All Rights Reserved. No part of this manual may be reproduced, transmitted, transcribed,
stored in a retrieval system, or translated into any other language or computer language in
whole or in part, in any form or by any means, whether it be electronic, mechanical,
magnetic, optical, manual, or otherwise, without the prior written consent of Teledyne
Analytical Instruments, 16830 Chestnut Street, City of Industry, CA 91749-1580.
Warranty
This equipment is sold subject to the mutual agreement that it is warranted by us free from
defects of material and of construction, and that our liability shall be limited to replacing or
repairing at our factory (without charge, except for transportation), or at customer plant at
our option, any material or construction in which defects become apparent within one year
from the date of shipment, except in cases where quotations or acknowledgements provide
for a shorter period. Components manufactured by others bear the warranty of their
manufacturer. This warranty does not cover defects caused by wear, accident, misuse,
neglect or repairs other than those performed by Teledyne or an authorized service center.
We assume no liability for direct or indirect damages of any kind and the purchaser by the
acceptance of the equipment will assume all liability for any damage which may result from
its use or misuse.
We reserve the right to employ any suitable material in the manufacture of our apparatus,
and to make any alterations in the dimensions, shape or weight of any parts, in so far as
such alterations do not adversely affect our warranty.
Important Notice
T hi s in str ument p ro v id es measur ement read in g s to it s user, an d serv es as a to o l b y w h i c h
v al uabl e d at a can b e g at h er ed . The i n fo rmat i on p r ov id ed by t h e in st r umen t may assi st th e user
i n el imi nati n g po ten ti al hazard s cau sed b y his p r ocess; ho wev er , it is essent ial t hat all
p er so nn el in v ol ved in th e u se o f t he in st ru men t or it s int er f ace, wi th t h e pr ocess b ein g
measu red , be pr op er l y tr ain ed i n t he pr ocess i tself , as well as all in s t r u m e n t a t io n rel at ed to i t .
The safety of personnel is ultimately the responsibility of those who control process
conditions. While this instrument may be able to provide early warning of imminent
danger, it has no control over process conditions, and it can be misused. In particular, any
alarm or control systems installed must be tested and understood, both as to how they
operate and as to how they can be defeated. Any safeguards required such as locks, labels,
or redundancy, must be provided by the user or specifically requested of Teledyne at the
time the order is placed.
Therefore, the purchaser must be aware of the hazardous process conditions. The purchaser
is responsible for the training of personnel, for providing hazard warning methods and
instrumentation per the appropriate standards, and for ensuring that hazard warning devices
and instrumentation are maintained and operated properly.
Teledyne Analytical Instruments, the manufacturer of this instrument, cannot accept
responsibility for conditions beyond its knowledge and control. No statement expressed or
implied by this document or any information disseminated by the manufacturer or its
agents, is to be construed as a warranty of adequate safety control under the user’s process
conditions.
Teledyne Analytical Instrumentsiii
BDS 3000
Specific Model Information
The instrument for which this manual was supplied may
incorporate one or more options not supplied in the standard instrument.
Commonly available options are listed below, with check boxes. Any
that are incorporated in the instrument for which this manual is supplied
are indicated by a check mark in the box.
Instrument Serial Number: _______________________
Options Included in the Instrument with the Above Serial Number:
• BDS 3000-V:Instrument configured for Vacuum Service
• 19" Rack Mnt:The 19" Relay Rack Mount units are
available with one BDS 3000 series
analyzers installed in a standard 19" panel
and ready to mount in a standard rack.
Teledyne Analytical Instrumentsiv
Oxygen Analyzer
Safety Messages
Your safety and the safety of others is very important. We have
provided many important safety messages in this manual. Please read
these messages carefully.
A safety message alerts you to potential hazards that could hurt you
or others. Each safety message is associated with a safety alert symbol.
These symbols are found in the manual and inside the instrument. The
definition of these symbols is described below:
GENERAL WARNING/CAUTION: Refer to the
instructions for details on the specific danger. These cautions
warn of specific procedures which if not followed could cause
bodily Injury and/or damage the instrument.
