Crowcon Tetra 3 User manual

Tetra 3
Personal Multigas Monitor
User Manual
M07654
August 2009
Issue 5

Safety information:
• Read and understand all instructions in the opera-
tion section of this manual before use.
• Do not substitute components as this may impair
intrinsic safety and invalidate warranty.
• Observe all warnings and instructions marked on
the unit and within this manual.
• Observe site health and safety procedures for
gases being monitored and evacuation proce-
dures.
• Make sure you understand the screen display and
alarm warnings.
• If this product is not working properly, read the
troubleshooting guide or call Crowcon.
• Ensure qualified service personnel change sensors
and operating system.
• Ensure maintenance and calibration are carried
out in accordance with the procedures in the man-
ual.
Instructions specific for use in hazardous areas
The following instructions apply to equipment cov-
ered by certificate numbers:
Tetra 3 = Baseefa 05ATEX0187
Tetra 3 = IECEx BAS 05.0059
The following information covers all relevant points list-
ed in clause 1.0.6 of the EHSR’s of the ATEX directive.
1. The certification marking is as follows:
2. The equipment may be used in zones 1 and 2 with
group IIA, IIB, and IIC flammable gases, tempera-
ture classes and vapours T1, T2, T3 and T4.
3. The equipment is certified for use in ambient tem-
peratures in the range –20°C to +55°C
(-4 to +131 F). The equipment should not be used
outside these ranges.
4. Compliance with the Essential Health and Safety
Requirements has been assured by compliance with
IEC 60079-0, 60079-1,60079-11, EN61779-5, as
certified by Baseefa. Compliance with gas detec-
tion performance standards EN50054, EN50057,
EN61779-1, EN61779-4 and EN50104 and
EN50270 has been certified by Lloyds Register.
5.Repair of this equipment and gas sensor replace-
ment shall be carried out by the manufacturer or
in accordance with the applicable code of prac-
tice.
6. If the equipment is likely to come into contact
with aggressive substances, then it is the responsi-
bility of the user to take suitable precautions that
prevent it from being adversely affected, thus
ensuring that the type of protection is not com-
promised.
7. The rechargeable battery must only be charged in
non-hazardous (safe) areas by connection to the
specified Crowcon charger power supply.
8. The equipment is not certified for use in atmos-
pheres 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 oper-
ating conditions.
Zone 2: An area classified as Zone 2 is not likely to
have ignitable concentrations of flammable
gases, vapours or liquids present under nor-
mal operating conditions.
© Copyright Crowcon Detection Instruments Ltd 2007.
All rights are reserved. No part of the document may be pho-
tocopied, reproduced, or translated to another language with-
out the prior written consent of Crowcon Detection
Instruments Ltd.
Publication number: M07654
Fourth edition: December 2007
Crowcon Detection Instruments Ltd
2 Blacklands Way, Abingdon
OX14 1DY UK
Tel. [phone]
Fax. [phone]
www.crowcon.com
Email: [email protected]
EEx ia d IIC T4
OX14 1DY
UNITED KINGDOM
II 2G
1180
4F/20 ºC Ta 131F/55 Cº
4F/20 C Ta 131F/55 Cºº
IEC Ex ia d IIC T4
BASEEFA05ATEX0187
IECEx BAS 05.0059
FOR INTRINSIC SAFETY PRECAUTIONS SEE
MANUAL. WARNING UNDERSTAND MANUAL
BEFORE OPERATING. ONLY CHARGE BATTERY
IN A NON HAZARDOUS AREA

Tetra 3
Personal Multigas Monitor
Contents
Unpacking ................................................1
Quickstart guide ........................................2
Introduction ..............................................6
Operation ..................................................8
Batteries ..................................................12
Alarm indications ....................................13
Fixing accessories ....................................14
Flow sampling ........................................15
Maintenance and calibration....................20
PC interface and software........................21
i-module replacement..............................22
Specification ............................................24
Accessories and spare parts ....................25
Troubleshooting guide ............................27
Appendix: Limitations of sensors..............28

