Analytik Jena compEAct N User manual

Operating instructions
compEAct N
Nitrogen Analyzer

Analytik Jena AG
Konrad-Zuse-Str.1
07745 Jena Germany
Phone + 49 3641 77 70
Fax + 49 3641 77 9279
Email [e-mail]
Analytik Jena AG
Konrad-Zuse-Str. 1
07745 Jena Germany
Phone + 49 3641 77 7407
Fax + 49 3641 77 7449
Email [e-mail]
http://www.analytik-jena.com
compEAct is a trademark of Analytik Jena AG registered in Germany.
The identification with ® or TM is omitted in this manual.
11-0205-001-23
01.17
Analytik Jena AG
© Copyright 2017 Analytik Jena AG
Manufacturer
Service
General Information
Copyrights and
Trademarks
Documentation number
Edition
Technical documentation
made by:

compEAct N Contents
3
Contents
1Basic information............................................................................................................. 7
1.1 Notes on these operating instructions ........................................................................ 7
1.2 Intended use ............................................................................................................... 8
1.3 Warranty and liability.................................................................................................. 9
2Safety instructions ......................................................................................................... 10
2.1 General notes............................................................................................................ 10
2.2 Safety markings on the compEAct N......................................................................... 10
2.3 Requirements for the operating personnel ............................................................... 11
2.4 Safety instructions – Transport and commissioning ................................................. 11
2.5 Safety instructions for operation............................................................................... 12
2.5.1 General instructions.................................................................................................. 12
2.5.2 Safety instructions – Protection against explosion and fire ...................................... 12
2.5.3 Safety instructions – Electrical equipment ................................................................ 12
2.5.4 Safety instructions for compressed gas containers and systems ............................... 13
2.5.5 Handling of auxiliary and operating materials and samples..................................... 13
2.5.6 Safety instructions – Service and repair .................................................................... 14
2.5.7 Safety instructions for the operation with auto-injector AI and autosampler LS ...... 14
2.5.8 Behavior in case of overpressure faults (gas pressure faults) ................................... 15
2.6 Safety equipment / Behavior during emergencies.................................................... 15
3Function and layout of the compEAct N ...................................................................... 16
3.1 Principle of operation................................................................................................ 16
3.2 Design of the compEAct N......................................................................................... 17
3.3 Type plate ................................................................................................................. 24
3.4 Sample supply ........................................................................................................... 24
3.4.1 Auto-injector AI......................................................................................................... 24
3.4.2 Autosamplers LS 1 and LS 2...................................................................................... 25
4Installation and commissioning ................................................................................... 27
4.1 Installation conditions............................................................................................... 27
4.1.1 Environmental conditions ......................................................................................... 27
4.1.2 Energy supply............................................................................................................ 27
4.1.3 Gas supply ................................................................................................................. 28
4.1.4 Device layout and space requirements...................................................................... 28
4.2 Supply and control connections ................................................................................ 29
4.3 Installing the compEAct N with sample introduction module ................................... 32
4.3.1 Setting up and connecting the compEAct N.............................................................. 32
4.3.2 Connecting the autosampler LS ................................................................................ 33
4.3.3 Connecting the auto-injector AI................................................................................ 34
5Operation........................................................................................................................ 36
5.1 Switching the compEAct N on and off....................................................................... 36
5.2 Measuring with auto-injector AI............................................................................... 37
5.3 Measuring with LS 1 or LS 2 ..................................................................................... 38
6Maintenance and care................................................................................................... 40
6.1 Maintenance intervals .............................................................................................. 40
6.2 Cleaning the compEAct N and its system components.............................................. 41
6.3 Checking system tightness ........................................................................................ 41
6.4 Adjusting the auto-injector AI................................................................................... 42
6.5 Adjusting the autosampler LS................................................................................... 43
6.6 Combustion furnace – maintenance ......................................................................... 44
6.6.1 Removing and cleaning the combustion tube........................................................... 44
6.6.2 Replacing quartz wool plug....................................................................................... 46
6.6.3 Inserting the combustion tube .................................................................................. 47

