Linde G-TECTA 4G User manual

G‑TECTA® 4G
Multi‑Gas
Detection Instrument
Operating Manual
UK

2
Contents
Safety and Warning information 3
Instructions – specific for use in hazardous areas 3
Instructions – specific for use in
non‑hazardous areas 4
Introduction 5
Sensors 5
Key Features 5
Software 5
Batteries 5
Product Features 5
Switching on 6
Auto Zero 7
Switching off 7
Instrument Storage 7
Confidence signals 7
Display Symbols 7, 8
Alarms 8, 9
Data & Event Logging 10
Wearing the Instrument 11
Gas Sampling 12
Maintenance, Calibration
and Gas Testing 12, 13, 14
G‑TECTA® 4G Instrument with Ozone Sensor 15
G‑TECTA® 4G Instrument with CO2 Sensor 15
PC Interface and PC Software 15
Gas Test/Calibration Troubleshooting 16
Product Specification 16
Accessories 17
Troubleshooting 18
Sensor Limitations 18
Available Sensors 19
Declaration of Conformity 20
The Linde Group Warranty 21
Whilst The Linde Group has made every effort
to ensure that the details and information given
in both our printed and online publications
are accurate at the time of issue, full technical
specifications are not necessarily included.
Furthermore The Linde Group policy is one of
continuous improvement and the right is reserved
to alter details and information as the need arises.
Accordingly the Customer should check any details
and information they wish to rely on with The Linde
Group at the time of purchase. The Linde Group
can not accept liability in respect of any errors
or omissions herein contained or for any loss or
damage malfunction or consequential lost arising
from reliance upon our publication.
The customer will be responsible for any risk
to health or safety from goods in the Customer’s
possession and/or control. The Customer’s attention
is drawn to the fact that statutory regulations and
recognised codes of practice exist covering the
use and handling of some goods (including safety
products.) The Customer must ensure that persons
who use the goods receive adequate training
and safety literature.

3
Safety and Warning information
WARNING

Read and understand all instructions
in the operation section of this operating manual
before use.
WARNING

Do not substitute components as this
may impair intrinsic safety and invalidate warranty.
WARNING

Observe all warnings and
instructions marked on the instrument and within
this operating manual.
WARNING

Observe site health and safety
procedures for gases being monitored and evacuation
procedures.
WARNING

Make sure you understand the
alarm warnings.
WARNING

If this product is not working properly,
read the operating manual or call The Linde Group.
WARNING

The accuracy of G-TECTA® 4G
instruments equipped with a toxic gas sensor should
be checked periodically with known concentration
calibration gas. Failure to check accuracy can lead
to inaccurate and potentially dangerous readings.
G-TECTA® 4G instruments equipped with an oxygen
sensor should be periodically calibrated in fresh air.
WARNING

Ensure maintenance and calibrations
are carried out in accordance with the procedures in
the operating manual.
WARNING

The equipment is not certified
for use in atmospheres containing more than
21% oxygen.
WARNING

G-TECTA® 4G portable gas detectors
have been designed for the detection of either oxygen
deficiencies or specific toxic gas accumulations.
An alarm condition indicates the presence of a
potentially life threatening hazard and should be
taken very seriously.
WARNING

Ensure only qualified service
personnel change sensors, batteries and
operating system.
WARNING

Only charge batteries in safe
(non-hazardous) areas.
Instructions – specific for use
in hazardous areas
The following instructions apply to
equipment covered by certificate numbers
IECEx BAS 09.0117 Baseefa09ATEX0245.
The following information covers all relevant
points listed in clause 1.0.6 of the Essential Health
& Safety Requirements of the ATEX directive.
1. The certification marking is as follows:
2. The G-TECTA® 4G may be used in Zones 1
and 2 with Groups IIA, IIB, and IIC flammable
gases and vapours for Temperature Classes
T1, T2, T3 and T4.
3. The equipment is certified for use in ambient
temperatures in the range –20°C to +55°C
(-4 to +131 F). The equipment should not
be used outside these temperature ranges.
Toxic and Oxygen sensors are not rated for
continuous operation at high temperatures
greater than 40°C (104°F).
4. Compliance with Essential Health and Safety
Requirements has been assured by compliance
with EN60079-0, EN60079-1, EN60079-11,
and EN61779-5 as certified by Baseefa.
Compliance with gas detection performance
standards EN50054, EN50057, EN61779-1
and EN50104 has been certified by Lloyd’s
Register. EMC compliance to EN50270 has been
certified by 3C Test Ltd.