CAUTION: HOT SURFACE WARNING: This warning is
specific to heated components within the instrument. Failure
to heed the warning could result in serious burns to skin and
underlying tissue.
WARNING: ELECTRICAL SHOCK HAZARD: Dangerous
voltages appear within this instrument. This warning is
specific to an electrical hazard existing at or nearby the
component or procedure under discussion. Failure to heed this
warning could result in injury and/or death from
electrocution.
Technician Symbol: All operations marked with this symbol
are to be performed by qualified maintenance personnel only.
NOTE: Additional information and comments regarding a
specific component or procedure are highlighted in the form
of a note.
CAUTION:THE ANALYZER SHOULD ONLY BE USED FOR THE
PURPOSE AND IN THE MANNER DESCRIBED IN
THIS MANUAL.
Teledyne Analytical Instrumentsv
BDS 3000
IF YOU USE THE ANALYZER IN A MANNER OTHER
THAN THAT FOR WHICH IT WAS INTENDED,
UNPREDICTABLE BEHAVIOR COULD RESULT
POSSIBLY ACCOMPANIED WITH HAZARDOUS
CONSEQUENCES.
This manual provides information designed to guide you through
the installation, calibration and operation of your new analyzer. Please
read this manual and keep it available.
Occasionally, some instruments are customized for a particular
application or features and/or options added per customer requests.
Please check the front of this manual for any additional information in
the form of an Addendum which discusses specific information,
procedures, cautions and warnings that may be peculiar to your
instrument.
Manuals do get lost. Additional manuals can be obtained from
Teledyne at the address given in the Appendix. Some of our manuals are
available in electronic form via the internet. Please visit our website at:
www.teledyne-ai.com.
This is a general purpose instrument designed for usage in a
nonhazardous area. It is the customer's responsibility to
ensure safety especially when combustible gases are being
analyzed since the potential of gas leaks always exist.
The customer should ensure that the principles of operating
of this equipment is well understood by the user. Misuse of
this product in any manner, tampering with its components,
or unauthorized substitution of any component may
adversely affect the safety of this instrument.
Since the use of this instrument is beyond the control of
Teledyne, no responsibility by Teledyne, its affiliates, and
agents for damage or injury from misuse or neglect of this
equipment is implied or assumed.
Teledyne Analytical Instrumentsxiii
Oxygen AnalyzerIntroduction
Introduction
1.1Overview
The Teledyne Analytical Instruments Model BDS 3000 Trace
Oxygen Analyzer is a versatile microprocessor-based instrument for
detecting oxygen at the parts-per-billion (ppb) level in a variety of gases.
This manual covers the Model BDS 3000 General Purpose flush-panel
and/or rack-mount units only. These units are for indoor use in a nonhazardous environment.
1.2Typical Applications
A few typical applications of the Model BDS 3000 are:
• Monitoring inert gas blanketing
• Air separation and liquefaction
• Chemical reaction monitoring
• Semiconductor manufacturing
• Petrochemical process control
• Quality assurance
• Gas analysis certification.
1.3Main Features of the Analyzer
The Model BDS 3000 Oxygen Analyzer is sophisticated yet simple
to use. The main features of the analyzer include:
• A 2-line alphanumeric vacuum fluorescent display (VFD)
screen, driven by microprocessor electronics. The screen
continuously prompts and informs the operator.
• High resolution, accurate readings of oxygen content from
low ppb levels through 100 ppm. Large, bright, meter
readout.
• New BDS Sensing technology, Patent pending.
Teledyne Analytical Instruments1
IntroductionBDS 3000
• Versatile analysis over a wide range of applications.
• Microprocessor based electronics: 8-bit CMOS
microprocessor with 32 kB RAM and 128 kB ROM.
• Three user definable output ranges (from 0-100 ppb through
0-100 ppm) allow best match to users process and
equipment, plus a fixed 100 ppm over range.
• Auto Ranging allows analyzer to automatically select the
proper preset range for a given measurement. Manual
override allows the user to lock onto a specific range of
interest.
