.1.3 Status messages............................................................................................... 108

3.1.4 Error messages ................................................................................................. 111

3.2 Remote control commands ..................................................................................... 116

3.2.1 Overview ............................................................................................................ 116

3.2.2 Description of the remote control commands.................................................. 143

3.3 Properties of the RS 232 Interface........................................................................... 180

3.3.1 Handshake ........................................................................................................ 180

3.3.2 Pin Assignment.................................................................................................. 183

3.3.3 What can you do if the data transfer does not work?....................................... 185

4 Error messages, Troubleshooting ...................................................................... 187

4.1 Error and special messages .................................................................................... 187

4.2 Diagnosis.................................................................................................................. 193

4.3 Initialize RAM ............................................................................................................ 204

4.4 Releasing a locked spindle with inserted Exchange Unit....................................... 205

5 Preparations ......................................................................................................... 206

5.1 Setting up and connecting the instruments ............................................................ 206

5.1.1 Titrino with Stirrer or Titration Stand.................................................................. 206

5.1.2 Titrino with external burets ................................................................................ 207

5.1.3 Connection of a printer...................................................................................... 208

5.1.4 Connection of a balance ................................................................................... 209

5.1.5 Connection of a Sample Changer .................................................................... 210

5.1.6 Connection of a computer ................................................................................ 211

5.1.7 Connection of a Remote Box ............................................................................ 212

5.2 Connection of electrodes, preparing titration vessel .............................................. 215

6 Appendix...............................................................................................................218

6.1 Technical specifications........................................................................................... 218

6.2 Pin assignment of the "Remote" socket................................................................... 221

6.2.1 Lines of the "Remote" socket during the titration.............................................. 223

6.2.2 Possible configurations of the activate pulse in SET, KFT and CAL ............... 224

6.3 Titrino validation ....................................................................................................... 225

6.3.1 Electronic tests .................................................................................................. 225

6.3.2 Wet tests ............................................................................................................ 225

6.3.3 Maintenance and adjustment of the Titrino...................................................... 225

6.4 Warranty and certificates.......................................................................................... 226

6.4.1 Warranty............................................................................................................. 226

6.4.2 Certificate of Conformity and System Validation .............................................. 227

6.5 Scope of delivery and ordering designations.......................................................... 229

Index ........................................................................................................................232

751 GPD Titrino

Overview

1 Overview

Front view of instrument: Rear view of instrument:

Remote

1.751

RS 232

Ref

Nr.

Dos1

Dos2

Pol

Ind I Ind II

Key-

board

Pt 100/1000

100 - 240 V f = 50 - 60 Hz S = 15 W

Made by Metrohm Herisau Switzerland

751 GPD Titrino

Overview

Front view of instrument:

1 Exchange Unit

2 Display

3 Control keys and indicator lamps on the Titrino

Key < > Power switch

Key < 4 > Switching stirrer ON/OFF

Key <DOS> Dosing key. Dispensing is performed as long as

<DOS> is being pressed. Used e.g. to prepare the Exchange Unit. The dispensing rate can be set with potentiometer (5).

Key <STOP/FILL> - Stops procedures, e.g. titrations, conditioning.

- Filling after manual dosing with <DOS>.

Key <START> Starts procedures, e.g. titrations, conditioning.

Identical with key <START> of the separate

keypad. Indicator lamps: "COND." Lamp flashes when conditioning is performed

and the titration vessel is still wet. It is on if con-

ditioning is ok. "STATISTICS" Lamp is on when the "statistics" function

(calculation of mean and standard deviation) is

on. "SILO" Lamp is on when silo memory (for sample data)

is on.

4 Setting of display contrast

5 Controls the dosing rate during manual dosing with <DOS> and

subsequent filling

6 Opening for the memory card

751 GPD Titrino

Rear view of instrument:

7 RS232 interfaces

2 separate interfaces for the connection of printer, balance, and computer

8 Remote lines (input/output)

for the connection of the Remote Box, Sample Changers, robots etc.

9 Connection of electrodes and temperature sensor

• 2 high-impedance measuring inputs for pH and U measurements.

They can either be used separately or for differential potentiometry, see page 215. Important: If you work with both measuring inputs in the same vessel, the same reference electrode must be used.

• 1 measuring input for polarized electrodes, e.g. KF electrode

• 1 measuring input for PT100 or Pt1000 temperature sensor

Overview

10 Connection for separate keypad

11 Connection for power cable

With power supplies where the voltage is subject to severe HF disturbances, the Titrino should be operated via an additional power filter, e.g. Metrohm 615 model.

12 Connection for external dosing units D1 and D2

685 Dosimats or 700 Dosinos

13 Connection for stirrer

728 Magnetic Stirrer, 722 Rod Stirrer, 703 or 727 Ti Stand

Supply voltage: 10 VDC (I ≤ 200 mA)

14 Rating plate

with fabrication, series and instrument number

751 GPD Titrino

2.1. Keypad

SILO

–9STATISTICS

MEAS/HOLD

+8USER

→↑←

↓

STOP

START

CARD

/6CAL.DATA

*5PREP

USER METH

)3DEF

(2C-FMLA

MODE

REPORTS

CURVE

2 Manual operation

2.1 Keypad

PARAMCONFIG

SMPL DATA

QUIT

ABC

–

6.2132.060

CLEAR ENTER

CONFIG Configuration.

PARAM Parameters.

SMPL DATA Sample data.

STATISTICS ON/OFF switching of statistics calcu-

lations of consecutive determination, see page 77.

MEAS/HOLD ON/OFF switching of measurements

between titrations and hold during titrations.

SILO ON/OFF switching of silo memory for

sample data, see page 96.

PREP Preselection of dosing units, see page

103.

CAL.DATA Calibration data, see page 94.

;

CARD Management of memory card, see

page 91.

C-FMLA Calculation values, see page 76.

DEF Formulas, data output, sequence for

TIP, see page 74ff.

USER METH Management of internal method mem-

ory, see page 89.

PRINT Printing of reports, see page 80.

REPORTS Result output.

MODE Mode selection, see page 14.

USER User name, see page 84.

CURVE Switching result/curve display.

←,→ Selection of special values (dialog

marked with ":")

↑,↓ Cursor key for navigation.

CLEAR Clears values, set special values.

ENTER Stores values.

STOP Stops methods.

QUIT Quits inquiries, waiting times, printing.

START Starts methods.

The third functions (inscriptions in the triangle) on the keys of the keypad are used for formula entry, see page 74.

751 GPD Titrino

2.2 Principle of data input

>prep.dosing elements

remote box: OFF

>prep.dosing elements

• If you press a key you will find a group of inquiries in

the display.

configuration >monitoring >peripheral units >auxiliaries >RS232 settings COM1 >RS232 settings COM2 >common variables

configuration >peripheral units send to COM1: IBM send to COM2: IBM man.reports to COM: 1 balance: Sartorius stirrer control: OFF

configuration >monitoring >peripheral units >auxiliaries >RS232 settings COM1 >RS232 settings COM2 >common variables

Example key <CONFIG>:

In the first line you see where you are: You pressed

key <CONFIG> and you are now in the inquiries "configuration".

• The cursor is inverted. In our example the cursor is

on the inquiry ">monitoring". You can move the cur-

sor up and down with keys <↑> and <↓>.

• If a dialog text is marked with ">", it contains a

group of inquiries itself. You go to this group pressing <ENTER>. Example inquiries of "peripheral units":

The first two lines indicate again where you are.

Then you find the inquiries. If a dialog text of an inquiry is marked with ":", you

can select a value with keys <←> and <→>

(forward/backward).

• A value is stored with <ENTER> and the cursor

moves to the next inquiry.

• With key <QUIT> you move one level up, in our ex-

ample you go back to ">peripheral units".

If you press <QUIT> once more you quit the in-

quiries in "configuration" altogether.

• If you can scroll, ↓ or ↑ appear in the right lower or

upper corner of the display.

2.2 Principle of data input

751 GPD Titrino

2.3. Text input

REPORTS

2.3 Text input

Example storing a method:

user methods >store method method name: ********

<CLEAR>

ABC

user methods >store method: method name:

ABCDEFGHIJKLMNOPQRSTUVWXYZ abcdefghijklmnopqrstuvwxyz µ°!"#$&'()*+,-./ 0123456789

<QUIT>

user methods >store method method name: Text

<ENTER>

• Press key <USER METH>.

Place the cursor to ">store method" and press <ENTER>. The name of the method which is currently in the working memory is displayed.

• Delete this name with <CLEAR>.

• Open the "text writing mode" with key <ABC>.

You can now select the desired character by means of the cursor keys, then confirm this character. Select the next character... When you confirmed the last character, i.e. your name is complete, you quit the text writing mode with <QUIT>. Confirm now the name with <ENTER>.

• During text input you can correct typing errors with

<CLEAR>: <CLEAR> deletes the characters one by one.

• If you wish to modify an existing name (e.g. if you

have names like Text 1, Text 2, Text 3), do not delete the existing name before you start the text input mode. Proceed then as follows:

1. Press <USER METH>, place the cursor to ">store method" and press <ENTER>.

2. Open the text writing mode directly: Press key <ABC>.

3. <CLEAR> now deletes the characters one by one or you can add additional characters.

4. If your text is complete, leave the text writing mode with <QUIT> and confirm the text with <ENTER>.

751 GPD Titrino

2.4 Configuration, key <CONFIG>

>prep.dosing element

Key <CONFIG> serves to enter device specific data.

CONFIG

configuration >monitoring >peripheral units >auxiliaries >RS232 settings COM1 >RS232 settings COM2 >common variables

The set values apply to all modes.

monitoring:

Monitoring of instrument validation, pH calibration, service interval and printout of diagnostic report. peripheral units: Selection of printer, balance, stirrer control and COM for manual report output. auxiliaries: e.g. setting of dialog language, date time, type of result display. RS232 settings COM1 and 2: RS parameters for the COM's. common variables: Values of common variables. prep.dosing element: Parameters for the preparation of the dosing units.

2.4 Configuration, key <CONFIG>

>monitoring

validation: OFF

time interval 365 d

time counter 0 d

calibration: OFF

The display texts of the Titrino are shown to the left. The values are the default values.

Monitoring functions

Monitoring the validation interval (ON, OFF)

Monitoring is carried out at the end of the titrations and when the Titrino is switched on. If the monitoring responds the message "validate instrument" appears. The message vanishes with <CLEAR>. At the same time the counter is reset to zero.

If "on" has been set:

Time interval for validation (1...9999 d)

see also page 103

Warning after power ON (ON, OFF)

If this function is on, a warning appears after switching on the Titrino, that a preparation should be executed.

Report of prep (ON, OFF)

With ON, a report will be printed automatically after prep. The report is outputted on the COM which is given for manual reports.

751 GPD Titrino

2.4 Configuration, key <CONFIG>

dos.element: internal D0

warn.interv.DX OFF min

dos.drive: Dosimat

volume DX 3.5 ml

cycles DX 2

dos.rate max. ml/min

fill rate max. ml/min

outlet: tip

Selection of the dosing element (internal D0, external D1, external D2)

internal D0: buret of the Titrino external D1/2: buret D1, D2, resp.

Warning interval for prep (5...9999 min, OFF)

Selection of the type of dosing element (Dosimat, Dosino)

The internal buret D0 reacts like a "Dosimat".

Parameters for the internal buret and for Dosimats:

Volume, that will be dosed with the preparation (0...99

999.99 ml)

Number of cycles (1...9)

Dosing rate (0.01...150 ml/min, max.)

Filling rate (0.01...150 ml/min, max.)

Parameters for Dosinos:

Location where the liquid will be expelled (tip, flask)

With "flask" the reagent will be re-expelled into the bottle. In this case, it is possible that the titer will be changed!

len.dos.tub.DX 40.0 cm

diam.dos.tub.DX 2.0 mm

len.asp.tub.DX 25.0 cm

diam.asp.tub.Dx 2.0 mm

dos.rate max. ml/min

fill rate max. ml/min

The next 4 entries serve to calculate the volumes which will be expelled in prep:

Length of the dosing tube (1...999.9 cm)

Diameter of the dosing tube (0.1...9.9 mm)

Length of the aspirating tube (1...999.9 cm)

Diameter of the aspirating tube (0.1...9.9 mm)

Dosing rate (0.01...150 ml/min, max.)

Filling rate (0.01...150 ml/min, max.)

751 GPD Titrino

2.4. Configuration, key <CONFIG>

Settings with key <CONFIG> and power ON

Proceed as follows:

1. Switch the Titrino OFF.

2. Press <CONFIG> and keep it pressed during switching the Titrino ON. The display shows the following:

Setup >lock >curve

>lock

<configuration>: OFF

<parameters>: OFF <smpl data>: OFF

recall method: OFF store method: OFF delete method: OFF

lock:

Locking keys <CONFIG>, <PARAM> and <SMPL DATA>, and the functions "recall method", "store method" and "delete method" of the internal method memory in the Titrino. curve: Changes the appearance of the curve printout.

lock

"ON" means that the corresponding function is not accessible anymore.

The corresponding key is locked.

The corresponding function in the internal method memory of the Titrino is locked.

751 GPD Titrino

2.4 Configuration, key <CONFIG>

>curve

grid: ON

frame: ON

scaling: Full

width 0.75

length 0.1

curve

The settings are valid for COM1 and COM2. If you change the printer type, the following settings are initialized according to the printer.

Grid drawing (ON, OFF)

Frame drawing (ON, OFF)

Type of scaling (Full, Auto)

Full: The scaling goes from the greatest to the smallest value. auto: The scaling from tick to tick, e.g. the smallest/greatest values lie in between the first/last tick.

Width (0.2...1.00)

1 is greatest width. If you set 1 you may loose the label at the right margin.

Length (0.01...1.00) Volume axis

Curve length per cylinder volume

0.01 100 cm

0.1 10 cm

0.5 2 cm 1 1 cm Time axis:

Curve length

0.01 100 cm

0.1 10 cm

0.5 2 cm 1 1 cm

751 GPD Titrino

2.5. Selection of the mode, key <MODE>

MODE

2.5 Selection of the mode, key <MODE>

;

–

mode mode: DET measured quantity: pH

Press key <MODE> until the desired mode is displayed and confirm with <ENTER>. Select the measured quantity pH, U, Ipol, Upol, (T) with

<←> or <→> and confirm it also with <enter>.

The following modes can be selected:

• DET: Dynamic Equivalence-point Titration

• MET: Monotonic Equivalence-point Titration

• SET: Set Endpoint Titration.

• KFT: Karl Fisher Titration, the determination of water

content.

• STAT: Keeping a measured value constant, i.e. pH-

STAT.

• DOS: Dosing function with volume, time, or rate

control.

• DOC: Dosing Controlled by a measured value

gradient.

• CAL: pH Calibration.

• MEAS: Measuring.

• TIP: Titration Procedure. Linking of various

commands and methods to a titration procedure.

These standard modes are equipped with a set of standard parameters. They only need few settings in order to be ready to work. TIP is an empty "shell". The TIP sequence has to be defined with <DEF>, see page 85.

You will find a survey of the modes in the short Instructions for use, page 12.

751 GPD Titrino

2.6 Parameters, key <PARAM>

The key <PARAM> is used for the entry of values that

PARAM

2.6.1 Parameters for DET and MET

determine the modes. Values marked with "cond." are accessible during the conditioning in the SET and KFT mode. "**titr." means that these values can be changed during the titration. They influence the ongoing determination. Other values can only be changed in the inactive state. The display texts of the Titrino are shown to the left. The values are the default values.

2.6 Parameters, key <PARAM>

parameters >titration parameters >stop conditions >statistics >evaluation >preselections

>titration parameters

meas.pt.density 4

DET

titration parameters

determine the course of the titration and measured value acquisition.

stop conditions:

Parameters for the automatic termination of the titration. statistics: Calculation of mean values and standard deviation, see page 77. evaluation: Parameters for the evaluation of EP's, fix EP's, and pK/HNP. preselections: ON/OFF of various auxiliary functions such as automatic requests after the start and activate pulse.

General titration parameters

Measuring point density (0...9)

0 means highest density, 9 lowest. Selection of the meas.pt.density, see page 21.

min.incr. 10.0 ul

DET

V step 0.10 ml

MET

751 GPD Titrino

Minimum increment (0...999.9 uL)

The increment is dispensed at the beginning of the titration and in the region of the equivalence point.

