Mettler Toledo DL31, DL38 Operating Instructions Manual
Operating Instructions
KF Titrators
DL31 / DL38
Contents
Page
1 The DL31/DL38 KF titrators .......................................................................................... 5
2 Safety measures.......................................................................................................... 6
2.1 Measures for your protection .......................................................................................... 6
2.2 Measures for operational safety ...................................................................................... 6
3 The titrator .................................................................................................................. 7
3.1 Putting into operation .................................................................................................... 8
3.2 The operating concept ................................................................................................... 8
3.2.1 The command keys....................................................................................................... 9
3.2.2 The menu keys ........................................................................................................... 10
3.2.3 The auxiliary function keys ........................................................................................... 10
3.2.4 The <i> key................................................................................................................11
3.2.5 The entry and arrow keys ............................................................................................. 11
3.3 Changing the language ............................................................................................... 12
4 Setup (<Setup> key).................................................................................................. 13
4.1 KF titrants ..................................................................................................................13
4.2 Br No. titrants (DL38 only) .......................................................................................... 15
4.3 KF standards .............................................................................................................. 16
4.4 Main methods (DL38 only).......................................................................................... 17
4.5 Peripherals................................................................................................................. 18
4.5.1 Printer ....................................................................................................................... 18
4.5.2 Balance ..................................................................................................................... 19
4.5.3 Titration stand............................................................................................................. 19
4.5.4 Computer ...................................................................................................................19
4.6 Settings .....................................................................................................................20
5 Methods (<Method> key)........................................................................................... 22
5.1 The KF standard method .............................................................................................. 23
5.2 KF method parameters ................................................................................................ 24
5.2.1 No. (of the method) .................................................................................................... 24
5.2.2 Title (of the method).................................................................................................... 24
5.2.3 Sample parameters ..................................................................................................... 24
5.2.4 Speed ........................................................................................................................ 24
5.2.5 Mix time .................................................................................................................... 24
5.2.6 Titrant ........................................................................................................................ 24
5.2.7 Volume (for predispensing).......................................................................................... 25
5.2.8 Wait time (after predispensing)..................................................................................... 25
5.2.9 Auto start (DL38 only)................................................................................................. 25
5.2.10 Control parameters...................................................................................................... 25
5.2.11 Termination parameters ............................................................................................... 25
5.2.12 Blank ........................................................................................................................ 26
5.2.13 Drift ........................................................................................................................... 26
METTLER TOLEDO DL31/DL38 1
5.2.14 Result (DL31 only) ..................................................................................................... 26
5.2.15 Calculation (DL38 only) .............................................................................................. 26
5.2.16 Standby ..................................................................................................................... 27
5.2.17 Report ....................................................................................................................... 27
5.2.18 Author of the method ................................................................................................... 27
5.3 Storage procedures ..................................................................................................... 28
5.4 User and METTLER methods (DL38 only) ...................................................................... 30
5.4.1 METTLER methods "908 Bromine No." and "909 Blank Br No." (DL38 only)..................... 31
5.4.2 METTLER method "910 Stromboli" (DL38 only) ............................................................. 32
6 Analysis (<Run> key) ................................................................................................ 34
6.1 Starting a method ....................................................................................................... 34
6.1.1 Menu sequence up to standby mode (KF methods) ........................................................ 35
6.1.2 Standby mode ............................................................................................................ 36
6.2 Sample determination.................................................................................................. 37
6.2.1 Weight transfer from a balance ..................................................................................... 40
6.2.2 Post consumption ....................................................................................................... 40
6.2.3 Calculations ...............................................................................................................40
6.2.4 Sample series with statistics (DL38 only) ...................................................................... 41
6.3 Concentration determination ......................................................................................... 42
6.4 Blank determination .................................................................................................... 44
