Metrohm 756KF User Manual
756/831 KF Coulometer
Manual
8.831.1003
CH-9101 Herisau/Switzerland
E-Mail info@metrohm.com
Internet www.metrohm.com
756 KF Coulometer
831 KF Coulometer
Program version 5.756.0012 and 5.831.0011
Instructions for Use
8.831.1003 04.2003 / chs
Contents
Contents
1 Introduction .......................................................... 1
1.1 Parts and controls............................................................................... 2
2 The wet chemistry workplace ............................. 4
2.1 Principle of coulometric KF determinations...................................... 4
2.2 Titration vessel setup.......................................................................... 5
2.3 Your first determination ...................................................................... 6
2.4 Generator electrode without diaphragm ........................................... 7
2.4.1 Reagents.........................................................................................7
2.4.2 Cleaning..........................................................................................7
2.5 Generator electrode with diaphragm................................................. 8
2.5.1 Reagents.........................................................................................8
2.5.2 Cleaning..........................................................................................8
2.6 Tips for working with water standards .............................................. 9
2.6.1 Recommendations for practise ......................................................9
2.7 Sample addition ................................................................................ 10
2.7.1 Sample size ..................................................................................10
2.7.2 Liquid samples .............................................................................10
2.7.3 Solid samples ...............................................................................10
2.7 Optimal working conditions ............................................................. 11
2.7.1 Drift ...............................................................................................12
2.7.2 Reagent exchange........................................................................13
2.7.3 Indicator electrode........................................................................13
3 Manual operation ............................................... 14
3.1 Keypad............................................................................................... 14
3.2 Principle of data input....................................................................... 15
3.3 Text input ........................................................................................... 16
3.4 Configuration, key <CONFIG>........................................................ 17
3.4.1 Reagent exchange procedure with Dosino..................................25
3.5 Mode selection, key <MODE> ........................................................ 26
3.6 Parameters, key <PARAM>............................................................. 27
3.6.1 Titration sequence ........................................................................31
3.6.2 Control parameters and Ipol ........................................................32
3.6.3 Drift ...............................................................................................32
3.6.4 Current at the generator electrode ...............................................33
3.7 Result calculations............................................................................ 34
3.8 Statistics calculations....................................................................... 37
3.9 Common variables ............................................................................ 39
3.10 Data output ........................................................................................ 40
3.10.1 Reports for the output at the end of a determination .................41
3.10.2 Additional possibilities for report outputs...................................42
3.10.3 Display of the titration curve .......................................................42
3.11 User name, key <USER>................................................................. 43
3.12 Method memory, key <USER METH> ............................................ 44
756/831 KF Coulometer, Instructions of Use
I
Contents
3.13 Current sample data, key <SMPL DATA> ...................................... 46
3.14 Silo memory for sample data ........................................................... 47
3.15 Storing determination results and silo calculations ....................... 50
3.15.1 Storing determination results..................................................... 50
3.15.2 Silo calculations......................................................................... 51
4 Operation via RS232 Interface........................... 53
4.1 General rules ......................................................................................... 53
4.1.1 Call up of objects ........................................................................ 54
4.1.2 Triggers........................................................................................ 55
4.1.3 Status messages ......................................................................... 56
4.1.4 Error messages............................................................................ 57
4.2 Remote control commands .................................................................. 60
4.2.1 Overview ...................................................................................... 60
4.2.2 Description of the remote control commands............................. 74
4.3 Properties of the RS 232 Interface....................................................... 97
4.3.1 Handshake................................................................................... 97
4.3.2 Pin Assignment .......................................................................... 100
5 Error messages, troubleshooting .................... 103
5.1 Troubleshooting .............................................................................. 103
5.2 Error and special messages........................................................... 105
5.3 Problem with an external printer.................................................... 159
5.4 Initialize KF Coulometer ................................................................. 110
5.5 Testing the measuring input........................................................... 111
6 Preparations ..................................................... 112
6.1 Coulometer setup................................................................................ 112
6.1.1 Connecting a Stirrer or Ti Stand ................................................ 112
6.1.2 Insert paper into built-in thermal printer .................................... 113
6.1.3 Titration vessel setup with Ti Stand ........................................... 114
