Buchi B-820 User manual

1
BÜCHI Fat Determination B-820/B-821 Contents
Contents
5 Operation 28
5.1 Control, operating and display elements 28
5.2 Operating the unit 31
5.2.1 User configuration 34
5.2.2 Printer configuration 35
5.2.3 System configuration 36
5.2.4 Autosampler configuration 37
5.2.5 Preheating/Separation column conditioning 38
5.2.6 Gas flow rate setup 39
5.2.7 Sample weight and mode adjustment 43
5.2.8 Determination 45
5.2.9 Data output 49
5.2.10 Statistics 51
5.2.11 Clearing data 54
6 Maintenance 55
6.1 Control checks 55
6.2 Replacing the septum in the injection head 55
6.3 Cleaning the FID 56
6.4 Replacing the ignition coil 56
6.5 Checking the formic acid 57
6.6 Installing a new separation column 57
6.7 Changing the printer paper roll 57
6.8 Changing the ribbon 58
6.9 Checking for fractures and cracks 58
6.10 Customer service 58
6.11 Maintenance of the Autosampler 59
6.11.1 General 59
6.11.2 Syringe and syringe needle 59
6.11.3 Replacing the main power fuse 59
7 Taking out of operation 60
7.1 Switching off the unit 60
7.2 Storage/Transport 60
7.3 Disposal 60
8 Replacement parts 61
9 Appendix 62
9.1 Technical data 62
9.2 Error messages 63
9.3 Materials used 64
9.4 FCC requirements (for USA and Canada) 65
9.5 Declaration of conformity 66
1 Scope of delivery 3
2 Safety 7
2.1 Symbols 7
2.2 Requirements for the customer 7
2.3 Proper use 7
2.4 Improper use 8
2.5 General hazards 8
2.6 Safety measures 9
2.7 Handling of gas cylinders in the laboratory 10
2.8 Modifications 10
2.9 Responsibility of the operator 10
3 Function 11
3.1 Operational principles 12
3.2 System description Autosampler B-821 14
3.2.1 Introduction 14
3.2.2 Carousel support 14
3.2.3 Carousel 14
3.2.4 Turntable 14
4 Putting into operation 15
4.1 Accessories 15
4.2 Location of unit 15
4.3 Power connections 16
4.4 Connecting periphery devices 16
4.5 Filling the formic acid 18
4.6 Gas connections 18
4.7 Checking supply lines for leaks 20
4.8 Installing the separation column 21
4.9 Setting the correct gas flow rate 22
4.10 FID ignition 22
4.11 Installation of Autosampler B-821 22
4.11.1 Unpacking and inspection 22
4.11.2 Retrofitting a manual basic system with
an Autosampler 23
4.11.3 Installing the mounting plate 23
4.11.4 Mounting the Autosampler on the B-820 unit 23
4.11.5 Removing the transportation belt 23
4.11.6 Installing the syringe/needle assembly 24
4.11.7 Connecting the signal cable to the B-820 unit 24
4.11.8 Connecting power to the Autosampler B-821 24
4.11.9 Aligning the syringe needle with the injection
head of the B-820 unit 25
4.11.10 Connecting the pneumatics to the Autosampler 26
4.11.11 Installing the solvent reservoir bracket 26
4.11.12 Routing and securing the solvent lines and
the waste line 26
en, Version H (66 pages) Order no.
B-820/B-821 Instructions 96571

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BÜCHI Fat Determination B-820/B-821
Please read these instructions thoroughly
before using the Fat Determination Unit
B-820/B-821. These instructions should
be kept near the unit for general reference.
Section 2 contains important notes on safety,
which must be observed if the Fat Determi-
nation Unit is to be operated safely.
Due to continuous improvement and updating, technical spe-
cifications may be altered without prior notice. No part of this
document may be reproduced, copied or transmitted in any
way nor by using electronic or optical systems without prior
agreement and written permission of Büchi Labortechnik AG.
All rights reserved. © Büchi Labortechnik AG, 1996, 1999