4
5. Repair of this equipment and gas sensor
replacement shall be carried out by the
manufacturer or approved service centre in
accordance with the applicable code of practice.
6. If the equipment is likely to come into contact
with aggressive substances, then it is the
responsibility of the user to take suitable
precautions that prevent it from being
adversely affected, thus ensuring that the type
of protection is not compromised.
7. The rechargeable battery must only be charged
in non-hazardous (safe) areas by connection
to the specified Linde charger. Rechargeable
batteries can only be replaced by a Linde Group
Authorised Service Centre.
8. The equipment is not certified for use in
atmospheres containing more than 21% Oxygen.
Area Classifications:
Zone 1: An area classified as Zone 1 is likely
to have ignitable concentrations of flammable
gases, vapours or liquids present under normal
operating conditions.
Zone 2: An area classified as Zone 2 is not likely
to have ignitable concentrations of flammable
gases, vapours or liquids present under normal
operating conditions.
Instructions – specific for use in
non-hazardous areas
G-TECTA® 4G with CO2 Sensor
The G-TECTA® 4G multi-gas instrument uses an
infrared gas sensor for CO2 detection. The G-TECTA®
4G with a CO2 sensor is not designed or certified
for use in hazardous areas, and the intrinsic safety
information for this instrument is not applicable.
Operation and maintenance of the G-TECTA®
4G with a CO2 sensor is essentially the same as
for other G-TECTA® 4G instruments but with the
following points to note:
CO2 is present in ambient air at a background
concentration of just under 400ppm (0.04%).
In any enclosed environment the ambient CO2
concentration will increase as a result of people
or animals breathing and if the room is poorly
ventilated concentrations well in excess of
1 000ppm (0.1%) can occur. CO2 levels in the
outdoor air will also be enhanced by any emitted
CO2 e.g. from vehicle exhausts or boiler flues
venting to atmosphere so it is normal to see
fluctuating levels of CO2 on the instrument display
whether indoors or outside.

5
G-TECTA® 4G Multi-Gas
Detection Instrument
Introduction
G-TECTA® 4G is a premium, portable Multi-Gas
Detection Instrument, designed to be carried
or worn by individuals working in potentially
hazardous environments such as confined spaces.
G-TECTA® 4G is certified for use in classified
hazardous areas and monitors up to four different
gases by displaying the readings simultaneously
on the instrument screen. Alarm warnings are
transmitted by means of a loud audible alarm,
a bright visual alarm of blue/red flashing LEDs
and an internal vibrating alarm.
Sensors
G-TECTA® 4G can be specified with a wide range
of intelligent gas sensors. The sensor is fitted to
an intelligent processor which contains calibration
and sensor information. The G-TECTA® 4G can be
reconfigured at any time by replacing the pre-
calibrated intelligent sensor(s) with alternative
gas types. Sensors should be replaced by trained
service personnel and are easy to fit using “plug
and play” technology. The intelligent sensor(s) are
immediately recognised by the instrument and are
ready to use after instrument calibration.
Key Features
G-TECTA® 4G has been designed to be a reliable
and robust personal monitoring system, whilst
being compact, light and easy to use. The
instrument is water and dust tight to IP65 and
IP67 ratings. The G-TECTA® 4G’s shape and
design ensures high levels of user comfort and
minimal interference with the user’s normal work
function. The non-slip grip and alligator clip ensure
secure handling and wear ability and additional
accessories such as shoulder straps and chest
harness allow flexible wearing options if desired.
The G-TECTA® 4G has a single mode button and a
high quality display with automatic backlight. The
instrument continuously monitors the gas level in
the environment providing current, peak, and time
weighted average (TWA) readings for the user.
The G-TECTA® 4G can be configured by utilising
Linde G-TECTA® PC software. Data and event
logging can also be downloaded and managed
whilst the instrument is being charged via the
optional charger with communication link.
Software
The instrument software has been written in
accordance with IEC 61508 to ensure quality and
integrity in operation. The internal circuitry monitors
for any malfunction and will display an error
warning to the user in the unlikely event they occur.
Batteries
G-TECTA® 4G is battery operated and is supplied
with a Lithium-Ion battery pack.
Battery Check
G-TECTA® 4G should arrive with sufficient charge
so that the instrument can be used straight out the
box. However, to attain the full operating time you
should charge the battery. (The actual operating
time will depend on the types of sensor installed.)
The G-TECTA® 4G will operate for at least 16 hours
on a fully charged battery.
WARNING

Only recharge the rechargeable
battery in a safe (non-hazardous) area with a
Linde G-TECTA® 4G charger. Failure to comply could
invalidate safety certification and may result in
permanent damage to the instrument.

6
G-TECTA® 4G – Product Features
Operation
Switching on
The G-TECTA® 4G is designed to be very easy to
operate. Please follow these simple steps to ensure
your instrument is ready for use:
Step 1
WARNING

Ensure the instrument is in clean air.
Step 2
Press and hold the mode button for approximately
2 seconds until the red LED flashes on the
instrument. The display screen will light up and the
instrument will begin its start up sequence
G-TECTA® 4G Start-Up Sequence
The instrument will test the alarm LEDs, the alarm
sounder, the vibration alarms and the display
screen. The sounder may be silenced by pressing
the mode button once.
The instrument will continue through a start
up sequence as shown below, this will take
approximately 45 seconds.
During the start up sequence, check the battery
display to ensure you have enough charge to
use the instrument.
Note: During the start up sequence the next
calibration date will be displayed.
If the calibration due date has expired, the
G-TECTA® 4G instrument will display a warning
message that calibration is due. As a default
the instrument can still function, however the
G-TECTA® 4G can be configured to automatically
shut down using G-TECTA® PC software if required.
The Linde Group strongly recommends that
instruments are calibrated as soon as possible
once the calibration date is due.
Auto Zero*
The Auto Zero function is enabled as a default
setting. During start-up, the instrument will display
Auto Zero and “????”. Press the mode button to
confirm the Auto Zero function.
5 – Sep – 2009
14 : 02 : 49
5 – Sep – 2009
14 : 02 : 49
CAL
G-TECTA 4G
v1.0
CH4 %LEL CO ppm
H2S ppm O2 %
0.0
0.0
0
20.9
G-TECTA 4G v1.0G-TECTA 4G v1.0
AUTO ZERO?
7 secs
? ? ? ? ? ? ?
5 – Sep – 2009
14 : 02 : 49
CAL
* This setting can be configured to operate automatically, on
user confirmation (default), or disabled, using G-TECTA
®
PC software
(see page 15).
Mode
Button
4 Alarm LEDs
Sensors Sounder
Outlet
Display Screen

