Interscience COMPACTGC Instruction Manual

COMPACT

GC

Instruction manual

version 2.01 (January 2005)

CompactGC manual

CompactGC Instruction Manual
January 2005 Edition
© 2005 Interscience B.V., The Netherlands. All rights reserved.

Published by Interscience B.V., The Netherlands, P.O. Box 2148, 4800 CC Breda
Tel: [phone] Fax: [phone]

Printing History: First Edition, version 1.04, released July 2003
Second Edition, version 2.01, released January 2005

Disclaimer

Technical Information contained in this publication is for reference purposes only and is subject to change
without notice. Every effort has been made to supply complete and accurate information; however,
Interscience B.V. assumes no responsibility and will not be liable for any errors, omissions, damage, or loss
that might result from any use of this manual or the information contained therein (even if this information is
properly followed and problems st ill aris e).

This publication is not part of the Agreement of Sale between Interscience B.V. and the purchaser of a
CompactGC system. In the event of any conflict between the provisions of this document and those
contained in Interscience B.V. Terms of Delivery, the provisions of the Terms of Delivery shall govern.
Reference to System Configurations and Specifications supersede all previous information and are subject
to change without notice.

Trademarks

CompactGC is a trademark of Interscience B.V. Other brand and product names may be trad emarks or
registered trademarks of their respective companies.
Valco® valves is a registered trademark of Valco Instruments Co. Inc. and Valco International.
EZChrom® is a trademark of Scientific Software, Inc.

ii

CompactGC manual

Manufacturer: Interscien ce B.V .
Interscience B.V. is the manufacturer of the instrument described in this manual and, as such, is responsible
for the instrument safety, reliability and performance only if:

• installa tion

• re-calibration

• changes and repairs
have been carried out by authorized personnel and if:

• the local installation complies with local law regulations

• the instrument is used according to the instructions provided and if its operation is only entrusted to
qualified trained personnel. The CompactGC should be handled as described in the pre-installation guide
“Gaschromatografiesystemen”.
Interscience B.V. is not liable for any d amages derived from the non-co mpliance wi th the aforementioned
recommendations.

Interscience B.V.

Postbus 2148
4800 CC BREDA
The Netherlands
tel: [phone]
fax: [phone]
www.interscience.nl
[e-mail]

iii

CompactGC manual

Table of contents

1. Safety 2

2. Installation 4

3. Instrument description 7

3.1 Digital gas supply 8

3.2 Valve oven 10

3.3 Column oven 10

3.4 Detectors 11

4. Pre-concentration Module (PM) 16

5. The CompactGC editor program 17

Command buttons 18
Tab pages 19
Pull down menu’s 22

6. Operation 28

6.1 Column installation 28

6.2 Leak check 30

6.3 Quick start up 31

7. Maintenance and troubleshooting 33

®

Appendix 1: EZChrom

/ EZStart® settings 34

Appendix 2: Electrical connenctions 39
Appendix 3: LED status display 41

Index

1

CompactGC manual

1. Safety

Safety summary

The following general safety precautions must be observed during all phases of
operation, service, and repair of this instrument. Failure to comply with these
precautions or with specific warnings elsewhere in this manual violates safety standards
of design, man u f a ct u r e , an d in tended use of this equipment. Interscience assumes no
liability for the customer’s failure to comply with these requirements.

Ground the instrument

To minimize shock hazard, the instrument chassis and cabinet must be connected to an
electrical ground, using the provided three-pin AC power cable.

Do not operate in an explosive atmosphere

Do not operate the instrument in the presence of flammable gasses or fumes.
Operation of any electrical instrument in such an environment constitutes a definite
safety hazard. Contact your supplier for purged housings if the CompactGC needs to
be applied in an EX classified zone.

Keep away from live circuits

Analytical column and component replacement and internal adjustments must be
made by qualified maintenance personnel. Do not replace components with the
power cable connected. Under certain conditions, dangerous voltages may exist even
with the power cable removed. To avoid injuries, always disconnect power and
discharge circuits before touching them.

Do not service or adjust alone

Do not attempt internal service or adjustment unless another person, capable of
rendering first aid and resuscitation, is present.

Do not substitute parts (electronics)

Because of the danger of introducing additional hazards, do not install substitute parts
or perform any unauthorized modification of the instrument. Contact Interscience
Services to ensure that safety features are maintained.

Do not over-pressurize the instrument

See ‘installation’ for maximum allowed pressures.

2

CompactGC manual

Hot surfaces should be avoided

The CompactGC has heated inlets. Contacting these inlets once they are at operating
temperatures can result in inju ry.

The use of hydrogen

The use of hydrogen for feeding the flame in certain types of detectors requires the
operator’s extreme attention and the compliance with special precautions due to the
hazards involved in the use of this gas. Moreover, the operator shall be present while
analyses are run to immedi ately detect any malfun ctioning. Hydrogen is a dangerous
gas (when mixed with air it may generate an explosive mixture), particularly when, in a
closed area, it reaches a concentration corresponding to its lower level of explosion
(4% in volume). For these reasons, before using hydrogen, the following
recommendations must be observed:

1. Ensure that all hydrogen cylinders are complying with the safety conditions provided

for their proper use and storage: they must be equipped with suitable safety valves,
automatic safety systems and all that is required by current regulations even with
regard to safety in sites with danger of explosion or fire.