1
Tetra 3 Unpacking
Tetra 3
Personal Multigas Monitor
Thank you for purchasing the new Tetra 3 Personal Multigas Monitor. Tetra 3
has redefined portable gas monitoring and will give you years of unparalleled
service and reliability.
Please read the instructions carefully before use. Keep the manual for future ref-
erence.
Unpacking
Remove the Tetra 3 Personal Multigas Monitor from the packaging. The Tetra 3
accessories will be located in the bottom of the box. Check the contents are
complete, you should have:
• Tetra 3 unit;
• Charger and power supply;
• A configuration report detailing the sensors installed, alarm
settings and a calibration certificate;
• Optional accessories such as aspirator plate, aspirator bulb and
comms lead.
Battery check
The Tetra 3 Personal Multigas Monitor has a lithium-ion rechargeable battery.
Tetra 3 will operate for a minimum of 16 hours when fully charged.
Tetra 3 uses a Li-ion battery pack and should arrive with sufficient charge so that
the unit can be used straight out the box. However, if this is the first time you
have used the Tetra 3 unit, you may need to charge the batteries to attain the
full 16 hour operating time. The actual operating time will depend on the types
of sensors installed.
Warning: rechargeable units
Do not attempt to use any other charger with this unit except the one sup-
plied by Crowcon. Failure to comply could invalidate safety certification and
may result in permanent damage to the unit.

Quickstart guide Tetra 3
Quickstart guide
1. Getting started
Review your Tetra 3 unit
Switching on your unit
Tetra 3 requires little setting up, follow these simple steps to get your unit ready
for use.
1. Ensure the unit is in clean air.
2. Switch on
Press and hold the operator
button until the red LED flashes.
The operator display screen will
light up and the unit will begin a
warm up sequence.
2
Operator
button
Pocket
clip lever
Side view
Top view
Front plate
4 Alarm LEDs
Operator LCD
display screen
4s

Tetra 3 warm up sequence
a) The unit will test the
alarm LEDs, sounder,
vibration alerts, and the
operator display screen.
The sounder may be
silenced by pressing the
button.
b) The unit will continue through a warm up sequence as shown below,
this will take approximately 45 seconds.
c) Auto zero
If auto zero is enabled (default), the unit will display the auto zero
menu. Press the operator button with a single click to confirm auto
zero. If the operator button is not pressed within the 10 second time
out, Tetra 3 will proceed directly to Run mode without performing zero.
3
Tetra 3 Quickstart guide
LEDs Alarm test Sounder Alarm test
Vibration test
Tetra3
vs. 1.00
AUTO ZERO?
Click to
confirm
in 7 secs
i
CH4 %LEL CO ppm
H2S ppm O2 %
CROWCON
Tetra3
Gas Detection You ..
TODAY IS
Wed
5-Sep-2005
14:02:49
i
NEXT CAL
5-Jan-2005
i
1-2 m
!
AUTO ZERO?
Click to
confirm
in 7 secs
i
CH4 %LEL CO ppm
H2S ppm O2 %
0.0
0.0
0
20.9
No auto zero
Auto zero
OK
AUTO ZERO
Auto zero in
progress
0.0
AUTO ZERO
0.0
CH4
H2S
Co
O2
AUTO ZERO
0.0
CH4
H2S
Co
O2
Run mode

Run mode
Your unit is now ready to use.
Below is a typical screen display showing the
unit in normal gas monitoring Run mode.
Familiarise yourself with the gases being
monitored in your unit and make sure you
understand site health and safety procedures
in the event of alarm conditions.
2. In the event of an alarm
Alarm signals
In the event of gas concentrations exceeding the alarm thresholds for any gas
being monitored, Tetra 3 will activate the alarm signals.
Alarm signals
The red and blue
alarm LEDs will flash,
the sounder will emit
a loud, fast series of
beeps, the internal
vibrator alarm will
activate. The operator
screen will display the
gas in alarm and the
alarm level. See the
figure to the left.
4
In the event of an alarm Tetra 3
CH4 %LEL CO ppm
H2S ppm O2 %
0.0
0.0
0
20.9
OK
OK
Flashing
icon, Tetra3
running
normally
Battery
Screen Icons
Auto zero
Warm up
Confidence signals
In normal Run mode, Tetra 3 will emit a short beep every 10 seconds and
the OK icon flashes to show operational health.
Gas example
under alarm
CH4 %LEL CO ppm
H2S ppm %
0.0
0.0
0
16.7
2
O2
Alarm icon

1. When the gas level returns to normal, press the operator button. This
will reset your Tetra 3 unit to normal Run mode. If gas levels are still in
alarm, the button will have no effect.
3. Switch off unit and storage
Switching off unit
1. Press and hold the button for 5 seconds. The shut down menu appears,
continue to hold button until the unit counts down to shut off.
Storing conditions
In order to optimise sensor performance and lifetime, your Tetra 3 unit should
be stored in a safe, non-hazardous area, 0-30°C, 10-90%RH.
4. Additional information
For battery recharging information go to section III.
For fixing accessories go to section V.
For sampling section go to section VI.
For calibration information go to section VII.
For troubleshooting guide go to section XII.
5
Tetra 3 Switching off
1 2
CH4 %LEL CO ppm
H2S ppm O2 %
0.0
0.0
0
20.8
OK
OFF IN
4 sec
For any one gas, there are
normally two alarm
thresholds. These are
indicated by the alarm
icons shown.
The Tetra 3 alarm is set to latch by default.
The unit will still continue in alarm mode
even when gas levels return to normal,
until the alarm is cleared, by pressing the
operator button.