Contents compEAct N
4
6.7 Replacing the membrane dryer................................................................................. 48
6.8 Servicing the auto-protection assembly.................................................................... 50
6.8.1 Removing and installing the auto-protection assembly............................................ 50
6.8.2 Checking and replacing the filter .............................................................................. 51
6.8.3 Replacing the pneumatic seal ................................................................................... 53
6.9 Opening and closing the side panel of the compEAct N............................................ 54
6.10 Replacing the absorber ............................................................................................. 55
6.11 Replacing chemical ozone decomposer and filter ..................................................... 57
6.12 Removing and installing the combustion furnace..................................................... 58
6.12.1 Removing the combustion furnace ........................................................................... 58
6.12.2 Installing the combustion furnace............................................................................. 60
7Troubleshooting............................................................................................................. 62
7.1 Troubleshooting according to software messages .................................................... 62
7.2 Equipment faults and analytical problems................................................................ 66
7.2.1 General notes............................................................................................................ 66
7.2.2 Equipment fault ........................................................................................................ 67
7.2.3 Analytical problems .................................................................................................. 68
8Transport and storage ................................................................................................... 70
8.1 Preparing the device for transport............................................................................ 70
8.1.1 Packing the autosampler LS...................................................................................... 70
8.1.2 Packing the auto-injector AI ..................................................................................... 71
8.1.3 Packing the compEAct N ........................................................................................... 71
8.2 Transporting the compEAct N................................................................................... 72
8.3 Moving the compEAct N in the laboratory................................................................ 72
8.4 Storage...................................................................................................................... 73
9Disposal........................................................................................................................... 74
10 Specification ................................................................................................................... 75
10.1 Technical data........................................................................................................... 75
10.1.1 Technical data of the compEAct N ............................................................................ 75
10.1.2 Technical data of the auto-injector AI....................................................................... 75
10.1.3 Technical data of the autosampler LS....................................................................... 76
10.2 Guidelines and standards.......................................................................................... 76

compEAct N Figures
5
Figures
Fig. 1 Safety instructions on the compEAct N ............................................................ 10
Fig. 2 Principle of operation ........................................................................................ 16
Fig. 3 Main components of the compEAct N.............................................................. 18
Fig. 4 Combustion tube................................................................................................ 19
Fig. 5 Connections to the combustion tube................................................................ 19
Fig. 6 Auto-protection assembly ................................................................................. 20
Fig. 7 Toggle switch for pneumatic seal ..................................................................... 20
Fig. 8 Membrane dryer ................................................................................................ 21
Fig. 9 Gas flow diagram of the compEAct N............................................................... 22
Fig. 10 Gas flow diagram of the chemiluminescence detector ............................... 23
Fig. 11 Layout of the auto-injector AI....................................................................... 24
Fig. 12 Autosampler LS.............................................................................................. 25
Fig. 13 Sample rack of the LS 2 ................................................................................. 25
Fig. 14 Solvent and waste containers of the LS ....................................................... 26
Fig. 15 Electrical connections of the LS .................................................................... 26
Fig. 16 Installation diagram for the compEAct N with LS ....................................... 29
Fig. 17 Connections on the rear of the compEAct N ................................................ 30
Fig. 18 USB port and hose bridge in the gas path behind the front door .............. 30
Fig. 19 Location of the switch on the compEAct N .................................................. 31
Fig. 20 Flow monitoring set....................................................................................... 42
Fig. 21 Components in the device interior................................................................ 56
Fig. 22 compEAct N with screwed-in carrying handles ........................................... 73