2. During the connection of hydrogen lines, ensure that the gas feeding inlet is

perfectly closed.

3. Before using the instrument, ensure that the lines designed for hydrogen are

perfectly leak-tight.
According to the results obtained, it will be possible to inspect each single section of
the pneumatic circuit as pointed out in said paragraph. Should it be necessary to
operate in the inside of the pneumatic compartment or column oven, the check shall
be carried out with all circuits under pressure. This procedure shall be repeated until all
causes of

leakage have been eliminated.

3

CompactGC manual

2. Installation

Instrument classification

The instrument classification is according to IEC 10.10:

• internal use

• temperature 18 to 30 °C

• maximum relative humidity between 50 % and 80 %

• transient overload in compliance with installation categories II

• pollution level according to IEC 664 (3.7.3) 2

Space requirements

The CompactGC measures approximately:
Width : 45.0 cm (without 19” mounting handles)
Height : 17.8 cm (4HE; 18.5 cm including sockets)
Depth : 54.0 cm (including handles)
Weight : depending on configuration, approximately 25 kg

The unit can be placed on a bench, or can be mounted in a standard 19” rack. For
installation of the analytical c olumn and for service, the instrument is accessed by
removing the top cover.

Ventilation

Depending on the configuration and operation parameters, sufficient ventilation must
be available for cooling purposes.

Gasses
Connections

All gas connections are 1/16” Swagelok, except for the actuator gas (1/8”).

Pressure

The maximum pressure for all gasses is 500 kPa. For carrier- and detector gas, 300
kPa is recommended. For fastest valve switching, helium is recommended for
actuator gas, but air can also be applied (350 kPa).
In case of the PDD (Pulsed Discharge Detector), the discharge gas is directly
connected to the Helium suppl y via an internal restrictor. A stable 350 kPa He
pressure is needed for this application.

Quality

For carrier gas, He 5.0 (N50) is recommended.

4

CompactGC manual

Demand

Carrier gas: 2-50 ml/min for each anal ysis ch annel , depending on settings
TCD: 2 ml/min (reference gas)
FID: 30 ml/min H

; 300 ml/min air

2

PDD: 30 ml/min He
PID 2 ml/min make-up

Power requirements

The CompactGC requires 220/230V single phase voltage, 50 Hz. With all options
installed, the maximum power consumption is 900 VA. In practice, depending on the
configuration, the typical power assertion is much lower.

Digital connections

CompactGC Editor

This 9-pole connection is used for RS-232 communication for parameter
programming and status readout. Maximum (tested) length is 10 m.

EZChrom

® /

EZStart®

This RS-232 connection is used for the digital detector data in case of the
EZChrom

®

/ EZStart ® data system. Maximum (tested) length is 10 m.

Wherever in this manual is spoken about EZChrom
for EZStart
Note that in case of the EZChrom
connections are needed.

®.

®

data system, two RS 232

®

, it is also applicable

Digital output

The GC-ready and GC-Start-out signals are available on this connector. (Start­out is used to start the data system in case of analog data signal). The
programmable output bits are also present on this connector. See appendix 2 for
more deta ils.

Digital input

Via this connector, the CompactGC can be started and stopped by remote
control hardware signals. See appendix 2 for more details.

Figure 2.1 is showing the electrical and pneumatic connections.

5

CompactGC manual

Carrier gas in
(1/16” Swagelok )

Mains switch

220V power
connec t io n

EZChrom
RS 232 connec t or
(D sub 9 pole)

Figure 2.1: electrical and pneumatic connections

Split out
(1/16” Swag elok)

CGC Editor
RS 232 connector
(D sub 9 pole)

Detector ga s in
1/16” Swag el o k)

Flash
programming

Actuator He-Air
(1/8” Swagelok)

Digital output
(D sub 15 po le)

Detector out
(1/16” Sw agelok)

Digital input
(D sub 15 pole)

6

CompactGC manual

3. Instrument description

The CompactGC is a fully digital 19” rack GC, dedicated for fast gas analysis (however
analysis of liquid samples is also possible). The instrument uses reliable well-known
technique like Valco
columns with down sized dimensions, to obtain short analysis times. Typical analysis
times are 10 seconds to 2 minutes. The CompactGC editor, a dedicated program for
method programming, sets all parameters. The CompactGC is an up to 3-channel
instrument, with a choice of four different detectors. The signal of the detectors is
available in digital format, for use with the EZChrom
form for connection to other data systems. The basic setup of the system is shown in
figure 3.1.