• Two adjustable concentration alarms and a system failure
alarm.
• Extensive self-diagnostic testing, at startup and on demand,
with continuous power-supply monitoring.
• Two way RFI protection.
• RS-232 serial digital port for use with a computer or other
digital communication device.
• Four analog outputs: two for measurement (0–1 VDC and
Isolated 4–20 mA DC) and two for range identification.
• Convenient and versatile, steel, flush-panel or rack-
mountable case with slide-out electronics drawer.
1.4Front Panel (Operator Interface)
The standard BDS 3000 is housed in a rugged metal case with all
controls and displays accessible from the front panel. See Figure 1-1.
The front panel has thirteen buttons for operating the analyzer, a digital
meter, an alphanumeric display, and a window for viewing the sample
flowmeter.
Function Keys: Six touch-sensitive membrane switches are used to
change the specific function performed by the analyzer:
•AnalyzePerform analysis for oxygen
content of a sample gas.
Teledyne Analytical Instruments2
Oxygen AnalyzerIntroduction
Figure 1-1: BDS-3000 Front Panel
•SystemPerform system-related tasks
(described in detail in chapter 4,
Operation.).
•SpanSpan calibrate the analyzer.
•ZeroZero calibrate the analyzer.
•AlarmsSet the alarm setpoints and
attributes.
•RangeSet up the 3 user definable ranges
for the instrument.
Data Entry Keys: Six touch-sensitive membrane switches are used to
input data to the instrument via the alphanumeric VFD display:
•Left & Right Arrows
Select between functions currently
displayed on the VFD screen.
Teledyne Analytical Instruments3
IntroductionBDS 3000
•Up & Down Arrows
Increment or decrement values of
functions currently displayed.
•EnterMoves VFD display on to the next
screen in a series. If none remains,
returns to the
Analyze
screen.
•EscapeMoves VFD display back to the
previous screen in a series. If none
remains, returns to the
Analyze
screen.
Digital Meter Display: The meter display is a Light Emitting Diode
(LED) device that produces large, bright, 7-segment numbers that are
legible in any lighting. It produces a continuous readout from 0-999.9
ppb and then switches to a continuous ppm readout from 0-100.00 ppm.
It is accurate across all analysis ranges without the discontinuity inherent
in analog range switching.
Alphanumeric Interface Screen: The VFD screen is an easy-to-use
interface from operator to analyzer. It displays values, options, and
messages that give the operator immediate feedback.
Flowmeter: Monitors the flow of gas past the sensor. Readout is 0.1 to
2.0 standard liters per minute (SLPM) of nitrogen
Standby Button: The Standby turns off the display and outputs, but
circuitry is still operating.
CAUTION:THE POWER CABLE MUST BE UNPLUGGED TO
FULLY DISCONNECT POWER FROM THE
INSTRUMENT. WHEN CHASSIS IS EXPOSED OR
WHEN ACCESS DOOR IS OPEN AND POWER
CABLE IS CONNECTED, USE EXTRA CARE TO
AVOID CONTACT WITH LIVE ELECTRICAL
CIRCUITS.
Access Door: For access t o the BDS S ensor , the front panel swi ngs open
when the l at ch in t he upper r ight corner of t he panel i s pressed al l the way
i n wi th a nar row gauge t ool . Accessi ng the mai n cir cuit boar d requir es
unf astening rear panel screws and sl i di ng t he uni t out of the case.
Teledyne Analytical Instruments4
Oxygen AnalyzerIntroduction
1.5Rear Panel (Equipment Interface)
The rear panel, shown in Figure 1-2, contains the gas and electrical
connectors for external inlets and outlets. Some of those depicted are
optional and may not appear on your instrument. The connectors are
described briefly here and in detail in Chapter 3 Installation.
Figure 1-2: Model BDS 3000 Rear Panel
•Power ConnectionUniversal AC power source.
•Gas Inlet and OutletOne inlet and one exhaust out.
•Analog Outputs0–1 VDC oxygen concentration
plus 0-1 VDC range ID, and
isolated 4–20 mA DC oxygen
concentration plus 4-20 mA DC
range ID.
