774 Oven Sample Processor
Revolutionary automation of Karl Fischer water determinations right down
to the trace level.
Karl Fischer instruments
Methodological and economic advantages
A new concept opens up attractive
applications
With the 774 Oven Sample Processor
Metrohm presents a revolutionary new
sample changer. It allows the application
of the KF oven method to a series of liquid
or solid samples. Combined with a coulometric or volumetric KF titrator, the Oven
Sample Processor forms the ideal analysis
system for the automatic determination of
water in samples that contain interfering
components or release their moisture only
reluctantly. Typical examples are
• crude oil and oil products such as hydraulic oil, multigrade oil or used motor
oil as well as
• organic amines, toners, plastics, pharmaceuticals, foodstuffs and freeze-dried
products (lyophilisates).
Convincing advantages
Compared with a conventional KF drying
oven the 774 Oven Sample Processor offers
many advantages:
• The automation of the water determination means a considerably increased
sample throughput and increased efficiency.
The new 774 Oven Sample Processor with the 756 KF Coulometer.
• Considerable savings in time.
• Manual sample preparation is reduced
to a minimum.
• No contamination of the oven and titration cell; this means that there are no
carryover or memory effects.
• Identical and reproducible analysis conditions for all samples; this is shown by
the considerably improved precision of
the results.
• Much lower reagent consumption as the
titration solution only requires changing
at infrequent intervals.
• Improved water release from the sample
as the carrier gas does not pass over the
sample but is led directly through it.
• The use of hermetically sealed sample
vessels means that the samples can be
transferred into the vials directly from
where they are taken. The PTFE-coated
septa guarantee a constant and unadulterated water content even after longer
storage periods.
Instead of a KF Coulometer a volumetric KF titrator can also be used for the water
determination; the new 784 KFP Titrino is shown here. The crimping tool in the foreground, a standard accessory, is used for sealing the sample vials.
2
774 Oven Sample Processor
Precise and fast results
Gaz inlet tube
Needle adapter made of PEEK
Heated transfer tube (outled heating)
Hollow needle with Luer connection (outlet)
Hollow needle (inlet)
Infrared sensors
Guide rod (adjustable)
Detail of the double needle system. The carrier gas takes up the
water released by the sample and is then led to the titration cell via
the heated transfer tube.
The 774 Oven Sample Processor’s tower is equipped with beaker
sensors based on infrared light for detecting whether a sample vial
is present.
Sophisticated construction
Refined methodology
The Oven Sample Processor is characterised by its extremely compact design. The oven heating block, gas
pump, solenoid valve, flow meter and flow controller as
well as a drying bottle are already built in. The turntable
accommodates 35 sample vessels plus one conditioning
vessel. If the «20 mm Headspace Vials» are used the
maximum sample volume is 7 mL. Airtight sealing of the
vials with PTFE-coated septa ensures that the samples
do not take up water from the ambient air.
The vial containing the sample to be analysed is moved
by the turntable to the appropriate position above the
oven and then lowered into the heating block. A double
hollow needle pierces the septum of the sample vessel. A stream of dry carrier gas (air or inert gas) is led
through the heated sample via the inlet needle, which
reaches down to the bottom of the vessel. The carrier
gas containing the released moisture flows through the
outlet needle and then through a heated transfer tube
directly into the titration cell, which is mounted on the
chassis of the 774 Oven Sample Processor together with
a 728 Magnetic Stirrer. Depending on the water content
of the sample, the subsequent KF water determination
can be carried out either volumetrically or, at the trace
level, coulometrically.
Simple sample preparation
Sample preparation could not be easier and consists
of weighing the sample into the sample vial, sealing it
with the crimping tool and then placing it in the rack of
the sample changer. Contaminating samples present
no problem as contamination is restricted to the particular sample vial. Neither the titration cell nor the oven
become contaminated; carryover effects therefore do
not occur. All samples are analysed under identical and
reproducible conditions, which ensures results of the
highest precision. Rapid and precise determination of
trace amounts of water in critical matrices – no problem
with the new 774 Oven Sample Processor.
774 Oven Sample Processor
3
774 Oven Sample Processor – overview
A nice specimen!
Lift
Gaz inlet tube
Air iinlet filter
Protective cover
Heatable transfer tube
Coulometric cell with generator and indicator
electrode
Doppelhohlnadel
728 Magnetic stirrer
Sample rack for 35 Sample vessels and
1 conditioning vessel
Durchflussregler
Inertgaseinlass
Anschlüsse für die Trockenflasche
Trockenflasche mit Molekularsieb
Plug cover
Oven with protective housing
4
774 Oven Sample Processor
774 Oven Sample Processor
5
Neue Massstäbe in Bedienung und Applikation
View of the heating block of the 774 Oven Sample Processor and the KF cell in which the coulometric water determination is carried out. Behind the splash guard the double needle system for the carrier gas inlet and outlet can be seen.