Introduction Tetra 3
I. Introduction
Thank you for purchasing the new Tetra 3 Personal Multigas Monitor. Tetra 3 is
a portable multigas detector, designed to be carried or worn by individuals
working in hazardous environments such as confined spaces. It is suitable for
use in Zone 1 and 2 hazardous areas. Tetra 3 can monitor up to four different
gases and display the readings simultaneously on a display screen. Alarm warn-
ings are given through a combination of a loud audible alarm, a bright visual
alarm of blue/red flashing LEDs and an internal vibrator. Tetra 3 is fitted with
modular, plug and play gas sensors. Each sensor carries an intelligent processor
which contains calibration and sensor information.
Tetra 3 is operated using a Lithium-ion rechargeable battery. A charger is avail-
able with a range of options.
At Crowcon we recognised the need for a reliable and robust personal moni-
toring system, which is both lightweight, compact, easy to use and cost effec-
tive. Tetra 3 has a single operator button, and an intelligent user-friendly display
with backlight. Gas levels are continuously monitored providing normal gas
readings, peak readings and time weighted averages (TWA). Tetra 3 is a diffu-
sion sampling instrument with an option to use a hand-operated aspirator.
Configuration and data/event logging is handled by Crowcon Portables PC soft-
ware, the PC communication link being provided through the charger.
Tetra 3’s shape and design makes it comfortable to wear and as non-intrusive
as possible, with a non-slip grip for better handling. Extra accessories, such as
shoulder strap and chest harness, can be purchased.
Tetra 3 has been designed from top to bottom to bring you ease of use, low
maintenance and extremely high reliability. Through an innovative and rigorous
design process, we have combined several features from our reliable Tetra and
Gasman products to produce the new Tetra 3.
i-module gas sensor
Tetra 3 uses unique plug and play i-module sensor technology. Each sensor unit
incorporates its own intelligent processor holding sensor configuration and cal-
ibration data. Different sensor modules can be purchased, and once inserted,
are immediately ready to run. Tetra 3 can operate with up to three sensors and
display simultaneously, information and gas readings, for all the sensors, on
one screen. This means no redundancy and assured future investment in your
Tetra 3 unit, allowing you to swap sensors between units or configure your unit,
6

as appropriate, to your current needs. Plug and play will ease maintenance time
and cost, and the intelligent modular system will remove the need to calibrate
each sensor. Additional i-modules can be purchased, pre-calibrated from your
local supplier.
Reliable, anti-shock mechanics and robust housing
The Tetra 3 housing is built from resilient material, giving it strength and flexi-
bility to withstand the hardest of working conditions, water and dust tight to
IP65 and IP67, and with a non-slip grip. The case has been carefully designed
to make servicing easy and at the same time very rugged. If the unit is dropped,
there will be no disruption of power or function, ensuring reliability and service
for years to come.
Software
The processes used to design and develop the Tetra 3 software ensure a high
degree of reliability and robustness. Thus Tetra 3 has been designed to be a truly
reliable personal gas monitoring system. The internal circuitry includes an exter-
nal watchdog, where the software monitors for any malfunction within the unit
and will display an error warning to the user should they occur.
7
Tetra 3 Introduction