3
BÜCHI Fat Determination B-820/B-821
1 Scope of delivery
1 Scope of delivery
Figure 1: Complete view of B-820/B-821 Figure 2: Complete view of B-820, Manual
Manual basic system
incl. individual
Version B-815 B-820 B-821 Total fat order no. fatty acids order no.
230V 230V 230V - 36925 37628
200V 120V 200V - 37109 37627
120V 120V 230V - 36924 37626
Automatic basic system
incl. individual
Version B-815 B-820 B-821 Total fat order no. fatty acids order no.
230V 230V 230V 230V 36923 37631
200V 120V 200V 230V 37108 37630
120V 120V 230V 230V 36922 37629
System prepared for Autosampler
incl. individual
Version B-815 B-820 B-821 Total fat order no. fatty acids order no.
230V 230V 230V - 37601 37634
200V 120V 200V - 37602 37633
120V 120V 230V - 37603 37632
Autosampler Retrofit 36926
Retrofit Fatty Acids manual 37635
Retrofit Fatty Acids automatic 37636
Table 1: Appliance models

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BÜCHI Fat Determination B-820/B-821
Figure 3: Accessories
햳햲햴햵 햶햹햺
햷햻햾햿햸
1 Scope of delivery
Accessories Manual Basic System
Accessories B-815 (refer to Manual B-815)
Accessories B-820 Manual (refer to Table 2)
Accessories Automatic Basic System
Accessories B-815 (refer to Manual B-815)
Accessories B-820 Automatic (refer to Table 3)
Accessories Autosampler B-821 (refer to Table 4)
Accessories Autosampler Retrofit
Accessories Autosampler B-821 (refer to Table 4)
Accessories retrofit kit (refer to Table 5)
EPROM Set B-821
Accessories Individual Fatty Acids
Separation Column Fatty Acids 37620
Calibration Set Fatty Acids 37622
EPROM Set manual or automatic
Accessories B-820 Manual
1 Soap bubble meter, compl. 햶34878
1 Separation column "Total Fat" 햻34916
1 Supply line H2햳36134
1 Supply line Air 햲36135
1 Syringe 10µl 햾34258
1 High temperature septum (50 off) 햿34382
4 Vespel seals 햹34229
2 Threaded column joints 1/4" 햸34228
2 Fork spanners w.a. flats 8 햵16522
1 Fork spanner w.a. flats 17 x 19 햴19831
1 Power cable (PNE, 2.5 m)
available in the following versions: 햷
Type CH 10010
Type Grounded (shock-proof) 10016
Type GB 17835
Type AUS 17836
Type USA, 230 V 33763
1 Instruction manual available in the following languages:
German 96570
English 96571
French 96572
Italian 96573
Spanish 96574
1 Packaging 34560
Table 2: Accessories B-820 Manual

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BÜCHI Fat Determination B-820/B-821
Accessories B-820 Automatic
1 Soap bubble meter, compl. 햶34878
1 Seperation column "Total Fat" 햻34916
1 Supply line H2햳36134
1 Supply line Air 햲36135
1 High temperature septum (50 pcs) 햿34382
4 Vespel seals 햹34229
2 Threaded column joints 1/4" 햸34228
2 Fork spanners w.a. flats 8 햵16522
1 Fork spanner w.a. flats 17 x 19 햴19831
1 T piece D1/8“ 36845
1 Jumper cord W VDE 30983
1 Power cable (PNE, 2.5 m)
available in the following versions 햷
Type CH 10010
Type Grounded (shock-proof) 10016
Type GB 17835
Type AUS 17836
Type USA, 230 V 33763
1 Instruction manual
available in the following languages:
German 96570
English 96571
French 96572
Italian 96573
Spanish 96574
1 Packaging 34560
Table 3: Accessories B-820 Automatic
1 Scope of delivery