Figures compEAct N
6

compEAct N Basic information
7
1Basic information
1.1 Notes on these operating instructions
The user manual describes the following model of the compEAct series:
compEAct N – Nitrogen analyzer
These operating instructions provide information about the design and operation of
the compEAct N and provide operating personnel the necessary know-how for the safe
handling of the compEAct N and its components. Furthermore, the operating
instructions include information on the maintenance and servicing of the device as
well as hints on potential causes of malfunctions and their correction.
The operating instructions are intended for users who are familiar with the principles
of nitrogen analysis. The user should at least be trained as a chemical laboratory
assistant or have an equivalent qualification. Knowledge of the safety guidelines for
working in a chemical laboratory and for handling the chemicals that are used are
required. Furthermore, the user must have basic knowledge of working with a
computer.
Instructions for actions which occur in chronological order are numbered and
combined in action units.
Warnings are indicated by warning triangles and a signal word. The type, source and
consequences of the danger are stated together with notes on preventing the danger.
The elements of the control and analysis program are indicated as follows:
Program terms are indicated by small caps (e.g., SYSTEM menu).
Buttons are shown by square brackets (e.g., [OK]).
Menu items are separated by arrows (e.g., SYSTEM DEVICE).
The operating instructions use the following symbols and signal words to indicate
hazards or instructions. The warnings are always placed before an action.
WARNING
Indicates a potentially hazardous situation which might cause death or very serious
injuries (deformities).
CAUTION
Indicates a potentially hazardous situation which might cause light or minor injuries.
Attention
Provides information on potential
material or environmental damage.
Contents
User requirements
Conventions
Symbols and signal words

Basic information compEAct N
8
1.2 Intended use
The compEAct N is a compact stand-alone elemental analyzer for determining
nitrogen contents in liquid, gaseous and LPG samples. The detection takes place
through pyrolysis followed by thermal oxidation in accordance with national and
international standards.
The compEAct N is equipped with at least one sample introduction module. The
compEAct N is equipped with an on-board computer with touchscreen and the
operating and control software EAvolution which is used to control the device and to
analyze the measured data. There is the alternative option to operate the software
using an external keyboard, mouse and monitor or via an external PC. The software
EAvolution advanced can be accessed remotely and provides the option to control the
device remotely. For this purpose, the compEAct N must be connected to a local
network or directly to the Internet.
The compEAct N may only be used for the methods described in these operating
instructions for determining nitrogen contents. Any other use is not as intended! The
operator is the sole responsible and liable for any damages that result from such
unintended use.
The following substances must not be analyzed with the compEAct N because they
pose a risk of explosion:
highly flammable organic compounds (e.g. isopentane)
substances tending to spontaneous decomposition (e.g. peroxides)
explosives, explosive materials (e.g. trinitrotoluol, inorganic azides)
The following substances must not be analyzed with the compEAct N because they
could damage the analysis system:
inorganic substances (e.g. nitric acid)
substances with a high content of alkaline ions and alkaline earth ions (e.g. sodium
acetate)
organometallic compounds (e.g. metal-organyls)
phosphorus and organic silicon compounds or samples with a high content of these
elements (e.g. the hydraulic fluid Skydrol)
substances or samples with a high content of fluoride ions

compEAct N Basic information
9
1.3 Warranty and liability
The warranty duration and liability comply with the legal requirements and the
provisions in the general terms and conditions of Analytik Jena.
Deviations from the intended use described in these operating instructions result in
limitations of warranty and liability in the event of a damage. Damage to wearing
parts is not included in the warranty.
Warranty and liability claims are excluded for personal injury and property damage
due to one or several of the following causes:
use of the device other than intended
improper commissioning, operation and servicing of the device
modifications of the equipment without prior consultation with Analytik Jena
operation of the device with faulty safety equipment or improperly fitted safety and
protection equipment
inadequate monitoring of the equipment components subject to wear
use of other than original spare parts, wearing parts or consumables
improper repairs
faults due to the non-observance of these operating instructions