Operation Tetra 3
II. Operation
2.1 Switch-on sequence
1. Ensure the unit is in clean air.
2. Switch on
Press and hold the operator button until the two red LEDs flash.
The instrument begins with testing all the LCD segments on the
operator display screen, the red and blue alarm LEDs, sounder and
internal vibrator alert for about 5 seconds. The sounder may be
silenced by pressing the button. The unit enters a warm up mode and
displays a sequence of screens, see page 3 for more details. At the end
of warm up, the auto zero menu will be displayed.
3. Auto zero menu
Press the operator button with a single click to confirm auto zero. If
the operator button is not pressed within 10 seconds, Tetra 3 will
proceed directly to Run mode without performing a zero. Flammable
and toxic sensors will be set to read zero and the oxygen sensor to
read 20.9%.
Switch off
To switch off the unit, press and hold the operator button for 5
seconds. A shut-down menu ‘OFF IN’ will appear. Continue to hold
button until the unit counts down to shut off.
NB. If auto zero fails, a warning message will be displayed
and an ‘X’ will appear against the sensor that has failed.
8
Battery check
Use this time to
check there is sufficient
charge in the battery pack
!
The auto zero function can be disabled or set
to run automatically, without user
confirmation: auto zero menu will not appear.
See section VIII PC Interface and software.
NB. During the warm up sequence, the date for next calibration will be
displayed. If the date has expired or has passed, the Tetra 3 unit will display a
warning message that calibration is due. The instrument can still function, but
it is strongly recommended the unit is sent for calibration as soon as possible.
Tetra 3 can be set, using the Portables PC software, for the instrument to shut
down automatically, if the calibration date is passed, to prevent further
operation of the instrument.

9
Tetra 3 Run mode
2.2 Run mode
The Tetra 3 unit will display up to four gas readings simul-
taneously on the operator display screen. A typical four
gas display is shown below.
Each channel will display the gas name, units and current
value. Familiarise yourself with the gases currently being
monitored in your unit. Ensure you understand site health
and safety procedures. For information on peak and TWA
readings, go to section 2.4.
2.3 Display symbol guide
Battery
A full battery is represented by a battery icon showing a full
six bars. A low battery charge will show 1 to 2 bars. When
zero bars are shown the battery icon flashes. The sounder
will emit warning bleeps.
If the battery becomes too low, Tetra 3 will display a ‘Battery
low’ warning message and switch off.
TWA alarm
Tetra 3 will display the TWA alarm when the 15 minute or 8
hour time weighted average alarm threshold is passed for
toxic gases.
Confidence signals
To reassure users the unit is working correctly, the Tetra 3 unit will
emit a short beep every 10 seconds and the OK icon will flash.
CH4 %LEL CO ppm
H2S ppm O2 %
0.0
0.0
0
20.9
OK
OK
Flashing
icon, Tetra3
running
normally
Battery
Screen Icons
Auto zero
Warm up
!
Full

2.4 Display options
Tetra 3 provides two additional selectable displays:
Peak display
When Peak mode is selected the instrument shows the highest value
for flammable and toxic gases and the lowest value for oxygen since
the unit was switched on or since the last peak clear.
After 5 seconds the screen will display 'Peak Clear'. If you press the
button within the 10 second countdown, the peak value is cleared. If the
button is not pressed, the display will revert to the stored peak value.
Whilst in Peak mode, new higher gas values are stored. Upon exit of
Peak mode, the stored peak values are not deleted.
This is useful for vertical entry checks where a whole instrument can be
lowered down the shaft rather than just a sampling tube.
TWA display
Shows the 8 hour time weighted average (TWA), for toxic gases,
monitored since last turn on.
1. To view the additional display option menu, double-click the operator
button.
2. Press the operator button with a single click to scroll through the list.
When your choice is highlighted, double-click the operator button.
The Tetra 3 operator screen will display the peak or TWA icon and the
gas readings recorded.
10
Display options Tetra 3
CH4 %LEL CO ppm
H2S ppm O2 %
0.0
0.0
0
20.8
OK
Gas
Peak
TWA
Zero
0
Gas
Zero
TWA
Peak
1. Scroll 2. Select
ppm
%
0
20.8
OK
Peak display

11
Tetra 3 Event logging
Zero
The Tetra 3 instrument can perform an auto zero by selecting the Zero
function from the menu. When Zero is completed, the instrument will
return to normal operation.
2.5 Logging
Tetra 3 incorporates data and event logging which can be accessed using the
communications link with Portable PC software. See section VIII.
The Tetra 3 event log 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, alarm on,
alarm off and the peak level during the alarm
• Zero, calibration and gas test with success or failure
• Pellistor saver on and off
• The battery condition is logged every time the Tetra 3 is
switched on or off, and when it is placed into or removed from
the charger
• Datalogging records reading sets data at a predetermined time
interval, usually set to one minute.