Teledyne Analytical Instruments5
IntroductionBDS 3000
•Alarm Connections2 concentration alarms and 1
system alarm.
•RS-232 PortSerial digital concentration signal
output and control input.
•Remote ProbeUsed in the BDS 3000 for
controlling external solenoid
valves only.
•Remote Span/ZeroDigital inputs allow external
control of analyzer calibration.
•Calibration ContactTo notify external equipment that
instrument is being calibrated and
readings are not monitoring
sample.
•Range ID ContactsFour separate, dedicated, range
relay contacts. Low, Medium,
High, Cal.
•Network I/OSerial digital communications for
local network access. For future
expansion. Not implemented at this
printing.
Note: If you require highly accurate Auto-Cal timing, use external
Auto-Cal control where possible. The internal clock in the
Model BDS 3000 is accurate to 2-3 %. Accordingly,
internally scheduled calibrations can vary 2-3 % per day.
Teledyne Analytical Instruments6
Oxygen AnalyzerOperational Theory
Operational Theory
2.1Introduction
The analyzer is composed of three subsystems:
• BDS Sensor
• Sample System
• Electronic Signal Processing, Display and Control
The sample system is designed to accept the sample gas and
transport it through the analyzer without contaminating or altering the
sample prior to analysis. The BDS Sensor is an electrochemical device
that translates the amount of oxygen present in the sample into an
electrical current. The electronic signal processing, display and control
subsystem simplifies operation of the analyzer and accurately processes
the sampled data. The microprocessor controls all signal processing,
input/output and display functions for the analyzer.
2.2BDS Sensor
2.2.1 Principles of Operation
The BDS oxygen sensor technology developed at Teledyne
Analytical Instruments is a result of TAI’s heavy investment on R&D
and expertise established during the half-century’s manufacturing of
electrochemical oxygen sensor. It stands for Bipotentiostat Driven
Sensor. A BDS oxygen sensor accurately translates the oxygen level in
the sample gas into to an electrical current signal.
A potentiostat contains three electrodes: a working electrode, a
reference electrode and a counter electrode. A Bipotentiostat is a
combination of two potentiostats that share the reference electrode and
the counter electrode. The potential at the working electrode is precisely
controlled with respect to the
is used to carry the current that flow through the sensor. A potentiostat is
typically constructed with several operational amplifiers. The three
electrodes in an electrochemical cell and the operational amplifiers in
Teledyne Analytical Instruments7
reference electrode. The counter electrode
Operational TheoryBDS 3000
the potentiostat constitute a feedback-control loop. The potentiostat
technology has been well accepted in the field of electrochemistry, and
proven effective in eliminating polarization of the reference electrode
and automatic compensating electric resistance in the cell.
In a BDS oxygen sensor, the sensing electrode is a working
electrode that is under precise potential control as discussed above. A
stable sensing electrode potential is very critical for an oxygen sensor to
achieve high stability, low noise and large dynamic range. The reference
electrode in a BDS sensor is a Ag/Ag
O electrode which is well known
2
for its stable electrode potential and compatibility with the KOH
electrolyte in an oxygen sensor. The counter electrode is made of a
Platinum wire.
The sensing process involves electrochemical reactions inside the
sensor. At the sensing electrode, oxygen is reduced at the controlled
potential:
+ 2H2O + 4e
O
2
-
— > 4OH
-
(1)
There is no net electrochemical reaction at the reference electrode
since it is connected to the high impedance input of the operation
amplifier.
The electrochemical reaction at the counter electrode is:
4OH- — > O2 + 2H2 O + 4e
-
It is noteworthy that reaction (2) is reverse of the reaction (1). It is
indicative of a net change of zero inside a BDS sensor throughout the
sensing process. This feature produces a long-term stability for the BDS
sensor.