7
Note: The instrument will time out in 10 seconds
then change to normal operating mode, without
performing an auto zero, if the mode button is
not pressed.
Note: If Auto Zero fails, a warning message will be
displayed and an X will appear against the sensor
that has failed (See the Troubleshooting section if
this occurs).
Switching Off
Press and hold the mode button for 5 seconds, the
display will count down until the display shows
OFF. If you release the mode button during the
countdown, the G-TECTA® 4G will return to normal
operating mode.
Instrument Storage
In order to optimise sensor performance and lifetime,
your G-TECTA
®
4G instrument should be stored in a
safe, non-hazardous area. The area should be clean
and dry, between temperature ranges 0-30°C, and at
a humidity level of 20-90%RH.
Normal Operation and Confidence Signals
The instrument will display up to four gas readings
and each channel will display the gas types, units
and current readings.
Screen Icons
Always check the gas type being monitored
by your instrument and ensure you have been
trained in your site health and safety procedures.
Confidence Signals
To give you added confidence the instrument
is operating correctly, the G-TECTA® 4G will
(every 10 seconds):
1. Sound a short beep
2. Flash a blue LED
In addition the “ ” icon will flash on the display.
Display Symbols
Battery
When the battery is fully charged, the battery icon
will show 6 black bars. When the battery is empty,
the battery icon flashes and the instrument will
sound warning beeps.
WARNING

When the battery charge is
completely empty, G-TECTA® 4G will switch
off automatically.
CH4 %LEL CO ppm
H2S ppm O2 %
0.0
0.0
0
20.9
!
Battery
Start Up Flashing icon,
G-TECTA® 4G in
normal operating mode
!
AUTO ZERO?
7 secs
? ? ? ? ? ? ?
CH4 %LEL CO ppm
H2S ppm O2 %
0.0
0.0
0
20.9
AUTO ZERO
CH4
H2S
CO
O2
AUTO ZERO
CH4
H2S
CO
O2

8
Alarm
The TWA alarm for toxic gases will operate when
the short-term (15 minute) or long-term (8 hour)
time weighted average alarm levels are exceeded.
WARNING

TWA alarms cannot be cleared. TWA
alarms are functional for toxic gas instruments only.
Display Menu Options
The G-TECTA® 4G menu is displayed
when you press the mode button twice.
There are up to 3 menu options plus the
home screen option. To scroll between
the different options, press the mode button once.
To select the menu option you require, double
click on the selected icon. When the Peak and TWA
menu options are selected the relevant icon will be
displayed on the screen.
The Peak menu option displays the highest gas
level for flammable and toxic gases, or the lowest
level of oxygen, since the instrument was switched
on or was last reset.
After 5 seconds the instrument will display Clear
Peak and “????”. Press the mode button to confirm
the Clear Peak function. The instrument will count
down and time out in 10 seconds and change back
to Peak mode if the mode button is not pressed.
The Peak feature is mainly used for confined space
entry checks, where the instrument is lowered into
a potentially hazardous environment (instead of
using a sampling hose), and also for viewing peak
gas exposure at the end of a shift.
The TWA menu option displays the 8 hour time
weighted average reading for toxic gases since the
unit was last switched on.
Zero
The Zero menu option will reset the sensor in the
instrument. When the zero function has been
completed, the instrument will return to normal
operating mode.
WARNING

Always ensure you are in fresh air
when using this feature. Zeroing an instrument in a
contaminated atmosphere could result in incorrect
gas readings.
Alarms
G-TECTA® 4G has two instantaneous alarm level
settings for each sensor – level 1 and level 2 –
and two additional Time Weighted Average (TWA)
alarms for toxic sensors.
Alarm Signals
The red and blue alarm LEDs will flash, the sounder
will emit a loud, fast series of beeps and the
internal vibrator alarm will activate. The display will
show the gas in alarm and the alarm level.
For any gas, there are
normally 2 alarm levels*
– these are indicated by
the alarm icons:
Zero
* The instrument has 2 alarm levels to give the user an indication
that the gas level may be rising. If any alarm warning is indicated
by the instrument the work area should be evacuated.
16.7
0
0 . 0
0 . 0
H2S ppm
CH4
O2 %
ppm
OO%LEL
Alarm icon
Gas example
under alarm
Peak

9
Note: The G-TECTA 4G is set to “latch” the alarm
by default.
This means that the instrument will continue
to alarm
until the operator presses the mode button.
Once you have evacuated the dangerous area, press
the mode button on the G-TECTA® 4G instrument;
this will reset your G-TECTA® 4G to normal operating
mode. If the G-TECTA® 4G continues to alarm, i.e. you
are still in a dangerous area, pressing the button will
have no effect.
Alarms
The TWA alarm for toxic gases will operate when
the short-term (15 minute) or long-term (8 hour)
time weighted average alarm levels are exceeded.
The G-TECTA® 4G will display and display
toxic gas levels.
WARNING