®

valves, robust detectors and standard available capillary

®

data systems, as well in analog

detector
electronics

digital
gas

power
supply

control

detectors

Figure 3.1: Basic system

column
oven

valve
oven

7

CompactGC manual

The front half of the instrument contains the ‘chromatography hardware’: on the right
side the valve oven for (maximum 3) heated valves, in the middle the isothermal
column oven(s) (maximum 3), on the left side the detector compartment, for up to 3
detectors. A module for cryogenic trapping, in case of trace gas analysis, can be
installed in place of one of the column ovens.
On the back half of the instrument, from right to left side, the power supply, the digital
gas supply, and detector controllers can be seen.

3.1

Digital gas supply

The gas control of the instrument is fully digital, and can be present in two types of
modules:

• Carrier Gas Module (CGM) for carrier gas

• Detector Gas Module (DGM) for detector gasses

CGM

The Carrier Gas Module is a sophisticated carrier gas supply device, which can be
operated in the following modes:

• Constant pressure

• Programmed pressure

• Pressure pulse (pressure surge)

Four different gasses can be used: helium, hydrogen, nitrogen and argon. In case of
change of carrier gas type, recalibration of the splitflow is needed. Contact your
service organization for more information. Hydrogen is not recommended for safety
reasons.

Constant pressure

The most common used operating mode is constant pressure, with digital control of the
split flow. See figure 3.2.

In this diagram, the constant pressure is obtained by the upper proportional valve and
pressure sensor (P). The lower proportional valve and pressure sensor, in combination
with a temperature compensated restrictor are controlling the split flow.

Normally, the optimum flow for a certain type of column is the starting point of method
development. The needed pressure can be determined by measuring the flow on the
detector outlet, of can be calculated using the available flow calculator (CGC editor).

8

CompactGC manual

Figure 3.2: Diagram CGM

Programmed pressure, pressure surge

These modes of carrier gas control are obtained by programming the targeted
parameters using the Run Time Table. See chapter 5 for more details.

If the CompactGC runs out of carrier gas (no inlet supply), the system switches to the
Hibernate mode (all flow and temperature channels are set to value 0) and cools
down.
The GC needs a reboot (mains power switch, or ‘warm reset’ from the CGC editor
menu) to return to normal operation.

DGM

The second type of digital gas supply contains two pressure channels, and is therefore
used to control two detector gasses, f.i. hydrogen and air in case of FID, or two
reference gasses in case of double TCD. In combination with a calibrated, temperature
compensated restrictor in the module, constant detector gas flows are obtained. See
figure 3.3. The flows needed for proper detector operation are entered using the CGC
editor program.

9

CompactGC manual

detector gas in

proportional

valve 1

P

Pressure
sensor

Fixed
restrictor

(temperature
compensated)

capillary column 1

PPM

TCD front

TCD

TCD 1 out

P

detector gas in

(second detector)

Figure 3.3: Diagram DGM

3.2 Valve oven

The valve oven is an independent heated temperature compartment that provides:

• housing for maxi mum 3 Valco

®

valves, for several configurations like injection,

backflush, streamselection, etc.

• heated sample inlet

• housing for sample conditioning (filtering, pressure reducing, etc.)

The oven can easily be accessed for maintenan ce, injection-loop changing, etc.

3.3 Column oven

In the CompactGC, up to three column ovens can be installed. In order not to lose
analysis time compared to a temperature programmed run (cooling down phase), the
analysis conditions are normally developed on base of isothermal analysis. Therefore
the applied ovens are isothermal and highly stable. The three ovens have independent
temperature control, so each column operates at its optimum temperature. The
standard supplied oven is used for fused silica columns with an internal diameter of 0.32
mm maximum. For wide-bore columns (0.53 mm id), metal columns are advised. The
most common used columns are 2-15 meter/0.32 mm id fused silica. In the oven,
columns with a winding diameter of 8 cm are installed. These columns can be ordered
in this dimension,
mentioned diameter. See chapter 6.1 for column installation.
Ovens for packed columns are available on request.

but also standard columns are used, after rewinding them to the

10

CompactGC manual

3.4 Detectors

Four detectors are available: Thermal Conductivity Detector (TCD), Flame Ionisation
Detector (FID), Pulsed Discharge Detector (PDD) and Photo Ionisation Detector (PID)
(available end 2003). Up to three of these detectors can be configured in the
CompactGC.

TCD

The TCD is a very widely used detect or for analysis of gases, but in principle all
components with different thermal conductivity in relation to the carrier gas can be
detected. The response is concentration dependant: a higher column flow or make-up
flow results in a decreased sensitivity.
This detector is a dual channel microvolume cell with two filaments on constant mean
temperature. See figure 3.4.

dual filaments

analysis flow

Figure 3.4: TCD detector

reference fl o w

Operation principle

The filaments are continuously losing heat to the wall of the detectorcell by the thermal
conducting carrier gas (see figure 3.5). When a component with a different thermal
conductivity compared to the carrier gas pass es the filament, the electronic circuit in
which both filaments are integrated (Wheatstone bridge) is adjusting the current to
maintain the constant filament temperature. This current change is dependant on the
component concentration, and is convert e d to a chromatographic signal that can be
handled by the data system.

11