6.5 Drift determination....................................................................................................... 44
6.6 Bromine number determination (DL38 only) .................................................................. 45
6.7 Sample determination with the oven sample changer Stromboli (DL38 only) ..................... 46
6.8 KF learn titration ......................................................................................................... 48
7 Auxiliary functions (<Stirrer>, <Burette>, <Pump>, <Results>)................................... 50
7.1 <Stirrer> ....................................................................................................................50
7.2 <Burette>................................................................................................................... 50
7.3 <Pump> .................................................................................................................... 51
7.4 <Results> .................................................................................................................. 52
7.4.1 All results ................................................................................................................... 52
7.4.2 Recalculation ............................................................................................................. 53
7.4.3 Report ....................................................................................................................... 54
7.4.4 Calculations (DL38 only) ............................................................................................ 54
7.4.5 Statistics (DL38 only) ................................................................................................. 54
7.4.6 Statistics series (DL38 only) ........................................................................................ 55
8 Information menu (<i> key) ....................................................................................... 56
9 Error messages, malfunctions and hardware tests ....................................................... 57
9.1 Error messages from the titrator .................................................................................... 57
9.2 Other errors and malfunctions ...................................................................................... 59
9.3 Hardware tests ........................................................................................................... 60
9.3.1 User interface .............................................................................................................60
9.3.2 Peripheral interfaces .................................................................................................... 60
9.3.3 Inputs and outputs ...................................................................................................... 61
2 METTLER TOLEDO DL31/DL38
10 Installation and maintenance ..................................................................................... 62
10.1 Equipping the titration stand ......................................................................................... 62
10.2 Installing the burette .................................................................................................... 63
10.3 Installing the solvent and waste bottles.......................................................................... 64
10.4 Attaching the magnetic stirrer, electrode and devices ....................................................... 65
10.5 Using TTL inputs and outputs (DL38 only)..................................................................... 66
10.6 Maintenance and servicing .......................................................................................... 66
11 Standard and optional equipment ............................................................................... 68
11.1 Standard equipment .................................................................................................... 68
11.2 Optional equipment ..................................................................................................... 70
12 Technical data ........................................................................................................... 73
13 Index ........................................................................................................................ 81
METTLER TOLEDO DL31/DL38 3
4 METTLER TOLEDO DL31/DL38
The DL31/DL38 KF titrators
1 The DL31/DL38 KF titrators
The METTLER TOLEDO DL31/DL38 titrators are microprocessor controlled analytical instruments which you
can use to perform Karl Fischer titrations simply, quickly and dependably.
You can attach a balance, the METTLER TOLEDO GA42 printer and a computer to the appropriate RS232C
interfaces as well as an EPSON- or HP-compatible printer to the Centronics interface and, at the DL38's TTLinterface, the METTLER TOLEDO oven sample changer Stromboli. The METTLER TOLEDO LabX titration
software allows you to control your titrator via a computer.
The titrators have a tutorial stored which quickly enables you to become acquainted with the operation and
method of functioning of the instrument.
The two titrators have the same operation. Differences in the hardware and software are mentioned in the
corresponding sections.
These Operating Instructions correspond to software version 2.0 or higher.
Where can you find what information?
These Operating Instructions and the Help texts integrated in the titrator provide a complete description of
the method of functioning of the two titrators. Explanations of parameters contained in the Help texts are
supplemented here when necessary.
On the Memo card you can find a short overview of menus and methods.
The Application brochure explains the theoretical fundamentals of the Karl Fischer titration, the control of
the titration in the DL31/DL38 and documents the METTLER methods stored in the DL38.
The Help texts in the titrator provide you with more information or refer you to the Operating Instructions or
the Application brochure.
You will find a detailed description of the communication between the titrator and a computer in the
Description of the computer interface.
METTLER TOLEDO DL31/DL38 5
Safety measures
2 Safety measures
The titrators have been tested for the experiments and intended purposes documented in these Operating
Instructions. However, this does not absolve you from the responsibility of performing your own tests of the
products supplied by us regarding their suitability for the methods and purposes you intend to use them for.
You should therefore observe the following safety measures.
2.1 Measures for your protection
– Ensure that you plug the power cable supplied into a receptacle outlet that is grounded! In
the absence of grounding, a technical fault could be lethal.
Risk of
electric shock
– Never work in an environment subject to explosion hazards! The housing of the instru-
ment is not gas tight (explosion hazard due to spark formation, corrosion caused by the
ingress of gases).
Risk of
explosion
– When using chemicals and solvents, comply with the instructions of the producer and
the general lab safety rules!
All Karl Fischer reagents are readily flammable and toxic.
– In the case of skin contact, immediately wash off with copious amounts of water!
– If eye contact occurs, rinse intensively with copious amounts of water and consult a
physician!
2.2 Measures for operational safety
– Have the instrument serviced only by METTLER TOLEDO Service!
– Make sure that every connector is in the correct position! Do not damage the connector
pins of the magnetic stirrer cable! Pins damaged by faulty insertion can cause a short
circuit at the "Stirrer" output. This renders the titrator non-functional.
– Always wipe off splashed liquids immediately! The instrument is not water-proof.