6.2 Connecting Coulometer to Dosino .................................................... 115
6.2.1 Setup with aspiration equipment............................................... 115
6.2.2 Equipping the titration vessel for aspiration .............................. 116
6.3 Connecting the KF Oven..................................................................... 117
6.3.1 Equipping the titration vessel with an oven............................... 118
6.4 Connecting the 774 Oven Sample Processor ................................... 119
6.4.1 Equipping the titration vessel with the Oven Sample Processor120
6.5 Connecting an external printer........................................................... 121
6.6 Connecting a balance ......................................................................... 122
6.7 Connecting a PC ................................................................................. 123
6.8 Connecting a Remote Box.................................................................. 124
6.8.1 Connecting a barcode reader.................................................... 124
6.8.2 Connecting a PC keyboard ....................................................... 125
756/831 KF Coulometer, Instructions for Use
II
Contents
7 Appendix ........................................................... 127
7.1 Technical specifications..................................................................... 127
7.2 Pin assignment of the "Remote" socket............................................. 129
7.2.1 Lines of socket "Remote"............................................................131
7.2.2 Activate pulse .............................................................................132
7.3 Coulometer validation, GLP mode..................................................... 133
7.3.1 Electronic tests ...........................................................................133
7.3.2 Wet tests .....................................................................................134
7.3.3 Maintenance and adjustment of the Coulometer.......................134
7.4 User methods ...................................................................................... 135
7.4.1 Working with the KF Oven..........................................................136
7.4.2 Working with the 774 Oven Sample Processor..........................138
7.5 Warranty and certificates.................................................................... 140
7.5.1 Warranty .....................................................................................140
7.5.2 Certificate of Conformity and System Validation:
756 KF Coulometer ..................................................................141
7.5.3 EU Declaration of Conformity: 756 KF Coulometer ...................142
7.5.4 Certificate of Conformity and System Validation:
831 KF Coulometer ..................................................................143
7.5.5 EU Declaration of Conformity: 756 KF Coulometer ...................144
7.6 Scope of delivery and ordering designations ................................... 145
Index...................................................................... 151
Abbreviations:
< > Key, e.g. <START>
date 2003-03-23 Display which appears in the standard operation level
run number 1 Display which appears in the expert operation level only
756/831 KF Coulometer, Instructions of Use
III
Contents
V
756/831 KF Coulometer, Instructions for Use
I
Introduction
1 Introduction
These instructions provide you with a comprehensive overview of the
installation, working principles and operation of the 756 KF Coulo-
meter and the 831 KF Coulometer. As these two instruments are,
aside from the built-in thermal printer of the 756 KF Coulometer,
identical, the Instructions for Use for both have been incorporated in
a single document. The report examples, mapped in this document,
were generated by a 756 KF Coulometer. They are identical for a 831
KF Coulometer, except from the instrument number. Functions,
which only apply on the 756 KF Coulometer are marked accordingly.
You can find a short summary of the Instructions for Use in the enclosed 756/831 KF Coulometer Quick References.
You can request descriptions for applications involving KF Titrations
in the form of Application Notes and Application Bulletins from
your local Metrohm agency or download them from the Internet under www.metrohm.com.
756/831 KF Coulometer, Instructions of Use
1
1.1 Parts and controls
1.1 Parts and controls
1
2
3
4
Frontview KF Coulometer
Built-in thermal printer (only at
1
756)
Ordering number for thermal paper:
6.2237.020
2 Display 4 Setting of display contrast
3 Control keys and indicator lamps
on the KF Coulometer
<Paper> only at 756 KF Coulometer
3 Control keys and indicator lamps on the KF Coulometer
Key < > Switches Coulometer ON/OFF
Key <
Key <PAPER> (Only at 756 KF Coulometer) Paper feed on printer (where
Key <STOP> Stops procedures, e.g. titration, conditioning.
Key <START> Starts procedures, e.g. titration, conditioning.
Indicator lampes:
"COND." Lamp flashes when conditioning is performed and the titra-
"STATISTICS" Lamp is on when the "statistics" function (calculation of
"SILO" Lamp is on when silo memory (for sample data) is on.
∞ > Switches stirrer ON/OFF
manually triggered reports are printed out).
Keys <STOP> and <START> are identical with the corresponding keys of the separate keypad.
tion vessel is still wet. It is on if conditioning is OK.
mean and standard deviation) is on.
756/831 KF Coulometer, Instructions for Use
2
Introduction
9
10
RS 232
1
Gen. EL.
2
5
6
Remote
7
Dos
8
Keyboard
Ind. EL.
Made by Metr ohm
Herisau Switzerland
1.756.
100 - 240 V
f = 50-60 Hz
P = 38 W
Nr.
14
13
12
11
Rearview KF Coulometer
RS232 interfaces
5
10 Connection of indicator electrode
2 separate interfaces for the connection of balance, computer, printer
etc.
6 Connection of generator electro-
de
11 Connection for stirrer
728 Magnetic Stirrer or 703 Ti Stand
Supply voltage: 10 VDC (I ≤ 200 mA)
7 Remote lines (input/output)
for the connection of remote box,
Oven, Sample Changer, robots etc.
12 Connection for power cable
With power supplies where the voltage is subject to severe HF disturbances, the Coulometer should be
operated via an additional power filter, e.g. Metrohm 615 model.
8 Connection of Dosino
13 Cooling fin
for automatic reagent exchange.
9 Connection for separate keypad 14 Rating plate
with fabrication, series and instrument number
756/831 KF Coulometer, Instructions of Use
3
2.1 Principle of coulometric KF determinations
2 The wet chemistry workplace
2.1 Principle of coulometric KF determinations
The coulometric Karl Fischer titration is a version of the classical
water determination method developed by Karl Fischer. The
traditional method utilises a methanolic solution of iodine, sulphur
dioxide and a base as buffer. Several reactions run in the titration of
a water-containing sample and can be summarised by the following
overall equation:
H
O + I2 + [RNH]SO3CH3 + 2 RN ⇔ [RNH]SO4CH3 + 2 [RNH]I
2
According to the above equation, I
This chemical relation forms the basis of the water determination.