Safety instructions compEAct N
10
2Safety instructions
2.1 General notes
For your own safety and to ensure error-free operation of the device, please read this
chapter carefully before commissioning.
Observe all safety notes listed in these operating instructions and all messages and
notes displayed by the control and analysis software on the monitor.
Besides the safety instructions in these operating instructions and the local safety
regulations that apply to the operation of the device, the general applicable
regulations regarding accident prevention, occupational health and safety and
environmental protection have to be observed and complied with.
References to potential dangers do not replace the work protection regulations which
must be observed.
2.2 Safety markings on the compEAct N
Warnings and information symbols have been attached to the compEAct N. These
must be observed under all circumstances.
Damaged or missing warnings and information symbols can cause incorrect actions
leading to personal injury or material damage! Symbol labels must not be removed or
wetted with methanol! Damaged symbol labels must be replaced without delay!
Fig. 1 Safety instructions on the compEAct N
Number
Warning
Position/meaning
1 On the cover plate in front of the combustion furnace +
On the cover plate above the combustion furnace (not
shown)
Warning against burns
There is a risk of burns at the combustion furnace. Allow the
furnace to cool down sufficiently before carrying out any
maintenance on or near the furnace.

compEAct N Safety instructions
11
Number
Warning
Position/meaning
2 and 3 On the flap inside the furnace chamber and on the
removable right side of the device
Warning against electric shock inside the device
The voltages applied within the device can be life-
threatening. Switch off the mains switch and pull the device's
mains plug from the power outlet before opening the device.
Not
shown
in Fig. 1
On the cover plate above the combustion furnace
Warning against hazard location
Do not reach into the travel path of the autosampler LS while
the sampler is moving.
Not
shown
On the autosampler LS
Warning against injuries caused by crushing
Do not reach into the travel path of the injector head while
the injector head is moving.
Not
shown
For China: The device contains controlled substances.
Analytik Jena AG guarantees that the substances will not leak
within the next 25 years and, therefore, will not cause any
environmental danger or health risk within this period of
time if the device is used as intended.
2.3 Requirements for the operating personnel
The compEAct N may only be operated by qualified specialist personnel instructed in
the use of the device. The personal instruction also includes conveying the contents of
these operating instructions. We recommend training by qualified employees of
Analytik Jena or its representatives.
The operating instructions must be accessible to the operating and service personnel.
2.4 Safety instructions – Transport and commissioning
Observe the following notes:
Incorrect installation can create serious hazards. Therefore, the compEAct N and its
system components are always installed by the service engineers of Analytik Jena
or its authorized and trained specialist personnel. Unauthorized assembly and
installation are not permitted.
Insufficiently secured components pose a risk of injury! During transport the
components of the equipment must be secured in accordance with the
specifications in these operating instructions. The combustion tube and the
combustion furnace must be removed before transporting the device.
Two people are required to transport the device or to move it inside the laboratory.
They must lift and hold the device on four hand-tightened screwed-in carrying
handles. The device weighs approximately 30 kg.

Safety instructions compEAct N
12
2.5 Safety instructions for operation
2.5.1 General instructions
Each time before starting up the compEAct N, the operator must make sure that the
device and its safety equipment is sound condition. This applies in particular after each
modification or extension of the device or its repair.
Observe the following notes:
The device may only be operated if all protective equipment (e.g. covers and doors)
are in place, properly installed and fully operational.
The operator must have free access to the front door and the mains switch located
behind it at any moment during operation.
The ventilation fittings at the rear and the bottom of the device must be
operational. Covered ventilation grilles or slits etc. may cause the device to break
down or may cause damage to it.
The furnace operates with temperatures of up to 1100 °C. Hot components must
not be touched during or directly after operating the compEAct N.
Ensure that no liquid reaches the plug connectors or enters the interior of the
device! Danger of electric shock!
Caution when handing quartz glass and glass parts. There is the risk that glass
components may break and cause injuries!
Keep all combustible materials away from the device.
2.5.2 Safety instructions – Protection against explosion and fire
The compEAct N must not be operated in an explosive environment.
Smoking or handling open flames are prohibited in the room in which the device is
operated!
2.5.3 Safety instructions – Electrical equipment
Contact with live components may cause death, serious injury or painful electrical
shock. Lethal voltages may occur in the compEAct N!
Observe the following notes:
The mains plug must be connected to a proper power outlet to ensure the device's
compliance with protection class I (ground connector). The device may only be
connected to power sources whose nominal voltage is the same as that on the
rating plate of the equipment. The protective effect must not be invalidated by the
use of an extension line which does not have a protective conductor.
The device and the system components may only be connected to the mains when
the device is switched off.
Electrical connection cables between the device and the system components may
only be connected or disconnected when the device is switched off.