Caution
– Exclude the following environmental influences:
• powerful vibrations,
• direct sunlight,
• atmospheric humidity greater than 80%,
• temperatures below 5 °C and above 40 °C,
• powerful electric or magnetic fields!
6 METTLER TOLEDO DL31/DL38
3 The titrator
Burette
The titrator
Titration stand
Titrant bottle
Arrestment knob
Pump knob
Keypad
Rear view
External stand (DV705)
Stirrer output
Electrode input (KF)
Solvent bottle
Waste bottle
Magnetic stirrer
Balance (RS232C)
GA42 printer (RS232C)
Computer (RS232C)
Stromboli, TBox, etc. (TTL I/O)
EPSON- and HP-compatible printers
(Centronics)
Pump unit
On/Off switch
Suction fitting
Output fitting
METTLER TOLEDO DL31/DL38 7
Socket for
external power pack
The titrator
3.1 Putting into operation
– Plug the supplied external power pack into the titrator’s socket, connect to the power supply and switch
on the titrator: A self-test is performed before the name of the titrator appears (example DL38).
Hello!
F3
Arrow keys
(
)
9
8
7
]
[
4
5
6
1
2
3
CE
*
.
Del
0
Shift
Entry keys
<Reset> key
<i> key
Auxiliary function keys
Display
Reset
i
Burette
Stirrer
*
Results
Pump
METTLER TOLEDO
DL38
Version 2.0
Esc
F1
Setup
Method
F2
Run
Command keys
Menu keys
The command key <F3>, "Hello", the <i> key and all Menu and Auxiliary function keys can be activated
after the titrator has been switched on.
3.2 The operating concept
– Press, e.g. the <Setup> key:
Title line
Selection bar
Resources SETUP
KF titrants
Br No. titrants
KF standards ▼
Print OK
Name of the key, in other words the displayed
list of resources belongs to the Setup menu
Commands
DL31: No "Br No. titrants"!
You can now also activate the arrow key (∇), the <Reset> key and the Command keys <F2>, "Print" and
<F3>, "OK".
▼ The arrow in the display means that the list contains more resources. If you press the arrow
key (∇), the lines are scrolled upward, the selection bar is fixed. The commands you can
execute always refer to the line that is selected.
Print Press <F2>: The list of KF titrants is printed out (if a printer is selected and defined).
OK Press <F3>: The list of KF titrants appears.
8 METTLER TOLEDO DL31/DL38
The titrator
3.2.1 The command keys
The commands which can be triggered with <F1>...<F3> change according to the selected menu item. The
following commands require an explanation:
Hello! When the instrument is delivered, the <F3> command in the initial mask "METTLER TOLEDO..."
is assigned to a Tutorial menu. This is deleted when you have performed the first titration with
the Tutorial.
Note You can call up the Tutorial at any time with the <i> key.
OK This command is always a confirmation for what you
• wish to view,
• have viewed or entered,
• wish to adopt from a selection.
Modify When this command appears a
• submenu can appear which can or must be modified,
• a selection menu appears from which you can or must accept values or names,
• an existing parameter value or name can be directly replaced.
If a value can be modified or entered only with the keypad, the "Modify" command is missing.
ABC This command always appears when you can select letters or characters, e.g. for a name. In
this case, you can not enter numbers until you have confirmed "ABC" (press <F1>).
Help Information about the selected resource appears.
The <Esc> key
If you have made changes in the current menu or submenu, they are discarded, in other words
Esc
the original values/names remain in force. <Esc> always effects a return to the previous display.
The <Reset> key
The initial mask "METTLER TOLEDO..." reappears: <Reset> is used to terminate analyses or
Reset
other actions. Data that are not stored are lost.
METTLER TOLEDO DL31/DL38 9
The titrator
3.2.2 The menu keys
In order to analyze a sample automatically, the required data must be stored. In the titrator, these data are
assigned to so-called task areas, the menus and can be accessed with the Menu keys. It is only the
coordination between these menus that makes the automatic analysis possible.
All resources required for the titration such as KF titrants and KF standards are stored in the
Setup
Setup menu and can be changed.
The sample is determined with the aid of a method. All methods necessary for the different
Method
analyses are stored in the Method menu and can be changed. All resources defined in the Setup
menu are available for these methods.
DL31: Only one method can be stored.
DL38: Fifty user methods can be stored.
The titration is performed in the Analysis menu. The method called up determines the analysis
Run
sequence.
Note Each menu is subdivided into task areas (submenus) which are designated menus, lists or
masks in these Operating Instructions.