Size of volume increment (0...9.999 mL)

Dosing step. Small volume increments are needed to determine blank values or to assure accuracy with highly unsymmetrical curves. Selection of size of the increment, see page 21.

2.6. Parameters, key <PARAM>

dos.rate max. ml/min **titr.

signal drift 50 mV/min **titr.

equilibr.time 26 s **titr.

Dosing rate for volume increments (0.01...150 mL/min, max.)

<CLEAR> sets "max.". The maximum rate depends on the Exchange Unit: Exchange Unit max.

5 mL 15 mL/min 10 mL 30 mL/min 20 mL 60 mL/min 50 mL 150 mL/min

Drift criterion for measured value acquisition. (input range depends on the measured quantity: pH, U, Ipol: 0.5...999 mV/min, OFF Upol: 0.05...99.9 uA/min, OFF)

<CLEAR> sets "OFF". This type of measured value acquisition is often called an equilibrium titration. "OFF" means that the measured value is acquired after an equilibration time. This may be useful for slow titration reactions or when the response of the electrode assembly is slow.

Waiting time for measured value acquisition. (0...9999 s, OFF)

<CLEAR> sets "OFF". If no new equilibration time has been entered, the Titrino calculates an equilibration time appropriate to the drift, see page 20. The measured value is acquired as soon as the first criterion (drift or time) has been met.

start V: OFF

start V 0.0 ml

factor 0

dos.rate max. ml/min **titr.

Type of start volume (OFF, abs., rel.)

"OFF": start volume switched off "abs": absolute start volume in mL "rel.": relative start volume to sample size.

If "abs." is set:

Absolute start volume (0...999.99 mL)

If "rel." is set:

Factor for relative start volume (0...±999 999).

Calculated as: start V in mL = factor * sample size

Dosing rate for start volume (0.01...150 mL/min, max.)

<CLEAR> sets "max.". Maximum rate depends on the Exchange Unit: Exchange Unit max.

5 mL 15 mL/min 10 mL 30 mL/min 20 mL 60 mL/min 50 mL 150 mL/min

751 GPD Titrino

2.6 Parameters, key <PARAM>

pause 0 s **titr.

dos.element: internal D0

meas.input: 1

I(pol) 1 uA

U(pol) 400 mV

electrode test: OFF

Waiting time (0...999 999 s)

Waiting time, e.g. for equilibration of the electrode after the start or reaction time after dosing of start volume. The pause can be aborted with <QUIT>.

Selection of the dosing element (internal D0, external D1, external D2)

internal D0: internal buret of the Titrino external D1/2: buret D1, D2, resp.

Measuring input for pH and U (1, 2, diff.)

Request for measuring input for pH and U. Measuring input 1 or 2 or differential amplifier; connection of electrodes, see page 215.

With polarized electrodes, instead of the measuring input the

polarization current (-127...127 uA)

or the

polarization voltage (-1270...1270 mV, in steps of 10 mV)

is inquired.

Electrode test (OFF, ON)

Test for polarized electrodes. Performed on changeover from the inactive standby state to a measurement. "OFF" means that the test is not performed.

temperature 25.0 °C

>stop conditions

stop V: abs. **titr.

stop V 99.99 ml **titr.

factor 999999 **titr.

Titration temperature (-170.0...500.0 °C)

The temperature is continuously measured if a T sensor is connected. This parameter is used for temperature compensation in pH titrations.

Stop conditions for the titration

If several stop conditions have been set, the criterion which is met first applies.

Type of stop volume (abs., rel., OFF)

"abs.": absolute stop volume in mL. "rel.": relative stop volume to sample size. "OFF": stop volume switched off. Stop volume is not

monitored.

If "abs." is set:

Absolute stop volume (0...9999.99 mL)

If "rel." is set:

Factor for relative stop volume (0...±999 999)

Calculated as: Stop V in mL = factor * sample size

751 GPD Titrino

2.6. Parameters, key <PARAM>

stop pH OFF **titr.

stop EP 9 **titr.

filling rate max. ml/min **titr.

>evaluation

Stop at measured value (input range dependent on measured variable:

pH: 0... ± 20.00, OFF U, Ipol: 0... ± 2000 mV, OFF Upol: 0... ± 200.0 uA, OFF)

<CLEAR> sets "OFF". "OFF" means that the criterion is not monitored.

Stop after a number of EP's have been found (1...9, OFF)

<CLEAR> sets "OFF". "OFF" means that the criterion is not monitored.

Filling rate (0.01...150 mL/min, max.)

<CLEAR> sets "max.". The maximum rate depends on the Exchange Unit: Exchange Unit max.

5 mL 15 mL/min 10 mL 30 mL/min 20 mL 60 mL/min 50 mL 150 mL/min

EP evaluation/recognition

See page 21 ff.

EPC 5

EP recognition: all

low lim.1 pH -20.00

up lim.1 pH 20.00

Equivalence point criterion (input range depends on mode. For DET:

0...200 For MET: pH: 0.10...9.99 U, Ipol: 1...999 mV Upol: 0.1...99.9 uA)

Threshold for the size of the jump, see page 23.

Recognition of EP's which fulfill the EP criterion. (all, greatest, last, window, OFF)

Selection of equivalence point recognition: "all": All equivalence points are recognized. "greatest": Only the greatest (steepest) equivalence

point is recognized.

"last": Only the last equivalence point is

recognized.

"window": Only EP's in specified windows are

recognized. "OFF": Evaluation switched off. If "window" is selected, lower and upper limits of windows are inquired.

Lower limit of window 1

and

upper limit of window 1 (Input ranges for both inquiries depend on the measured quantity): pH: 0...±20.00, OFF U, Ipol: 0...±2000 mV, OFF Upol: 0...±200.0 uA, OFF)

751 GPD Titrino

2.6 Parameters, key <PARAM>

<CLEAR> sets "OFF". Only equivalence points are recognized which lie within the set lower and upper limits. The equivalence point numbering is defined with the windows, see page 23. Window inquiries continue until the lower limit is set to "OFF". Up to 9 possible windows.

Always set both limits to ≠ OFF for a valid window.

fix EP1 at pH OFF

pK/HNP: OFF

>preselections

req.ident: OFF

Interpolation of volumes at fixed times (input range depends on the measured quantity: pH: 0...±20.00, OFF U, Ipol: 0...±2000 mV, OFF Upol: 0...±200.0 uA, OFF)

<CLEAR> sets "OFF". If a fix end point has been set, the volume value for the input measured value is interpolated from the curve, see also page 24. The volume values are available as C5X. Fix EP's are inquired until "OFF" is set. Up to 9 fix EP's.

Evaluation of pK or HNP (ON, OFF)

pK evaluation in case of pH titrations and half neutralization potential for U, see page 24.

Preselections for the sequence

Request of identifications after start of titration. (id1, id1&2, all, OFF)

After start, sample identifications can be inquired automatically: Only id1, id1 & id2, all three id's or no inquiries.

req.smpl size: OFF

limit smpl size: OFF

low lim. 0.0 up lim. 999999

activate pulse: OFF

Request of sample size after start of titration (value, unit, all, OFF)

"all" requests the value, then the unit.

Limiting value check for sample size (ON, OFF)

With "on" the error message "sample size out." appears if the entry is outside the set limits. The limiting values are shown in the display window. The absolute value of the limit is checked during sample size input and during the calculation of the results. If "on" has been set:

Lower limit for sample size (0.0...999 999) Upper limit for sample size (0.0...999 999)

Pulse output on I/O line "activate" (L6, pin 1) of the remote socket (ON, OFF)

see page 223.

751 GPD Titrino

2.6. Parameters, key <PARAM>

<START>

(Start delay)

(Start conditions)

Stop conditions

Calculations

(Stirrer OFF)

Data output

Titration sequence of DET and MET

(Activate pulse)

(Stirrer ON)

(Request ident.)

(Request smpl size)

Titration: Dispense increments Acquire meas.values

After the start, the activate pulse is outputted and the stirrer switched on.

The start delay time is waited off.

The sample identifications and the sample size are requested.

The start volume is dispensed (no meas.value acquisition) and the pause is waited off.

During the titration the volume increments are dispensed and after each increment a measured value is acquired. Meas.values are either acquired drift controlled ("equilibrium titration") or a after a fixed waiting time. If you have not intentionally changed the equilibration time, it is calculated according to the formula:

150

equilibr.time in s = —————— + 5

ûDrift + 0.01

The criterion (drift or equilibration time) which is first met applies. This avoids "infinite" titrations. If the parameter "signal drift" is set "OFF", the measured values are acquired after a fixed equilibration time.

The titration is terminated according to the first criterion which is met.

The stirrer is switched off.

Evaluations and calculations are carried out.

Data are outputted.

751 GPD Titrino

2.6 Parameters, key <PARAM>

Reagent feeding and EP evaluation of DET

The reagent feeding of DET is similar to the controlling, a human being would apply in manually controlled titrations: Great volume increments are dosed far away from the EP, small increments in the region of the equivalence point. The size of the volume increments dosed by the Titrino is determined by the following parameters:

meas.pt.density The measuring point density is entered as a relative

value from 0...9. Input of a low number means small volume increments, i.e. a large measuring point density on the curve. A curve results which reproduces all fine details. "Fine details", however, also include signal noise, which can easily lead to unwanted equivalence points. A high number, i.e. low measuring density, on the other hand, allows a more rapid titration. The standard value of 4 is suitable for most cases. If you work with small cylinder volumes (1 or 2 ml), a small measuring point density may be advisable. In these cases you should also lower the drift for meas.value acquisition and set a higher EPC.

min.incr. Defines the minimum possible increment. This minimum

increment is dosed at the beginning of the titration and in the region of the equivalence point (for steep curves). Use low minimum increments only, if small volumes of titrant consumption are expected, e.g. in micro titrations; otherwise unwanted equivalence points may arise. The standard value of 10.0 uL is suitable for most cases.

EPC

The EP's are evaluated according to a special METROHM procedure which is so sensitive that even weak equivalence points are determined correctly.

Equivalence Point Criteria. The preset EPC is compared to the found ERC (Equivalence point Recognition Criteria) for each evaluated equivalence point. The size of the ERC is displayed in the titration curve, see page 83. The ERC is the first derivative of the titration curve overlaid with a mathematical function so that small maxima become higher and great maxima smaller. EP's whose ERC is below the preset EPC will not be recognized. For most cases the standard value of 5 is suitable. The evaluation can be repeated at any time after the titration in a "dry run" with changed evaluation criteria. The old titration data are not deleted until a new titration is started.

751 GPD Titrino

2.6. Parameters, key <PARAM>

Reagent feeding and EP evaluation of MET

In monotonic titrations, the volume increment is constant over the whole titration curve.

V step Volume increment.

A prerequisite for good accuracy is the correct size of the volume increments. A good value is given by V step = 1/20 VEP (VEP = volume of the EP). In any case, the increment size should always be between 1/10 VEP and 1/100 VEP; with steep jumps preferably in the region of 1/100 and with flat jumps preferably in the region of 1/10. The accuracy of the evaluation can not be increased by dispensing small increments as the changes in the measured value can then be of the same order of magnitude as the noise. This can produce "ghost EP's"!

The EP's are localized with an algorithm which is based on Fortuin and has been adapted by METROHM for numeric procedures. (METROHM Bulletin 2, No. 10,

1971). Here, the greatest change in the measured value

is sought (∆

). The exact equivalence point is

determined with an interpolation factor, which depends

on the delta values before and after ∆

VEP = V

+ ρ ∆V

VEP: EP volume V

: Total dispensed volume before ∆

∆V: Volume increment ρ : Interpolation factor (Fortuin)

EPC

∆

+∆

n-2

+∆n+∆

n-1

n+1

+∆

n+2



(In certain cases there are only 3 or 1 summand). EP's whose ERC is below the preset EPC will not be recognized. For most titrations the standard value is suitable. The evaluation can be repeated at any time after the titration in a "dry run" with changed evaluation criteria. The old titration data are not deleted until a new titration is started.

751 GPD Titrino

2.6 Parameters, key <PARAM>

U/mV

V/ml

U/mV

V/ml

EP recognition criteria for DET and MET

The parameter "EP recognition" offers you a range of possibilities to ensure selection of the EP you are interested in: If the desired jump is very large, you can select the "greatest" jump (with DET the steepest jump will be evaluated). Thus you always obtain just one EP per titration (EP1). If you wish to determine the sum of different components (e.g. acid or base numbers), the "last" jump can be the correct one. And finally you can set a "window" for each expected EP.

EP windows EP windows are used

• to suppress disturbing influences and EP's which are not needed.

• to increase the liability for the calculation of the results. The EP windows make an

unequivocal assignment of the EP's possible: per window one EP is recognized; the numbering of EP's is defined by the windows so that even if EP's are missing, the calculations are still performed with the correctly assigned EP volumes.

An EP window defines the range in which an EP is expected. EP's outside these ranges are not recognized. Windows are defined on the measured value axis.

EP window 2

EP window 1

EP 1

upper lim. 1

lower lim. 1

EP 1

+EP window 1

EP 2

2 EP's are recognized. Their numbering is defined by the windows:

Window 1 ⇒ EP1 Window 2 ⇒ EP2

If more than 1 EP is expected, a window must be set for each EP.

Windows must not overlap. They may only touch each another.

Rule: If there are more than 1 EP in a window, the first jump is recognized as EP1, the second is not recognized. EP1 is marked as EP1 + to indicate that more than one EP has been found in the window

751 GPD Titrino

2.6. Parameters, key <PARAM>

Fix EP's

Fix EP's allow determination of the associated volume value for every inputted measured value on the titration curve. This function is useful for performing standard methods such as TAN/TBN determinations. For the evaluation of fix EP's, the pH calibration is advisable. The volume values of the fix EP's are available for the calculation as C5X:

Fix EP1 ⇒ C51

Fix EP9 ⇒ C59 Maximum 9 fix EP's are possible.

pK and HNP evaluation

The following relation (Henderson-Hasselbach), derived from the law of mass action, exists between the activities of a conjugate acid-base pair in aqueous solutions:

pH = pK + log (aB/aA) When the activities aB = aA, then pH = pK is valid. This value corresponds to the pH at the half neutralization point and can be taken from the titration curve. For pK determinations, a careful pH calibration is necessary. The pK value determined is an approximate value owing to the fact that the ionic strength of the solution has not been taken into account. For more exact values, titrations must be performed with decreasing ionic strength and the results extrapolated to zero ionic strength. The evaluation of pK's in aqueous solutions is limited to pK>3.5 due to the leveling effect of strong acids in aqueous solutions pK<10.5 because for weaker acids no inflection points can be found aqueous

solutions.

pK evaluation for polybasic acids and for acid mixtures is also possible.

In non-aqueous solutions, the half neutralization potential (HNP) is often used instead of pK. The HNP is evaluated accordingly.

A start volume must be smaller than half of the equivalence point volume of the first EP.

The pK/HNP values are available for calculation as C6X.

Minimum/maximum evaluation

Volumes at minimum or maximum voltage values are extrapolated. These volumes are accessible as variables C49 and C48 resp. and can be used in formulas.

751 GPD Titrino

2.6.2 Parameters for SET

2.6 Parameters, key <PARAM>

parameters >SET1 >SET2 >titration parameters >stop conditions >statistics >preselections

>SET1

EP at pH OFF **titr.

SET1, SET2:

Control parameters for EP1 and EP2.

titration parameters

are valid for the global titration sequence.

stop conditions:

Parameters for the termination of the titration. statistics: Calculation of mean values and standard deviation, see page 77. preselections: ON/OFF of various auxiliary functions such as automatic requests after the start and activate pulse.

Control parameters for EP1 or EP2, resp.

Preset EP1 (input range depends on the measured quantity: pH: 0...±20.00, OFF U, Ipol: 0...±2000 mV, OFF Upol: 0...±200.0 uA, OFF)

<CLEAR> sets "OFF". If EP1 is "OFF", no further inquiries under SET1 appear.

dynamics OFF **titr.

max.rate 10.0 ml/min **titr.