compEAct N Safety instructions
13
Before opening the compEAct N the device must be switched off using the mains
switch and the mains plug must be disconnected from the power outlet! Work on
the electronics may only be carried out by the customer service of Analytik Jena and
specially authorized technicians.
2.5.4 Safety instructions for compressed gas containers and systems
The carrier gas (argon and oxygen) is taken from compressed gas cylinders or local
compressed gas systems. Make sure that the carrier gas has the specified purity!
Work on compressed gas cylinders and systems may only be carried out by individuals
with specialist knowledge and experience in compressed gas systems.
Observe the following notes:
The safety instructions and guidelines for operating compressed gas cylinders or
compressed gas systems that apply at the operating location must be strictly
complied with.
Compressed air hoses and pressure reducers may only be used for the assigned
gases.
Pipes, hoses, screw connections and pressure reducers for oxygen must be kept free
from grease.
All pipes, hoses and screw connections must be checked regularly for leaks and
externally visible damage. Leaks and damaged must be repaired without delay.
The gas supply must be closed prior to inspections, service and repairs!
After successful repair and service of the components of the compressed air
containers or system the compEAct N must be checked for sound operation prior to
recommissioning!
Unauthorized assembly and installation are not permitted!
2.5.5 Handling of auxiliary and operating materials and samples
The operator is responsible for the selection of substances used in the process as well
as for their safe handling. This is particularly important for radioactive, infectious,
poisonous, corrosive, combustible, explosive and otherwise dangerous substances.
When handling hazardous substances the locally applicable safety instructions and/or
instructions in the EC safety data sheets provided by the manufacturer of the auxiliary
and operating materials must be complied with.
The combustion tube is filled with a quartz wool plug. Observe the following
instructions when working with quartz wool:
Only store quartz wool in closed containers.
When working with quartz wool avoid the formation of dust! Inhaled dust might
cause irritation to respiratory tracts.
Wear personal protective equipment (laboratory coat, protective gloves, safety
goggles, breathing mask) when replacing the quartz wool and when cleaning the
combustion tube.

Safety instructions compEAct N
14
Collect used quartz wool in suitable, sealed containers and dispose of the material
in accordance with applicable legal regulations. Contact the responsible waste
disposal company to organize the disposal of the waste.
2.5.6 Safety instructions – Service and repair
Observe the following notes:
The compEAct N is usually serviced by the customer service department of Analytik
Jena or its authorized and trained specialist personnel. Unauthorized servicing can
lead to maladjustment or damage of the device and its system components.
Therefore, the tasks that the operator is allowed to carry out are strictly limited to
the tasks listed in the chapter "Maintenance and care" on page 40.
The exterior of the compEAct N may only be cleaned with a piece of cloth wetted
with water but not dripping, after the device has been switched off.
Generally, all service and repair work on the device must be carried out in switched-
off condition (unless stated otherwise).
Service tasks and the replacement of system components (e.g. removal of the
combustion tube) may only be carried out after a sufficiently long cooling-down
phase.
Prior to servicing or repair the energy and gas supplies must be turned off and the
compEAct N must be vented!
Only original accessories and original replacement parts from Analytik Jena may be
used.
All protective equipment must be reinstalled correctly immediately after
completion of the service and repair work and be checked for operation!
2.5.7 Safety instructions for the operation with auto-injector AI and autosampler LS
Observe the following instructions when installing and operating the auto-injector AI
and the autosampler LS:
When positioning the compEAct N with an LS autosampler on the laboratory desk
consider the movement range of the injector head during operation. Make sure
that the movement range is clear.
There is a risk of injury within the movement range of the injector head during
operation. Keep a safe distance from the device.
The autosampler LS and the auto-injector AI may only be opened by authorized
Analytik Jena service personnel. Disconnect the power supply before opening the
sample introduction system. Danger of electric shock!
Only use the designated connection terminals to connect the autosampler LS and
the auto-injector to the compEAct N (9, 10 in Fig. 17).