Flexible and user-friendly
Interesting application possibilities
The 774 Oven Sample Processor offers freely programmable processing sequences, a removable sample rack
and the flexible connection to various Metrohm instruments via the serial RS 232C interface or the «Remote»
interface. Standard methods for common applications
are preprogrammed in the instrument; this makes
routine work much easier. For more demanding applications these methods can be simply modified with
user-specific sequences and thus be adapted to the requirements of your analysis. Programming and entering
of commands are carried out conveniently in English,
German, French or Spanish via the separate keypad.
The 774 Oven Sample Processor thus provides the
optimal solution for both routine tasks and demanding
special applications.
The oven temperature can be programmed as required
in the range 50 ... 250 °C, the heating rate being up to 15
°C/min. An optimised determination procedure or even
a special temperature profile can be developed for each
sample and stored as a method. In this way it is possible
to heat up sensitive samples gently whereas thermally
stable, unproblematic substances can be heated to the
required temperature in a very short time.
Freely programmable, special temperature profiles offer,
for example, the possibility of recording the kinetics of
water release as a function of the temperature.
Combined with a Metrohm KF Coulometer or KF Titrator,
the Oven Sample Processor forms a powerful standalone analysis system for the automatic determination
of water according to the KF oven method. Connection
of a PC equipped with TiNet 2.4 or VESUV 3.0 Metrodata software opens up even more possibilities with
regard to the flexibility of the processes as well as for
documentation and data management.
6
774 Oven Sample Processor
Technical specifications of the 774 Oven Sample Processor
Oven
Temperatures
Temperature range
50…250 °C
Heating power
82 W
Heating rate (50…150 °C)
15 °C/min
Gas pump
Flow range (air)
0…300 mL/min
or 0…18 L/h
Nominal operating range
5...40 °C at 20…80%
relative humidity
Transport and storage
–20...+60 °C
60 °C
<50% relative humidity
50 °C
<85% relative humidity
40 °C
<95% relative humidity
Power connection
Display
LCD, 2 lines of 24 characters each, height 5 mm
Sample changer
Voltage
100...120 V, 220...240 V
Frequency
50...60 Hz
Power consumption
120 VA
Capacity
35 sample vessels plus
1 conditioning vessel
Sample vessels
als»
«20 mm Headspace Vi-
Design and testing in accordance with IEC 1010 / EN
61010 / UL 3101-1, safety class I
Dimensions (approx.)
Height 38,3 mm
Diameter 21,8 mm
Protection code IP 22
Seal
Septum cover consisting
of a PTFE-coated siliconrubber septum and an
aluminium crimp-cap
Sample volume
Maximum 7 mL
Materials
Sample changer housing
tiple
Metal housing with mulstove enamel
Keypad housing
Crastin (PBTB), inside
aluminium-coated
Keypad cover
Polyester, chemically
resistant
Safety specifications
Dimensions
Height
51 cm
Width
38 cm
Depth
55 cm
Weight (without accessories)
15,9 kg
Oven
Oven block
Aluminium
Cover
PTFE
Inner sleeve
Chromium steel
RS 232C data interface
For computer or printer connection
Programmable for communication with external devices
Remote-I/O-lines
Programmable parallel port for controlling external
devices
774 Oven Sample Processor
7
Ordering information, options
774 Oven Sample Processor
2.774.0010
774 Oven Sample Processor
Highly flexible instrument combining sample changer, oven and gas pump. Accommodates 35 sample
vessels («20 mm Headspace Vials») and one conditioning vessel. Programming and manual operation
via keypad equipped with a two-line LCD display. Extensive accessories including, e.g., crimping tool,
1000 sample vials and 1000 septum covers.
Options
Connecting cables
6.2141.020
Cable Remote 774 – Titrino or 756 KF Coulometer
6.2125.110
Cable RS 232C 774 – Titrino or 756 KF Coulometer
6.2125.060
Cable RS 232C 774 – PC (25 pins – 25 pins)
6.2125.110
Cable RS 232C 774 – PC (25 pins – 9 pins)
Consumables and additional items
6.2419.000
Sample vials («20 mm Headspace Vials»), 1000 pieces, total volume 9 mL, maximum sample volume
7 mL
6.1448.050
Septum covers, 1000 pieces, consisting of a PTFE-coated silicon-rubber septum and an aluminium
crimp-cap
2.728.0040
728 Magnetic Stirrer
6.2816.050
Inlet needle
Accessories for mounting the inlet needle at a higher position:
6.1808.040
Adapter, M6 exterior thread, M8 interior thread
6.1808.090
Adapter, M8 exterior thread, M6 interior thread
Subject to modifications
Printed byMetrohm Ltd., Herisau, Switzerland
11-1999-11 – 8.774.6003
8
774 Oven Sample Processor