The classical Karl Fischer method has undergone constant
development in the past years. This further development has
involved not only refinement and automation of the reagent
dispensing, but also improvement of the end point indication and the
reagents. Despite the progress made, the classical, volumetric Karl
Fischer method suffers from the disadvantage that the reagents are
not completely stable resulting in the need to redetermine the titer at
intervals.
In the coulometric Karl Fischer titration, the iodine needed is
generated directly in the electrolyte by electrochemical means
("electronic buret"). The rigorously quantitative relationship between
the electric charge and the amount of iodine generated is used for
high-precision dispensing of the iodine. As the coulometric Karl
Fischer method is an absolute determination no titer need be
determined. It is necessary only to ensure that the reaction which
generates the iodine runs with 100% current efficiency. With the
reagents available today this is always the case.
The end point is indicated voltametrically by applying an alternating
current of constant strength to a double Pt electrode. This results in
a voltage difference between the Pt wires of the indicator electrode
which is drastically lowered in the presence of minimal quantities of
free iodine. This fact is used to determine the end point of the
titration.
reacts quantitatively with H2O.
2
756/831 KF Coulometer, Instructions for Use
4
2.2 Titration vessel setup
2.2 Titration vessel setup
1. Attach titration vessel with holder to the support
rod.
Drying tube
Generator
electrode
Stirring bar
Indicator
electrode
Septum stopper
1) When cutting the ground joint sleeves take care that no rough
edges are formed. The ground joint sleeves must not project
beyond the lower edge of the joint.
If no ground joint sleeves are used then the joints must be
greased. In this case the joints must be checked periodically
and re-greased while otherwise problems with blocked joints
could occur.
2) For the generator electrode with diaphragm: Fill the generator
electrode with approx. 5 ml catholyte. Fill the titration vessel with
anolyte until the anolyte level is 1-2 mm above that of the catholyte (approx. 100 ml).
2. Place stirring bar in titration vessel.
3. Cut 6.2713.XXX ground joint sleeves to the correct lengths and use them for all the joints of the
inserts
4. Insert indicator electrode in the left-hand joint
opening, screw on 6.2104.020 electrode cable
and plug it into the "Ind.El" socket of the Coulometer.
Mark the screw head of the electrode cable so
that it is impossible to confuse the indicator and
generator electrodes!
5. Insert generator electrode in the central joint
opening, screw on 6.2104.120 electrode cable
and plug it into the "Gen.El" socket of the Coulometer.
6. Fill the drying tube with molecular sieve and insert
into generator electrode.
7. Place septum in the screw cap and screw this
onto the titration vessel. Only tighten it enough to
ensure that it is tight. (The septum should not be
deformed!)
8. Fill titration vessel with 80-100 ml reagent
9. Close last joint opening: either with glass stopper,
aspiration device or gas inlet from oven (see
pages 114ff).
1)
.
2)
.
756/831 KF Coulometer, Instructions of Use
5
2.3 Your first determination
2.3 Your first determination
KFC ********
KFC wait
drift ⇓ 53 ug/min
KFC ready
drift ⇔ 4.3 ug/min
smpl size 1.0 g
KFC ready
drift ⇔ 5.3 ug/min
content 38.5 ppm
The titration vessel has been prepared (see page 5) and the
Coulometer is switched on. In the display appears
Press the <START> key.
Pre-conditioning begins, i.e. the titration vessel is dried. The
"COND" LED blinks. The arrow in the drift display shows the
drift tendency (falling, rising, stable).
When the titration vessel is dry an acoustic signal is heard
and the "COND" LED shows a steady light.
Press <START> and inject the first sample.
Enter the sample size and confirm it with <ENTER>.
During the titration you will see the curve µg H
O against
2
time. To the left of the curve the following measurements are
displayed:
O in µg
H
2
Rate in µg/min
Time in s
After the titration the result is displayed and printed out by the
internal printer (with the 831, a printer needs to be installed;
see page 121). The titration vessel is continuously kept dry
and the current drift is displayed.
If you want to determine further samples press <START>
again and inject the next sample...
756/831 KF Coulometer, Instructions for Use
6
2.4 Generator electrode without diaphragm
2.4 Generator electrode without diaphragm
The 6.0345.100 generator electrode without diaphragm poses no
handling problems and is easy to clean. It only requires one reagent
and is quickly ready for use (no moisture depots in the diaphragm!).
The generator electrode without diaphragm is the best choice for
most applications. It is particularly suitable for use with very polluting
samples.
2.4.1 Reagents
Only use those reagents which are specially intended for use with
generator electrodes without diaphragm; see the reagent manufacturer's documentation.
2.4.2 Cleaning
The electrolyte solution can normally be exchanged without any special cleaning of the parts being necessary. If cleaning is necessary
then care should be taken that the Pt grid of the generator electrode
is not damaged.
Pollutants containing oil:
Clean with a solvent (e.g. hexane) and then rinse with ethanol.
Salt-like deposits:
Clean with water and then rinse with ethanol.
Dry all parts thoroughly after cleaning. A hot-air blower can be used
for this. If the parts are dried in a drying oven take care that the temperature does not exceed 70°C (plastic components!).
756/831 KF Coulometer, Instructions of Use
7
2.5 Generator electrode with diaphragm
2.5 Generator electrode with diaphragm
The 6.0344.100 generator electrode with diaphragm should be used
when your samples contain ketones and aldehydes because special
reagents for aldehydes and ketones are only available for generator
electrodes with diaphragms.
If your reagent has a low conductivity, e.g. if you have had to add
chloroform because of the solubility of the sample then you should
use the generator electrode with diaphragm as first choice.
It can also be recommended when you require very good accuracy
in the lowest trace analysis ranges.
2.5.1 Reagents
Reagents for coulometric water determination with generator electrodes with diaphragms consist of an anode solution (anolyte), which
is filled into the titration vessel and a cathode solution (catholyte)
which is filled into the generator electrode.
Special reagents must be used for water determination in ketones
and aldehydes; please refer to the reagent manufacturer's instructions.
2.5.2 Cleaning
The electrolyte solution can normally be exchanged without any special cleaning of the parts being necessary. If cleaning is necessary
then care should be taken that the Pt grid of the generator electrode
is not damaged.
Resinous deposits on the diaphragm:
Hang the generator electrode vertically from a support rod, fill with
conc. HNO
and allow to stand overnight. Rinse with water followed
3
by ethanol.
Pollutants containing oil:
Clean with a solvent (e.g. hexane) and then rinse with ethanol.
Salt-like deposits:
Clean with water and then rinse with ethanol.
Cleaning (rinsing) the diaphragm:
Fill the cathode compartment of the generator electrode with methanol and allow the filling to drain out. Repeat the process 2-3 times.
This process should also be carried out when the electrode has
been cleaned as described above.
Dry all parts thoroughly after cleaning. A hot-air blower can be used
for this. If the parts are dried in a drying oven take care that the temperature does not exceed 70°C (plastic components!).
756/831 KF Coulometer, Instructions for Use
8
2.6 Tips for working with water standards
2.6 Tips for working with water standards
For validation of the instrument, as a fully integrated measuring system, commercial, certified water standard solutions with water contents of 1.00 ± 0.003 mg/g and/or 0.10 ± 0.005 mg/g should be applied (The 1.0 mg/g Standard is easier to handle and therefore to
prefer).
Recommended initial weight range:
Liquid standard 1.0 mg/g 0.2-2.0 g
Liquid standard 0.1 mg/g 0.5-1.5 g
2.6.1 Recommendations for practice
For validation of the system very accurate handling is needed. To
minimise possible measuring inaccuracies the sample preparation
and handling should run accordingly to the following procedure:
1. Wear gloves (As always in KF Titration).
2. Take a fresh plastic syringe and open it.
3. Take a fresh ampoule of KF standard and shake it for 10
seconds.
4. Open the ampoule and suck 1 ml of the standard into the
syringe
5. Pull the piston of the syringe up to the end and shake the
syringe for a few seconds, so that the inner part of the syringe is rinsed with standard and gets rid of water
contamination.
6. Splash the used standard into a waste bottle.
7. Repeat the same procedure with another ml of the standard
solution.
8. Suck the whole rest of the standard into your syringe.
Thereafter, verify that there is no more solution in the needle
by sucking a small amount of air into the syringe.
9. Clean the needle by wiping it with a soft tissue. Close the
needle with the corresponding cap.
10. Place the syringe on the balance and press TARA.
11. As soon as the drift at your Coulometer is stable, you can
take the syringe, press <Start> at the Coulometer and inject around 1 ml of the standard. This can be done in two
different ways:
a. The standard is injected without dipping the needle. If
a small drop keeps hanging at the needle, aspirate it
back into the needle, before pulling the needle out of
the septum.
b. The standard is injected directly under the surface of
the KF solution.
Furthermore, make sure that the standard doesn’t splash
on the wall of the vessel or on the electrode.
756/831 KF Coulometer, Instructions of Use
9
2.7 Sample addition
12. Close the syringe and put it back on the balance.
13. Read the indicated value off the balance and feed it at your
Coulometer as sample size.
14. As soon as the determination has finished and the titration
cell is conditioned again, you can start with the next determination.
2.7 Sample addition
This section contains some information about sample addition. A detailed description of this topic is not possible here. You can find further information in the reagent manufacturer's documentation and in
Metrohm Application Bulletins.
Metrohm Application Bulletins:
No. 142: Karl Fischer water determination in gaseous samples
No. 145: Determination of small amounts of water in plastics
No. 209: Water determination in insulating oils, hydrocarbons and
their products
No. 273: Validation of KF Coulometers according to GLP/ISO 9001.
2.7.1 Sample size
The sample size should be small so that as many samples as possible can be titrated in the same electrolyte solution and the titration
time kept short. However, take care that the sample contains at least
50 µg H
2
weight.
Content of sample Sample weight H
100000 ppm = 10 %
10000 ppm = 1 %
1000 ppm = 0.1 %
100 ppm = 0.01 %
10 ppm = 0.001 %
2.7.2 Liquid samples
Liquid samples are added with the aid of a syringe. Either a syringe
with a long needle is used with the needle being immersed beneath
the surface of the reagent during injection or a short needle is used
with the last drop being sucked back into the needle.
The best way of determining the actual sample weight is by weighing
the syringe before and after injection.
Volatile or low-viscosity samples should be refrigerated before
that sample is taken in order to prevent handling losses. In contrast,
the syringe itself should not be directly refrigerated as this could
cause the formation of condensate. For the same reason aspirating
air into a syringe which has been cooled by taking up a refrigerated
sample should be avoided.
O. The following table provides guidelines for the sample
O to be determined
2
50 mg
10 mg... 100 mg
100 mg... 1 g
1 g
5 g
5000 µg
100 µg...1000 µg
100 µg...1000 µg
100 µg
50 µg
756/831 KF Coulometer, Instructions for Use
10
2.7 Sample addition
Highly viscous samples can be warmed to lower their viscosity;
the syringe must also be warmed. The same goal can also be
reached by dilution with a suitable solvent. In this case the water
content of the solvent must be determined and deducted as a blank
value correction.
Pastes, greases can be placed in the measuring cell by using a
syringe without a needle. The joint opening can be used for this
purpose. If aspiration is additionally required the opening with the
septum stopper can be used.
The best way of determining the actual sample weight is by weighing
the syringe before and after injection.
With samples containing a lot of water care must be taken that
the needle is not introduced into the measuring cell through the
septum before <START> has been pressed as otherwise the drift
and therefore the result of the analysis could be falsified.
With samples containing only a trace of water the syringe must
be thoroughly dried beforehand. If possible the syringe should be
rinsed with the sample solution by taking up the sample solution
several times and then discarding it.
2.7.3 Solid samples
Whenever possible solid samples should be extracted or dissolved
in a suitable solvent and the resulting solution injected; a blank value
correction should be made for the solvent.
If no suitable solvent can be found for a solid sample or if the
sample reacts with the Karl Fischer solution the drying oven should
be used.
If solid samples have to be placed in the measuring cell directly then
the generator electrode without diaphragm should be used. The
sample can be added through either the joint opening or through the
opening at the side. Take care that:
• The sample releases its moisture completely
• No side reaction occurs with the Karl Fischer solution
• The surface of the electrodes is not covered by the sample
substance (incomplete KF reaction!)
• The Pt grid of the generator electrode is not damaged
• The Pt wires of the indicator electrode are not damaged
756/831 KF Coulometer, Instructions of Use
11
2.8 Optimal working conditions
2.8 Optimal working conditions
If a thoroughly dry titration vessel with a generator electrode without
diaphragm is used then the basic drift is reached within approx. 30
minutes. It is recommended that the titration vessel is carefully
shaken several times during this time.
For generator electrodes with diaphragm a preparation period of
approx. 2 hours must be expected.
If the 768 KF oven is used it is recommended that the oven is allowed to run overnight with the oven valve set to "purge".
For precise determination of amounts of water below 100 µg it may
also be an advantage to condition the instrument overnight before
use.
If the instrument is switched off for a longer period of time with a
filled titration vessel then a certain time is required for it to become
dry again after it is switched on.
During continuous operation the instrument should not be switched
off overnight.
2.8.1 Drift
A constant drift of the order of about ≤ 4 µg/min is good. However,
lower values are certainly possible. If higher, stable values occur
then the results are normally still good as the drift can be compensated (drift correction see page 29).
The drift is shown together with the "drift trend":
⇔ constant drift and drift below the start drift, see page 32.
↑ drift increasing
↓ drift falling
A drift which remains high may be caused by water-containing depots in inaccessible locations inside the cell. In such cases a reduction in the value would be achieved by shaking the titration vessel.
Take care that no drops above the level of the liquid are formed in
the titration vessel.
For generator electrodes with diaphragms shaking must not be so
vigorous as to cause the catholyte and anolyte to become mixed
with each other.
If even after shaking the drift remains too high over longer periods of
time then the electrolyte solution must be exchanged.
When working with the oven a drift ≤ 10 µg/min is good. The drift depends on the gas flow (the smaller the gas flow the lower the drift).
756/831 KF Coulometer, Instructions for Use
12
2.8 Optimal working conditions
2.8.2 Reagent exchange
In the following cases the electrolyte solutions should be exchanged:
• When the titration vessel is too full.
• When the capacity of the reagent is exhausted.
• If the drift is too high and shaking the cell does not result in any
improvement.
• If a two-phase mixture is formed in the titration vessel. In this case
only the sample phase can be aspirated off, see also page 25.
• If during the determination the error message
electr.
Removal of the used electrolyte solutions from the cell is most easily
carried out by aspiration as it is not necessary to disassemble the
cell.
If strong pollution occurs the cell can be rinsed with a suitable solvent which should also be aspirated off.
A Dosino or Titration Stand 703 can be used to aspirate the electrolyte solutions, see pages 114ff.
For the generator electrode with diaphragm the catholyte should be
exchanged approx. once a week. Extended use may cause darkening of the catholyte and yellow participation in the cathode compartment. An unpleasant smell indicates the need for catholyte exchange also.
" appears (see page 105).
"check generator
2.8.3 Indicator electrode
A new indicator electrode may require a certain running-in period for
the formation of the surface. This may cause unusually long titration
times and measurement results which are too high. These phenomena vanish after a short period of use. In order to speed up the running-in of a new indicator electrode the Coulometer can be conditioned overnight, for example.
A polluted indicator electrode can be carefully cleaned with an abrasive cleansing agent (aluminium oxide (6.2802.000 Polishing Set) or
toothpaste). After cleaning it should be rinsed with ethanol.
The two Pt wires of the indicator electrode should be as parallel to
one another as is possible. Check on insertion.
756/831 KF Coulometer, Instructions of Use
13
3.1 Keypad
3 Manual operation
3.1 Keypad
tions of consecutive determination, see
page 37.
sample data, see page 47.
Dosino, see page 25.
page 44.
page 40.
marked with ":"), switching result/curve
display
error messages.
CONFIG
STATISTICS
7
PARAM
USER
H2O
8
SMPL
DATA
+
–
SILO
9
CONFIG Configuration.
PARAM Parameters.
SMPL DATA Sample data.
STATISTICS ON/OFF switching of statistics calcula-
USER User name, see page 43.
SILO ON/OFF switching of silo memory for
4
5
EXCH
*
/
6
RS
C-FMLA
1
PRINT
0
C
DEF
2
(
USER METH
3
MN
REPORTS
.
ABC
MODE
–
)
;
EXCH Reagent exchange with connected
C-FMLA Calculation values, see page 35.
DEF Formulas, data output, see page 34ff.
USER METH Management of method memory, see
PRINT Printing of reports, see page 42.
REPORTS Result output at the end of titration, see
←
→ ↑
CLEAR ENTER
↓
MODE Mode selection, see page 26.
←,→ Selection of special values (dialog
STOP START
QUIT
6.2130.040
↑,↓ 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 34.
756/831 KF Coulometer, Instructions for Use
14
3.2 Principle of data input
3.2 Principle of data input
• If you press a key you will find a group of inquiries in
the display.
parameters
>titration parameters
>statistics
>preselections
parameters
>preselections
req.ident: OFF
req.smpl size: value
cell: no diaph.
parameters
>titration parameters
>statistics
>preselections
Example key <PARAM> (in the standard operation
level):
In the first line you see where you are: you pressed
key <PARAM> and you are now in the inquiries
rameters
• The cursor is inverted. In our example the cursor is
on the inquiry
the cursor up and down with keys <↑> and <↓>.
If a dialog text is marked with
of inquiries itself. You go to this group pressing
<ENTER>.
Move the cursor to
<ENTER>:
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
If you press <QUIT> once more you quit the inquiries in
• If you can scroll, ↓ or ↑ appear in the right lower or
upper corner of the display.
pa-
.
>titration parameters. You can move
>, it contains a group
>preselections and press
>preselections.
parameters altogether.
756/831 KF Coulometer, Instructions of Use
15
3.3 Text input
3.3 Text input
user methods
>store method
method name: ********
<CLEAR>
REPORTS
ABC
.
user methods
>store method:
method name:
ABCDEFGHIJKLMNOPQRSTUVWXYZ
abcdefghijklmnopqrstuvwxyz
µ°!"#$&'()*+,-./ 0123456789
<QUIT>
user methods
>store method
method name: Text
You may also enter texts by means of a connected PC keyboard, see page 124.
<ENTER>
Example: storing a method:
• 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 have confirmed the last character, i.e.
your name is complete, you quit the text writing
mode with <QUIT>.
Now confirm 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 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>.
756/831 KF Coulometer, Instructions for Use
16
3.4 Configuration, key <CONFIG>
3.4 Configuration, key <CONFIG>
CONFIG
configuration
>monitoring
>peripheral units
>auxiliaries
>RS232 settings COM1
>RS232 settings COM2
>report
>common variables
>monitoring
reagent: OFF
The key <CONFIG> is used for the entry of instrument-specific data. The set values apply for all modes.
All entries are only possible in the inactive basic status
of the Coulometer.
Two different operating modes are available: standard
mode and expert mode. Inquiries which appear in the
standard mode are highlighted in gray.
Monitoring functions (only in expert mode):
Monitoring the reagent, validation interval, service interval and printout of diagnostic reports.
Peripheral units (only in expert mode):
Selection of printer, balance, PC keyboard, barcode
reader, stirrer control and selection of the COMs for
manual report output.
Auxiliaries:
e.g. selection of operating mode, setting dialog language, date, time.
Settings for RS-COM1 and 2 (only in expert mode):
RS parameters for the interfaces.
Report (only in expert mode):
Configuration of the report.
Common Variable (only in expert mode):
Values of the common variables.
The display texts of the Coulometer are shown to the
left. The values are the default values.
Monitoring functions
Monitoring the reagent (ON, OFF)
Monitoring is carried out at the end of the titrations and
when the Coulometer is switched on. If a monitoring
function responds the message "change reagent"
appears. The message vanishes when the reagent is
changed automatically or with <EXCH>. The message
can also be cleared with <CLEAR>. At the same time
all counters are reset to zero.
For generator electrodes with diaphragms the katholyte
normally needs to be changed more frequently than
the anolyte.
756/831 KF Coulometer, Instructions of Use
17
3.4 Configuration, key <CONFIG>
number of determ. 1
determ.counter 0
reagent lifetime 7 d
time counter 0 d
reagent capacity 1000 mg
capacity counter 0 mg
drift OFF ug/min
reagent change: OFF
waiting time 0 s
If on has been set:
Monitoring according to the number of determinations
carried out (1...999, OFF)
The number of determinations which can be carried out
depends on the type of sample (very polluting,
lowering the conductivity) and on the amount of
sample which is to be injected.
OFF means that monitoring is not active.
Determination counter (0...999)
Counts the number of determinations carried out since
the last time the counters were reset to zero.
Monitoring according to the lifetime of the reagent
(1...9999 d, OFF)
OFF means that monitoring is not active.
Time counter (0...9999 d)
Counts the number of days since the last time the
counters were reset to zero.
Monitoring the reagent capacity (1...9999 mg, OFF)
With the generator electrode without diaphragm and a
filling volume of 100 ml the capacity is 1000 mg water.
For the generator electrode with diaphragm the
capacity of the katholyte is 300 mg (with 5 ml filling
volume).
OFF means that monitoring is not active.
Counting the capacity (0...9999 mg)
Adds the weight of water since the last time the
counters were reset to zero.
Monitoring of drift (0...99 ug/min, OFF)
If the current drift value is stable for 2 minutes and
above the set value for drift monitoring (but not
max.=2240 ug/min), the message "change reagent"
appears.
OFF means that monitoring is not active.
Reagent exchange (auto, man., OFF)
auto: the reagent is automatically exchanged by the
connected Dosino when the reagent monitoring responds (see above). The reagent can also be exchanged manually at any time with <EXCH>.
man.: the reagent can be exchanged with <EXCH>.
The reagent exchange procedure is described on page
255.
OFF: the key <EXCH> is not active.
If "auto" or "man." has been set:
Waiting time before aspiration (0... 999 999 s)
E.g. the waiting time can be used in order to wait for
the phase separation between sample and reagent
when the sample is to be aspirated off.
756/831 KF Coulometer, Instructions for Use
18
3.4 Configuration, key <CONFIG>
aspirate volume 100 ml
reagent volume 100 ml
rinsing volume 0 ml
rinsing cycles 1
validation: OFF
time interval 365 d
time counter 0 d
service: OFF
next service YYYY-MM-DD
system test report: OFF
>peripheral units
send to COM1: IBM
send to COM2: IBM
Aspirate volume (0...9999 ml)
Volume to be aspirated.
Reagent volume (0...9999 ml)
Volume to be added.
Rinsing volume (0...9999 ml)
Normally rinsing is not necessary.
When ≠
0 ml has been set
Number of rinsing cycles (1...9)
Monitoring the validation interval (ON, OFF)
Monitoring is carried out at the end of the titrations and
when the Coulometer 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.
on has been set:
If
Time interval for validation (1...9999 d)
Validation can be carried out in the GLP mode, see
page 133.
Time counter (0...9999 d)
Counts the number of days since the last time the
counter was reset.
Monitoring the service interval (ON, OFF)
Monitoring is carried out after the Coulometer has been
switched on. If the monitoring responds the message
Service is due appears. The message vanishes with
<CLEAR>.
on has been set:
If
Date of next service (YYYY-MM-DD)
System test report printout (ON, OFF)
on the report of the system test is printed out after
With
the Coulometer has been switched on, see also page
133.
Settings for peripheral units
Selection of printer (Epson, Seiko, Citizen, Custom, HP,
IBM) at the Coulometer COM1
Epson, for Epson
Seiko, e.g. for DPU-414
Citizen, e.g. for iDP 562 RS, Custom DP40-S4N
HP e.g. for Desk Jet types. Always place curves at the
beginning of a page as you cannot have them over 2
pages.
IBM for all printers with IBM character set Table 437 and
IBM graphics, as well as for the data transmission to a
computer or a data system.
756/831 KF Coulometer, Instructions of Use
19
3.4 Configuration, key <CONFIG>
man.reports to:
int. (only 756)
COM1
COM2
balance: Sartorius
stirrer control: ON
remote box: OFF
keyboard: US
barcode: input
> auxiliaries
dialog: english
date 1998-04-23
time 08:13
Target for the output of manually triggered reports (1, 2,
1&2 and only at 756: int., 1&int., 2&int, all)
Manually triggered reports e.g. with <PRINT> .... .
Exception <PRINT><REPORTS>: These reports are
outputted at the target as defined in the method.
Selection of balance (Sartorius, Mettler, Mettler AT,
AND, Precisa)
Sartorius: Models MP8, MC1
Mettler: Models AM, PM and balances with 011,
012, and 016 interfaces
Mettler AT: Model AT
AND: Models ER-60, 120, 180, 182, FR-200, 300
and FX-200, 300, 320
Precisa: Models with RS232C interface
Automatic switching ON/OFF of the stirrer in the titration
sequence (ON, OFF)
If stirrer control is
ON, the stirrer will be switched
automatically. For stirrer control the red switch on the
stirrer unit must be ON.
Connection of a remote box (on ,OFF)
To the remote socket for PC keyboard and barcode
reader, see page 124.
on has been set:
If
Type of PC keyboard (US, German, French, Spanish,
Swiss.)
The PC keyboard is used as an input aid, see page
125.
Target for barcode reader (input, method, id1, id2, id3,
smpl size)
The barcode reader is used as an input aid, see page
124.
Input: The barcode string goes to the entry field in
which the cursor is currently located.
Method: The barcode string goes to the entry field
"Methods" in the silo memory.
Id1: The barcode string goes to the entry field
"Id1". (Similar for Id2 and Id3.)
Smpl size: The barcode string goes to the entry field
"smpl size".
Various auxiliary settings
Selection of dialog language (english, deutsch,
francais, español, italiano, portugese, svenska)
Current date (YYYY-MM-DD)
Format: year-month-day, entry with leading zeros.
Current time (HH-MM)
Format: hours-minutes, entry with leading zeros.
756/831 KF Coulometer, Instructions for Use
20
3.4 Configuration, key <CONFIG>
run number 0
operator level: standard
start delay 0 s
result display: bold
dev.label.
beeps 1
display value: OFF
program 5.756.0010
>RS232 settings COM1
baud rate: 9600
data bit: 8
stop bit: 1
parity: none
handshake: HWs
Current run number for result output (0...9999)
The sample number is set to 0 when the instrument is
switched on and incremented on every determination.
Operating mode (standard, expert)
Determines the number of inquiries which are
accessible. Operation in the standard mode contains
only a few inquiries and is recommended for routine
applications.
Inquiries which are accessible in the standard mode
are highlighted in gray in these Instructions for Use.
Start delay (0...999 999 s)
Delay time after start of methods. Abort start delay time
with <QUIT>.
Type of result display at the end of the determination
(bold, standard)
bold: the calculated results are displayed in bold
characters.
standard: displays the whole information, e.g. results,
water, messages etc.
Individual identification of devices (up to 8 ASCII
characters). Is automatically printed in reports.
Number of beeps (1...3, OFF)
when instrument is ready (conditioning OK), end of
titration and Cond.OK, reception of sample data from
the balance and with sample sizes outside the limiting
values.
Display of measured value (ON, OFF)
Display of U-value during conditioning and titration.
Display of program version. At 831: 5.831.0011 ; at 756:
5.756.0012 .
Settings of RS232 interface
see also pages 97ff. Identical for COM2.
Baud rate (300, 600, 1200, 2400, 4800, 9600)
Data bit (7, 8)
Stop bit (1, 2)
Parity (even, odd, none)
Handshake (HWs, SWline, SWchar, none)
see page 97.
756/831 KF Coulometer, Instructions of Use
21
3.4 Configuration, key <CONFIG>
>report
report id: ON
instrument id: ON
date, time: ON
run number: ON
method: ON
sample: ON
drift: ON
titr.time: ON
H2O: ON
statistics: ON
signature: OFF
> common variables
C30 0.0
etc.
Configuration of the report
Printing report lines or data can be switched on and
off. This means that the report can be arranged
according to your requirements.
Prints the line "Report-Id" (ON, OFF)
e.g. 'fr.
If you use Vesuv 3 the report identification is switched
on automatically.
Prints the line(s) "instrument-Id" (ON, OFF)
756 (or 831) KF Coulometer, instrument-Id and
program version.
Prints the line(s) "date, time" (ON, OFF)
If you use Vesuv 3 then date/time is switched on
automatically.
Prints the sample number (ON, OFF)
The date line is printed without the sample number.
Prints the line "Method" (ON, OFF)
e.g. KFC ********
Prints the line "Smpl size" (ON, OFF)
Prints the line "Drift" (ON, OFF)
Prints the line "Titr.time" (ON, OFF)
Prints the line "H2O" (ON, OFF)
Continuously prints the statistical results (ON, OFF)
With "OFF" the statistical results will only be printed out
when the number n for statistics has been reached.
Prints the line "Signature" (ON, OFF)
Values of the common variables
±
Common variables C30...C39 (0..
999 999)
The values of all common variables are displayed. For
creating common variables see page 39.
756/831 KF Coulometer, Instructions for Use
22
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