compEAct N Safety instructions
15
2.5.8 Behavior in case of overpressure faults (gas pressure faults)
Greatest caution is necessary during an overpressure in the system! With incorrect
operation the operating personnel may be endangered and the analysis system will be
damaged. In case of an overpressure fault, the EAvolution software displays a warning
message and starts the routine to reduce the overpressure.
Observe the following notes:
Never switch off a device that is subject to overpressure!
Do not introduce any samples.
Do not shut down the EAvolution software.
Do not cut the external gas supply.
Wait until the overpressure in the system has dropped to normal pressure. The
routine for reducing the overpressure is an automatic process.
After the routine has ended, follow the instructions in the software.
In case the routine does not achieve to reduce the pressure: Pierce a cannula into
the septum of the injection port so that the gas can escape via the cannula.
2.6 Safety equipment / Behavior during emergencies
Observe the following notes:
In case of hazardous situations or accidents and if there is no immediate risk of
injury, switch off the compEAct N and the connected system components
immediately using the mains switch (behind the front door) and/or disconnect the
mains plugs from the power outlets, if possible!
Cut the oxygen supply immediately or as soon as possible after the device is
switched off!

Function and layout of the compEAct N compEAct N
16
3Function and layout of the compEAct N
3.1 Principle of operation
The compEAct N is a compact elemental analyzer for determining nitrogen contents in
liquid samples. The separately available LPG module 2.0 allows feeding the analyzer
with pressurized liquefied gas samples (LPG). The combined GSS/LPG module allows
feeding the analyzer with both LPG samples and pressurized gaseous samples.
The samples are digested at temperatures between 1000 and 1100 °C in a two-stage
process consisting of a pyrolysis followed by thermal oxidation. During the first phase
of the digestion the sample components are vaporized or pyrolized in the Argon flow
and the generated pyrolysis gases incinerated in the oxygen flow. Next the remaining
pyrolysis products are re-incinerated in the pure oxygen flow during the second phase.
The digestion can be summed up by the following equation:
R* - N + O2→NOx+ CO2+ H2O
R* = residual hydrocarbons
NOx= mixture of nitrogen monoxide (NO) and nitrogen dioxide (NO2) of various compositions
The sample aliquot (liquid, gaseous, LPG) is metered directly into the combustion tube
within the sample introduction module (autosampler LS, auto-injector AI, LPG
module 2.0, combined GSS/LPG module) via the injection port with septum
After leaving the combustion tube the reaction gas mix is fed to the measuring gas
drying process. The measuring gas is dried in a membrane dryer. The dried measuring
gas is fed to the chemiluminescence detector (CLD).
Fig. 2 Principle of operation
The detection is done using the chemiluminescence method. The reaction of nitrogen
monoxide (NO) with ozone (O3) results in the short-term production of nitrogen