Distance from EP where constant dosing should stop and controlling begins. (control range, input range depends on the measured quantity: pH: 0.01...20.00, OFF U, Ipol: 1...2000 mV, OFF Upol: 0.1...200.0 uA, OFF)

<CLEAR> sets "OFF". "OFF" means largest control range, i.e. low titration. Outside the control range, dispensing is performed continuously, see also page 31.

Maximum dosing rate (0.01...150 mL/min, max.)

<CLEAR> sets "max.". This parameter determines primarily the addition rate outside the control range, see also page 31. The maximum rate depends on the Exchange Unit: Exchange Unit max.

5 mL 15 mL/min 10 mL 30 mL/min 20 mL 60 mL/min 50 mL 150 mL/min

751 GPD Titrino

2.6. Parameters, key <PARAM>

min.rate 25.0 ul/min **titr.

stop crit: drift **titr. stop drift 20 ul/min **titr.

t(delay) 10 s **titr.

stop time OFF s **titr.

Minimum dosing rate (0.01...999.9 uL/min)

This parameter determines the addition rate right at the start and the end of the titration, see also page 31. This parameter influences the titration speed and therefore its accuracy very strongly: A smaller min.rate results in a slower titration.

Type of stop criteria (drift, time)

Titration stops if EP is and stop drift is reached. (1...999 uL/min)

Titration stops if there is no dosing during t(delay). (0...999 s, INF)

<CLEAR> sets "INF" Switch off when the end point is reached and the set time after the last dispensing has elapsed. If "INF" is set, an inquiry regarding the stop time appears. If t(delay) is "INF"

Stop after a time (0...999 999 s, OFF)

<CLEAR> sets "OFF". Stop after the set time after the start of the titration. "OFF" means no stop, i.e. titration for an "infinitely" long time.

>titration parameters

titr.direction: auto

pause 1 0 s **titr.

start V: OFF cond.

start V 0.0 ml cond.

General titration parameters

Direction is set automatically (+, -, auto)

auto: The direction is set automatically by the Titrino

(sign [U

- EP]).

first

+: Direction of higher pH, higher voltage (more

"positive"), larger currents.

- : Direction of lower pH, lower voltage, smaller currents.

The titration direction is fixed if two EP's are set. In this case, an input for titration direction has no meaning.

Pause 1 (0...999 999 s)

Waiting time before start volume, e.g. for equilibration of the electrode after the start. The waiting time can be aborted with <QUIT>.

Type of start volume (OFF, abs., rel.)

"OFF": start volume switched off "abs.": absolute start volume in mL "rel.": relative start volume to sample size.

If "abs." is set:

Absolute start volume (0...999.99 mL)

factor 0 cond.

If "rel." is set:

Factor for relative start volume (0...±999 999).

Calculated as: start V in mL = factor * sample size

751 GPD Titrino

2.6 Parameters, key <PARAM>

dos.rate max. ml/min **titr.

pause 2 0 s **titr.

extr.time 0 s **titr.

dos.element: internal D0

Dosing rate for start volume (0.01...150 mL/min, max.)

<CLEAR> sets "max.". The maximum rate depends on the Exchange Unit: Exchange Unit max.

5 mL 15 mL/min 10 mL 30 mL/min 20 mL 60 mL/min 50 mL 150 mL/min

Pause 2 (0...999 999 s)

Waiting time after start volume, e.g. reaction time after dosing of a start volume. The waiting time can be aborted with <QUIT>.

Extraction time (0...999 999 s)

During this time the titration is already running. It will be not stopped (also if the EP is already reached) before the extraction time is terminated. The extraction time can be aborted with <QUIT>.

Selection of dosing element (internal D0, external D1, external D2)

internal D0: internal buret of the Titrino external D1/2: buret D1, D2, resp.

meas.input: 1

I(pol) 1 uA

U(pol) 400 mV

electrode test: OFF

temperature 25.0 °C cond.

time interval 2 s cond.

Measuring input (1, 2, diff.)

Inquiry only with measured quantities pH and U. Measuring input 1 or 2 or differential amplifier; connection of electrodes, see page 215.

With polarized electrodes, instead of the measuring input the

polarization current (-127...127 uA)

or the

polarization potential (-1270...1270 mV, in steps of 10 mV)

is inquired.

Electrode test (OFF, ON)

Test for polarized electrodes. Performed on changeover from the inactive state to a measurement. "OFF" means that the test is not performed.

Titration temperature (-170.0...500.0°C).

Temperature is measured at the start of the titration if a T sensor is connected. The value is used for temperature compensation in pH titrations.

Time interval (1...999 999 s)

Time interval for acquisition of a measured value into the measuring point list.

751 GPD Titrino

2.6. Parameters, key <PARAM>

>stop conditions

stop V: abs. **titr.

stop V 99.99 ml **titr.

factor 999999 **titr.

filling rate max. ml/min

Stop conditions for titration

If this is not "normal", i.e. after reaching the EP.

Type of stop volume (abs., rel., OFF)

"abs.": absolute stop volume in mL. "rel.": relative stop volume to sample size. "OFF": stop volume switched off. Stop volume

is not monitored.

If "abs." is set:

Absolute stop volume (0...9999.99 mL)

If "rel." is set:

Factor for relative stop volume (0...±999 999)

Calculated as: Stop V in mL = factor * sample size

Filling rate after the titration (0.01...150 mL/min, max.)

<CLEAR> sets "max.". The maximum rate depends on the Exchange Unit: Exchange Unit max.

5 mL 15 mL/min 10 mL 30 mL/min 20 mL 60 mL/min 50 mL 150 mL/min

>preselections

conditioning: OFF

display drift: ON cond.

drift corr: OFF cond.

drift value 0.0 ul/min cond.

req.ident: OFF cond.

Preselections for the sequence

Automatic conditioning of titration vessel. (ON, OFF)

If conditioning is "on", between the titrations the titration solution is constantly maintained at the (1st) end point. When conditioning is performed, the volume drift can be displayed during the conditioning:

Display of drift during conditioning (ON, OFF).

Volume drift.

Type of drift correction (auto, man. OFF)

auto: The value of the drift will be stored automatically at the start of the titration.

Value for manual drift correction (0...99.9 ul/min)

Request of identifications after start of titration (id1, id1&2, all, OFF)

After start, sample identifications can be requested automatically: Only id1, id1 & id2, all three id's or no inquiries.

751 GPD Titrino

2.6 Parameters, key <PARAM>

req.smpl size: OFF cond.

limit smpl size: OFF cond.

low lim. 0.0 cond. up lim. 999999 cond.

activate pulse: OFF cond.

Request of sample size after start of titration (value, unit, all, OFF)

"all" the value and the unit will be requested.

Limiting value check for sample size (ON, OFF)

Lower limit for sample size (0.0...999 999)

Upper limit for sample size (0.0...999 999)

Pulse output on I/O line 6 (L6, pin 1) of the remote socket (first, all, cond., OFF)

see page 224.

751 GPD Titrino

2.6. Parameters, key <PARAM>

<START>

(Start delay)

(Start conditions)

Calculations

Data output

(Reconditioning)

(Stirrer OFF)

Titration sequence of SET

(Activate pulse)

(Stirrer ON)

(Preconditioning)

(<START>

(Activate pulse)

(Start delay)

(Request ident.)

(Request smpl size)

(Extraction time)

Titration with test of

stop criterion

After the start, the activate pulse is outputted and the stirrer switched on.

The start delay time is waited off.

If conditioning is on, the sample solution is titrated until the (first) EP is reached. The display shows then

drift OK 2.3 ul/min

SET pH conditioning

The vessel is now conditioned. The titration can be started with <START>.

The sample identifications and the sample size are requested.

The temperature is measured if a T sensor is connected.

Pause 1 is waited off, the start volume is dispensed and pause 2 waited off.

The titration to EP1 then to EP2 is executed. If the extraction time is not yet over when EP1 has been reached, the titration will only be terminated after the extraction time is over.

The stirrer is switched off when there is no conditioning.

Calculations are carried out.

Data are outputted.

Conditioning is carried out.

751 GPD Titrino

2.6 Parameters, key <PARAM>

U/mV

V/ml

U/mV

V/ml

Control parameters

The control parameters can be set separately for each end point. Optimize your control parameters for routine analyses for samples with a rather low content.

During the titration, reagent dosing occurs in 3 phases:

U/mV

1. Initial dosing: Here the dosing rate increases constantly. The rate starts with "min.rate" and goes up to "max.rate".

2. Continuous dosing:

V/ml

t/s

Dosing is performed at the maximum rate "max.rate" until the control range (dynamics) is reached.

3. Control range (dynamics): In this range, dosing is performed in single steps. The last dosing steps are controlled by the parameter "min.rate".

Initial

dosing

Continuous

dosing

V/ml

Control

range

Trial settings for the size of the control range

Set a large control range for steep curves. Relatively flat curves, on the other hand, need a smaller control range. You can get an initial, good approximation for the start of the control range from the intersection point of the tangents:

Control range

751 GPD Titrino

"steep curves" "flat curves"

Control range

2.6. Parameters, key <PARAM>

Relation between the stop criteria "time" and "drift" The stop criterion "time", t(delay), means that the end point must be exceeded for a certain period of time. In other words, after the last dosed increment, time t is allowed to elapse before the titration is stopped. The size of this last increment depends on the volume of the Exchange Unit used. With a 20 mL Exchange Unit, the smallest possible increment is 2 ul. With a t(delay) = 5 s, the last 2 ul reagent must thus suffice for 5 s or

longer. This results in a drift of ≤ 2 uL/5 s = 24 uL/min (the drift can be less than 24

uL/min as it is not known whether the last increment would also suffice for 10 s). If you have been working up to this point with a 20 mL Exchange Unit and a t(delay) = 5 s, you

can set a value of ≤ 24 uL/min as stop drift. The following table shows several values for

the maximum stop drift.

t(delay)

5 s 10 s 20 s

min.incr. (Exchange Unit)

0.5 uL (5 ml) 6 uL/min 3 uL/min 1.5 uL/min

1 uL (10 ml) 12 uL/min 6 uL/min 3 uL/min

2 uL (20 ml) 24 uL/min 12 uL/min 6 uL/min

5 uL (50 ml) 60 uL/min 30 uL/min 15 uL/min

Same t(delay) with a range of extremely small volume increments means different switchoff points. In case the stop criterion "drift" is used, the stopping point remains the same.

751 GPD Titrino

2.6 Parameters, key <PARAM>

If you have entered the endpoint and the control range (dynamics), the default values for the other control parameters should suffice for the first titration. If you encounter difficulties in optimizing your titration, the following table will be of use.

How to proceed if ...

Problem Possible causes and corrective measures

Dosing at the end too long and with too small increments. "Never ends!"

• Increase "min.rate". Perform an experiment with a

much higher min.rate.

• Change switch-off criterion. Attempt, e.g. to increase

the stop drift or use a shorter t(delay) as stop criterion.

• Possibly pass an inert gas through the titration

vessel.

"Overshoots". Titration is not controlled, i.e. at the end single pulses are not dosed.

• Lower "max.rate".

• Set larger control range.

• Set "min.rate" much lower.

• Optimize arrangement of electrode and buret tip and

improve stirring, see page 217. This is particularly important with very fast titration reactions and with steep curves.

Titration time is too long. • Set higher "min.rate".

• Set higher "max.rate".

• Lower "dynamics".

Scatter in titration results is too great.

• Set "min.rate" lower.

751 GPD Titrino

2.6. Parameters, key <PARAM>

2.6.3 Parameters for KFT

parameters >control parameters >titration parameters >stop conditions >statistics >preselections

>control parameters

EP at U 250 mV **titr.

dynamics 100 mV **titr.

control parameters:

for the EP.

titration parameters

control the general course of the titration.

stop conditions:

Control parameters

Endpoint (input range depending on the measured quantity: U, Ipol: 0.. ±2000 mV I, Upol: 0...±200.0 uA)

Control (input range depends on the measured quantity: U, Ipol: 1...2000 mV I, Upol: 0.1...200.0 uA)

Outside of the control range: constant dosing, see page 40.

max.rate max. ml/min **titr.

min.volume incr. min. ul **titr.

Maximum dosing rate (0.01...150 mL/min, max.)

<CLEAR> sets "max.". This parameter determines primarily the addition rate outside the control range, see page 40. The maximum rate depends on the Exchange Unit: Exchange Unit max.

5 mL 15 mL/min 10 mL 30 mL/min 20 mL 60 mL/min 50 mL 150 mL/min

Minimum volume increment (0.1...9.9 ul)

This parameter determines the addition rate at the start and the end of the titration, see also page 40. This parameter influences the titration speed and therefore its accuracy very strongly: A smaller "min.volume incr." results in a slower titration.

751 GPD Titrino

2.6 Parameters, key <PARAM>

stop crit: drift **titr. stop drift 20 ul/min **titr.

t(delay) 10 s **titr.

stop time OFF s **titr.

>titration parameters

titr.direction: -

Type of stop criteria (drift, time)

Titration stops if EP and stop drift are reached (1...999 uL/min)

Titration stops if there is no dosing during t(delay) (0...999 s, INF)

<CLEAR> sets "INF" Switch off when EP is reached and the set time after the last dosing has elapsed. If "INF" = an inquiry for the stop time appears.

Stop after a time (0...999 999 s, OFF)

<CLEAR> sets "OFF". Stop after the set time after start of titration. "OFF" means no stop, i.e. titration for an "infinitely" long time.

Titration parameters

Direction is set automatically (+, -, auto)

auto: The direction is set automatically by the Titrino. +: Direction of higher voltage (more "positive"),

larger currents.

- : Direction of lower voltage, smaller currents.

pause 1 0 s **titr.

start V: OFF cond.

start V 0.0 ml cond.

factor 0 cond.

dos.rate max. ml/min **titr.

Waiting time before start volume (0..999 999 s)

Waiting time, e.g. for equilibration of the electrode after start. The waiting time can be aborted with <QUIT>.

Type of start volume (OFF, abs., rel.)

"OFF": start volume switched off "abs.": absolute start volume in mL "rel.": relative start volume to sample size.

If "abs." is set:

Absolute start volume (0...999.99 mL)

If "rel." is set:

Factor for relative start volume (0...±999 999).

Calculated as: start V in mL = factor * sample size

Dosing rate for start volume (0.01...150 mL/min, max.)

<CLEAR> sets "max.". The maximum rate depends on the Exchange Unit: Exchange Unit max.

5 mL 15 mL/min 10 mL 30 mL/min 20 mL 60 mL/min 50 mL 150 mL/min

751 GPD Titrino

2.6. Parameters, key <PARAM>

pause 2 0 s **titr.

extr.time 0 s **titr.

dos.element: internal D0

I(pol) 1 uA

U(pol) 400 mV

electrode test: OFF

Waiting time after start volume (0...999 999 s)

Second waiting time, e.g. reaction time after dosing of a start volume. The waiting time can be aborted with <QUIT>.

Extraction time (0...999 999 s)

During the extraction time no dosing occurs but the titration does not stop. The extraction time can be aborted with <QUIT>.

Selection of dosing element (internal D0, external D1/ D2)

internal D0: internal buret of the Titrino external D1/2: Buret D1, D2, resp.

Polarization current (-127...127 uA)

or the

polarization potential (-1270...1270 mV, in steps of 10 mV) is inquired.

Electrode test (OFF, ON)

Test for polarized electrodes. Performed on changeover from the inactive standby state to a measurement. "OFF" means that the test is not performed.

temperature 25.0 °C cond.

time interval 2 s cond.

Titration temperature (-170.0...500.0°C).

The temperature is measured at the start of the titration if a T sensor is connected.

Time interval (1...999 999 s)

Time interval for acquisition of a measured value into the measuring point list.

751 GPD Titrino

2.6 Parameters, key <PARAM>

>stop conditions

stop V: abs. **titr.

stop V 99.99 ml **titr.

factor 999999 **titr.

filling rate max. ml/min

Stop conditions for titration

If this is not "normal", i.e. after reaching the EP

Type of stop volume (abs., rel., OFF)

"abs.": absolute stop volume in mL. "rel.": relative stop volume to sample size. "OFF": stop volume switched off. Stop volume is not

monitored. The stop volume applies for one single titration. The conditioning volume is not monitored.