3.2.3 The auxiliary function keys
To rinse the burette or recalculate results, the required commands are also assigned to menus. As they are
independent of a sample analysis, but can support it, we call them auxiliary functions. They are accessible
under the corresponding keys.
You can switch the stirrer on or off and change the stirring speed.
Stirrer
Pump
Burette
You can add or siphon off solvent.
You can rinse the burette and the tip of the dispensing tubing and add a specified volume.
*
Results
10 METTLER TOLEDO DL31/DL38
You can view the result list of analyzed samples, perform recalculations, change the statistical
evaluation of a series (DL38 only!) and print out additional reports.
3.2.4 The <i> key
The value of the current solvent capacity, the last drift determination, the last blank value
i
determination for DL38/Stromboli (METTLER method 910), the "Hello!" Tutorial, the KF
learn method and a menu for testing the titrator hardware are accessible with this key.
3.2.5 The entry and arrow keys
The titrator
Shift
CE
Del
Shift
Shift
Shift
Shift
With the <Shift> key, you can activate the characters above the numbers.
CE You delete all entered numbers/characters/letters.
Del You delete the number/character/letter last entered.
+
7
+
4
+
+
You can move the cursor to the right or left (only if letters/characters are selected), see
example:
User a
Cursor
abcdefghijklm
nopqrstuvwxyz
ABCDEFGHIJKLM ▼
Help Select OK
skips 3 lines of the display upward (page up),
skips 3 lines of the display downward (page down).
▲▼ The arrow appears in the display when there are more lines to the list than are visible.
When you press the arrow keys (∇∆) next to the display, the lines are scrolled downwards or upwards. The selection bar is fixed. By pressing <Shift>, ∇ or <Shift>, ∆ the
lines are moved a page at a time. The commands that can be executed always refer to
the line highlighted by the selection bar.
METTLER TOLEDO DL31/DL38 11
The titrator
3.3 Changing the language
All texts in the titrator are stored in English, German, French, Spanish, Italian and Russian. If you have not
run the Tutorial and understand one of the available languages better than the one displayed, you should
select it:
Setup
Resources SETUP
KF titrants
Br No. titrants
KF standards ▼
Print OK
▼
Resources SETUP
Peripherals
Settings
OK
▼
Settings SETUP
Language English
User list
Date 20-08-1998▼
Modify OK
–Press the <Setup> key.
– Press the <Shift> and Arrow (∇) once, then press only the Arrow key
to select "Settings".
– Press <F3>, "OK".
– Press <F2> repeatedly until, e.g. "Español" appears.
▼
Settings SETUP
Lengua Español
Lista usarios
Fecha 20-08-1998 ▼
Modif. OK
12 METTLER TOLEDO DL31/DL38
With "OK" or <Esc> the "Resources" mask reappears.
OK Spanish texts appear.
Esc English texts appear.
Setup (<Setup> key)
4 Setup (<Setup> key)
In order to perform titrations, the titrator must know the titrants and their concentration. It must know the
settings of the attached instruments to transfer the data. In this menu you define and store these resources:
You set up your titrator.
When you press the <Setup> key, the list of resources appears:
KF titrants
Br No. titrants (DL38 only)
KF standards
Main methods (DL38 only)
Peripherals
Settings
The most commonly used titrants and KF standards are already stored in the titrator. You can not only delete
these or change their parameters, but also define new ones.
All titrants and KF standards needed for the METTLER methods are stored! If you delete
one of these resources, the error message that it is missing does not appear until the start
of the titration.
Print Depending on your choice of resource, its list with the corresponding parameters will be printed
out.
OK The list of the selected resources appears.
4.1 KF titrants
With <F3>, "OK" the stored KF titrants appear.
1-comp 5 1 component reagent: 5 mg/mL
1-comp 2 1 component reagent: 2 mg/mL
2-comp 5 2 component reagent: 5 mg/mL
2-comp 2 2 component reagent: 2 mg/mL
Pyridine 5 Pyridine (1 component reagent): 5 mg/mL
1-comp 5K 1 comp. reagent for ketones: 5 mg/mL
... free line for a new titrant
METTLER TOLEDO DL31/DL38 13
Setup (<Setup> key)
Delete The titrant is deleted.
Print The parameters of the titrant are printed out.
Modify The parameters of the titrant appear:
Name 1-comp 5
Conc.[mg/mL] 5.0000
Type 1 component
Burette 5 mL
Fill rate [%] 100
Batch
Check after [day] 0
Date 00-00-0000
Time 0:00
Name Press <F1>, "ABC" to change the name. The titrant with its parameters will be stored under this
name.