compEAct N Function and layout of the compEAct N
17
dioxide (NO2*) in excited state which emits electromagnetic radiation in the range of
visible light when it transforms to normal state. The emitted amount of light is
proportional to the NO2concentration. Consequently, the detected light can be used to
measure the concentration. NO is the only substance involved in the reaction which
means that this method is very selective and not influenced by any other constituents
of the measuring gas.
NO + O3 →NO2* + O2
NO2* →NO2+ hν
The NOxcontained in the measuring gas is a mixture of NO and NO2. The measuring
gas is passed through a converter which renders the NO2portion usable for the
reaction and hence for detection purposes. Inside the converter the NO2is reduced to
NO.
The ozone (O3) required for the reaction is produced within the device using pure
oxygen (O2) that is fed into the device interior. Excess O3is removed in the ozone
decomposer after the reaction and will not be discharged into the environment.
3.2 Design of the compEAct N
The compEAct N consists of the following main components:
Electronics
Internal computer with touchscreen
Gas supply
Combustion system
Auto-protection assembly (APB)
Measuring gas dryer
Chemiluminescence detector (CLD)
Sample introduction system
All components of the compEAct N to be operated or serviced by the user can be
reached via the front door and the opening at the top of the device.
Main components of the
compEAct N

Function and layout of the compEAct N compEAct N
18
Fig. 3 Main components of the compEAct N
1
Touchscreen
2
ON/OFF switch
3
Mains switch
4
Auto-protection assembly
5 Combustion furnace
6 Membrane dryer
7 Head of the combustion tube with injection
port and gas terminals
Electrical connections, gas connections and the connections for the sample
introduction module are located on the rear panel of the compEAct N (→Fig. 17,
p. 30).
The two process gases argon and oxygen are controlled via the gas box in the
compEAct N. The gas box does not require any maintenance from the user.
The compEAct N is a stand-alone device with integrated computer. The control and
analysis software EAvolution is operated via the touchscreen on the right-hand side of
the device.
In the compEAct N a resistor-heated combustion furnace is used for digestion
temperatures between 700 °C and 1100 °C. Depending on the application, the samples
are digested inside the combustion tube at temperatures between 950 °C and 1100 °C.
A combustion tube has been inserted into the combustion furnace of the compEAct N
which is used for all standard applications. The combustion tube is made of quartz
glass. A quartz wool plug inserted in the inner tube ensures a slow and steady
vaporization of the sample. The connection between the combustion tube and the
measuring gas dryer is implemented via the auto-protection assembly.
Electrical components
and gas supply
Combustion system

compEAct N Function and layout of the compEAct N
19
Fig. 4 Combustion tube
1
Connection to the auto-protection assembly
2
Glass drip
3
Internal tube with quartz wool plug
4
Head with injection port and gas terminals
The injection port and the gas terminals are located on the head of the combustion
tube.
Fig. 5 Connections to the combustion tube
1
Oxygen connection (hose no. 3, blue)
2
Argon connection (hose no. 4, gray)
3
Injection port
The auto-protection assembly is used to couple the combustion tube to the measuring
gas dryer. The assembly has an integrated replaceable filter. The filter protects the
downstream membrane dryer and the detector against soot particles and solid
pyrolysis products in case of incomplete combustion. The filter also retains condensed
water and other aerosols; only water vapor passes through.
The auto-protection assembly is mounted to a plug-in unit below the furnace.
Auto-protection assembly

Function and layout of the compEAct N compEAct N
20
Fig. 6 Auto-protection assembly
1
Membrane dryer
2
Plug-in unit for the auto-protection assembly
3
Gas connection for the pneumatic seal (argon)
4
Pneumatic seal
5 Holder
6 Connection to the membrane dryer
7 Electrical connection
The combustion tube is plugged into the auto-protection assembly and sealed with a
pneumatic seal. The seal is operated using argon.
A toggle switch is used to open and close the seal:
Toggle switch down: combustion tube is sealed
Toggle switch up: combustion tube is released
Fig. 7 Toggle switch for pneumatic seal
1
Mounted auto-protection assembly
2
Connection of the auto-protection assembly
3 Toggle switch for the pneumatic seal
The measuring gas is dried by means of a membrane dryer which is attached to the
furnace. Oxygen is used as a purge gas for the operation of the membrane dryer. To
increase the drying effectiveness a pump is used to aspirate the rinse gas through the
membrane dryer.
Measuring gas dryer