If "abs." is set:

Absolute stop volume (0...9999.99 mL)

If "rel." is set:

Factor for relative stop volume (0...±999 999)

Calculated as: Stop V in mL = factor * sample size

Filling rate after titration (0.01...150 mL/min, max.)

<CLEAR> sets "max.". The maximum rate depends on the Exchange Unit: Exchange Unit max.

5 mL 15 mL/min 10 mL 30 mL/min 20 mL 60 mL/min 50 mL 150 mL/min

>preselections

conditioning: ON

display drift: ON cond.

drift corr: OFF cond.

drift value 0.0 ul/min cond.

req.ident: OFF cond.

Preselections for the sequence

Automatic conditioning of titration vessel (ON, OFF)

If conditioning is "on", the solution is constantly kept at the endpoint. When conditioning is performed, the volume drift can be displayed during the conditioning:

Display of drift during conditioning (ON, OFF).

Volume drift.

Type of drift correction (auto, man., OFF)

Type of drift correction: (EP - drift * time) auto: drift value at start is valid man.: see below OFF : no correction

Value for manual drift correction (0.0...99.9 ul/min)

Request of identifications after start of titration (id1, id1&2, all, OFF)

After start, sample identifications can be requested automatically: Only id1, id1 & id2, all three id's or no inquiries.

751 GPD Titrino

2.6. Parameters, key <PARAM>

req.smpl size: OFF cond.

limit smpl size: OFF cond.

low lim. 0.0 cond. up lim. 999999 cond.

Oven: no cond.

Request of sample size after start of titration (value, unit, all, OFF)

"all" the value and the unit will be requested.

Limiting value check for sample size (ON, OFF)

Lower limit for sample size (0.0...999 999)

Upper limit for sample size (0.0...999 999)

Connected oven (COM1, COM2, no)

COM of the Titrino to which the oven is connected. If an oven is connected via RS232 an inquiry will be made for the oven results and these will be inserted into the result report of the Titrino. The report output on the oven must be switched OFF. Set "no" if no oven has been connected or if you have not connected the oven to Titrino the via RS232 interface.

activate pulse: OFF cond.

Pulse output on I/O line L6 (L6, pin 1) of the remote socket (first, all, cond., OFF) e.g. start of a Dosimat,

see page 224.

751 GPD Titrino

Titration sequence of KFT

<START>

(Start delay)

(Start conditions)

Calculations

Data output

(Reconditioning)

(Stirrer OFF)

2.6 Parameters, key <PARAM>

(Activate pulse)

(Stirrer ON)

(Preconditioning)

(<START>

(Activate pulse)

(Start delay)

(Request ident.)

(Request smpl size)

(Extraction time)

Titration with test of

stop criterion

After the start, the activate pulse is outputted and the stirrer switched on.

The start delay time is waited off.

If conditioning is on, the sample solution is titrated until the EP is reached. The display shows then

drift OK 2.3 ul/min

KFT conditioning

The vessel is now conditioned. The titration can be started with <START>.

The sample identifications and the sample size are requested.

The temperature is measured if a T sensor is connected.

Pause 1 is waited off, the start volume is dispensed and pause 2 waited off.

The titration is executed. If the extraction time is not yet over when the endpoint has been reached, the titration will only be terminated after the extraction time is over.

The stirrer is switched off when there is no conditioning.

Calculations are carried out.

Data are outputted.

Conditioning is carried out.

751 GPD Titrino

2.6. Parameters, key <PARAM>

Control parameters for KFT

The control parameters can be set according to your samples. The default parameters are already set to get satisfactory results. Optimize the control parameters for specific samples only.

During the titration, reagent dosing is carried out in 3 phases:

U/mV

t/s

Initial

dosing

I/uA

KFT Ipol

Continuous

dosing

Control

range

V/ml

1. Initial dosing: Here the dosing rate increases constantly up to "max.rate".

2. Continuous dosing: Dosing is performed at the maximum rate "max.rate" until the control range (dynamics) is reached.

3. Control range (dynamics): In this range, dosing is performed in single steps. The last dosing steps are controlled by the parameter "min.volume incr.".

KFT Upol

V/ml

Remarks:

• Titer determination should have the same modes and the same parameters as the

sample titrations.

• In most cases the preset default parameters provide precise and reproducible results.

• Ipol gives relatively steep curves. They are flatter with Upol.

751 GPD Titrino

Mechanisms of the KFT parameters in Ipol mode

U/mV

2.6 Parameters, key <PARAM>

Titration

(direct titration)

EP at U

Titration (Back titration)

I(pol)

Excess H2O

Excess Iodine-

darker solution

I/uA

• The position and curve characteristics of the line between the ranges of excess water

or excess iodine depends on the type of sample and the ingredients of the working media.

• The endpoint has to be set close to the range margin, but always within the iodine

excess range. If the endpoint is set too close to the limit, an overdose of KF reagent may be dispensed. The steeper the curve at the preset polarization current I(pol), the more delicate it is to titrate to a steady and reproducible endpoint. For the titration of troublesome samples, the particular conditions must be optimized by trial and error. Always mind the color of the working medium at the end point as your guideline. Remark: In most cases the preset default parameters provide precise and reproducible results.

• If you select negative values for a parameter, you should choose negative values for all

other parameters too in order to have compatible parameter sets.

• In KFT Upol mode, all parameters work in a similar manner as in KFT Ipol mode.

751 GPD Titrino

2.6. Parameters, key <PARAM>

The determination of the free water is easily done, as far as the specifications of the reagent manufacturer regarding the "water capacity" of the reagents are considered. Problems may occur with specific sample matrices. The relevant literature contains many precise analysis instructions. In the following table we attempt to show you solutions related more to the instrument's side:

What to do if ...

Problem Possible causes and remedial action

Dosing at end too long and increments too small. "Is never finished!"

The increments at the end of the titration are too large. "Overshoots".

Solution becomes too brown at the end of the titration.

Solution becomes darker with every titration.

• Increase "min.volume incr.".

• Change stop criterion. Try to increase stop drift or

use a short stopping time as stop criterion, e.g.

• With problematical samples change solvents with

ketones or aldehydes in 2-methoxyethanol or with amines mixture in methanol/glacial acetic, e.g., see literature.

• Lower "max.rate". The following experiment gives you

a reference point for the optimum max.rate: Drift display during conditioning and add sample without starting the titration. Select a value below the maximum drift as "max.rate".

• Optimize setup of electrode and buret tip and

improve stirring.

• The methanol fraction in the solvent is too low.

Change the solvent.

• Electrode could be coated; wipe off with acetone.

• Renew solvent.

• Electrode could be coated; wipe off with acetone.

The drift increases with every titration.

The endpoint is reached "too rapidly".

The titration times become longer and longer.

• Does your sample evolve water extremely sluggishly?

Work with the KF oven.

• Are acids esterified in your sample? Change solution

more frequently. Increase buffer capacity of the solvent.

• Does your sample contain ketones or aldehydes?

Use special reagents suitable for ketones and aldehydes.

• Reduce "max.rate".

• With 2-component reagents the buffer capacity of the

solvent can be exhausted. Change solution.

• If the drift increases at the same time, see above.

751 GPD Titrino

2.6.4 Parameters for STAT

>preselections

2.6 Parameters, key <PARAM>

parameters >control parameters >titration parameters >stop conditions >statistics >evaluation >monitoring

>control parameters

EP at pH OFF **titr.

control parameters:

for reaching the control point.

titration parameters

control the global course of the titration.

stop conditions:

Parameters for automatic termination of the titration. statistics: Calculation of mean values and standard deviation, see page 77.

evaluation:

Evaluation of rates, fix volumes and fix times.

monitoring

of limit values for the measured value, temperature and rate. preselections: ON/OFF of various auxiliary functions such as automatic requests after the start and activate pulse.

Control parameters

Control point: (input range depends on the measured quantity: pH: 0...±20.00, OFF U, Ipol: 0...±2000 mV, OFF Upol: 0...±200.0 uA, OFF)

<CLEAR> sets "OFF".

dynamics 1 **titr.

max.rate 10.0 ml/min **titr.

751 GPD Titrino

Controlling range (input range depends on the measured quantity: pH: 0.01...20.00, OFF U, Ipol: 1...2000 mV, OFF Upol: 0.1...200.0 uA, OFF)

<CLEAR> sets "OFF". "OFF" means largest control range, i.e. always controlled reagent addition. Outside: constant dosing, see also page 51.

Maximum dosing rate (0.01...150 mL/min, max.)

<CLEAR> sets "max.". This parameter determines primarily the addition rate outside the control range, see page 51. The maximum rate depends on the Exchange Unit: Exchange Unit max.

5 mL 15 mL/min 10 mL 30 mL/min 20 mL 60 mL/min 50 mL 150 mL/min

2.6. Parameters, key <PARAM>

min.rate 25.0 ul/min **titr.

>titration parameters

start V: OFF

start V 0.0 ml

factor 0

dos.rate max. ml/min

**titr.

Minimum dosing rate (0.01...9999 uL/min)

This parameter determines the addition rate in the range of the control point. Rule of thumb for "min.rate" in uL/min = (expected rate of the reaction in uL/min)/10.

Titration parameters

Type of start volume (OFF, abs., rel.)

"OFF": start volume switched off "abs.": absolute start volume in mL "rel.": relative start volume to sample size.

If "abs." is set:

Absolute start volume (0...999.99 mL)

If "rel." is set:

Factor for relative start volume (0...±999 999).

Calculated as: start V in mL = factor * sample size

Dosing rate for start volume (0.01...150 mL/min, max.)

<CLEAR> sets "max.". The maximum rate depends on the Exchange Unit: Exchange Unit max.

5 mL 15 mL/min 10 mL 30 mL/min 20 mL 60 mL/min 50 mL 150 mL/min

pause 0 s

**titr.

start time 0 s

start pH OFF

Waiting time after start volume (0...999 999 s)

Waiting time, e.g. for equilibration of the electrode after start or reaction time after dosing of a start volume. The waiting time can be aborted with <QUIT>.

Start time for data acquisition (0...999 999 s)

Measured values will be acquired only after the start time has elapsed.

Start measured value for data acquisition (input range depends on the measured quantity: pH: 0...±20.00, OFF U, Ipol: 0...±2000 mV, OFF Upol: 0...±200.0 uA, OFF)

<CLEAR> sets "OFF". Measured values will be acquired only after start of measured value has been reached.

751 GPD Titrino

2.6 Parameters, key <PARAM>

start rate OFF ml/min

time interval 2 s

titr.direction: auto

dos.element: internal D0

meas.input: 1

Start rate for data acquisition (0.01...150 mL/min, OFF)

<CLEAR> sets "OFF". Measured values will be acquired only if the current rate is below the start rate. This criterion effective 10 s after the start.

Time interval for data acquisition (1..999 999 s)

Time interval for the entry of the values in the measuring point list. The measuring point list can contain max. 500 points.

Direction is set automatically (+, -, auto)

auto: The direction is set automatically by the Titrino

(sign [U

- EP]).

init

+: Direction of higher pH, higher voltage (more

"positive"), larger currents.

- : Direction of lower pH, lower voltage, smaller currents.

Selection of dosing element (internal D0, external D1, external D2)

internal D0: internal buret of the Titrino external D1/2: buret D1, D2, resp.

Measuring input for pH and U. (1, 2, diff.)

Request only with measured quantities pH and U. Measuring input 1 or 2 or differential amplifier; connection of electrodes, see page 215.

I(pol) 1 uA

U(pol) 400 mV

electrode test: OFF

temperature 25.0 °C

With polarized electrodes, instead of the measuring input the

polarization current (-127...127 uA)

or the

polarization potential (-1270...1270 mV, in steps of 10 mV)

is inquired.

Electrode test (OFF, ON)

Test for polarized electrodes. Performed on changeover from the inactive standby state to a measurement. "OFF" means that the test is not performed.

Temperature (-170.0...500.0 °C)

If a T sensor is attached, the temperature is measured continuously and the pH values corrected accordingly. The last measured value is entered as the "temperature" parameter.

751 GPD Titrino

2.6. Parameters, key <PARAM>

>stop conditions

stop time: OFF

**titr.

stop time 999999 s

t(delta) 999999 s

t(delay) 999999 s

**titr.

factor 999999

**titr.

stop V: abs.

**titr.

Stop conditions

The condition which is met first will be effective.

Type of stop time (abs.,rel., delta, delay, OFF)

"abs": absolute stop time in s "rel.": relative stop time to sample size. "delta" Time after having reached the EP the first time. "delay" Time after last dosing increment. "OFF": stop time switched off. Stop time is not

monitored.

See page 52.

If "abs.", "delta" or "delay" are set:

Request of time (0...999 999 s)

If "rel." is set:

Factor for relative stop time (0...±999 999)

Calculated as: Stop time in s = factor * sample size

Type of stop volume (abs., rel., OFF)

"abs.": absolute stop volume in mL. "rel.": relative stop volume to sample size. "OFF": stop volume switched off. Stop volume is not

monitored.

stop V 99.99 ml

**titr.

factor 999999

**titr.

stop rate OFF ml/min

**titr.

filling rate max. ml/min

**titr.

If "abs." is set:

Absolute stop volume (0...9999.99 mL)

If "rel." is set:

Factor for relative stop volume (0...±999 999)

Calculated as: Stop V in mL = factor * sample size

Stop when dosing rate is smaller than the preset rate. (0.01...150 mL/min, OFF)

<CLEAR> sets "OFF". Stop if the current rate is below the stop rate. This criterion becomes effective 10 s after start.

Filling rate (0.01...150 mL/min, max.)

<CLEAR> sets "max.". The maximum rate depends on the Exchange Unit: Exchange Unit max.

5 mL 15 mL/min 10 mL 30 mL/min 20 mL 60 mL/min 50 mL 150 mL/min

751 GPD Titrino

2.6 Parameters, key <PARAM>

>evaluation

low lim.1 OFF s

up lim.1 OFF s

fix V1 OFF s

fix time 1 OFF V(tot)

Evaluation

see also page 54.

Evaluation of dosing rates within time windows (0...999 999 s, OFF)

Up to 9 time windows in which a rate should be calculated. The rates are available for calculations as C8X. For the calculation of a rate, the measuring point list in the time window must contain at least 4 points. If no point falls on the window limits, the next outer one is used.

Interpolation of the volume at a fixed time (0...999 999 s, OFF)

Up to 9 fix V. The associated volumes are available for calculations as C5X.

Interpolation of times at volume ratios at the end V (0.01 ... 1.00, OFF)

The volume is entered as a fraction of the final volume, e.g. 0.25 = 25% of the final volume. Up to 9 fix times. The associated times are available for calculations as C6X.

>monitoring

meas.val: OFF

**titr.

low lim. pH -20.00

up lim. pH 20.00

**titr

action: none

**titr.

Monitoring of limit values

Out of limits are marked in the measuring point list. Measured values and temperatures are only stored in the measuring point list if their monitoring is active.

Monitoring of measured values (ON, OFF)

With "on" follow the requests:

Limits for measured values (input range depends on the measured quantity): pH: 0...±20.00 U, Ipol: 0...±2000 mV Upol: 0...±200.0 uA)

Action if a limit is exceeded (end, hold, wait, none)

end: Abort. hold: Hold reagent addition until manually restarted. wait: Hold reagent addition until limits are again

complied with, then continue automatically.

751 GPD Titrino

2.6. Parameters, key <PARAM>

rate: OFF

**titr.

low lim. 0.000 ml/min

up lim. 150 ml/min

action: none

**titr.

temperature: OFF

**titr.

low lim. -170.0 °C

up lim. 500.0 °C

action: none

**titr.

Monitoring of rate (ON, OFF)

With "on" follow the requests:

Limit values (0.000...150 mL/min)

Action if a limit is exceeded (end, hold, wait, none)

end: Abort. hold: Hold reagent addition until manually restarted. wait: Hold reagent addition until limits are again

complied with, then automatically continue. If the lower limit has been exceeded, "wait" is senseless as the rate will only become smaller during the waiting time-

Monitoring of temperature (ON, OFF)

With "on", the following requests:

Limit values (-170.0...500.0°C)

Action if a limit is exceeded (end, hold, wait, none)

end: Abort. hold: Hold reagent addition until manually restarted. wait: Hold reagent addition until limits are again

complied with, then continue automatically.

assign output L10: none

violated limit: any

output L10: pulse

Assignment of output L10 for monitoring (meas, temp, rate, all, none)

A signal can be output at L10 (pin 8) of the remote socket if a limit has been violated.