Batteries Tetra 3
III. Batteries
3.1 Rechargeable batteries
Tetra 3 uses a rechargeable Lithium-ion battery which must only be charged
using a Crowcon battery charger. A 5 hour recharge from flat will provide at
least 12 hours operating time. A fully charged battery will provide more than
16 hours of continuous use.
Charging the batteries
1. Ensure you are in a safe area.
2. Plug the charger power supply into a
mains socket.
3. Connect the power supply to the
charger. Insert the Tetra 3 into the
charger.
Switch on the charger's power supply.
The unit would normally be left
switched off for charging. When
charging is complete the red LED is
extinguished. (Early units had a green
LED illuminate on completion of
charge). If the unit is switched on
during charge the normal display
battery icon sweeps from empty to
full. On disconnecting the charger power supply this display icon will
update in 20 seconds to show actual charge state.
In Run mode, the battery icon will display six bars when it is full.
4. Remove the Tetra 3 from the charger and switch on to use.
12
Communications
socket
Battery full
Low battery
Battery needs
recharging
25
i
WARNING
Tetra warning message
Battery fully charged
The charging time will be longer if the unit is switched on during charging.

13
Tetra 3 Alarm indications
IV. Alarm indications
Tetra 3 provides two instantaneous alarm levels for each installed sensor, desig-
nated level 1 and level 2. For toxic gas sensors, there are also two time weight-
ed average alarms (TWA), one for short term exposure (STEL): based on a 15
minute time weighted average, and the second TWA alarm is for long term
exposure: based on a 8 hour time weighted average.
Alarm configurations are set via the Crowcon Portables PC software.
The following settings can be made:
Alarm thresholds for each sensor: Level 1
and level 2 alarms can be set for each individual
gas sensor.
Alarm type: This can be set to rising levels of gas concentra-
tion, or as falling. Oxygen are set to falling for deficiency
monitoring as a default.
Alarm latching: Alarms can be set to be latched or
unlatched. Latched alarms will require the operator button to
be pushed in order to clear the alarm. This is the default set-
ting. Unlatched alarms will clear automatically when the gas
hazard has passed.
Alarm mute: The sounder can be set to mute for level 1
alarm only; pressing the operator button during an alarm
condition i.e. presence of hazardous gas, will silence the
sounder and stop the vibration alarm. The alarm LEDs will
continue to flash.
Alarm sounder tone: Different tones can be selected to
achieve the best performance for the monitoring conditions
available.
In the event of a Time Weighted Alarm (TWA)
In the event the 15 minute or the 8 hour TWA is triggered,
Tetra 3 will go into alarm and display the TWA icon with the
toxic gas readings. Neither the 15 minute alarm or 8 hour
alarm can be cleared.
1 2

V. Fixing Accessories
Belt clip
Tetra 3 has a strong alligator clip located on the back of the unit. Lifting the
small lever will allow the unit to be attached to a belt more easily.
Universal harness plate
Crowcon provide a universal harness plate which can be used with either a
chest harness or a shoulder strap.
How to wear your Tetra 3 unit
Chest harness
Use the M3 fixing on the back
of your Tetra 3 unit to attach
the chest harness plate.
Create a chest harness by
attaching one strap to the top
connectors, to go around the
neck, and the other to link
around the waist using the
side connectors. Adjust the
lengths until the Tetra 3 unit is
in a comfortable working
position.
Shoulder strap
With the universal harness plate in place, attach the shoulder strap accessory
onto the top connectors. Adjust to a comfortable working position.
See accessories, section XI, for full list.
14
Fixing Accessories Tetra 3
Shoulder/neck
connectors
Universal harness plate

Tetra 3 Flow sampling
VI. Flow sampling
Attaching the flow adaptor plate
To perform manual sampling using Tetra 3, a flow adaptor plate must be fitted
onto the front of the instrument.
1. To fit the flow adaptor plate, clip the plate in place over the sensor
grills and screw the thumbscrew until the plate is tightly fitted into
place.
2. Attach the sampling tube or flow accessory onto the gas inlet nozzle.
3. Attach the aspirator bulb onto the gas outlet nozzle.
4. To remove the flow adaptor plate, unscrew the thumbscrew and lift
the plate away from the instrument.
15
Flow adaptor
Gas in
Gas out
The sampling tube supplied is normally a 2m (6ft) length. Longer lengths of sampling
tube can be provided, but will increase the time taken to get a sample from the point
of sampling to the Tetra 3 instrument. When using an extended length of tubing a
response time test is recommended. Gas of known concentration should be sampled
along the full length of tubing to be used and the time taken for the sensor reading to
reach the known gas levels should be noted. This time should be used as the minimum
for sampling before readings should be taken.

Flow sampling Tetra 3
Diffusion instruments
When using the manual aspirator kit, adopt a consistent style whilst using the
hand aspirator. Crowcon recommend squeezing once per second to achieve a
flow rate of approximately 0.5 - 1 litre/min. At least 10 pumps per sample are
recommended.
16