Conc. You can change the concentration or its range. You should change the concentration only if you
know the correct value!
Type Select one of the preset titrant types: 1 component, 2 components, Pyridine and Others. The
correct selection is important (see "Control parameters", Section 5.2).
Burette Select the burette (volume) which is used to dispense the titrant.
Batch Press <F1>, "ABC" to enter the batch number specified on the bottle.
Storage procedure
The titrant with its changed parameters is stored when you confirm the parameter list with <F3>, "OK". If
you press the <Esc> key, no changes will be made.
New KF titrant
You add a titrant to the titrant list when you confirm the free line with <F3>, "OK" The parameters always
appear, only the name of the titrant is missing.
– Change the parameters as described above.
The name of the new titrant must differ from those already stored, otherwise an existing
titrant will be overwritten!
Note In the DL31 you can store 10 titrants, in the DL38 20.
14 METTLER TOLEDO DL31/DL38
Setup (<Setup> key)
4.2 Br No. titrants (DL38 only)
With <F3>, "OK" the stored titrants for determination of the bromine number appear:
Br-/BrO
... free line for a new titrant
-
Bromide/bromate solution
3
Delete The titrant is deleted.
Print The parameters of the titrant are printed out.
Modify The parameters of the titrant appear:
Name Br-/BrO
Conc. [mol/L] 0.05
Burette 5 mL
Fill rate [%] 100
Batch
-
3
Name Press <F1>, "ABC" to change the name. The titrant and its parameters will be stored under this
name.
Burette Select the burette (volume) which is used to dispense the titrant.
Batch Press <F1>, "ABC" to enter the batch number specified on the bottle.
Storage procedure
The titrant with its changed parameters is stored when you confirm the parameter list with <F3>, "OK". If
you press the <Esc> key, no changes will be made.
New Br No. titrant
You add a new titrant to the titrant list when you confirm the free line with <F3>, "OK". The parameters
always appear, only the name of the titrant is missing.
– Change the parameters as described above.
The name of the new titrant must differ from the one already stored, otherwise an existing
titrant will be overwritten!
Note You can store 5 titrants for the bromine number.
METTLER TOLEDO DL31/DL38 15
Setup (<Setup> key)
4.3 KF standards
With <F3>, "OK" the stored Karl Fischer standards appear which you can use to determine the concentration of the KF titrants.
di-Na tartrate di-sodium tartrate . 2 H2O
H2O standard 10 Water standard : 10 mg/g
H2O standard 1 Water standard: 1 mg/g
H2O standard 5 Water standard: 5 mg/mL
H2O ISO 3696 pure water following ISO standard
... free line for a new standard
Delete The standard is deleted.
Print The parameters of the standard are printed out.
Modify The parameters of the standard appear:
Name di-Na tartrate
H2O content 15.660
Unit %
Batch
Type Mass
Weight [g]0 0.0500
Name Press <F1>, "ABC" to change the name. The standard and its parameters will be stored under
this name.
Batch Press <F1>, "ABC" to enter the batch number specified on the bottle.
Type You can select mass or volume. "Weight" changes accordingly to "Volume".
Weight Optimum values for a titrant concentration of 5 mg/mL and a burette volume of 5 mL are stored:
• 0.05 g for the tartrate standard,
• 0.75 g for the H2O standard 10,
• 3.5 g for the H2O standard 1,
• 0.01 g for the H2O standard ISO 3696,
Volume • 3 mL for the H2O standard 5.
Storage procedure
The standard with its changed parameters is stored when you confirm the parameter list with <F3>, "OK".
If you press the <Esc> key, no changes are made.
New KF standard
You can add a standard to the list of KF standards if you confirm the free line with <F3>, "OK". The
parameters always appear, only the name of the standard is missing.
– Change the parameters as described above.
The name of the new standard must differ from those already stored, otherwise an existing
standard will be overwritten!
16 METTLER TOLEDO DL31/DL38
Setup (<Setup> key)
Note
• In the DL31 you can store 10 standards, in the DL38 20.
• The Application brochure offers tips on sample preparation, sampling and the optimum amount of sample.
4.4 Main methods (DL38 only)
When the titrator is delivered, the <F3> command is assigned to the Tutorial "Hello!", in other words you
can select its sequence immediately. In this menu you can assign methods to command keys <F1>...<F3>
or delete "Hello!".