TWA alarms are functional for toxic
gas instruments only.
WARNING

The TWA alarms cannot be cleared.
Flammable Over-range Alarm
If flammable gas levels exceed 100% LEL, G-TECTA®
4G locks into alarm and displays “ ” showing an
over-range condition. G-TECTA® 4G will temporarily
cut off power to the sensor to prevent burn out,
and display a progress bar for 200 seconds.
Note: The alarm remains active until the instrument
sensor is in normal operating mode.
When the power timeout is complete, the symbol
changes to “ ” and the mode button should be
pressed to put the instrument back into normal
operating mode. The symbol will change to an egg
timer to indicate that the sensor is warming up.
At the end of the warm up period and assuming the
instrument is in fresh air, the sensor will revert to a
numeric display.
Note: If the instrument is still in the hazardous area
when the sensor is re-set, the sensor will revert to
an over-range alarm.
The G-TECTA® 4G can optionally be configured to
force the operator to switch the instrument off and
on to restart. This option is programmable with
G-TECTA® PC Software.
Note: All alarm configurations can be set with
G-TECTA® PC Software.
WARNING

If the sensor power is reconnected
when the unit is exposed to an over-range gas
concentration there is a risk of damage to the
pellistor sensor.
WARNING

Depleted oxygen levels can reduce
the flammable gas reading. If oxygen levels are
below safe breathing limits it should be assumed
that the flammable reading is low.
Instrument Settings
The following instrument settings can be altered
using G-TECTA® PC Software:
Alarm levels for the sensor:
Level 1 and level 2 alarms can be set for each
gas sensor.
Alarm trigger:
The alarm trigger can be set for rising levels of gas
(toxic and flammable), or for falling levels of gas
(oxygen deficiency monitoring).

10
Alarm latching:
Latched alarms require the operator to press the mode
button to clear the alarm (default setting). The alarm can
be set to be latched or unlatched. Unlatched alarms will
clear automatically when the gas hazard has passed.
Alarm sounder mute:
The G-TECTA® 4G sounder can be set to mute for
level 1 alarms only; pressing the mode button
during an alarm condition, will silence the sounder
and stop the vibrating alarm. The alarm LEDs will
continue to flash.
Alarm sounder tone:
Different distinctive tones can be selected for each
alarm condition. This optional feature can assist the
operator to ascertain the level of hazard.
WARNING

This feature should only be set
following extensive instrument user training.
Data & Event Logging
The G-TECTA® 4G instrument records both gas
data and events. The logs can be accessed
and downloaded by using the G-TECTA® 4G
charger with PC interface and by using G-TECTA® PC
software.
Data is recorded in 1 minute intervals (the intervals
can be adjusted using the PC software).
G-TECTA
®
4G also records the time and date for a
number of operating and diagnostic events including:
• Switch on and switch off
• Level 1, Level 2 and Time Weighted Average
Alarms (TWA) – alarm on, alarm off and peak
gas levels during the alarm
• Zero, calibration and gas testing –
success or failure
• Flammable sensor alarms – on and off
• The battery condition – switch on, switch off,
when placed into or out of the charger
Batteries
Rechargeable Batteries
The re-chargeable batteries in the G-TECTA® 4G are
Lithium-Ion batteries. The batteries will re-charge
in 5 hours when fully discharged. The battery life is
16+ hours in continuous use.
G-TECTA® 4G Battery Chargers
There are 4 battery charger options for the
G-TECTA® 4G instrument. The standard battery
charger is a single drop in charger cradle with
a power lead. Optional charger units include;
single drop in charger cradle with integral PC
interface, a 12V vehicle charger and a 5
instrument multi-charger.
The chargers are powered by a nominal 15 V
dc input. The multi-charger includes a universal
power supply. To ensure compliance with product
certification requirements, charging voltages must
be limited to less than 9 V.
WARNING

Only re-charge the rechargeable
battery in a safe (non-hazardous) area and with a
Linde G-TECTA® 4G charger. Failure to comply could
invalidate safety certification and may result in
permanent damage to the instrument.
Charging the Batteries
1. Ensure you are in a safe area.
2. Plug the charger power supply into a mains
socket, and connect to the charger.

11
3. Switch off the G-TECTA® 4G
and place the instrument
into the charger in an
upright position with the
screen facing outwards.
When the instrument is charging, the red LED on
the charger cradle will be lit. When the instrument
is fully charged, the red LED will fade. When
G-TECTA® 4G is fully charged and switched on the
battery icon will show six black bars.
Note: If the G-TECTA® 4G is switched on during
charging, the battery icon will sweep from empty
to full, the instrument will take longer to charge,
and the battery icon will take 20 seconds to update
on removal from the charging cradle.
Changing Rechargeable Batteries
If you experience a noticeable reduction in
battery life in the instrument, rechargeable
batteries should be replaced by a Linde Group
Authorised Service Centre.
Note: To ensure hazardous area and instrument
ingress protection certification is maintained,
battery replacement should only be carried out by
trained and certified personnel.
Wearing G-TECTA® 4G Instruments
G-TECTA® 4G is supplied with a strong and durable
alligator clip. The alligator clip will securely attach
the instrument to a pocket, lapel, sleeve, belt etc.
G-TECTA® 4G Chest/Neck Harness
The optional chest/neck harness allows the user
to mount the instrument on the chest or around
the neck for additional comfort.
Attaching the Chest Harness Plate
The chest harness plate is attached to the
instrument by replacing the alligator clip.
1. Remove the M3 screw on the back of the
G-TECTA® 4G.
2. Remove the alligator clip.
3. Position the chest harness plate and align
the screw holes.
4. Attach the screw and tighten.
Neck Strap
Attach the strap to the top connectors and place
around the neck. Adjust the length of the strap until
the instrument is in a comfortable working position.
Chest Harness
Leave the neck strap in position. Attach the other
strap to the side connectors and link around the
chest. Adjust the strap lengths until the instrument
is in a comfortable working position.