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BÜCHI Fat Determination B-820/B-821
Accessories B-821 Automatic
1 Septum *
1 Cylinder (reservoir) holder *
2 Glass cylinders for rinsing solvent and
waste 37069
1 Carousel 37085
1 Serial number label for carousel 37103
1 Mounting plate *
1 Sample vessel 2ml, compl. (100 ) 37068
4 Washers 16 mm *
2 Fuses 240V, 0.2A *
1 Fuse 250V, 0.5A *
1 Hamilton syringe 37066
1 Needle for Hamilton syringe 37067
1 Tubing PUR 1/8“ L = 3000 *
1 Foam rubber of neoprene length 100mm *
Table 4: Accessories Autosampler B-821
* Compare with spare parts list of the original operating instructions for
the 8200 CX.
Accessories Retrofit Kit
1 Cover for Autosampler 36758
1 Plate for Autosampler 36726
4 Spacers 36727
1 FID cap 34124
1 T piece D1/8“ 36845
2 LZS-K M4*10 10355
3 LZS-K M3*6 20390
3 FAE-SCH M3 10717
3 U-SCH M3 10571
4 SS-K M4*10 20909
1 Jumper cord W VDE 30983
5 Cable binders 2.6*200MM WS 03572
1 LZS-K M5*10 19645
Table 5: Accessories retrofit kit
1 Scope of delivery

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BÜCHI Fat Determination B-820/B-821
2 Safety
This unit has been built in accordance with the state of
engineering and the recognized rules of safety.
Nevertheless, it can still be a source of risks and hazards:
• if used by persons with insufficient training
• if used for purposes other than that for which it is intended.
2.1 Symbols
Stop
Information about hazards which can lead to serious material
damage or cause serious or potentially fatal injury.
Warning
Information about hazards which can be harmful to the user’s
health or lead to material damage.
Please note
Information about technical requirements which if not observed
can lead to malfunctions, inefficiency and production loss.
2.2 Requirements for the customer
The device must only be operated by persons who have the
training or professional experience to comprehend the hazards
that can arise when using the unit.
Personnel without such training or persons currently under-
going a course of training should be trained thoroughly. This
Instruction Manual should be the basis for this training.
2.3 Proper use
The unit is designed and built for use in laboratories. It is intended
to be used for determining the fat content based on fatty
acids or the butyric acid. Its function depends on the Büchi
Extraction Unit B-815: Some microliters of the upper extracted
phase which contains the fatty acids and the internal standard
are injected either manually into the Fat Determination Unit
B-820, or automatically into the Fat Determination Unit with
Autosampler B-821. The detection occurs with a flame
ionization detector (FID). The subsequent evaluation is made
by integrating the total peak areas.
Only original Büchi replacement parts and accessories may
be used. Any modifications to the device or accessories shall
be permitted only upon consultation with and obtaining a
written authorization from the manufacturer.
2 Safety

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BÜCHI Fat Determination B-820/B-821 2 Safety
2.4 Improper use
Any use other than those already listed, and any application
that does not conform with the technical data is deemed to
be improper use. The customer shall bear sole responsibility
for any damage resulting from improper use.
Use of this instrument is strictly prohibited in:
• explosion-proof environments,
• rooms where gas cylinders cannot be stored.
2.5 General hazards
General hazards arise from:
• covering the ventilation slots
• an insufficient distance from the back of the unit to the
wall (see Section 4 "Putting into operation“).
• touching the injection head and the FID (risk of burning).
• improper storage of gas cylinders.
• inadequate installation of connections to gas cylinders.
Apart from authorized maintenance personnel, no one is
allowed to remove any safety devices and covers.
Touching live parts may result in fatal injury!
Electrical danger
Before connecting the unit to power make sure that the opera-
ting voltage shown on the serial plate agrees with the mains
voltage.
The power plug may only be inserted into a socket
with grounded contact. Its protective effect may not
be suppressed by an extension line not having a
ground wire.
Warning:
a) Any interruption of the ground wire inside or outside of the
unit or a disconnection of the ground wire may cause
potential problems. Deliberate tampering is prohibited.
b) When opening covers or removing parts, unless this can
be done by hand, live parts may be exposed. Bear in mind
that connecting parts may also be live.