Assignment of a violated limit (any, upper, lower)

The signal will be set if the assigned limit is violated.

Type of signal to be set when limits are violated. (active, pulse)

active: Output line is set to 0 V. pulse: Pulse > 100 ms. Important: An active line will be set inactive with an impulse!

Same possibilities for lines L11, L12, L13. Pin assignment on socket "Remote": L10 Pin 8 L11 Pin 13 L12 Pin 19 L13 Pin 20

751 GPD Titrino

2.6 Parameters, key <PARAM>

>preselections

req.ident: OFF

req.smpl size: OFF

limit smpl size: OFF

low lim. 0.0

up lim. 999999

display rate: OFF

activate pulse: OFF

Preselections for the sequence

Request of sample identifications after start of titration (id1, id1&2, all, OFF)

After start, sample identifications can be inquired automatically: Only id1, id1 & id2, all three id's or no inquiries.

Request of sample size after start of titration (value, unit, all, OFF)

Limiting value check for sample size (ON, OFF)

Lower limit for sample size (0.0...999 999) Upper limit for sample size (0.0...999 999)

Display rate (ON, OFF)

Display current rate during the titration.

Pulse output on line "activate" (L6, pin 1) of the remote socket (ON, OFF)

see page 223.

751 GPD Titrino

2.6. Parameters, key <PARAM>

<START>

(Start delay)

(Start conditions)

Stop conditions

Calculations

(Stirrer OFF)

Data output

Sequence for STAT

(Activate pulse)

(Stirrer ON)

(Request ident.)

(Request smpl size)

Controlling

Acquisition of meas.

(Monitoring)

After the start, the activate pulse is output and the stirrer switched on.

The start delay time is waited off.

The sample identifications and the sample size are requested.

The start volume is dispensed (without controlling or measured value acquisition and there is no monitoring during this time) and the pause is waited off. Then the other start conditions are worked off in the order given below: Start time Start measured value Start rate During this time the controlling is active as well as the monitoring. However, there is no acquisition of measured values.

Once the start conditions have been met, measured values (time, volume) are acquired and stored in the measuring point list. If monitoring of measured values and/or temperature is active, these values will also be stored in the measuring point list. If limits are violated it will be marked in the measuring point list. If a T sensor is connected, the temperature is measured continuously (in intervals of 2 s). In pH titrations, the pH will be corrected as a function of temperature. Without T sensor the values are measured without interrupt by T measurements. The manually set temperature is then valid.

The titration is terminated according to the first stop criterion which has been met.

Stirrer is switched off.

Evaluations and calculations are carried out. The measuring point list is the base for evaluations (and curves).

Data are output.

751 GPD Titrino

Control parameters

U/mV

V/ml

t/s

V/ml

Control range

2.6 Parameters, key <PARAM>

Dosing outside the control range: The dosing rate is given mainly by the parameter "max.rate". Optimize the parameters "max.rate" and "dynamics" together to avoid overtitration the first time the control point is reached. Set "dynamics" such that the measured value lies inside the control range during the phase where the value is kept. Set "dynamics" to e.g. pH=3, U=180 mV for slow reactions. You can also make a SET pretitration to reach the control point. In this case, "dynamics" of the STAT titration is not very crucial.

Dosing inside the control range: Here the dosing rate is given mainly by the parameter "min.rate". Rule of thumb for "min.rate" in ul/min = (expected rate of the reaction in ul/min)/10.

How to proceed if ...

Problem Possible causes and corrective action

Adherence to the control point is not good. The measured value is too high, then too low. "The controller oscillates".

Time for reaching the control point is too long.

• Set "max.rate" and possibly also "min.rate" lower.

• Set "dynamics" larger.

• Is the stirring efficiency adequate?

• Arrange electrode and buret tip properly, see page

217.

• Are the tubing lengths kinked?

• Possibly use Exchange Unit with a small cylinder

volume (smaller volume increment per pulse).

• Set "dynamics" smaller.

• Set "min.rate" higher.

• Set "max.rate" higher.

751 GPD Titrino

2.6. Parameters, key <PARAM>

Stop times

V/ml

Last dosing

Control point (EP) reached the first time

t(delay)

t(delta)

stop time

t/s

Stop time: The stop time runs over the whole controlling time of the determination: It

starts after dosing of the start volume and after the pause: The stop time can be absolute (in s) or relative to the sample size (time in s = factor * smpl size).

t(delta): t(delta) starts after controlling point (EP) has been reached the first time.

t(delay): t(delay) can be used as "after reaction time". It starts after the last dosing

step, i.e. with every dosing, t(delay) will be restarted from zero.

751 GPD Titrino

2.6 Parameters, key <PARAM>

Measuring point list and monitoring

General information on measuring point list:

• Measured points are entered in the measuring point list at the preset time interval.

• If one (or more) entries appear during the refilling time, one measured point is entered

immediately after the refilling. The time reference otherwise remains unchanged, however.

• If the stop time occurs within the refilling time period, after filling one measured point is

entered and only then the determination is stopped.

• The measuring point list always includes the values of time and volume. If monitoring

of measured values and/or temperature is active, the corresponding values are entered too.

• The "mess." column shows a message if a limit value was exceeded in the last time

interval, see example below. "* " is used to mark if dosing was interrupted, e.g. owing to refilling, action "wait" or "hold" on limit value violation or manual <HOLD>.

• The volume of the last measured point entry can differ from the final volume as time

may have elapsed between the last entry and the actual stop. The final volume is available as variable C41 and can be used to calculate results.

Example of a measuring point list. Monitoring of measured value and temperature active.

'mp

751 GPD Titrino 0P1/101 751.0020

date 1999-06-22 time 08:54 14

pH(init) 7.42 STAT pH ********

smpl size 1.0021 g

t/s V/ml pH T/°C mess.

0 0.0000 7.434 35.5 limit

30 0.9140 3.039 35.7 limit

60 1.0010 3.056 36.0 temp.

90 1.0780 3.022 36.2

120 1.1470 2.972 36.4 meas

150 1.2250 3.018 36.5 *

: :

More than 1 monitored quantity violated.

Temperature limit violated.

pH limit violated. Dosing interruption.

751 GPD Titrino

2.6. Parameters, key <PARAM>

Evaluation

Rates C8X The rates are calculated by linear regression.

C80 is the mean rate over all points of the measuring point list.

C8X (9≤X>0) are the rates in the specified time windows. At least 4 points are

necessary for an evaluation. If the limit of the time window does not coincide with a current measured point, the next outer is taken as the limit, see example below. In monitoring, neither "wait" nor "hold" should be used as an action as otherwise the resulting volume/time curve is no longer linear. The linear regression of such a curve then results in high standard deviations.

Fix volume C5X The associated volume at a specified time is interpolated from the measuring

point list.

Fix time C6X The associated time at a specified volume is interpolated from the measuring

point list. The volume is entered as a fraction of the total dispensed volume. If the volume remains constant over several measured points, the last associated time value is taken. The fix time for 1.0 V(tot) is evaluated after the final volume.

Example:

'mp

751 GPD Titrino 0P1/101 751.0020

date 1999-06-22 time 08:54 14

pH(init) 7.42 STAT pH ********

smpl size 1.0021 g

t/s V/ml pH T/°C mess.

0 0.0000 7.434 35.5

30 0.9140 3.039 35.7

60 1.0010 3.056 36.0

90 1.0780 3.022 36.2

120 1.1470 2.972 36.4

150 1.2250 3.018 36.5

1560 6.3290 2.994 37.0

1590 6.3290 2.998 37.0

1620 6.3290 2.998 37.0

1650 6.3290 2.998 37.0

1680 6.3465 2.975 37.0

Specified time window for rate evaluation: 40...100 s.

Used for the regression: 30...120 s

Fix time: 0.8 V(tot) ⇒ 1650 s

751 GPD Titrino

2.6.5 Parameters for DOS

2.6 Parameters, key <PARAM>

parameters >dosing parameters >stop conditions >statistics >monitoring >preselections

>dosing parameters

dispensing type: volume

volume 10.00 ml

dosing parameters

control the dosing

stop conditions:

Parameters for termination. statistics: Calculation of mean values and standard deviation, see page 77.

monitoring

of limit values for the measured value and temperature. preselections: ON/OFF of various auxiliary functions such as auto-

matic requests after the start and activate pulse.

Dosing parameters

Type of dosing (volume, time, rate)

Main parameters. Two parameters of the equation "rate = volume/time" are specified, the third is calculated.

The requests which appear depend on the type of dosing selected:

Volume (0...99 999.99 mL)

disp.time 100 s

rate max. ml/min

disp.crit: rate

pause 0 s

**titr.

time interval 10 s

dos.element: internal D0

Dispensing time (1...999 999 s)

Dispensing time only. Waiting times, e.g. for refilling are not included.

Rate (0.001...150 mL/min, max.)

Dispensing criterion (volume, time, rate)

Selection of the second dispensing parameter. The request which appears depends on the dispensing criterion selected.

Pause (0...999 999 s)

Waiting time, e.g. for stabilization of the electrode after start. The waiting time can be aborted with <QUIT>.

Time interval (1...999 999 s)

Time interval for the entry of the values in the measuring point list. The measuring point list can contain max. 500 points.

Selection of dosing element (internal D0, external D1, external D2)

internal D0: internal buret of the Titrino external D1/2: buret D1, D2, resp

751 GPD Titrino

2.6. Parameters, key <PARAM>

temperature 25.0 °C Temperature (-170.0...500.0 °C)

If a T sensor is connected, the temperature is measured continuously and the pH values are corrected accordingly. The last measured value is entered as the "temperature" parameter. Without a T sensor, the temperature entered manually applies.

>stop conditions

stop V: OFF

**titr.

stop V 99.99 ml

**titr.

factor 999999

**titr.

filling rate max. ml/min

**titr.

Stop conditions

If a stop is not made after the dispensing time or after the dispensed volume.

Type of stop volume (abs., rel., OFF)

"abs": absolute stop volume in mL "rel.": relative stop volume to sample "OFF": stop volume switched off, not

monitored.

If "abs." is set:

Absolute stop volume (0...99 999.99 mL)

If "rel." is set:

Factor for relative stop volume (0...± 999 999)

Calculated as: Stop V in mL = factor * sample size

Filling rate (0.01...150 mL/min, max.)

<CLEAR> sets "max.". The maximum rate depends on the Exchange Unit: Exchange Unit max.

5 mL 15 mL/min 10 mL 30 mL/min 20 mL 60 mL/min 50 mL 150 mL/min

>monitoring

meas.mode: OFF

**titr.

meas.input: 1

Monitoring of measured values

Limit value violations are marked in the measuring point list. Measured values and temperatures are only stored in the measuring point list if their monitoring is active.

Measured values (pH, U, Ipol, Upol, OFF)

If ≠ "OFF" follow the requests:

Measuring input (1, 2, diff.)

Request only with measuring modes pH and U. Measuring input 1 or 2 or differential amplifier; connection of electrodes, see page 215.

751 GPD Titrino

I(pol) 1 uA

U(pol) 400 mV

electrode test: OFF

2.6 Parameters, key <PARAM>

With polarized electrodes, the request of the measuring input is replaced by one regarding the polarization current (-127...127 uA), or the

polarization voltage (-1270...1270 mV, in steps of 10 mV) Electrode test (OFF, ON)

Test for polarized electrodes. Performed on the switchover from inactive basic status to a measurement. "OFF" means the test is not performed.

low lim. pH -20.00

up lim. pH 20.00

**titr

action: none

**titr.

temperature: OFF

**titr.

low lim. -170.0 °C

up lim. 500.0 °C

action: none

**titr.

assign output L10: none

Limit values for the measured value (input range depends on the measured quantity: pH: 0...±20.00 U, Ipol: 0...±2000 mV Upol: 0...±200.0 uA)

Action if a limit is exceeded (end, hold, wait, none)

end: Abort hold: Hold reagent addition until manually restarted. wait: Hold reagent addition until limits are again

complied with, then continue automatically.

Monitoring of temperature (ON, OFF)

With "on", the following requests:

Limits (-170.0...500.0 °C)

Action if a limit is exceeded (end, hold, wait, none)

end: Abort hold: Hold reagent addition until manually restarted. wait: Hold reagent addition until limits are again

complied with, then continue automatically.

Assignment of output I/O lines (meas, temp, all, none)

L10 output sets a signal when values are out of limit (pin 8). With an assignment, the following requests:

violated limit: any

output L10: pulse

751 GPD Titrino

Assignment of a violated limit (any, upper, lower)

The signal will be set if the assigned limit is violated.

Type of signal to be set when limits are violated. (active, pulse)

active: Output line is set to 0 V. pulse: Pulse > 100 ms. Important: An active line will be set inactive with an impulse!

Same possibilities for lines L11, L12, L13. Pin assignment on socket "Remote": L10 Pin 8 L11 Pin 13 L12 Pin 19 L13 Pin 20

2.6. Parameters, key <PARAM>

>preselections

req.ident: OFF

req.smpl size: OFF

limit smpl size: OFF

low lim. 0.0

up lim. 999999

activate pulse: OFF

Preselections for the sequence

Request of sample identifications after start of titration (id1, id1&2, all, OFF)

After start, sample identifications can be inquired automatically: Only id1, id1 & id2, all three id's or no inquiries.

Request of sample size after start of titration (value, unit, all, OFF)

Limiting value check for sample size (ON, OFF)

Lower limit for sample size (0.0...999 999) Upper limit for sample size (0.0...999 999)

Pulse output on line "activate" (L6, pin 1) of the remote socket (ON, OFF)

see page 223.

751 GPD Titrino

Sequence with DOS

(Activate pulse)

<START>

(Start delay)

(Pause)

Calculations

Data output

2.6 Parameters, key <PARAM>

After the start, the activate pulse is output.

The start delay time is waited off.

(Request ident.)

(Request smpl size)

Dosing

Acquisition of meas.

(Monitoring)

The sample identifications and the sample size are requested.

The pause is waited off. During this time the limits are not yet monitored.

During the dosing, measured values (time, volume) are acquired and stored in the measuring point list. If monitoring of measured values and/or temperature is active, these values will also be stored in the measuring point list. If limits are violated it will be marked in the measuring point list. If a T sensor is connected, the temperature is measured continuously (in intervals of 2 s). The pH will be corrected as a function of temperature. Without T sensor the values are measured without interrupt by T measurements. The manually set temperature is then valid. In dosings which use "time" or "rate" as dispensing type, the volume goes up to 99 999.99 ml. After that it will be set to zero and the dosing continues. The dosing is terminated when the dosing volume or the dosing time is reached.

751 GPD Titrino

Calculations are carried out.

Data are output. The measuring point list is the base for curves.

2.6. Parameters, key <PARAM>

Filling times

Refilling times are not incorporated by the Titrino in the calculation of the rate. The filling times can be calculated using the following formula:

max. filling rate

filling rate in s = ДДДДДДДДДДДДДДД * 20 s + 3 s

current filling rate

The max. filling rate depends on the Exchange unit installed, see page 56. The filling times (incl. stopcock rotation) can be estimated with the aid of the following table and taken into account in your dosing routine:

Exchange

Unit

Filling rate

"max."

Filling rate

"100 ml/min"

Filling rate

"50 ml/min"

Filling rate

"10 ml/min"

5 ml 23 s --- --- 33 s

10 ml 23 s --- --- 63 s

20 ml 23 s --- 27 s 123 s

50 ml 23 s 33 s 63 s 303 s

Example: Dispensing of 1 L reagent is required over a period of 1 hour with a 50 mL Exchange unit. Calculate the rate to be set.

Dispensing time = 60 min. Dispensed volume = 1000 mL Filling time = 23 s (filling rate = max.) Volume of the Exchange Unit = V(B) = 50 mL

Number of refills = Dispensed volume/V(B) = 1000/50 = 20

If this division does not result in a remainder, the last filling is no longer a "refilling" and must be deducted. In our example, 19 refills are required. During this time, dispensing is not performed, i.e. the actual dispensing time is 3600 s - 19 * 23 s = 3163 s =

52.717 min.