12
Gas Sampling
To take a sample of a gas in a confined space or
where there are unknown levels of gas present
using G-TECTA® 4G, the flow sample method can be
used. A flow cap must be fitted over the sensors
on the front of the instrument and a hose and an
aspirator bulb fitted onto the flow cap nozzles.
Note: A flow cap and a 2 metre length of hose are
included in the box with your G-TECTA® 4G instrument.
The aspirator bulb and hose (Article Number ASGTAK2
or ASGTAK3) is an additional accessory.
1. To fit the flow cap, clip the flow cap over the
sensor grills on the front of the instrument and
screw the thumbscrew until it is tightly fitted
into place.
2. Attach the sampling hose onto the gas in nozzle.
3. Attach the aspirator bulb onto the gas
out nozzle.
4. Check the aspirator bulb is attached correctly
by covering the end of the bulb and by
squeezing it gently. If there are no leaks, the
aspirator bulb should remain deflated for a
few seconds.
5. Squeeze the aspirator bulb once per second to
create a steady flow of air into the instrument.
We recommend the operator squeezes the
aspirator bulb at least 10 times (using the
2 metre hose supplied). Longer lengths of
hose and metal probes can be purchased. For
additional lengths of hose, we recommend
that the aspirator bulb is squeezed once for
every 30cm of hose to enable the gas sample
to reach the sensor. Continue to squeeze the
bulb for an additional 45 seconds, or until gas
readings stabilise.
6. To remove the flow cap, unscrew
the thumbscrew and lift it away from
the instrument.
WARNING

Manual aspirator remote sampling
only provides continuous gas readings for the area
in which the hose or probe is located and when the
aspirator bulb is being continuously squeezed. Each
time a new gas reading is required, the aspirator bulb
must be squeezed a sufficient number of times to bring
a fresh sample and a stabilised reading to the sensor.
Maintenance, Calibration
and Gas Testing
Cleaning
Ensure the G-TECTA® 4G display, operator button
and sensor filter remain free from dirt build up.
Regularly wipe over your G-TECTA® 4G instrument
with a damp cloth and inspect the sensor filters for
dirt or damage.
Gas (bump) Testing
The atmosphere in which G-TECTA
®
4G instruments
are used can have lasting effects on the sensors.
Sensors may suffer losses in sensitivity leading to
degraded performance if exposed to certain substances.
Gas in
Gas out

13
The Linde Group recommends a bump test each
time G-TECTA® 4G instruments are used or issued for
use. As a minimum, a monthly bump test is required
to confirm sensor operation. Test gases of known
composition (compatible with the settings on the
instrument sensor modules) need to be applied,
to verify sensor response and alarm function.
Note: Please see The Linde Group data sheet
“Gas Detector Calibration Frequency” for further
advice on bump testing and calibration.
The Linde Group manufactures and supplies
Gas Test Cylinders under numerous global product
brands, including Linde, BOC, AGA, Afrox etc.
The Linde Group gases supplied for use with your
G-TECTA® 4G gas detection instruments are specially
formulated, high stability long life multi-gas mixes.
The G-TECTA® 4G instrument will determine Pass/
Fail status for the gas test.
In order to perform successful gas tests ensure:
• The gas used has the recommended gas
concentration and it is within the validity date
specified by The Linde Group
• The gas flow path is leak tight. It is important to
check that the flow cap is properly fitted to the
G-TECTA® 4G instrument, the outlet hose is
not restricted in any way, nor additional hose
length used
The G-TECTA® Gas Test Kit comprises a full gas
cylinder and regulator with interconnecting hose, a
gas test key (used to activate Gas Test Mode on the
instrument), a flow cap to attach to the G-TECTA®
4G, and a vent line. The Gas Test Kit is supplied in a
convenient carry case.
How to Perform a Gas Test
1. Ensure the G-TECTA® 4G is switched on and in
normal operating mode.
2. Fit the flow cap onto the front of the sensors
and attach the hose from the regulator. Attach
the outlet hose to ‘vent gas away’ – do not
extend this hose, restrict or allow kinks.
3. Swipe the Gas Test Key over the Linde label
on the front of the instrument. The G-TECTA®
4G
will activate the Gas Test Mode and show TEST
and “x” next to the sensors on the display.
4. G-TECTA® 4G will display a progress bar.
5. Apply the gas whilst the progress bar is
counting down.
6. Wait for the progress bar to complete
(40 seconds). G-TECTA® 4G will display a
“” or “x” against each sensor and a master
“” or “x” to indicate PASS or FAIL.
In the event G-TECTA® 4G displays FAIL,
please see the troubleshooting guide
(Page 17) or contact The Linde Group.
7. To abort the gas test press the mode button at
any time whilst the test is in progress.
Instrument Calibration
Calibration of the gas sensor should be performed
regularly every 6 months. Over time the accuracy
of the gas sensor can drift outside of what is
considered a safe range and regular calibration is
essential to ensure accuracy of gas readings.