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BÜCHI Fat Determination B-820/B-821
c) Before an alignment, maintenance, repair or replacement
of parts, the unit must be disconnected from all sources of
electric current, whenever it becomes necessary to open
the unit.
If any of the services above must be performed on a powered
on unit, it should only be done by a specialist who is famlilar
with the dangers involved.
d) It should be ensured that only fuses of the type and rated
amperage as indicated are used for replacement. The use
of repaired fuses or short-circuiting the fuse block is
prohibited.
e) If an operation free from danger cannot be ensured, the
unit must be put out of operation and protected from any
unauthorized use.
It can be assumed that an operation free from danger cannot
be ensured any more if:
• the unit shows visible damages,
• the unit does not work any more,
• after long-term storage under inadequate circumstances,
• after having been exposed to considerable strain during
transport.
2.6 Safety measures
The steel lines for hydrogen and synthetic air supplied with
the equipment have different connections to the unit preventing
improper connections.
Please make sure that connections at reduction valves are
correct.
If, due to a lack of gas pressure in the system, the electronic
valves will close preventing any hydrogen or synthetic air leaks.
Personal protective garments must be worn, such as goggles,
gloves and a laboratory coat.
The Instruction Manual is a component of the Fat Determi-
nation Unit B-820/B-821 and should remain with the unit for
easy reference by any user. This also applies to the additional
language variants of these instructions, which can be ordered
separately.
2 Safety

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BÜCHI Fat Determination B-820/B-821
2.7 Handling of gas cylinders in the laboratory
Gas cylinders should be handled according to the pertinent
local regulations and provisions. The following are general
safety measures.
1. Protect gas cylinders from excessive heat, mechanical
damage and corrosive substances.
2. Gas cylinders should not be stored or connected in areas
with a major risk of fire.
3. Gas cylinders should be easily accessible at all times.
4. Full and empty gas cylinders should be stored separately
according to the type of gas.
5. Gas cylinders should only be stored and transported with
the protective cap screwed on.
6. Gas cylinders should be protected from falling down and
rolling away.
7. In case of leak and fire: Close cylinder valves immediately.
Cool any overheated cylinder with plenty of water.
8. Only keep as many replacement cylinders in the laboratory
as are necessary for continuous operation.
9. Open cylinder valves slowly.
10. Cylinder valves must neither be oiled nor greased.
11. Close cylinder valves when switching the unit off.
12. Close valves of empty cylinders.
2.8 Modifications
Modifications on the unit or on replacement parts or accessories
as well as the use of any other replacement parts or
accessories as those indicated in this Manual are only permitted
after consulting with Büchi Labortechnik AG and obtaining
written consent.
2.9 Responsibility of the operator
The operator is responsible for instructing personnel. For
manuals in other languages refer to Table 2, Section 1.
The operator should inform the manufacturer about events
relevant to safety which occur with operating the Fat Determi-
nation Unit.
2 Safety

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BÜCHI Fat Determination B-820/B-821
3 Function
The Fat Determination Unit B-820, which can be completed
with the Autosampler B-821 (refer to Figure 5) is an instrument
which determines total fat on the basis of fatty acids or individual
fatty acids in organic matrices using a gas-chromatographic
technique.
It is designed to function with the Büchi Extraction Unit B-
815. The temperature program and the evaluation function
are preprogrammed and have an extremely short analysis
run time, enabling the user to carry out the fat determination
process quickly and easily. The appliance is not a universal
gas-chromatograph.
3 Function
Figure 5: Fat Determination Unit B-820, Automatic
Figure 4: Fat Determination Unit B-820, Manual