The dispensing rate is thus given by 1000 mL/52.717 min = 18.972 mL/min

Summary in a formula:

Volume 1000

Rate = ДДДДДДДДДДДДДДДДДДДДДДДДДДДД = ДДДДДДДДДДДДДД=18.972 ml/min

Disp.time - Refills * Fill.time * 1/60 60 - 19 * 23 * 1/60

751 GPD Titrino

2.6 Parameters, key <PARAM>

Action:

Measuring point list and monitoring

• Measured points are entered in the measuring point list at the preset time interval. The

input times represent the clock time. This must be distinguished from the dispensing time: The dispensing time does not include any waiting times which can arise in refilling, hold or wait as a result of limit value violations.

• If one (or more) entries occur in the time during refilling, one measured point is entered

immediately after the refilling. The time reference otherwise remains unchanged, however.

• The measuring point list always includes the values "time" and "volume". If monitoring

of measured values and/or temperature is active, the corresponding values are also entered.

• The "mess." column shows a message if a limit value was violated in the last time

interval, see page 53. "*" is also used in this column to mark when the dispensing was interrupted: refilling, action "wait" or "hold" on limit value violation or manual <HOLD>.

• The volume of the last measured point entry can differ from the final volume as time

may have elapsed between the last entry and the actual stop. The end volume (C41) can be used for calculations.

The values from the measuring point list can be shown graphically. Example: Profile of the pH value during a dispensing with the "wait" action.

Curve pH vs. time ("meas crv") Curve volume vs. time ("curve")

'mt 'cu

751 GPD Titrino 0P1/101 751.0020 751 GPD Titrino 0P1/101 751.0020

date 1999-06-27 time 08:54 14 date 1999-06-27 time 08:54 14

DOS ******** DOS ********

10.0 s/div dpH=0.5/div 10.0 s/div dV=2 ml/div

wait

============ ============

751 GPD Titrino

2.6. Parameters, key <PARAM>

2.6.6 Parameters for DOC

parameters >dosing parameters >stop conditions >statistics >monitoring >preselections

>dosing parameters

begin at pH init

end at pH OFF

dosing parameters

control the dosing

stop conditions:

Parameters for termination. statistics: Calculation of mean values and standard deviation, see page 77.

monitoring

of limit values for the measured value and temperature. preselections: ON/OFF of various auxiliary functions such as auto-

matic requests after the start and activate pulse.

Dosing parameters

Start of the measured value for the beginning of dosing (input range depends on the measured quantity: pH: 0...±20.00, init U, Ipol: 0...±2000 mV, init Upol: 0...±200.0 uA, init)

<CLEAR> sets "init" = initial measured value.

Final measured value (input range depends on the measured quantity: pH: 0...±20.00, OFF U, Ipol: 0...±2000 mV, OFF Upol: 0...±200.0 uA, OFF)

<CLEAR> sets "OFF"

sweep time 300 s

dynamics 0.25 **titr.

Sweep time for measured value (0...999 999 s)

The change in the set measured value from the initial to the final value within the sweep time is linear.

Control range (input range depends on the measured quantity: pH: 0...20.00, OFF U, Ipol: 0...±2000 mV, OFF Upol: 0...±200.0 uA, OFF)

<CLEAR> sets "OFF". "OFF" means largest control range (dynamics), i.e. slow reagent addition. Outside the control range, dispensing is performed continuously, see also page 68.

751 GPD Titrino

2.6 Parameters, key <PARAM>

max.rate max. ml/min **titr.

min.rate 5.0 ul/min **titr.

direction: auto

Maximum rate (0.01...150 mL/min, max.)

<CLEAR> sets "max.". This parameter primarily determines the addition rate outside the control range, see also page 68. The maximum rate depends on the Exchange Unit: Exchange Unit max.

5 mL 15 mL/min 10 mL 30 mL/min 20 mL 60 mL/min 50 mL 150 mL/min

Minimum rate (0.01...9999 uL/min)

This parameter determines the rate within the control range.

Direction is set automatically (+, -, auto)

auto: The direction is set automatically by the Titrino

-U

end

]).

init

+: Direction of higher pH, higher voltage (more

"positive"), higher current.

- : Direction of lower pH, lower voltage, lower currents.

The direction is used only when "init" has been selected as start value.

start V: OFF

start V 0.0 ml

factor 0

dos.rate max. ml/min

**titr.

pause 0 s

Type of start volume (OFF, abs., rel.)

"OFF": start volume switched off "abs": absolute start volume in mL "rel.": relative start volume to sample

If "abs." is set:

Absolute start volume (0...999.99 mL)

If "rel." is set:

Factor for relative start volume (0...±999 999)

Calculated as: Start V in mL = factor * sample size

Dosing rate for start volume (0.01...150 mL/min, max.)

<CLEAR> sets "max.". The maximum rate depends on the Exchange Unit: Exchange Unit max.

5 mL 15 mL/min 10 mL 30 mL/min 20 mL 60 mL/min 50 mL 150 mL/min

Waiting time (0...999 999 s)

Waiting time, e.g. for stabilization of the electrode after start or reaction time after dosing of a start volume. The waiting time can be aborted with <QUIT>.

time interval 10 s

751 GPD Titrino

Time interval (1...999 999 s)

Time interval for the entry of the measured values in the measuring point list. The measuring point list can contain max. 500 points.

2.6. Parameters, key <PARAM>

dos.element: internal D0

meas.input: 1

I(pol) 1 uA

U(pol) 400 mV

electrode test: OFF

temperature 25.0 °C

Selection of dosing element (internal D0, external D1, external D2)

internal D0: internal buret of the Titrino external D1/2: buret D1, D2, resp.

Measuring input (1, 2, diff.)

Measuring input for pH and U. Measuring input 1 or 2 or differential amplifier; connection of electrodes, see page 215.

With polarized electrodes, the request of the measuring input is replaced by one regarding the polarization current (-127...127 uA), or the

polarization voltage (-1270...1270 mV, in steps of 10 mV) Electrode test (OFF, ON)

Test for polarized electrodes. Performed on the switchover from the inactive basic status to a measurement. "OFF" means the test is not performed.

Temperature (-170.0...500.0 °C)

If a T sensor is connected, the temperature is measured continuously and the pH values are corrected accordingly. The last measured value is entered as the "temperature" parameter.

>stop conditions

stop V: abs.

**titr.

stop V 99.99 ml

**titr.

factor 999999

**titr.

filling rate max. ml/min

**titr.

Stop conditions

Type of stop volume (abs., rel., OFF)

"abs": absolute stop volume in mL "rel.": relative stop volume to sample size. "OFF": stop volume switched off, not monitored.

If "abs." is set:

Absolute stop volume (0...9999.99 mL)

If "rel." is set:

Factor for relative stop volume (0...±999 999)

Calculated as: Stop V in mL = factor * sample size

Filling rate (0.01...150 mL/min, max.)

<CLEAR> sets "max.". The maximum rate depends on the Exchange Unit: Exchange Unit max.

5 mL 15 mL/min 10 mL 30 mL/min 20 mL 60 mL/min 50 mL 150 mL/min

751 GPD Titrino

2.6 Parameters, key <PARAM>

>monitoring

meas.val: OFF

**titr.

low lim. pH -20.00

up lim. pH 20.00

**titr

action: none

**titr.

temperature: OFF

**titr.

low lim. -170.0 °C

up lim. 500.0 °C

action: none

**titr.

Monitoring of measured values

Limit value violations are marked in the measuring point list. Measured values and temperatures are only stored in the measuring point list if their monitoring is active.

Monitoring of measured values (ON, OFF)

With "ON", the following requests:

Limits for measured values (input range depends on measured quantity: pH: 0...±20.00 U, Ipol: 0...±2000 mV Upol: 0...±200.0 uA)

Action if a limit is exceeded (end, hold, wait, none)

end: Abort hold: Hold reagent addition until manually restarted. wait: Hold reagent addition until limits are again

complied with, then continue automatically.

Monitoring of temperature (ON, OFF)

With "ON", the following requests:

Limits for measured values (-170.0...500.0 °C)

Action if a limit is exceeded (end, hold, wait, none)

end: Abort hold: Hold reagent addition until manually restarted. wait: Hold reagent addition until limits are again

complied with, then continue automatically.

assign output L10: none

violated limit: any

output L10: pulse

751 GPD Titrino

Assignment of output I/O lines (meas, temp, all, none)

L10 output sets a signal when values are out of limit (pin 8). With an assignment, the following requests:

Assignment of a violated limit (any, upper, lower)

The signal will be set if the assigned limit is violated.

Type of signal to be set when limits are violated. (active, pulse)

active: Output line is set to 0 V. pulse: Pulse > 100 ms. Important: An active line will be set inactive with an impulse!

Same possibilities for lines L11, L12, L13. Pin assignment on socket "Remote": L10 Pin 8 L11 Pin 13 L12 Pin 19 L13 Pin 20

2.6. Parameters, key <PARAM>

>preselections

req.ident: OFF

req.smpl size: OFF

limit smpl size: OFF

low lim. 0.0

up lim. 999999

display rate: OFF

activate pulse: OFF

Preselections for the sequence

Request of sample identifications after start of titration (id1, id1&2, all, OFF)

After start, sample identifications can be inquired automatically: Only id1, id1 & id2, all three id's or no inquiries.

Request of sample size after start of titration (value, unit, all, OFF)

Limiting value check for sample size (ON, OFF)

Lower limit for sample size (0.0...999 999) Upper limit for sample size (0.0...999 999)

Display rate (ON, OFF)

Display current rate during the titration.

Pulse output on line "activate" (L6, pin 1) of the remote socket (ON, OFF)

see page 223.

751 GPD Titrino

Sequence with DOC

<START>

(Start delay)

(Start conditions)

Termination

Calculations

(Stirrer OFF)

Data output

2.6 Parameters, key <PARAM>

(Activate pulse)

(Stirrer ON)

(Request ident.)

(Request smpl size)

Controlling

Acquisition of meas.

(Monitoring)

After the start, the activate pulse is output and the stirrer switched on.

The start delay time is waited off.

The sample identifications and the sample size are requested.

The start volume is dispensed (without controlling or measured value acquisition and there is no monitoring during this time) and the pause is waited off.

The determination is terminated when the end of the measured value ramp is reached, i.e. after the sweep time. If measured value monitoring is active, the current measured value also must have reached the end of the ramp.

The stirrer is switched off.

Calculations are carried out.

Data are output. The measuring point list is the base for curves.

751 GPD Titrino

2.6. Parameters, key <PARAM>

U/mV

t/s

V/ml

t/s

Measured value ramp

In DOC the set value of a measured quantity is changed linearly from a start value to a final value during a preset sweep time (measured value gradient). The reagent addition is controlled so that the current measured value follows the nominal value. DOC is stopped when the sweep time is at an end and (if the measured value monitoring is active) when the current measured value corresponds to the end of the ramp. The control deviation nominal-actual value can be kept very small by a suitable choice of parameters and reagent concentration.

If the current measured values is still outside of the control range,

Ende

the dosing rate is mainly given by the parameter "max.rate".

EP "running"

If the current measured values is

Start

Control range

inside the control range, the dosing rate is mainly given by the parameter "min.rate".

Here the final meas.val. was reached

Sweep time

If a T sensor is connected, the temperature is measured continuously and pH values compensated accordingly.

Measuring point list and monitoring

• Measured points are entered in the measuring point list at the preset time interval. The

inputted times represent the clock time. This must be distinguished from the dispensing time: The dispensing time does not include any wait times which can arise in refilling, hold or wait as a result of limit value violations.

• If one (or more) entries occur in the time during refilling, one measured point is entered

immediately after the refilling. The time reference otherwise remains unchanged, however.

• The measuring point list always includes the values "time" and "volume". If monitoring

of measured values and/or temperature is active, the corresponding values are also entered.

• The "mess." column shows a message if a limit value was violated in the last time

interval, see example of a measured point list on page 53. "*" is also used in this column to mark when the dispensing was interrupted: refilling, action "wait" or "hold" on limit value violation or manual <HOLD>.

• The volume of the last measured point entry can differ from the final volume as time

may have elapsed between the last entry and the actual stop.

• If the last measured value is important, set the sweep time 1 s higher than the last

expected measured value, i.e. sweep time = (time interval*number meas.values)+1.

751 GPD Titrino

2.6.7 Parameters for MEAS

2.6 Parameters, key <PARAM>

parameters >measuring parameters >statistics >preselections

>measuring parameters

signal drift OFF mV/min

equilibr.time OFF s

measuring parameters

determine the measurement. statistics: Calculation of mean values and standard deviation, see page 77. preselections: ON/OFF of various auxiliary functions such as automatic requests after the start and activate pulse.

Measuring parameters

Drift criterion for measured value acquisition (input range depends on the measured quantity: pH, U, Ipol: 0.5...999 mV/min, OFF Upol: 0.05...99.9 uA/min, OFF T: 0.5...999 °C/min, OFF)

<CLEAR> sets "OFF". "OFF" means that the measured value is acquired after a fixed equilibration time.

Waiting time for measured value acquisition (0...9999 s, OFF)

<CLEAR> sets "OFF". If no new equilibration time has been entered, the Titrino calculates an equilibration time appropriate to the drift with the formula

150

equilibr.time (in s) = ДДДДДДДДД + 5

ûDrift + 0.01

The measured value is acquired when the first criterion (drift or time) is met. With drift and time "OFF", you will have an "infinite" measurement.

meas.input: 1

I(pol) 1 uA

U(pol) 400 mV

electrode test: OFF

751 GPD Titrino

Measuring input for pH and U. (1, 2, diff.)

Inquiry only with measured quantities pH and U. Measuring input 1 or 2 or differential amplifier; connection of electrodes, see page 215.

With polarized electrodes, instead of the measuring input the

polarization current (-127...127 uA)

or the

polarization potential (-1270...1270 mV, in steps of 10 mV)

is inquired.

Electrode test (OFF, ON)

Test for polarized electrodes. Performed on changeover from the inactive standby mode to a measurement. "OFF" means that the test is not performed.

2.6. Parameters, key <PARAM>

temperature 25.0 °C

time interval 2 s

>preselections

req.ident: OFF

req.smpl size: OFF

limit smpl size: OFF

low lim. 0.0

up lim. 999999

Temperature (-170.0...500.0 °C)

Temperature is measured at the start if a T sensor is connected. This parameter is used for temperature compensation in pH measurements.

Time interval (1...999 999 s)

Time interval for acquisition of measured values.

Preselections for the sequence

Request of sample identifications after start of titration (id1, id1&2, all, OFF)

After start, sample identifications can be inquired automatically: Only id1, id1 & id2, all three id's or no inquiries.

Request of sample size after start of titration (value, unit, all, OFF)

Limiting value check for sample size (ON, OFF)

Lower limit for sample size (0.0...999 999) Upper limit for sample size (0.0...999 999)

activate pulse: OFF

Pulse output on line "activate" (L6, pin 1) of the remote socket (ON, OFF)

see page 223.

751 GPD Titrino

2.6.8 Parameters for CAL

The calibration interval may be monitored, see page 7.

2.6 Parameters, key <PARAM>

parameters >calibration parameters >statistics

>calibration parameters

meas.input: 1

cal.temp. 25.0 °C

buffer #1 pH 7.00

buffer #2 pH 4.00

buffer #3 pH OFF

calibration parameters

determine the calibration procedure. statistics: Calculation of mean values and standard deviation, see page 77.

Calibration parameters

Measuring input (1, 2, diff.)

Measuring input 1 or 2 or differential amplifier; Connection of electrodes, see page 215.

Calibration temperature (-20.0 ... 120.0 °C)

If a T sensor is connected, the temperature will be measured. The calibration temperature can also be input during the calibration sequence.

pH value of first buffer (0...±20.00)

The pH value of the buffers can be put in during the calibration sequence.

pH value of second and the following buffers (0...±20.00, OFF)

<CLEAR> sets "OFF". Buffers are requested until "OFF" is set. This gives an n-point calibration. Up to 9 buffers. A regression line will be calculated in calibrations with more than 2 buffers.

signal drift 2 mV/min

equilibr.time 110 s

electr.id

sample changer cal: OFF

751 GPD Titrino

Drift for measured value acquisition (0.5...999 mV/min, OFF)

<CLEAR> sets "OFF". "OFF" means that the measured value is acquired after an equilibration time.