14
WARNING

The accuracy of G-TECTA® 4G
instruments should be checked periodically with
known-concentration of calibration gas. Failure
to check accuracy can lead to inaccurate and
potentially dangerous readings.
There are three methods of instrument calibration
available: G-TECTA® 4G calibration can be
performed directly on each instrument (one button
calibration), by utilising G-TECTA® PC software or by
using the Linde G-DOCKA® Hub. Certified calibration
gases should be used.
How to Perform a One Button Calibration Test
1. Ensure you are in clean air and the
instrument is in normal operating mode.
Double click the mode button and select
“Zero” from the options menu by double
clicking on the “Zero” icon. G-TECTA® 4G
will perform an Auto Zero.
To perform a one button calibration,
complete the next steps within 15 minutes
of completing the Auto Zero.
2. Fit the flow cap onto the front of the sensors
and attach the hose from the regulator. Attach
the outlet hose to ‘vent gas away’ – do not
extend this hose, restrict or allow kinks.
3. Swipe the Gas Test Key over the Linde label on
the front of the instrument. The G-TECTA® 4G
will activate the Calibration Mode and show
“CAL” and “????” on the display.
4. Press the mode button within 10 seconds to
confirm calibration.
Note: If the mode button is not pressed within 10
seconds then the instrument mode will change to
Gas Test Mode.
5. G-TECTA® 4G will display a progress bar and
an “x” will appear against each gas type.
6. Apply the gas whilst the progress bar is
counting down.
Note: You can abort the Calibration test by
pressing the mode button at any time whilst
the test is in progress.
7. The G-TECTA® 4G instrument will adjust the
value on the gas sensor to match the stored
calibration gas value within the sensor module.
8. G-TECTA® 4G will display a “ ” or “x” against
each sensor to indicate PASS or FAIL.
9. If any of the G-TECTA® 4G sensors do not
calibrate successfully, the gas type will remain
marked with a “x” and the warning messages
“Gas Test Failed” and “Send for Calibration” will
be displayed. The G-TECTA® 4G must be sent
to a Linde Group Authorised Service centre for
re-calibrating or sensor replacement.
Note: Gas Test pass and fail, and calibration
pass, fail and values are stored in the Event log.
Note: Some sensors may not be calibration
enabled. Oxygen sensors are by default not
calibration enabled as they are calibrated in fresh
air by zeroing.
WARNING

One button calibration will check
for small drifts of stored calibration value. The Linde
Group recommends the G-TECTA® 4G is sent for full
certified calibration at six monthly intervals.

15
G-TECTA 4G Instrument with Ozone
(O3) Sensor
Due to the reactive nature of ozone (O3) special
procedures should be followed when calibrating
gas detectors that incorporate an ozone sensor.
Fittings
For ozone calibrations all fittings and pipe work
should be stainless steel, brass, aluminium or PTFE.
Fittings or pipe work in other plastic materials such
as Tygon must not be used.
Gas flow rate
It is important that the flow rate is set correctly as
otherwise pressure effects may distort calibration
values and prevent the gas detector from working
correctly. To calibrate, the flow rate should be set
between 0.8-1.0 litres / minute (0.03-0.04 cubic
feet / minute)
Normal safety precautions for handling ozone
should always be observed along with any special
instructions that accompany the calibration gas
cylinder or generator being used.
For calibrating the ozone sensor, the special flow
cap assembly marked “Ozone Only” (article number
AS4G2009) must be used.
Note: The standard flow cap assembly supplied
with the instrument must be used for calibrating
the other gas sensors.
G-TECTA® 4G Instrument
with CO2 Sensor*
When a G-TECTA® 4G CO2 sensor is zeroed
in fresh air it automatically sets the CO2 baseline
level to 0.04%. When zeroing the instrument in air,
ensure you are outside in clean air well away from
buildings, vehicles or any CO2 emissions. Please
ensure the instrument is held well away from
the breathing zone of the operator.
A G-TECTA® 4G CO2 sensor can also be set to
zero in nitrogen by using G-TECTA® PC software**.
This is a zero point calibration rather than a normal
zero. In the PC software, set the calibration value
to 0.00%, apply nitrogen gas and click the
calibrate button.
Note: After the zero point calibration is completed,
remember to re-set the calibration gas level to its
previous level.
* Please also see the section – Instructions – specific for use in non-hazardous areas (Page 4)
** Recommended calibration gas is 2% CO2 in a background of nitrogen with a regulated flow of 0.5 l/min (1 SCFH). Care should be taken to
vent the nitrogen flow away from the operator and not allow nitrogen flow for longer than necessary. If indoors, it is recommended to vent
gas out of a window or into an extracted fume cupboard.