With <F3>, "OK", the following appears (example on delivery of the titrator):
Main methods SETUP
F1: Free
Modify OK
Main methods SETUP
User methods
METTLER methods
OK
Main methods SETUP
F1: Method 910
Title Stromboli
Delete Modify OK
Main methods SETUP
F2: Free
Modify OK
With <F2>, "Modify", the following appears:
You can select a method from the METTLER methods (or from the user
methods if available), e.g. "910 Stromboli":
With <F3>, "OK", the following appears:
You can select a different method to configure the <F2> command (press
<F2>, "Modify").
If you confirm this display with <F3>, "OK", the following appears:
Main methods SETUP
F3: Hello!
You can either delete "Hello!" with <F1> or overwrite it by a different
Delete Modify OK
METTLER TOLEDO DL31/DL38 17
method (press <F2>, "Modify").
Setup (<Setup> key)
4.5 Peripherals
With <F3>, "OK" the names of the instruments which you can attach to the titrator via the RS232C interfaces, the Centronics interface, the stirrer output and the DV705 connection appear. You must define these
and possibly change the preset settings.
Printer
Balance
Titrn stand
Computer
If you have the METTLER TOLEDO oven sample changer Stromboli connected to the TTL I/O interface, no
further entries are necessary.
4.5.1 Printer
With <F3>, "OK" the names of the printers which you can attach to the titrator appear.
HP
GA42
EPSON
None
– Select the attached printer.
– With an EPSON or HP printer change the type and possibly the settings with <F2>.
Type Select "PCL3+", "PCL3", "LQ/Stylus" or "LX/SX"
Paper Select "Single sheet" or "Fanfold" (see "Feed")
Format A4 width = 21 cm, length = 29.7 cm
81/2 * 11" width = 81/2 inches, length = 11 inches
81/2 * 12" width = 81/2 inches, length = 12 inches
Feed Select "Yes" or "No".
Yes Each report starts on a new page; with "Paper: Single sheet" a footer is printed out
on each page.
No The individual reports are separated by a distance of 2 lines.
– If you select an EPSON- or HP-compatible printer, you must enter the following settings:
Standard settings for the printer are printed in bold
HP-compatible EPSON-compatible
Type PCL3+ or PCL3 LQ/Stylus or LX/SX
Paper Single sheet Single sheet or Fanfold
Format A4 or 81/2 * 11" A4, 81/2 * 11" or 81/2 * 12"
Automatic feed Yes Yes or No
18 METTLER TOLEDO DL31/DL38
Setup (<Setup> key)
4.5.2 Balance
Unidirectional
Bidirectional
None
Unidirect. On request for the weight, the balance continuously transfers the current weight value.
Bidirect.
Titrator Balance
Data to titrator
On request for the weight, the balance transfers the current weight value when ordered by the titrator.
Titrator Balance
Command from titrator
Data to titrator
Configuration: "Send Cont."
Configuration: "Send Stable"
("Send on Transfer")
With METTLER TOLEDO balances AB, AG, AT and AX always use the setting "Bidirectional" and the following
settings on the balance: Baud rate: 2400, Data bits: 7, Parity: Even, Handshake: No.
4.5.3 Titration stand
Internal
External
As an external titration stand you can attach the DV705 KF Titration Stand from METTLER TOLEDO whose
magnetic stirrer and pump are controlled via the DV705 connection ("External stand").
4.5.4 Computer
Defined
Not defined
– If you attach a computer, you must select "Defined" and possibly change the settings.
Baud rate Select 1200, 2400, 4800 or 9600.
Parity Select "Even", "Odd" or "None".
Data bits Select 7 or 8 bits.
Stop bits Select 1 or 2 bit(s).
Character set Select "ASCII" or "DL".
Note If you select "DL", you must specify 8 for the number of data bits!
Start/end Select "'{'/CR" or "STX/ETX".
METTLER TOLEDO DL31/DL38 19
Setup (<Setup> key)
Default settings for the computer
Baud rate 4800
Parity Even
Number data bits 8
Number stop bits 1
Character set ASCII
Start/end '{'/CR
Note
• The METTLER TOLEDO LabX titration software allows you to control your titrator via a computer.
•
You will find additional information on the communication between titrator and computer in the Description
of the computer interface.
4.6 Settings
You can or must select or define the following settings for the titrator:
Language
User list
Date
Time
Titrator ID
Access for
Beep
Solv. capac.[mL]
Pumping time [s]
Language Select English, German, French, Spanish, Italian or Russian.
User list Press <F2>, "Modify", and a list of defined names and an empty line ("…") appears
where you can enter a new name. Press "ABC" and you can enter your name. Erase a
selected name with "Delete".
You can then select your name for both the development of a method and the performance
of the analysis.
Date You can set the date and select the format.
Day 26
Month 8
Year 1998
Format 31-08-1998
Format Select "31-08-1998", "08/31/1998", "31-Aug-1998" or "Aug/31/1998".
Time You can set the time and select the format.
Hour 10
Minute 20
Format 24 h
Format Select "24 h" or "am/pm".
20 METTLER TOLEDO DL31/DL38
Setup (<Setup> key)
Titrator ID To enter an identification for your titrator, press <F1>, "ABC". The ID is always reported.
Access for
You can decide whether all persons who work with the titrator should also have access to
the Setup and Method menus, in other words have the right to modify resources or methods.
Expert When the titrator is delivered, you have access to all menus. To change this,
select "Routine".
Routine You can
• in the Setup menu only print out the defined resources and view the list of
• in the Method menu only print out the list of methods (DL38 only) and
• in the Results menu not perform any recalculation and not change any
• under the <i> key, select neither the Tutorial, the KF learn titration nor the
Renewed access for experts is described on the last page of these Operating Instructions.
Beep You can select:
Yes
Minimum
No
Minimum A beep sounds on transition from pretitration to standby, on display of the
results and in the case of error messages.
settings.
each method.
statistical data.
Hardware tests menu.
Yes A beep also sounds after each keystroke.
Solv. capac. You can perform several titrations in the same solvent in succession, but its capacity is
limited. In the vicinity of the capacity limit, the reaction rate decreases.
You should enter a value for the maximum titrant volume which is suitable for your
sample determinations. If this value is exceeded, the error message "Solvent capacity
exhausted" appears.
Only the titrant volume which is consumed during the analysis is summed. The volume
which is added, e.g. using the auxiliary function "Dispense" is not taken into account.
The difference between the defined value and the titrant consumption is shown under the
<i> key.
Pumping time The defined time is a safety criterion: the pump will shut off after this time if you, e.g.
leave the titrator while the pump is running.
METTLER TOLEDO DL31/DL38 21
Methods (<Method> key)
5 Methods (<Method> key)
The titrator automatically performs analyses with the help of predefined methods. On delivery of the instrument
in the DL31 the KF standard method specified by us
is stored. You can modify this method and save it
under a number.
Methods METHOD
KF standard method
Help Modify
▼
Method METHOD
No. 0
of the method
Help OK
When you have modified and saved the method,
the following appears (example):
Methods METHOD
in the DL38 the KF standard method specified by us
and 11 METTLER methods are stored. You can modify
these methods and save them as user methods.
Methods METHOD
User methods
METTLER methods
KF standard method
Help Print OK
Print The list of methods you have developed is
printed out.
OK The user methods with their defined numbers
and titles appear (example):
Methods METHOD
22 Coffee
33 Tea
113 Powdered milk
Delete Print Modify
123 Cellulose
KF standard method
Print Modify
A complete titration method comprises sample preparation, mixing and wait times, the actual titration,
result calculation and a report. These partial steps are defined in the titrator as parameters which determine
the progress of an analysis.
You modify a method
by changing its parameters.
22 METTLER TOLEDO DL31/DL38
Methods (<Method> key)
5.1 The KF standard method
You can use the KF standard method to develop your own method. In this you are guided from one parameter to another in the specified order. Exceptions are sample, control, termination and report parameters,
which are shown as a group in a mask. In the case of the DL38, this also applies to the calculation
parameters.
With the user and METTLER methods, all parameters appear as a list in a mask. Exceptions are
again the above-mentioned groups. The last parameter of a method "Author of the method" always appears
in its own mask.
The method is always shown with the following default parameters. The parameters which you can modify
are listed in Section 5.2.
No. of the method 0
Title of the method
Sample parameters
ID
Type Mass
Minimum [g] 0.0000
Maximum [g] 5.0000
Entry Before
Speed [%] 35
Mix time [s] 10
Titrant 2-comp 5
Volume [mL]
for predisp. 0.0000
(Wait time [s]
after predisp. 0)
Auto start No → DL38 only
Control parameters
Current [µA] 20
End point[mV] 100
∆Vmin [µL] 0.5
∆Vmax [µL] 8.0
∆Vmax factor [%] 30
Start Cautious
Termination param.