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BÜCHI Fat Determination B-820/B-821
3 Function
3.1 Operational principles
Figure 6: Diagram
햲햳
햴 햵
햷
햶
헀햿
햸
햾
햹
햽
햺
햻
헁
헂
햲Synthetic air
햳Hydrogen (percentage purity 5.0)
햴Pressure reducing valve for synthetic air
햵Pressure reducing valve for hydrogen
햶Electronic valve for synthetic air
햷Electronic valve for hydrogen
햸Damping tube for synthetic air
햹Damping tube for hydrogen
햺Absorption tube
햻Gas saturation vessel (formic acid 85 %)
햽Forced-air oven
햾Separation column
햿Injection head
헀Flame ionization detector (FID)
헁Electronic
헂Output
Main principle
1. Switch on the unit (the switch is located on the back of
the unit). Perform the input steps as described in Section
5 «Operation».
2. Using a syringe, extract some solution from the upper phase
of the extracted and saponified sample (see operating in-
structions for Extraction Unit B-815) and inject into the Fat
Determination Unit.
3. A temperature program is performed automatically accor-
ding to the selected method. The fatty acids are separated
from the solvent and internal standard and detected by
the flame ionization detector.
4. An evaluation program, specifically developed for this unit,
calculates the content of total fat of individual fatty acids.

13
BÜCHI Fat Determination B-820/B-821 3 Function
Depending on the determination parameters, nine different
determination modes can be selected:
Mode Abbreviat. Description
Factor General Fact.gen Determines the factor that will be necessary for the determination of the
total fat content.
General correction Gen.corr. Determines the fat content of all products. It will still determine milk or
dairy products though, but it is not appropriate for products with a
significant butyric acid content. In this case use "Spec.corr."
Special correction Spec.corr. Determines the fat content for milk or dairy products, or products with a
significant butyric acid content.
Blank value for butyric acid Bl.butyr. Determines the blank value for the butyric acid determination.
Butyric acid factor Fact.b.a. Determines the factor that will be necessary for the determination of the
butyric acid content.
Butyric acid But.acid Simultaneous determination of the butyric acid content, the milk fat
content (optional), and the overall fat content (optional) in all products.
Fatty acid calibration FA-calib. Determines the retention period for six saturated fatty acids (calibration
set “Fatty Acids”).
Fatty acid factor FA-factor Determines the factor that will be necessary for the determination of the
fatty acids
Fatty acids FA-det. Identification and determination of the contents of the individual fatty
acids and calculation of the sum parameter of the saturated, mono-
and polyunsaturated fatty acids in all products.
Table 6: Overview of the determination modes
Application Column (Order No.) Start temperature /Analysis time Mode
Total fat 34916 130 °C / 8 min. Gen.fact.
130 °C / 8 min. Gen.corr.
90 °C / 10 min. Spec.corr.
90 °C / 10 min. Butyr.con.
Butyric acid 34916 90 °C / 10 min. Bl.butyr.
90 °C / 10 min. Butyr.fact.
90 °C / 10 min. Butyr.con.
Individual fatty acids 37620 150 °C / 41 min. FA-calib.
150 °C / 41 min. FA-fact.
150 °C / 41 min. FA-det.
Table 7: Overview of the determination parameters
The analysis time is calculated from the start of the determi-
nation to the re-start of the next determination. The analysis
time therefore contains the following time sectors:
•Separation time for the separation of the fatty acids
•Preheating of the separation column at 260 °C at the end
of the separation
•Conditioning of the column for the next analysis depending
on the mode of determination.

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BÜCHI Fat Determination B-820/B-821
3.2 System description Autosampler B-821
3.2.1 Introduction
The Autosampler is comprised of essentially three modules:
the storage module, the injection tower module, and the pneu-
matics module. It is mounted on the Büchi Fat Determination
Unit B-820 above the injection head. The Autosampler is
operated through the keypad of the B-820.
The Autosampler is powered through the B-820 via a
connection cable. The power entry module as well as the
power on/off switch and the voltage selector module are
located at the rear of the Autosampler. If you want to connect
the Autosampler directly to the mains, you can adjust voltages
of 100, 120, 230, and 240 Volts and frequencies of 50/60 Hz
at the voltage selector module. Refer to paragraph 4.11.8
(Mains voltage connection to Autosampler B-821) to adjust
your own country’s voltage.
햲Turntable
햳Pneumatics module
햴Power on/off switch
햵Power entry module
햶Carousel support
햷Carousel
햸Injection tower module
3.2.2 Carousel support
The carrousel support comprises a carousel, a position sensor,
a vial sensor, and the turntable. It is secured to a rotating
hinge on the injection tower. An indicator (LED) is located on
the front side of the carousel support; the LED lights when
the unit is ON.
3.2.3 Carousel
The carousel can hold up to forty-eight sampling vials of
2 ml. It may be removed for placing the vials. The serial number
label which is lettered from 1 through 48 may be glued on the
carousel. A small raised indicator at the center knob marks
the correct position.
3.2.4 Turntable
The turntable is driven by two motors, one to rotate the turn-
table (clockwise) and another to move the turntable forward
or backward.
The carousel mounts on the turntable and is fixed by a vertical
pin.
Figure 7: Autosampler B-821
3 Function
햲
햳
햴
햵
햶
햷
햸