Equilibration time (0...9999 s, OFF)

<CLEAR> sets "OFF". If a new equilibration time has not been entered, the Titrino calculates an equilibration time appropriate to the drift, see page 69. The measured value is acquired as soon as the first criterion (drift or time) has been met. If drift and time are both set to "OFF", the measured value acquisition is immediate.

Electrode identification (up to 8 characters).

Calibration with sample changer (ON, OFF)

In calibrations with a sample changer, there are no

2.6. Parameters, key <PARAM>

<START>

(Start delay)

Buffer 1 pH

etc.

Measuring buffer 1

Measuring buffer 2

Data output

(Activate pulse)

hold points in the calibration sequence for inputs. Calibration temperature and pH values of the buffers (which are temperature dependent) must therefore be entered in advance. The inputs in key <PARAM> are valid.

activate pulse: OFF

Calibration sequence

Measuring cal.temp.

entry

Pulse output on the line "activate" (L6, pin 1) of the remote socket (all, first, OFF)

See page 224.

After the start, the activate pulse is output.

The start delay time is waited off.

Then, the calibration temperature is measured. It no T sensor is connected, you enter the temperature manually. Store the value with <ENTER> or continue with <START> (T is not stored).

Enter the nominal value of the first buffer. Store the value with <ENTER> or continue with <START> (the value is not stored).

The first buffer is measured.

Enter the nominal value of the second buffer. Store the value with <ENTER> or continue with <START> (the value is not stored).

Leave the calibration with <STOP> ⇒ 1 point calibration.

The second buffer is measured.

As many buffers appear as have been specified in the <PARAM> key (up to 9). You may leave the calibration any time with <STOP>.

Data are output. The calibration data are available for calculation: C46: pHas C47: Electrode slope Calibration data can be viewed at any time with the <CAL.DATA> key and the calibration report printed out using the key sequence <PRINT><CAL.DATA><ENTER>.

751 GPD Titrino

2.6 Parameters, key <PARAM>

2.6.9 Parameters for TIP

In TIP, several commands and methods can be linked to make a titration procedure. The TIP sequence can be defined with <DEF>, see page 85.

parameters >sequence >statistics >preselections

>preselections

req.ident.: OFF

req.smpl size: OFF

limit smpl size: OFF

low lim. 0.0

up lim. 999999

sequence

Parameters for the TIP sequence see page 86. statistics: Calculation of mean values and standard deviation, see page 77. preselections: ON/OFF of various auxiliary functions such as automatic requests after the start and activate pulse.

Preselections for the sequence

Request of sample identifications after start (id1, id1&2, all, OFF)

After start, sample identifications can be inquired automatically: Only id1, id1 & id2, all three id's or no inquiries.

Request of sample size after the start (value, unit, all, OFF)

Limiting value check for sample size (ON, OFF)

Lower limit for sample size (0.0...999 999) Upper limit for sample size (0.0...999 999)

meas.mode: OFF

meas.input: 1

I(pol) 1 uA

U(pol) 400 mV

electrode test: OFF

temperature 25.0 °C

751 GPD Titrino

Measured quantity (pH, U, Ipol, Upol, T, OFF)

Quantity for measurements with key <MEAS/HOLD>.

Measuring input (1, 2, diff.)

Inquiry only with measured quantities pH and U. Measuring input 1 or 2 or differential amplifier; connection of electrodes, see page 215.

With polarized electrodes, inquiry of

polarization current (-127...127 uA) or polarization potential (-1270...1270 mV, steps of 10 mV) Electrode test (OFF, ON)

Test for polarized electrodes. Performed on changeover from the inactive standby state to a measurement. "OFF" means that the test is not performed.

Temperature (-170.0...500.0 °C)

Temperature for pH compensation. Its value has to be entered manually even if a T sensor is connected.

2.7. Result calculations

2.7 Result calculations

Formula entry, key <DEF>

DEF

(

def >formula >silo calculations >common variables >report >mean >temporary variables

>formula

RS?

RS1=

RS1=EP1*C01/C00

Key <DEF> contains various inquiries for result calculations and data output. The data of this key are method specific and they are stored in the method memory together with the method.

formula: Formulas for result calculations.

The display texts of the Titrino are shown to the left. The values are the default values.

Input of formulas

Enter formula number (1...9)

You can calculate up to 9 results per method. Enter a number 1...9.

Input of formula

Example: RS1=EP1*C01/C00 Enter formula by means of 3rd functions of keyboard. Here you will find operands, mathematical operations and parentheses. Operands require a number as an identification. You can use the following operands: EPX: EP's. X = 1...9 RSX: Results which have already been calculated with

previous formulas. X = 1...9.

CXX: Calculation constants. XX = 00...89.

Rules:

• Calculation operations are performed in the

algebraic hierarchy: * and / before + and -.

• Store formula with <ENTER>.

• Calculation quantities and operands can be deleted

with <CLEAR> one by one.

• To delete a complete formula press <CLEAR>

repeatedly until only RSX remains in the display. Confirm with <ENTER>.

If a formula is stored with <ENTER>, result text, number of decimals and result unit will be requested:

751 GPD Titrino

2.7 Result calculations

RS1 text RS1

Text for result output (up to 8 characters)

Text input see page 6.

RS1 decimal places 2

RS2 unit: %

Number of decimal places for result (0...5)

Selection of result unit (%, ppm, g/l, mg/ml, mol/l, mmol/l, g, mg, ml, mg/pc, s, ml/min, no unit or up to 6 characters).

RS1 limit control: OFF

Limit control for the result (on, off)

The limits are checked each time a result is calculated.

If "on" has been set:

RS1 low lim. 0.0

RS1 up lim. 0.0

RS1 L13 output: OFF

Lower limit (0.0...999 999) Upper limit (0.0...999 999)

Sets line L13 of the remote socket (OFF, active, pulse)

if the result lies outside the limits.

Enter next formula, e.g. for RS2.

Meaning of the calculation variables CXX:

C00 Sample size, see page 95. C01...C19 Method specific operands, see page 76. They are stored with the

method in the method memory. C21...C23 Sample specific operands, see page 95ff. C26, 27 Mean values from silo calculations. C30...C39 Common variables. C40 Initial measured value of the sample, last measured value in MEAS. C41 End volume. C42 Determination time. C43 Volume drift for KFT and SET with conditioning. C44 Temperature. C45 Dispensed start volume. C46 Asymmetry-pH (calibration). C47 Electrode slope (calibration). C48 Volume value at maximum voltage in the curve (for STAT, DOS, DOC

measured value monitoring has to be active; no evaluation in CAL and

TIP). C49 Volume value at minimum voltage in the curve (for STAT, DOS, DOC

measured value monitoring has to be active; no evaluation in CAL and

TIP). C51...C59 Fix EP for DET and MET or Fix V for STAT. C61...C69 pK/HNP values for DET and MET or Fix V for STAT. C70...C79 Temporary variables for calculations in TIP. C80 Mean rate for STAT. C81...C89 Rates, evaluated in preset time windows for STAT.

751 GPD Titrino

2.7. Result calculations

C-FMLA

Input method specific operands C01...C19, key <C-FMLA>

With <C-FMLA> the operands C01...C19 can be put in. For the calculation, the operands are used, which were introduced in the formula.

The inputs method specific and are store in method memory.

The calculation report can be printed with the key sequence

<PRINT><←/→> (press keys repeatedly until "calc" appears in the display) <ENTER>

751 GPD Titrino

2.8 Statistics calculation

DEF

2.8 Statistics calculation

Mean values, absolute and relative standard deviations are calculated.

(

def >formula >silo calculations >common variables >report >mean >temporary variables

>mean

MN1=RS1

MN2=

MN9=

PARAM

The <DEF> key is used to allocate results for statistics calculation. The entries are specific to the method and are stored in the method memory.

mean: Assigns values for statistics calculations.

The display texts of the Titrino are shown to the left. The values are the default values.

Allocations for statistics calculations

Number n of single values for statistics calculation. (1...9)

You can perform statistics calculation using up to 9 results (RSX), endpoints (EPX) or variables (CXX). For MN1, the default value RS1 is entered. Delete allocation with <CLEAR> + <ENTER>

Each mode has an inquiry group ">statistics" in key <PARAM>

>statistics

status: OFF

mean n= 2

res.tab: original

delete n= 1

751 GPD Titrino

Statistics calculation

Status of statistics calculation (OFF, ON)

If the statistics calculation is switched off, the following inquiries regarding the statistics do not appear.

Mean value calculation from n single results (2...20)

Result table (original, delete n, delete all)

"original": The original table is used. Deleted

individual results are again incorporated in

the evaluation. "delete n": Deletion of single results with the index n. "delete all": The entire table is deleted.

Delete data from sample number n (1...20)

The deleted result is removed from the statistics calculation.

2.8. Statistics calculation

How do you obtain statistics calculations?

1) Enter the allocations for the statistics calculation, see page 77.

2) Switch on the statistics calculations: Either with <STATISTICS> or set the status under <PARAM>, "> statistics" to "ON". The "STATISTICS" LED is on. Storing a method in the method memory, the status of the statistics calculation is retained.

3) Change the number of the individual values n under "mean n", if necessary.

4) Perform at least 2 titrations. The statistics calculation are constantly updated and printed. The values are printed in the short and full result report.

5) The statistics report can be printed with <PRINT><STATISTICS><ENTER>.

Rules:

• Recalculated results are incorporated in the statistics calculation.

• If a result of a particular titration can not be calculated, no results for this determination

are incorporated in the statistics calculation. However, the sample counter is still operative, i.e. the statistics calculation start afresh when the number of required individual determinations has been performed.

• If the statistics are switched off ("statistics" LED no longer on), results are no longer

entered in the statistics table. But the table remains unchanged. When the statistics are switched on again, you can immediately continue working.

• If you delete results, all results of the determination with index n are removed from the

statistics evaluation.

• On method change, the old statistics table is cleared and the statistics instructions of

the new method followed.

• Old results in the statistics table can be deleted with "delete all" (<PARAM>,

">statistics", "res.tab:").

751 GPD Titrino

2.9 Common variables

Common variables are used for:

• Determination of a titer with a method. This titer is stored permanently as C3X. The

operand C3X can be used in various other methods like any other operand.

• Determination of a blank values with a method . Using this blank value in various other

methods.

• Determination of a result with method. Reconciliation of this result in various other

methods.

You may view the values of the common variables with <CONFIG>.

DEF

(

def >formula >silo calculations >common variables >report >mean >temporary variables

>common variables

C30=

C31

C39=

With <DEF>, results (RSX), endpoints (EPX), variables (CXX) or mean values (MNX) can be allocated as common variables. The entries are specific to the method and are stored in the method memory.

common variables: Assigns values as common variables.

The display texts of the Titrino are shown to the left. The values are the default values.

Allocation for common variables

Common variable C30...C39 (RSX, EPX, CXX, MNX)

Results (RSX), endpoints (EPX), variables (CXX), and means (MNX) can be assigned. The values of the common variables remain in force for all methods until they are overwritten or deleted. They can be viewed under the <CONFIG> key. Delete allocation with <CLEAR>+<ENTER>.

751 GPD Titrino

2.10. Data output

DEF

2.10 Data output

2.10.1 Reports for the output at the end of a determination

(

def >formula >silo calculations >common variables >report >mean >temporary variables

>report

report COM1:

With <DEF>, the report sequence at the end of the determination is defined. The entries are specific to the method and are stored in the method memory.

report: Definition of report blocks to be printed automatically at the end of the determination.

The display texts of the Titrino are shown to the left. The values are the default values.

Report sequence for COM1 (input range depends on the mode: DET: full, short, mplist, curve, derive, comb, scalc full,

scalc srt, param, calc, calib, ff

MET, SET, MEAS:

full, short, mplist, curve, scalc full, scalc srt, param, calc, calib, ff

STAT, DOC:

full short, mplist, curve, meas crv, temp crv, scalc full, scalc srt, param, calc, calib, ff

DOS: full, short, mplist, curve, meas crv, temp crv,

scalc full, scalc srt, param, calc, ff

CAL: full, short, scalc full, scalc srt, param, calc, calib,

KFT: full, short, mplist, curve, scalc full, scalc srt,

param, calc, ff

TIP: full, short, scalc full, scalc srt, param, calc, ff

report COM1:full;curve

Select a block. If you require more than one report block, set a ";" as a delimiter between the blocks.

Identical for COM2.

Meaning of the report blocks:

full Full result report with raw results, calculations and statistics. short Short result report with calculations and statistics. mplist Measuring point list. curve Titration curve (with DET and MET) or volume vs. time (with SET, KFT, STAT,

DOS, and DOC) or measured value vs. time (with MEAS) derive 1st derivative of the titration curve (with DET) comb Combined titration curve and 1st derivative (with DET) meas crv Measured value vs. time (with STAT, DOS and DOC; monitoring of meas

active). temp crv Temperature vs. time (with STAT, DOS and DOC; monitoring of temperature

active).

751 GPD Titrino

2.10 Data output

scalc full Full report of silo calculations. scalc srt Short report of silo calculations. param Parameter report. calc Report with formulas and operands. calib Calibration data. ff Form feed on printer.

Original reports which are put out automatically at the end of the titration can be printed with recalculated values at any time. Key sequence:

<PRINT><REPORTS><ENTER>.

Original reports have double dashes ==== at the end, whereas recalculations are marked by single dashes ----.

Report outputs can be stopped with <QUIT>.

Example of reports:

Full result report

'fr

751 GPD Titrino 0P1/101 751.0020

date 1999-06-27 time 08:54 14

card label: Appl.751

pH(init) 2.88 DET pH ********

smpl size 0.372 g

EP1 2.083 ml 7.64

RS1 3.80 g/l

device label Titr 1 sign:

============

Card label if a card was inserted, see page

92.

Device label (if there is a designation) and manual signature

'cu

751 GPD Titrino 0P1/101 751.0020

date 1999-06-27 time 08:54 14

start V 0.000 ml DET pH ********

1.0 ml/div dpH=1.0/div

============

Titration curve

Scaling of volume and pH axis

751 GPD Titrino

2.10. Data output

Additional possibilities for report outputs

In addition to the reports which are printed at the end of the titration, various other reports can be put out. There are 2 possibilities to select the reports:

1) <PRINT><←/→><ENTER> Cursor is pressed repeatedly until the desired report

appears in the display.

2) <PRINT><keyX><ENTER> key X is the key under which the appropriate data

are entered.

List of the "keys X":

Report <Key X>

Configuration report CONFIG

Parameter report PARAM

Current sample data SMPL DATA

Statistics report with the individual results STATISTICS

All sample data from the silo memory SILO

Preparation of titration burets PREP

Calibration data CAL.DATA

Content of the current card directory CARD

Operands C01...C19 C-FMLA

Contents of the <DEF> key DEF

Contents of the method memory with details of the memory

USER METH

requirements of the individual methods and the remaining bytes

Complete report sequence of the last determination, as defined

REPORTS

under the <DEF> key in the method

Result display without printer

If you work without printer, we recommend to work with the standard character set for result display (settings in key <CONFIG>, ">auxiliaries", see page 10). You will get the complete information on your determinations: Calculated results, endpoints, messages etc.

751 GPD Titrino

2.10.2 Display of the titration curve

After the titration, the curve can be viewed. Switch between "curve" and "result display" with key <CURVE>.

You can trace the curve with keys <↑> and <↓>. In

the text field to the left of the curve the index of the current measured value is displayed in the first line. In the subsequent lines, the corresponding measured values are shown.

If you place the cursor in DET and MET curves onto the EP, the data of this EP are also shown.

• The EP number and its ERC (Endpoint Recognition

Criterion).

• The EP volume.

2.10 Data output

751 GPD Titrino

2.11. User name, key <USER>

USER

2.11 User name, key <USER>

←

user name: Boss >delete

The key <USER> manages the user names. User names can be entered directly or selected with

the keys <←> and <→>.

Name: Selection or input of user name. Delete: Delete user name.

The display texts of the Titrino are shown below at the left.

name: User name (up to 10 ASCII characters)

User names can be entered directly or selected with

the keys <←> and <→>.