Max. time [s] 600
Drift stop Rel.
Drift [µg/min] 15
Vmax [mL] 10.000
Blank [µg] 0
Drift Online
Result % → DL31 only
Calculation 1 %
R1 = x [%]*f1
f1 = 1.0000
Unit %
Decimal places 2
Statistics Yes
Max. srel [%] 0.00
Calculation 2
R2 = No calculation
f2 = 1.0000
Unit → DL38 only
Decimal places 2
Statistics Yes
Max. srel [%] 0.00
Calculation 3
R3 = No calculation
f3 = 1.0000
Unit
Decimal places 2
Statistics Yes
Max. srel [%] 0.00
Standby Yes
Report
Output Print.+Comp.
Type GLP
Author of the method
The METTLER methods 900 – 910 and specific parameters for automation with the METTLER TOLEDO oven
sample changer Stromboli are described in a separate chapter.
METTLER TOLEDO DL31/DL38 23
Methods (<Method> key)
5.2 KF method parameters
The following parameters can be changed. This will either cause some parameters to appear or disappear.
5.2.1 No. (of the method)
The method is stored under this number. The numbers 900 – 999 are reserved for METTLER methods.
5.2.2 Title (of the method)
You can give the method a specific name.
5.2.3 Sample parameters ID You can enter an identification for the sample(s) now or just before the titration for every sample
("Request").
Type Select "Mass", "Fixed mass", "Volume", "Fixed volume", "Pieces" or "Fixed pieces".
Weight appears when "Fixed mass" is selected.
Volume appears when "Fixed volume" is selected.
Number appears when "Fixed pieces" is selected.
Density appears when "Volume" or "Fixed volume" is selected.
Minimum/Maximum
appears when "Mass", "Volume" or "Pieces" is selected. The unit depends on the type of sample:
g, mL or pcs.
<F1>, "Help" For a fixed or variable amount of sample you can have the titrator calculate
and enter values if you know the approximate water content of your sample.
Entry of the amount of sample before or during the actual titration. "Entry" is faded out when "Fixed
mass", "Fixed volume" or "Fixed pieces" is selected.
DL38:
If you select "Yes" for the parameter "Auto start", on storage "Before" is automatically
set to "During".
5.2.4 Speed
Stirring should guarantee quick and thorough mixing of the electrolyte. We rocommend the setting: 40%.
The magnetic stirring rod should not "jump". Only use the magnetic stirring rod included in the delivery.
5.2.5 Mix time
This value for time is an empirical value and can be entered specific to the samples ("Request").
5.2.6 Titrant
You can select from the titrants stored in the Setup menu.
24 METTLER TOLEDO DL31/DL38
Methods (<Method> key)
5.2.7 Volume (for predispensing)
A predispensing shortens the titration time and can be entered specific to the sample ("Request").
Note In the user and METTLER methods the parameter is called "Predis.".
5.2.8 Wait time (after predispensing)
The parameter does not appear in the KF standard method if you have entered "0" for the predispensing.
This parameter always appears in the user methods.
5.2.9 Auto start (DL38 only) Yes The DL38 begins analysis as soon as a sample has been added. The time for adding a sample
may not exceed 30 seconds or the instrument will revert to its "Standby" mode. You should
select "Yes" for determinations in which, e.g. side-reactions could occur during the titration.
5.2.10 Control parameters
The following holds for all control parameters: You should not modify the preset default values for the
different reagent types until you have evaluated the titration curve of your sample (see Application brochure).
1 component 2 components Pyridine
Current 20 µA 20 µA 20 µA
End point 100 mV 100 mV 100 mV
∆Vmin 0.5 µL 0.5 µL 0.5 µL
∆Vmax 4.0 µL 8.0 µL 3.0 µL
∆Vmax factor 100% 30% 100%
Note ∆Vmin and ∆Vmax depend on the burette volume; the values listed apply to the 5 mL burette.
In the Tutorial and KF standard method these default values are automatically entered for the selected titrant
and hence the type. This does not apply to user methods: When you select a titrant whose type differs from
the previous one, you should also adapt the control parameters.
Current Select 1, 2, 5, 10, 15, 20, 30 or 40 µA for polarization current.
5.2.11 Termination parameters
To terminate the titration you must define "Vmax" and "Drift stop" ("Delay" respectively) as a condition; the
maximum time is an additional termination condition. The titration is terminated when the first of the
selected conditions is met.
METTLER TOLEDO DL31/DL38 25
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