16
G-TECTA® 4G – PC Interface
and PC Software*
G-TECTA® PC Software gives the user access
to data and event log files, printing reports,
reconfiguring alarm levels, instrument operation
functions, and running calibrations.
G-TECTA® 4G can be connected to a PC by using
the G-TECTA® 4G single drop in charger cradle with
optional PC interface. The charger cradle is fitted
with a D-type 9 pin RS232 socket. The PC requires
G-TECTA® PC software and is connected to the
charger via a RS232 cable.
Note: A USB-RS232 adaptor is required for most
PCs or Laptops.
Set-up
1. Install G-TECTA® PC software on the PC.
2. Where applicable, install USB software**
(supplied in USB adaptor box).
3. Attach the RS232 cable to the charger and
the RS232 cable with the USB adaptor
(where applicable) to the PC.
4. When using a USB adaptor to connect the
instrument, follow the procedure below:
(i) Before connecting the instrument, check the
available communications ports available on
the G-TECTA® PC software options screen and
note the ports available
(ii) Switch on the G-TECTA® 4G instrument and drop
it into the charger cradle
(iii) Check the available communications ports
available again and select the new port or port
4, 5 or 6 and save your changesby clicking
the save button on the bottom right of the
options screen
(iv) Close the G-TECTA® PC software.
Note: If the instrument does not connect to
the PC, select a different communications port
and try again.
5. Switch on the G-TECTA® 4G instrument and drop
it into the charger cradle ensuring it is upright
and the display is facing forward.
6. Open the G-TECTA® PC software and using
either the Wizard or the Engineer’s Form,
select G-TECTA® 4G and upload the data from
the instrument.
7. The software will allow you to access data or
configure the instrument as required.
Note: For more information on using the G-TECTA®
PC software, see the installed help file.
* G-TECTA® PC Software can be downloaded free of charge from www.g‑tecta.com
** If the USB adaptor software does not start automatically, select UC232A, the appropriate operating system and install the driver

17
Gas Test/Calibration Troubleshooting
Problem Possible Cause Solution
No response to gas Gas Cylinder Empty Check cylinder gauge. Replace cylinder
Hose blocked or kinked Check hose and ensure no gas flow restriction
Instrument fails gas test Gas cylinder empty Check cylinder gauge. Replace cylinder
Gas cylinder out of date Check cylinder expiry date. Replace cylinder
Hose blocked or kinked Check hose and ensure no gas flow restriction
Calibration drifted Calibrate instrument
Gas flow not started in time Repeat gas test. Start gas immediately
Instrument fails calibration Gas cylinder empty Check cylinder gauge. Replace cylinder
Gas cylinder out of date Check cylinder expiry date. Replace cylinder
Hose blocked or kinked Check hose and ensure no gas flow restriction
Calibration drifted Calibrate instrument
Instrument stabilisation time
too short
Reset instrument stabilisation time using G-TECTA® PC
Software
Instrument passes gas test but
will not enter calibration mode
Zero not performed
from options menu
Initiate zero on instrument menu
Instrument incorrectly configured Re-configure instrument.
Send to Linde Group service centre
G-TECTA® 4G Product Specification
Dimensions 71 x 114 x 48 mm
Weight 295g (with alligator clip & 3 sensors)
IP Rating (Dusts & Liquids) IP65 & IP67
Operating Temperature Rating -20°C Ta +55°C (-4°F Ta +131°F)
Humidity Rating 20-90% RH – non-condensing, continuous operation
Display 128 x 64 Pixel with backlight
Warm-up time period Approx 45 seconds
Typical response time T90: 10 seconds (oxygen)
20 seconds (toxic & flammable)
Alarm sounders* 95dB(A) Optional multiple alarm sounds
Visible alarms Dual colour Blue/Red flashing LEDs
Vibrating alarm Internal vibrating
Repeatability ±2% FSD, 6 months
Electromagnetic Compatibility 2004/108/EC
Explosion Protection Certification IECEx/ATEX/CSA
IECEx IECEx BAS 09.0117
ATEX BASEEFA09ATEX0245
CSA CSA22.2, 152
Approval Codes
Global IECEx II 2G Ex ia d IIC T4 Gb
CSA Class I Division 1, Groups A, B, C and D
Safety & Operation Standards EN50014, EN50020, EN50018, 94/9/EC
EN50270, EN50271
* It is recommended that the sounder output is periodically tested to ensure the instrument continues to operate as specified