The operator name is printed out in the report. The operator name remains in the instrument until it is deleted (or until the RAM is initialized). If no operator name is to be printed out the operator "blank" can be selected.

>delete

name:

Delete user name

Enter the name directly or select it with the keys <←> and <→>. <ENTER> will delete the name from the

list of user names.

751 GPD Titrino

2.12 TIP, Titration procedure

TIP (Titration Procedure) is used to link several commands in a sequence. TIP is selected with <MODE> and <ENTER>. TIP is an "empty shell" in which the sequence of the determination must be defined.

Definition of the sequence

DEF

(

def >sequence >formula >silo calculations >common variables >report >mean

>sequence

1.step: OFF

<ENTER>

1.method: 5-TIP

<ENTER>

With key <DEF> the TIP can be defined.

sequence: of TIP.

The display texts of the Titrino are shown to the left. The values are the default values.

Sequence

Select a step with keys <←> and <→>:

method: Method from the user memory or from

the card. pause: Waiting time L4, L6 output: Set an output. info: Hold sequence and write a message

into the display. prep Preparation of titrating burets. stirrer ON/OFF

etc.

2 x <QUIT>

Confirm the step with <ENTER> and enter the parameter for the selected step, see below. The request for the second step follows etc. Up to 30 steps can be selected. On completion of the sequence definition, exit the inquiry with <QUIT>.

751 GPD Titrino

2.12. TIP, Titration procedure

Information for the commands (steps):

Command Meaning Input range

method Method from the user memory or from the card. This

Name

method runs as a submethod.

pause Waiting time. The waiting time can be aborted with

<QUIT>.

0...999 999 s, inf.

<CLEAR> sets "inf" (= infinitely long pause time).

L4, L6 output Set L4 output (pin 3) resp. L6 output (pin 1) of the

remote socket. active = 0 V, inactive = 5 V, pulse > 100 ms, off =

active, inactive,

pulse, off output is not used. Cable Titrino (L6) - Dosimat: 6.2139.000.

Important: A pulse (e.g. a pulse from monitoring or an activate pulse in a submethod) can set an active output to inactive! At the end of the TIP method, the outputs are set to "inactive".

info Message in the display .

The TIP sequence is held and the message displayed.

up to 16

characters Continue the sequence with <START>, <QUIT> or <ENTER>.

prep Preparation of titrating burets. internal D0,

external D1,

external D2

stirrer Switching stirrer ON/OFF.

ON, OFF In TIP the stirrer is not switched automatically in the submethods. At the end of TIP the stirrer is switched off (if stirrer control is ON).

The parameters of the sequence can be viewed and changed at any time under the <PARAM> key.

751 GPD Titrino

2.12 TIP, Titration procedure

<START>

(Start delay)

Switching ON stirrer

Set output

TIP calculations

Pause

Info

C7X

TIP data output

Prep

Sequence of TIP

As there is no preset sequence of TIP, in what follows the procedure is illustrated by a sequence that contains all available commands.

The start delay time is waited off.

(Request ident.)

(Request smpl size)

Submethod

Calculations

Data output

The sample identifications and the sample size are requested.

Stirrer is switched on. The stirrer is not operated automatically in submethods of TIP. At the end of TIP, however, the stirrer is switched off (with stirrer control ON).

Submethods are processed according to their parameters. They run to completion, including calculations and data output (e.g. curves). The determination data of submethods are overwritten in the next sequence step of TIP. Those values which are needed for higher-level calculations must therefore be assigned to temporary variables C7X.

The pause is waited off.

Outputs on the socket "Remote" can be set.

A message can be written in the display. The sequence is held until it is continued manually (with <START>, <QUIT> or <ENTER>).

751 GPD Titrino

The titration burets can be prepared.

TIP higher-level calculations are carried out.

Data output in TIP (TIP contains no more determination data, i.e. curves must be put out within the submethods).

2.12. TIP, Titration procedure

DEF

Preparation of submethods for use in TIP

All titration data, i.e. curves and lists of measured points must be put out in the submethod as they are overwritten on return to TIP. Individual values from the submethod, e.g. endpoints or calculated results must be stored as temporary variables C7X. This allows them to be used in TIP for further calculations. Reevaluations of data of a submethod are not possible in TIP. The submethods should thus be thoroughly wet tested before they are used in TIP.

Assignment of temporary variables in the submethod:

(

def >formula >silo calculations >common variables >report >mean >temporary variables

>temporary variables

C70=

C71=

C79=

Calculations in TIP

With key <DEF> temporary variables can be assigned. The entries are specific to the method and are stored in the method memory.

temporary variables

for higher-level calculations.

The display texts of the Titrino are shown to the left. The values are the default values.

Temporary variables

Assignment of result, endpoints or variables (RSX, EPX, CXX)

Values of the submethod to be used in TIP calculations.

In TIP calculations variables C7X from different submethods can be used, formula entry see page 74.

Note: We recommend to execute the calculations in TIP, as they can only be recalculated "dryly" in TIP itself, e.g. with a different sample size.

751 GPD Titrino

2.13 Method memory, keys <USER METH> and <CARD>

USER METH

2.13 Method memory, keys <USER METH> and <CARD>

2.13.1 Key <USER METH>

user methods >recall method >store method >delete method

>recall method

method name:

)

Management of the internal method memory with key <USER METH>.

Select method name with keys <←> and <→>.

recall method: Loads a method from the internal method memory into the working memory. store method: Stores the method which is in the working memory in the internal method memory. delete method: Deletes a method from the internal method memory.

The display texts of the Titrino are shown to the left. The values are the default values.

Recall method

Recall method from the internal method memory to the working memory (input of method name, which is included in the memory).

If a method identification is entered which is not found in the method memory, the selected value blinks.

>store method

method name:

>delete method

method name:

751 GPD Titrino

Store method

Store method from the working memory to the internal method memory (up to 8 ASCII characters).

If a method with an identical name is already stored, you are requested if you wish to overwrite the old method. With <ENTER> it is overwritten, with <QUIT> you return to the entry.

Delete method

Delete method from the internal method memory (input of method name, which is included in the memory).

For safety, you are again asked if you really wish to delete the method. With <ENTER> it is deleted, with <QUIT> you return to the working memory. If a method name is entered which is not found in the method memory, the selected value blinks.

2.13. Method memory, keys <USER METH> and <CARD>

The contents of the method memory can be printed with the key sequence

Document your methods (e.g. parameter report, def. report and C-fmla report)! With a PC and the 6.6008.XXX Vesuv program or with the 6.6028.100 menu program, you should carry out a complete method backup from time to time. Making the backup on the card, pay attention of the exchange date of the battery!

751 GPD Titrino

2.13.2 Key <CARD>

CARD

2.13 Method memory, keys <USER METH> and <CARD>

user meth. >recall method >store method >delete method >change directory >create directory >delete directory

>backup ↓

Management of the method memory on the card with key <CARD >.

Select names with keys <←> and <→>.

On the first line you find the name of the current directory (here user meth.).

recall method: Loads a method from the current directory of the card into the working memory. store method: Stores the method, which is in the working memory, in the current directory of the card. delete method: Deletes a method from the current directory of the card. change directory: Changes the current directory of the card. create directory: Creates a new directory on the card. delete directory: Deletes a directory on the card. backup: Backup of the internal method memory on the card. reload: Reloads a backup from the card into the internal method memory. format: Formats the card. change battery: Date for changing the battery.

>recall method

>store method

>delete method

>change directory

>create directory

>delete directory

dir.name:

751 GPD Titrino

The display texts of the Titrino are shown to the left. The values are the default values.

Recall, store, delete method

Identical with the corresponding function of the internal method memory. The functions operate on the current directory of the card.

Change, create, delete directory

If a directory is deleted, it is deleted together with all its methods.

(directory name with up to 10 characters)

2.13. Method memory, keys <USER METH> and <CARD>

>backup

dir.name:

>reload

dir.name:

>format

card label

Backup of the internal method memory on the card

(directory name with up to 10 characters)

Existing methods in this directory will be deleted, and all methods from the internal method memory are stored in the directory.

Reload methods from the card to the internal method memory

(directory name with up to 10 characters)

Primary all methods from the internal method memory are deleted. Afterwards all methods from the directory of the card are copied into the internal method memory.

Format the card

Card label (with up to 8 characters)

The card label will be printed in the card report and in the full result report (if the card is inserted, see page

81).

format: no

Confirmation of formatting the card (yes, no)

Upon formatting the card, all data on the card are deleted. After formatting a new card, the date for battery change must be entered.

>change battery

date

Battery change date

Date for changing the battery (YYYY-MM-DD)

see page 93.

Possibilities of the card

Methods can be stored on the card.

• Simple exchange of methods between different users, laboratories, factories. Every

user can use his card with his own methods. The user specific card label will be printed in the full result report, if the card remains inserted.

• Methods can be stored in different directories, e.g. in directories depending on the

sample type or the user.

• The card can be used as an extended memory.

• You will find many application methods on the application card 6.6029.010.

751 GPD Titrino

2.13 Method memory, keys <USER METH> and <CARD>

Internal method memory and methods on the card

If methods are called from TIP or from the silo memory, the Titrino will search these methods primary in the internal method memory, and afterwards in the current directory of the card. Important: We do not recommend not to store identical methods in the current directory of the card as well as in the internal method memory at the same time. Otherwise, you have to update both methods!

Card battery

The card is supplied by a battery. This battery must be changed periodically. Note the lifetime of the battery which is indicated in the manual of the card. If the card is inserted in the Titrino you will receive a warning if the battery is low on switching on the Titrino or if the battery change date is expired. The battery is in a case of the card. Read the note enclosed with the card before changing the battery. Leave the card in the Titrino when you change the battery to ensure sufficient power supply. Important: The battery lifetime refers to a storing temperature of 25 °C. With higher temperatures, the lifetime is shorter. Therefore do not

• carry the card on the body

• store the card near radiators

• have the card in the sun.

Write protection

The write protection prevents all functions, which write on the card (store methods, delete methods, change directory - the current directory is written on the card, create directory, delete directory, backup, format the card, change date of the card battery). Reading functions are possible. Write protection is on, if the lash in front of the card is on the right.

Reports

• Methods of the current directory, key sequence <PRINT><CARD><ENTER>.

• Methods of the whole card: key sequence <PRINT><←/→><ENTER>; press the

cursor keys repeatedly until "card" appears in the display.

Ordering designations

Memory card with 128 Kbytes memory space............................................ 6.2245.010

Application card with application file ........................................................... 6.6029.010

751 GPD Titrino

2.14. Calibration data, key <CAL.DATA>

CAL.DATA

2.14 Calibration data, key <CAL.DATA>

cal.data >input 1 >input 2 >input diff.

>input 1

pH(as) 7.00

slope 1.000

temp 25.0 °C

With <CAL.DATA>, the current pH calibration data of all measuring inputs can be seen. Calibration data are entered here automatically on completion of a calibration.

input 1: Calibration data for measuring input 1. Identical for input 2 and diff.

The display texts of the Titrino are shown to the left. The values are the default values.

pH calibration data for measuring input 1

Asymmetry pH (0...±20.00)

Entered automatically after a calibration with measuring input 1.

Slope (0...±9.999)

Entered automatically after a calibration with measuring input 1.

Calibration temperature (-20.0...120.0 °C)

Will be printed automatically after calibration with measuring input 1.

cal.date

Date of last calibration (no entry possible)

If the calibration data "pH(as)" and/or "slope" are changed by a manual entry, the date entry is deleted. This date is the reference date for calibration monitoring, see page 7.

electr.id

Electrode identification of calibrated electrodes (no entry possible)

If an electrode identification has been entered in the CAL mode, it is automatically entered after the calibration.

The calibration report with the current measuring input data can be printed at any time with the key sequence

<PRINT><CAL.DATA><ENTER>.

751 GPD Titrino

2.15 Current sample data, key <SMPL DATA>

SMPL

2.15 Current sample data, key <SMPL DATA>

The key <SMPL DATA> can be used to enter the

DATA

smpl data

id#1 or C21 id#2 or C22 id#3 or C23

smpl size 1.0 g smpl unit: g

current sample data. The contents of this key change when the silo memory is switched on, see page 97. Instead of entering the current sample data with <SMPL DATA>, you can request these data automatically after start of determinations. Configuration: <PARAM>, ">preselections". Current sample data can be entered live. For working with the silo memory see page 96.

id#1...3 or C21...C23, sample identifications:

The sample identifications can also be used as sample specific calculation variables C21...C23. smpl size: Sample size. The sample size can be monitored, see e.g. page 19. The limits are then displayed in this window. smpl unit: Unit of the sample size.

smpl data

id#1 or C21 id#2 or C22 id#3 or C23

smpl size 1.0 g

smpl unit: g

The display texts of the Titrino are shown to the left. The values are the default values.

Sample data

Sample identification 1...3 or sample specific operand C21...C23 (up to 8 characters).

Sample identifications or sample specific operands can be entered using the keypad, via a balance with a special input device or via barcode reader.

Sample size (6-digit number: ±X.XXXXX)

Entry using keypad, via balance or via barcode reader.

Unit of sample size (g, mg, ml, ul, pc, no unit or up to 5 characters)

Select unit with <←/→>.

751 GPD Titrino

2.16. Silo memory for sample data

2.16 Silo memory for sample data

In the silo memory or pushup storage, sample data (method, identifications and smpl size) can be stored. This is useful, e.g. when you work with Sample Changers and other automatic sample addition systems or if you wish an overview of your determination results, see page 100.

SILO

Press the key <SILO> for working with the silo memory. The status LED "silo" is on when the silo memory is switched on. The silo memory works by the FIFO principle (First In, First Out).

If the silo memory is switched on, sample data are routed to the last free line of the silo memory. If no new value is put in, the value from the last line is automatically copied. In this manner, data can be simply taken over when they remain unchanged. When the instrument is started, the sample data are fetched from the next silo line.

Organization of the silo memory

255

Silo memory contains 35 lines. Next free line is 36

6 of the 35 lines have been processed. Free lines from 36 to 255 and from 1 to 6.

1 silo line needs between 18 and 120 bytes memory capacity.

Filling the silo memory with a connected balance

If the silo memory is filled from the balance, you must ensure that there is sufficient space in the silo memory for the required number of silo lines! The number of free bytes is given in the user memory report.

When the sample data are entered from a balance, the transfer of the sample size is taken as the end of the silo line. You should not send data from the balance and edit the silo memory at the same time. For mixed operation, manual input of identifications and sample sizes from a balance, the values from the balance are sent into the line in which editing just takes place. Confirmed the data with <ENTER> at the Titrino.

751 GPD Titrino

2.16 Silo memory for sample data

SMPL

Key <SMPL DATA> with the silo memory switched on

Sample data can be entered into the silo memory with key <SMPL DATA>.

DATA

edit silo lines:

smpl data >edit silo lines >delete silo lines >delete all silo lines cycle lines: OFF save lines: OFF

Entering sample data into the silo memory. delete silo lines: Deletes single silo lines. delete all silo lines: Deletes the whole silo memory.

The display texts of the Titrino are shown to the left. The values are the default values.

>edit silo lines

silo line 1

method:

id#1 or C21 id#2 or C22 id#3 or C23

smpl size 1.0 g

smpl unit: g

Input for silo memory

Silo line (1...255)

The next free line is displayed automatically. Lines already occupied can be corrected.

Method with which the sample is processed (method name from the method memory)

If no method name has been entered, the sample is processed with the method in the working memory.

Selection of the method with <←/→>.

Sample identification 1..3 or sample specific calculation variables C21...C23 (up to 8 characters)

Sample size (6-digit number: ±X.XXXXX)

The method specific limits are tested on result calculation.

Unit of sample size (g, mg, ml, ul, pc, no unit or up to 5 characters)

Select unit with <←/→>.

>delete silo lines

delete line n OFF

751 GPD Titrino

Delete individual silo lines

Line number of the line to be deleted(1...255, OFF)

<CLEAR> sets "OFF". Deleted lines remain in the silo memory. Access is blocked during the processing. To show that a line has been deleted, they are marked with "*". The symbol * indicates that the line has been deleted. Deleted lines can be reactivated if the appropriate line is re-edited.

Metrohm 751 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual