Metrohm 768 KF Oven User manual

Metrohm AG CH-9101 Herisau (Switzerland)
The following parts around the heating tube of the KF Oven can
become hot:
Heating tube, lateral shielding walls of the heating tube, guard grill
of the heating tube, jacket of the outlet heating.
Caution: Never touch these parts and ensure they never come
into contact with solvents!
98.12 Ti
8.768.1003
KF Oven 768
Series 01...
!

Inhalt
Inhaltsverzeichnis
1. Introduction......................................................................................................................1
1.1 Overview.......................................................................................................................1
1.2 Operating principle........................................................................................................4
2. Operating conditions.......................................................................................................5
2.1 Handling the sample boat .............................................................................................5
2.2 Automatic sequence of a determination........................................................................6
2.3 Settings on KF Oven.....................................................................................................7
2.3.1 Keypad ...................................................................................................................7
2.3.2 <CONFIG> key.......................................................................................................9
2.3.3 <PARAM> key......................................................................................................11
2.3.4 Special settings ....................................................................................................12
2.4 Practical tips ...............................................................................................................13
3. Operation via RS232 interface (green pages) ...............................................................15
3.1 General rules..............................................................................................................15
3.1.1 Call up of objects..................................................................................................16
3.1.2 Triggers................................................................................................................17
3.1.3 Status and error messages...................................................................................18
3.2 Remote control commands.........................................................................................20
3.2.1 Overview...............................................................................................................20
3.2.2 Description of the remote control commands........................................................23
3.3 Characteristics of the RS232 interface........................................................................31
3.3.1 Data transfer protocol...........................................................................................31
3.3.2 Handshake ...........................................................................................................31
3.3.3 Pin assignment.....................................................................................................35
4. Troubleshooting, rectification of malfunctions ...........................................................37
4.1 Troubleshooting..........................................................................................................37
4.2 Error messages ..........................................................................................................39
4.3 Troubles with a connected printer...............................................................................40
4.4 Flow test .....................................................................................................................41
4.5 Check of valve functions.............................................................................................41
4.6 Initializing the RAM.....................................................................................................42
5. Preparations...................................................................................................................44
5.1 Setting up the Oven....................................................................................................45
5.2 Connection of the 756 KF Coulometer or of a Titrino..................................................47
5.2.1 Installation of the coulometric cell (756 KF Coulometer).......................................48
5.2.2 Installation of the titration vessel for Titrinos (volumetry) ......................................48
5.3 Connection of the 737 KF Coulometer........................................................................49
5.4 Connection of the outlet heating .................................................................................50
5.5 Connection of a printer................................................................................................51
5.6 Connection of a computer...........................................................................................52

Inhalt
6. Appendix.........................................................................................................................53
6.1 Technical specifications..............................................................................................53
6.2 "Remote" socket .........................................................................................................54
6.2.2 Status of the lines during the automatic determination..........................................55
6.3 Checking sample temperature....................................................................................56
6.4 Warranty and certificates............................................................................................57
6.5 Accessories, scope of delivery....................................................................................60
Index ...................................................................................................................................62

1.1 Overview
768 KF Oven 1
1. Introduction
1.1 Overview
Front
Rear
12 3
4
56789
10 12 14 16 18
11 13 15 17

2768 KF Oven
Front 1Drying flasks
filled with molecular sieves. For drying the carrier gas.
2Tubing connections
with 6.1805.180 Tubing.
3Tubing connections
with 6.1805.080 Tubing.
4Adjustment for gas flow
5Oven insert tube
contains sample boat with guide rod.
6Control panel
with display, keypad and status lamps.
7Temperature sensor
for measuring the sample temperature.
8Heating tube
with lateral shielding walls and guard grill.
9Outlet tubing
leads into titration vessel. 6.1805.070 Tubing or 6.1830.000
Heatable Outlet Tubing (option).

768 KF Oven 3
Rear
10 Tubing connection
with 6.1805.040 Tubing.
11 Contrast adjustment for the display
12 Dust filter
13 Connection for titrators
14 Connection for temperature sensor
plug the grey connector of the cable into the red socket of the
KF Oven!
15 Connection for outlet heating
16 RS232 interface
for connection of a printer or computer.
17 Model plate
with manufacturing, serial and instrument number.
Display of the set mains voltage, the mains frequency and the
power consumption. Before switching on for the first time,
check that the set mains voltage matches the voltage of your
power supply. If this is not the case, disconnect mains cable
and change over voltage, see page 43.
18 Power supply unit
with mains switch and mains connection.
With power supplies in which powerful HF disturbances are
superimposed on the mains voltage, the KF Oven should be
operated with an additional mains filter, e.g. METROHM model
615.

1.2 Operating principle
4768 KF Oven
1.2 Operating principle
Operating scheme:
Sample temp.
Heater glass
Air filter
Measurement of
Sample boat
Air pump
Valve
To KF titration cell
Moves
Drying flasks with molecular sieves
Magnet
Setting the
gas flow
the gas flow
Interior of the oven
sample boat
"PURGE"
"TRANSFER" Valve to
Valve to
Gas flow
If air is used as the carrier gas, work is carried out with the air pump built into the oven.
The pump draws in the air through the air filter.
If a different gas is used as carrier gas, this is introduced via the connection "Air/N2in".
The gas flow is set with the valve on the side of the oven and the gas led through the
drying flasks. The gas flow is measured immediately before entry into the insert tube.
If the valve is set to "PURGE", the gas flows out again through the opening "Purge". It is
thus led through the cold, front part of the insert tube.
If the valve is set to "TRANSFER", the gas flows through the entire insert tube, i.e. also
through the hot zone of the oven. The gas exits through the outlet at the end of the insert
tube and is led to the titration cell where the moisture of the sample is determined by
titration.
To Oven
From Oven
To Oven
Purge
Air/N2 in
Air out

2.1 Handling the sample boat
768 KF Oven 5
2. Operating conditions
2.1 Handling the sample boat
Sample boat and guide rod should always be handled using
the 6.2056.000 Holding Clamp to ensure the measurement
results are not falsified by skin moisture adhering to the
glass.
Always dry sample boat and guide rod well (hair dryer, dry-
ing oven) after cleaning. Store sample boats in a desiccator.
There is no need to clean the sample boat if the aluminum
inserts (order number 6.2623.000) are used (recommended
especially when the samples melt or decompose).
Inserting sample boat in the oven
Hold boat with clamp so that the eye of the boat fits in the
opening of the clamp.
Place boat in insert tube. The eye should protrude from
the tube.
Grip guide rod with the clamp. The two teeth of the clamp
should be at the bottom.
Engage guide rod in the eye of the boat and slide into in-
sert tube.
The boat can also be gripped with the guide rod and in-
serted in the oven as a unit "boat and guide rod".
Close insert tube with cover.
Start determination with <START>.
Removing sample boat from the oven
Open cover of the insert tube.
Grip guide rod with the clamp and withdraw until the end
of the sample boat protrudes sufficiently out of the insert
tube to be easily grasped by the clamp. Disengage guide
rod from the eye of the boat and put aside, e.g. on the
oven at the rear. Position so that the holding lug of the
guide rod projects over the oven edge and can be easily
gripped by the clamp.
Grip boat with clamp and take out.
Boat and guide rod can also be withdrawn from the oven
together.

2.2 Automatic sequence of a determination
768 KF Oven
6
2.2 Automatic sequence of a determination
The automatic sequence facilitates the work when a KF Titrator is attached. After the start,
all steps necessary for the determination are performed at the KF Oven.
After being switching on, the oven heats up to the set
temperature (when "auto preparation: on" is set in
<CONFIG>). Until the set temperature is reached, the
"READY" lamp flashes.
Once the set temperature is in the range of the start-
ing temperature, the "READY" lamp is on continu-
ously.
Set the desired gas flow (e.g. 100 mL/min). Set gas
flow when oven is hot!
Position the sample boat and the guide rod in the cold
part of the insert tube.
Start the sequence at the KF Oven with the <START>
key.
If a purge time has been entered, this is allowed to
elapse.
The valve switches from "PURGE" to "TRANSFER",
i.e. the gas is now led to the titration vessel.
If a conditioning time has been entered, this is al-
lowed to elapse.
The attached titrator is tested to see whether the ti-
tration vessel is conditioned (if "start if cond ok: on" is
set in <CONFIG>), the titrator is then started auto-
matically and the sample boat moved to the hot part
of the oven. The sample is heated, the evolved water
led to the titration vessel with the carrier gas and
there titrated.
On completion of the titration and if "valve control" is
ON, the valve is automatically set to "PURGE" and
the sample boat moved out of the hot part.
If "valve control" is OFF, the valve remains on
"TRANSFER".
When the set temperature has been reached, "READY"
lights up and the oven is ready for the next determina-
tion.
READY
READY
START
purge time 13 s
cond.time 5 s
VALVE
TRANSFER
VALVE
TRANSFER
VALVE
PURGE
READY

2.3 Settings on KF Oven
768 KF Oven 7
2.3 Settings on KF Oven
2.3.1 Keypad
Keys for individual manual functions
<HEATER> Switches heating off/on. The "HEATER" lamp lights up or
flashes when the heating is switched on. (The lamp is on
continuously when full heating power is used; it flashes with
reduced heating power.)
Note:
If the heating is switched off and if the valve is on
"TRANSFER", the solvent may be sucked back from the ti-
tration vessel.
<PUMP> Switches pump off/on. The "PUMP" lamp lights up when the
pump is switched on.
<VALVE> Switches valve. The "VALVE, PURGE" and "VALVE,
TRANSFER" lamps show the position of the valve. For
safety reasons, the valve is always set to "PURGE" at the
end of an automatic determination as well as on switching
off the Oven (suck-back of solution from the titration vessel!)
<BOAT IN> Inserts the sample boat in the hot part of the oven. The boat
continues to move until the key is pressed again or until the
boat reaches the inner stop.
<BOAT OUT> Withdraws the sample boat from the hot part of the oven.
The boat continues to move until the key is pressed again or
the boat reaches the outer stop.
<PRINT> Triggers report printout
Key sequence:
<PRINT><SELECT><ENTER>; press <SELECT> repeat-
edly until the desired report appears in the display
or
<PRINT><Key X><ENTER>; Key X = PARAM or CONFIG
7
HEATER
8 9
PUMP
4 5
VALVE
6
PUMP
1
BOAT IN
2 3
BOAT OUT
0
PRINT
.–QUIT ENTER PARAM START
SELECT CLEAR CONFIG STOP
TRANSFER
PURGE
HEATER
PUMP
VALVE
READY

2.3 Settings on KF Oven
768 KF Oven
8
Input and determination control keys
<SELECT> Used to select different input quantities. The ":" character
following the dialog text means that <SELECT> is used for
selection of the input quantities.
<SELECT> can also be used to select the contents of the
2nd display line: Switching from display of the gas flow to
messages, to display of the oven temperature.
<CLEAR> - Clearing of input values
- Sets special values, e.g. "off"
<QUIT> - Exits inquiries
- Aborts wait times
- Aborts report outputs
- Exits error messages
<ENTER> - Acceptance of input values
- Conclusion of command sequences
Keys with rolling inquiries Repeat pressing of these keys leads to next inquiry (group).
<CONFIG> Configuration data, see page 9.
The inquiries are divided into groups. The titles of the inquiry
groups are marked with the ">" character. Entry into the in-
quiry groups with <ENTER>.
<PARAM> Parameters for the automatic determination, see page 11.
Keys for the automatic determination
<STOP> Stops the automatic determination.
<START> Starts the automatic determination. The start is possible only
when the "READY" lamp is continuously lit up, i.e. the cur-
rent temperature lies in the range of the starting tempera-
ture.

2.3 Settings on KF Oven
768 KF Oven 9
2.3.2 <CONFIG> key
>oven settings
auto preparation: OFF
valve control: ON
start if cond.ok: OFF
start temp.range 5 °C
temp.correcture 0 °C
send to: IBM
report: OFF
Inquiry group: General oven settings
Automatic preparation after switching on (ON, OFF)
"ON " means: Automatic heating to the sample tempera-
ture.
Valve control (ON, OFF)
"ON" means automatic switching of the valve from
"PURGE" to "TRANSFER" at the end of the determination.
With "OFF", the valve remains on "TRANSFER".
Start possible only when the attached titrator is condi-
tioned (ON, OFF)
"ON" means: The sample boat is not moved to the hot part
of the oven until the attached titrator is conditioned.
If no titrator is attached, "OFF" must be set.
Temperature range for starting (1...100 °C)
Starting the determination is only possible if the current
temperature is in the range of ±X °C from the sample
temperature.
Temperature correction (0...±99.9 °C)
Correction for sample temperature, see page 55.
Selection of the printer type/character set (Epson, Seiko,
Citizen, HP, IBM)
"Epson" for Epson Mode
"Seiko", e.g. for DPU-414
"Citizen", e.g. for i560 RS
"HP" for HP mode
"IBM" for all printers with IBM character set table 437, as
well as for data transmission to a computer or a data sys-
tem.
Report output at the end of the automatic determination
(OFF, ON)
Report example:
'fr
768 KF Oven 0D1/108 768.0010
run number 1
purge time 10 s
cond.time 5 s
smpl heating time 587 s
sample temp. 150 °C Set temperature
lowest temp. 147 °C During sample heating
highest temp. 150 °C During sample heating
gas type: air
gas flow 87 mL/min Mean gas flow
=============
The inquiries are divided into groups. The titles of the in-
quiry groups are marked with the ">" character. Entry into
the inquiry group with <ENTER>.
CONFIG

2.3 Settings on KF Oven
768 KF Oven
10
>auxiliaries
dialog: english
run number 0
auto start OFF
start delay 0 s
beeper 1
device label
program 768.0012
Inquiry group: Auxiliaries
Selection of the dialog language (english, deutsch, fran-
cais, español)
Current run number (0...9999)
The run number is set to 0 when the oven is switched on.
Automatic, internal apparatus start (1...9999, OFF)
Number of automatic starts.
Start delay (0...9999 s)
Delay time following the start before the automatic deter-
mination begins. The wait time can be aborted with
<QUIT>.
Audio signal (1...9, OFF)
Number of beeps when the oven is ready.
Device label for the individual identification of devices in
the device network (up to 8 ASCII characters)
Display of the program version
>RS232 settings
baud rate: 9600
data bit: 8
stop bit: 1
parity: none
handshake: Hws
RS control: ON
Inquiry group: RS settings
Baud rate (300, 600, 1200, 2400, 4800, 9600)
Data bits (7, 8)
Stop bits (1, 2)
Parity (even, odd, none)
Handshake (HWs, HWf, SWline, SWchar, none)
see also page 31 ff.
Control via RS232 interface (OFF, ON)
"OFF" means the receipt of commands and data via the
RS232 interface is blocked. Data output is possible.

2.3 Settings on KF Oven
768 KF Oven 11
2.3.3 <PARAM> key
temperature 50 °C
unit gas flow: mL/min
min.gas flow 5 mL/min
gas type: air
purge time 0 s
*live
cond.time 0 s
*live
Sample temperature (50...300°C)
Temperature to which the sample is heated.
Unit for display of the gas flow (mL/min, L/h)
All displays and entries for the gas flow depend on the
selected unit.
Minimum gas flow (0...999 mL/h or 0...59.9 L/h)
The automatic determination can be started only when the
set minimum gas flow has been reached.
Selection of the carrier gas type (air, N2, other) or selec-
tion of the gas for moisture determinations in gas
If "other" is selected, the factor for the gas flow measure-
ment must also be entered. The following values can be
used as a basis for the factor:
Ar 1.456 Air 1.000
CH40.717 N20.999
CO20.738 N2O0.666
Natural gas 0.681 O20.992
He 1.456 Propane 0.357
Purge time (0...99 999 s)
Wait time before the heating time, i.e. before the boat is
slid into the oven. The valve remains on "PURGE".
The wait time can be aborted with <QUIT>.
The purge time should be used only when the cold sample
evolves moisture with difficulty.
Conditioning time (0...99 999 s)
Wait time before the sample heating, i.e. before the boat
is slid into the oven. The valve is switched to
"TRANSFER".
The wait time can be aborted with <QUIT>.
The conditioning time should be used only when the cold
sample evolves moisture with difficulty.
Contains the parameters for the automatic determina-
tion. *live means: These parameters can be edited
during the automatic determination.
PARAM

2.3 Settings on KF Oven
768 KF Oven
12
2.3.4 Special settings
>lock
<configuration> OFF
<parameters> OFF
<heater> OFF
<pump> OFF
<valve> OFF
<boat> OFF
Locking keys
Key <CONFIG> (ON, OFF)
Key <PARAM> (ON, OFF)
Key <HEATER> (ON, OFF)
Key <PUMP> (ON, OFF)
Key <VALVE> (ON, OFF)
Key <BOAT IN> and <BOAT OUT> (ON, OFF)
>T controller
init.heat.factor 100 %
add.heat.factor 100 %
Factors for T controller of Oven
The controller is optimized, therefore it normally isn't nec-
essary to change the following factors.
Initial heating factor (0...200 %)
Operative after the sample has been moved into the Oven.
Set a lower value if the temperature is below the nominal
temperature, and much above afterwards.
Additional heating factor (0...200 %)
After the initial heating, the heating is controlled by meas-
urements.
Set a greater value if the temperature is not reached dur-
ing too long a time. In this case, a higher "init.heat.factor"
may also help.
Switch the Oven OFF. Press key <CONFIG>, keep key
pressed and switch the Oven ON again.
CONFIG +Switching ON

2.4 Practical tips
768 KF Oven 13
2.4 Practical tips
Sample introduction via top opening of the insert tube
This possibility can be used if several samples can be
heated in succession in the same sample boat.
Add samples to sample boat with a syringe or open screw
cover.
Selection of the carrier gas
N2should always be used as the carrier gas when the hot
sample is sensitive to air or oxygen and evolves substances
which interfere with the KF reaction.
Temperature setting
Select temperature as high as the sample allows (high tem-
perature = shorter analysis time): The sample must evolve no
oxidizable substances except water.
Extraction time
An extraction time of ca. 2 min should be set on the attached
titrator to prevent the titration being aborted before the sample
evolves water.
Conditioning system
To condition the entire system (without sample boat and without
sample) before the start, the valve can be set to "TRANSFER"
at the KF Oven.
References
- Hydranal ® Practical Course, Riedel-deHaën, 1987
- G. Wieland, Karl Fischer Titration, GIT Verlag, Darmstadt,
1985
- Following Metrohm Application Bulletins (available free of
charge):
No. 109 KF water determination with the KF Drying Oven
No. 145 Determination of low water contents in plastics
No. 217 KF water determinations in pharmaceutical prepara-
tions by the KF oven method.

2.4 Practical tips
768 KF Oven
14

3.1 General rules
768 KF Oven 15
3. Operation via RS232 interface
3.1 General rules
The 768 KF Oven has an extensive remote control facility that allows full control via the
RS232 interface, i.e. the instrument can receive data from an external controller or it can
send data to an external controller. CRand LFare used as terminators for the data transfer.
The 768 KF Oven sends 2xCRand LFas termination of a data block, to differentiate
between a data line which has CR and LFas terminator. The controller terminates its
commands with CR and LF. If the controller sends more than one command per line, the
character ';' is used as separator between the commands.
The commands are grouped logically and are simple to understand. Thus, e.g. for the
selection of the dialog language the command
&Config.Aux.Language ”english”
must be sent, but only the boldface characters need be inputted, thus
&C.A.L "english" .
The data groups of this order are:
Config Entries for the configuration
Aux Auxiliaries, various subjects
Language Dialog language
The commands have a hierarchial structure (tree structure). The quantities that appear in
this tree are called objects in what follows. The dialog language is an object that is called up
with the command &Config.Aux.Language ”english”
If one is at the desired location in the tree, the value of the appropriate object can be
queried:
&Config.Aux.Language ”english” $Q Q for Query
$Q triggers the output of the value from the 768 KF Oven. Entries that are introduced with
the character dollar ($) trigger something. They are thus called triggers in what follows.
Values of objects can not only be requested, however, they can also be modified. Values are
always entered in quotation marks (”), e.g.
&Config.Aux.Language ”english”

3.1 General rules3.1 General rules
768 KF Oven
16
3.1.1 Call up of objects
All objects are grouped hierarchically. They have a tree structure. A section of this tree is shown
below:
Language Prog
Aux
Config
&
Root
RSSet
Mode
3rd node
2nd node
1st node
0st node
Rules Example
The root of the tree is designated with &.
For the call up of an object the nodes (levels)
of the tree are marked with a point (.).
The call up of the objects requires as many
letters as necessary to ensure unequivocal the
object. If the call is not unequivocal, the first
object in the series is recognized.
Call up of dialog language:
&Config.Aux.Language
or &C.A.L
Upper or lowercase letters can be used. &C.A.L
or &c.a.l
An object can be assigned a value. Each value
is marked at the beginning and end with
quotation marks ("). A value can contain up to
24 characters. Numeric values can include up
to 6 digits, a negative sign and a decimal point.
Numbers with more than 6 digits will not be
accepted; more than 4 decimal places are
rounded off. With numbers <1, it is necessary
to enter leading zeros.
Input of dialog language:
&C.A.L"english"
Correct entry of a number:
"0.1"
Incorrect entry:
"1,5" or "+3" or ".1"
If a new object is not called up, the old object
remains current. Input of a different dialog language:
"deutsch"
New objects can also be addressed relative to
old objects: A preceding point moves one
node forwards in the tree.
From the root to node 'Aux':
&C.A
From node 'Aux' to 'Prog':
.P
More than one preceding point moves one
node backwards in the tree. n nodes
backwards require n + 1 preceding points.
Jump from node 'Prog' to node 'Aux' and
selection of a new object at this node:
..L
If a jump is to be made back to the root, a
preceeding & is entered. Jump from node 'Language' via root to the node 'Mode':
&M

3.1 General rules
768 KF Oven 17
3.1.2 Triggers
Triggers initiate an action at the KF Oven, e.g. starting of a mode or sending of data.
Triggers are marked with the introducer: $
The following triggers are possible:
$G Go: Starts operations, e.g. start of the automatic determination or setting
of the RS232 interface parameters
$S Stop: Stops operations
$Q Query: Used for inquiry of all information from the current node in the tree
upwards up to and including the values
$Q.P Path: Used for inquiry of the path from the root of the tree up to the current
node
$Q.H Highest index:Used for inquiry of the number of son nodes of the current node
$Q.N”i” Name: Used for inquiry of the name of the son node with index i, i = 1...n
$D Detailed Info: Used for inquiry of the detailed status
$U qUit: Used to abort the data flow of the 768 KF Oven, e.g. after $Q
The triggers $ G and $S are linked to objects, see overview table, pages 20ff.
The other triggers, however, can be used at any time and at all locations on the object tree.
Examples:
Inquiry of baud rate: &Config.RSSet.Baud $Q
Inquiry of all values of the node RSSet: &Config.RSSet $Q
Inquiry of the path of node RSSet: &Config.RSSet $Q.P
Starting a mode: &Mode $G
Inquiry of the detailed status: $D