18
G-TECTA® 4G Accessories
ASGTK G-TECTA® SG/4G/4GP Gas Test Key
AS4GBC12V G-TECTA® 4G 12v Battery Charger
AS4GBCC12V G-TECTA® 4G 12v Battery Charger c/w computer interface
AS4GBCAU G-TECTA® 4G 230v Battery Charger Australian
AS4GBCUK G-TECTA® 4G 230v Battery Charger UK
AS4GBCEU G-TECTA® 4G 230v Battery Charger Europe
AS4GBCUS G-TECTA® 4G 110v Battery Charger USA
AS4GBCCAU G-TECTA® 4G 230v Battery Charger Australian c/w computer interface
AS4GBCCUK G-TECTA® 4G 230v Battery Charger UK c/w computer interface
AS4GBCCEU G-TECTA® 4G 230v Battery Charger Europe c/w computer interface
AS4GBCCUS G-TECTA® 4G 110v Battery Charger USA c/w computer interface
AS4GBC5AU G-TECTA® 4G 5-Way Multi-charger Australian
AS4GBC5UK G-TECTA® 4G 5-Way Multi-charger UK
AS4GBC5EU G-TECTA® 4G 5-Way Multi-charger Europe
AS4GBC5US G-TECTA® 4G 5-Way Multi-charger USA
AS4GBCC5AU G-TECTA® 4G 5-Way Multi-charger Australian c/w computer interface
AS4GBCC5UK G-TECTA® 4G 5-Way Multi-charger UK c/w computer interface
AS4GBCC5EU G-TECTA® 4G 5-Way Multi-charger Europe c/w computer interface
AS4GBCC5US G-TECTA® 4G 5-Way Multi-charger USA c/w computer interface
ASGTAK2 G-TECTA® Aspirator and 2m hose
ASGTAK3 G-TECTA® Aspirator and 3m hose
AS4G2003 G-TECTA® 4G Flow cap assembly
ASGTSP G-TECTA® 4G/4GP 1m Sample probe
ASGTTSP G-TECTA® 4G/4GP Telescopic sample probe
ASGTAH G-TECTA® 4G/4GP Aspirator hose
ASGTPF G-TECTA® 4G/4GP In line water trap/particulate filter inc filter element
ASGTFE G-TECTA® 4G/4GP Filter element for inline water trap
ASGTDL6 G-TECTA® 4G/4GP 6 m drop line
AS4G2004 G-TECTA® 4G Harness Assembly including shoulder strap
ASGTCHS G-TECTA® 4G/4GP Chest harness straps
AS4G2005 G-TECTA® 4G Carry Case
AS4G2006 G-TECTA® 4G Dust Filter
AS4G2007 G-TECTA® 4G Hard Shell Case
ASGTPCI G-TECTA® SG/4G PC Interface Lead with USB to RS232 Adaptor

19
G-TECTA® 4G Troubleshooting
Problem/Error Message Possible Cause Solution
Instrument won’t
switch on
Battery has no charge Re-charge or replace battery
Mode button released
too soon
Press mode button until LEDs flash
No confidence beep Instrument function disabled Reconfigure instrument using
G-TECTA® PC Software
Gas reading on display
when in clean air
Instrument zero drifted Restart instrument in clean air
Unstable or inaccurate
gas readings
Sensor failure Do NOT use instrument
Exit hazardous area immediately
and return instrument for service
Auto Zero failure Instrument zeroed in
contaminated atmosphere
Switch off instrument
and restart in clean air
Alarm preventing
Auto Zero
Instrument zeroed in
contaminated atmosphere
Switch off instrument
and restart in clean air
Calibration expired Calibration due date has passed Return instrument for calibration
Display shows empty
battery symbol
Battery has no charge Re-charge or replace battery
LCD too faint/dark
Instrument contrast
setting incorrect
Adjust instrument using
G-TECTA® PC Software
If you experience any other issues with the operation of the G-TECTA® 4G instrument, please go to www.g‑tecta.com or contact an
Authorised Linde Group Service Centre.

20
Sensor Limitations
The sensors used in the G-TECTA® 4G have
limitations common to all gas sensors, and users
should be aware of the points listed below.
The Linde Group can advise on particular situations
and suggest alternative sensors if the instrument
is likely to experience extreme conditions.
G-TECTA
®
4G flammable instruments use a catalytic
pellistor gas sensor. Common with sensors of this
type, instrument readings will be unreliable over
concentrations of approximately 120% LEL and
oxygen is necessary for catalytic sensors to operate.
A ‘pellistor saver’ is used to disconnect power to
the pellistor sensor in the event of “over-range”
(above 100% LEL) to prevent burn out.
This feature “locks out” the sensor for 200
seconds, after which a press of the mode button
on the instrument will reconnect power to the
pellistor. Restart should be carried out in a known
clean air environment.
WARNING

If the sensor power is reconnected
when the unit is exposed to an over-range gas
concentration there is a risk of damage to the
pellistor sensor.
WARNING

Depleted oxygen levels can reduce
the flammable gas reading. If oxygen levels are
below safe breathing limits it should be assumed
that the flammable reading is low.
G-TECTA® Electrochemical gas sensors (toxic gases
or oxygen), contain chemicals. Extreme levels of
humidity can cause problems. The sensors are rated
for an (average) ambient humidity of 20-90% R.H.
However the sensors are commonly used from the
tropics, to deserts, to tundra without any functional
issues. Water should not be allowed to collect on
the sensor as this may impede gas diffusion.
Persistent exposure to high levels of toxic gas
will shorten the life of a toxic sensor. If the high
level gas is corrosive (e.g. hydrogen sulphide),
damage may occur over time to metal components.
Sensors may be cross sensitive to other gases.
If unsure, contact The Linde Group.
Available Sensors
Sensor Type Range
(LEL) Methane 0-100%
(LEL) Propane 0-100%
(LEL) Pentane 0-100%
(LEL) Butane 0-100%
(LEL) Ethylene 0-100%
(LEL) Hydrogen 0-100%
(LEL) Flammable alcohols,
ketones, general solvents
0-100%
(O2) Oxygen 0-25%
(O3) Ozone* 0-1 ppm
(CO) Carbon Monoxide 0-500 ppm
(H2S) Hydrogen Sulphide 0-100 ppm
(CO/H2S) Carbon Monoxide/
Hydrogen Sulphide
0-500ppm/0-100ppm
(SO2) Sulphur Dioxide 0-10 ppm
(NH3) Ammonia 0-100 ppm
(CO2) Carbon Dioxide
(non Ex areas)
0-5%
* Reactive gases – see G-TECTA® datasheet on gas sampling
with reactive gases