15
BÜCHI Fat Determination B-820/B-821
4 Putting into operation
Unpacking and checking the B-820 unit
Open the carton carefully in order to avoid breaking the glass
of the enclosed separation column, soap bubble meter and
syringe. Unpack the unit with care and check for any possible
damage. It is important that any damage incurred during transit
is determined and reported immediately. If this is the case, a
full statement of facts must be immediately reported to the
shipping agent.
Autosampler B-821
For unpacking and checking refer to Section 4.11.1.
It is advisable to keep the packaging for future transport.
4.1 Accessories
The following accessories necessary to operate the unit are
not included in delivery and cannot be ordered from the manu-
facturer:
• Hydrogen (percentage purity 5.0, gas cylinder or central
supply)
• Synthetic air (gas cylinder or central supply)
• 2 pressure reducing valves for gas cylinders
• Two G 1/8” connections to the reducing valves
(oxygen and synthetic air)
• Formic acid (85%)
• Stopwatch
• Soap solution
• When using the Autosampler: n-butanol (pure) (for rinsing
the syringe)
4.2 Location of unit
The unit must only be operated in ventilated rooms (window
or artificial ventilation). It must be installed on a stable, clean
and even surface.
For safety reasons and to ensure sufficient cooling of the oven,
the back and side walls of the unit must be placed at least
13 cm (5.2 inch) away from the walls or any other object.
No containers or chemicals should be placed behind the unit
(due to outflow of the hot air).
4 Putting into operation

16
BÜCHI Fat Determination B-820/B-821
4.3 Power connections
Check that the voltage of the socket is identical to the voltage
specified on the serial plate. Only connect the unit to a plug
which is grounded. External couplings and extension cables
must be grounded (3-contact couplings, cables and connec-
tors). The ground wire must not be tampered with in any way.
Risks caused by possible internal defects are thus prevented.
Check the frequency of the power supply and adjust the unit
accordingly (see Section 5.2.3, "System configuration“).
4.4 Connecting periphery devices
The unit has three serial and one parallel interface (RS-232C).
This enables connection of a computer, a balance, an external
printer and the Autosampler B-821 to the rear of the unit.
If a balance or printer is connected, the proper balance or
printer type must be entered in the initialization menu under
system configuration or printer configuration (see Section 5.2.3,
"System configuration" or Section 5.2.2, "Printer configura-
tion“).
PC
Any IBM or IBM compatible PC may be used for data output
to a PC. The computer connection cable is available as an
accessory (cable length: 10 meters):
B-820 Computer cable 29502
Balance
The following types can be connected:
Mettler: All AT balances, as well as AE types with
upgraded interface option 012 and hand key
or foot pedal.
Sartorius: All analytical balances of the type MC1 as well
as balances with interface MP8-4.
A&D: FR and HA series.
The interface parameters in B-820 are preset and cannot be
modified.
The balance parameters are as follows:
• 2400 baud
• even parity
•7bit
• 1 stop bit
• Software handshake
Figure 8: Connection of periphery devices to back of unit
4 Putting into operation

17
BÜCHI Fat Determination B-820/B-821
The balance connection cables are available as accessories
(cable length: 9 meters):
B-820 Mettler AE 30699
B-820 Mettler AT 30498
B-820 Sartorius 30760
B-820 A&D 30699
Please consult the balance operating instructions before
making adjustments!
Printer
The following printers can be connected*, whereby the printer
languages (PCL: Printer Control Language; LQ: Epson Emula-
tion) are supported:
• Epson
• Canon
• HP DeskJet
• HP LaserJet
* The following printers have been tested at Büchi:
• Epson Stylus Color 440
• Canon Bubble Jet BJC-600, BJ-200 EX (DIP switch
setting LQ)
• HP DeskJet 550C/690C
• HP LaserJet 4L
The printer connection cable is available as accessories (cable
length: 3 meters, type: Centronics):
B-820 Printer cable 30754
The B-820 supports the IBM character set. Please consult
printer operating instructions before making adjustments!
Autosampler B-821
Installation of the Autosampler is described in Section 4.11.
4 Putting into operation

18
BÜCHI Fat Determination B-820/B-821
Figure 9: Gas saturation bottle with formic acid, 85%
4.5 Filling the formic acid
A small gas saturation bottle is located at the back of the unit,
which must be filled with max. 20 ml of formic acid (85%). The
gas saturation bottle must always contain some formic acid
(85%); do not exced arms of vessel. In this way, it is ensured
that the hydrogen is saturated with formic acid vapor.
The gas saturation bottle must be kept tightly
closed in order to ensure that the hydrogen
system is hermetically sealed.
Caution: The bottle is under pressure
- Do not open when the B-820 is in opera-
tion/hot
- Do not fill up while the B-820 is in opera-
tion/hot
- Do not overfill, max. 20 ml or less 1 cm
below the vessel's arms!
- Only fill when the unit is turned off and is
at room temperature
- Filling under any other circumstances may
lead to system contamination!
4.6 Gas connections
Gases used:
Gas function Gas type Setting pressure
Combustible + hydrogen 5.0 5 bar (72.5 psi)
separating gas
Auxiliary gas synthetic air 5 bar (72.5 psi)
Autosampler synthetic air 5 bar (72.5 psi)
Operating gas
Only use synthetic air, and not compressor air generated and
filtered on-site.
General
Synthetic air and hydrogen from gas cylinders must be equipp-
ed with a two-stage pressure reducing valve. The exit ports of
this valve should be threaded. To enable a precise adjustment
of the output pressures, use a pressure reducing valve with a
measuring capacity of 0 to 10 bar (0 to 150 psi). The output
pressures at the valves to the B-820 unit should be 5.0 bar
(72.5 psi) both for synthetic air and for hydrogen.
4 Putting into operation
Newer instrument models
see mark "-MAX-"

19
BÜCHI Fat Determination B-820/B-821 4 Putting into operation
Gas supply connection to the B-820
1/8” copper capillaries 햴with pre-fitted quick-lock couplings
are included in the delivery. To connect the gas supply, the
quick-lock couplings are fitted to the corresponding couplings
(labelled with “H2” and “Synth. Air”) on the back of the B-820.
(See Figure 10: Gas connection layout, Page 19)
Ensure the correct connection of the gas cylinder to the unit.
The following are included in the Büchi delivery:
H2connection 햲inc. copper capillary 36134
Air connection 햳inc. copper capillary 36135
To be supplier by the user:
햵Hydrogen 5.0
햶Synthetic air
햷Cylinder pressure 햸pressure reducing valve (two-
햹Required pilot pressure stage) for hydrogen and syn-
thetic air in the range from
0-10 bar ( 0-150 psig)
햺Connecting parts to the pressure reducing valve
Figure 10: Gas connection layout
}

20
BÜCHI Fat Determination B-820/B-821 4 Putting into operation
4.7 Checking supply lines for leaks
After connecting the pressure lines to the unit, open both cyl-
inder valves before switching on the unit, and then close them
again once the pressure is achieved. The pressure indicator
on the pressure reducing valve should remain constant for
approx. 10 minutes. The cylinder valves can be reopened
once this check is completed.
The primary pressure, the tightness of the supply lines and
the gas flow (see Section 4.9, "Setting the correct gas flow
rate“) must be rechecked every time a gas cylinder is changed.
Check the separation column for possible fractures and cracks
before each use. The unit must not be operated if the
separation column is damaged (hydrogen leak).