There are two resources of oxygen being reduced at the sensing
electrode: from the sample gas and dissolved oxygen within the
electrolyte. The oxygen molecules in the sample gas diffuse to the
sensing electrode through a diffusion barrier (controlled diffusion) to
produce a current signal which is proportional to the oxygen level in the
sample gas. However, the dissolved oxygen in the electrolyte also
diffuses through the electrolyte. It is reduced at the sensing electrode and
produces a background current. This background current represents the
detection limit of an oxygen sensor.
The main advantage of the BDS technology lies in the unique
second potentiostat. It is designed to remove dissolved oxygen and other
( 2)
Teledyne Analytical Instruments8
Oxygen AnalyzerOperational Theory
impurities in the electrolyte. It eliminates the internal background
current which previously limited the detection process.
The second potentiostat is located adjacent to the sensing electrode.
It uses a novel material, Reticulated Vitreous Carbon (RVC) and precise
control of the potential to remove the dissolved oxygen and impurities in
the electrolyte efficiently. As the result, the BDS sensor achieves an
outstanding feature of absolute zero output in the absence of oxygen.
Figure 2.1: Cross Section of the BDS Oxygen Sensor
Figure 2.1 shows the schematic of a BDS oxygen sensor. The
sample gas enters the sensor through the gas inlet port and exits at the
gas outlet. A portion of oxygen in the sample gas diffuses through the
diffusion barrier to be reduced at the sensing electrode to form OH- in
the electrolyte. OH- can move freely through the porous 2nd working
electrode. At the Counter Electrode, OH- is oxidized back to oxygen.
While the 2nd working electrode allows OH- to move through, it
prevents the dissolved oxygen from the top portion of the sensor to reach
Teledyne Analytical Instruments9
Operational TheoryBDS 3000
the sensing electrode. The reference electrode provides a potential
reference for both the sensing electrode and the 2nd working electrode.
NOTE: BDS technology and sensor is a patent pending
technology of Teledyne Analytical Instruments in the
United State of America as well as many foreign countries.
To learn more about BDS technology, please visit TAI’s web page at
http://www.Teledyne-AI.com
To learn more about potentiostat, visit Electochemical Society’s web
page at http://www.electrochem.org
2.2.2 Gas Flow Rate
The output from a BDS oxygen sensor is relatively insensitive to
change of gas flow rate if operated in the range of 1 - 3 SCFH (in
nitrogen). The output drops when the flow rate is below 1 SCFH. Figure
2.2 is a typical curve showing the sensor outputs at different flow rate.
Figure 2.2: BDS sensor output at different gas flow rate
Teledyne Analytical Instruments10
Oxygen AnalyzerOperational Theory
2.2.3 Gas Pressure
The analyzer is equipped with a flow restriction tube (from the
back panel of the analyzer to the left side of the BDS sensor) as shown
in Figure 2-3. The sensor is not affected by pressure as long as the
analyzer vents to atmosphere. If the analyzer is not vented to
atmosphere, the downstream pressure must not exceed 10 inch of water.
A clogged or restricted vent or excessive pressure will force gas into the
electrolyte and cause damage to the BDS sensor.
Figure 2-3: BDS Sample System
2.2.4 Temperature effect
The raw output from a BDS oxygen sensor has a temperature
coefficient about 0.25% / °C. This temperature effect is compensated by
the software throughout the operation temperature range (5 – 40°C).
2.2.5 Recovery from High Level Oxygen Exposure
The ambient air contains about 210,000,000 ppb (2.1 x 108)
oxygen. Figure 2.4 is a typical purge-down curve for a new BDS sensor
which had been air saturated. It is normal to take several hours, even
days for an air saturated BDS to purge down to a low ppb level.
Teledyne Analytical Instruments11
Operational TheoryBDS 3000
Figure 2.4 Typical Purge-down Curve After Air Saturation
S h or t e n i ng t h e ai r exp o s u r e wi l l al l o w a f a s t e r se ns o r r ec o v e r y.
A ty p i c a l BD S se n s o r wi l l re c o v e r t o 1 pp m i n ap p r ox i m a t el y 25
m i nu t e s , t o 10 0 pp b af t e r 80 m i n , an d 10 pp b i n ab ou t 8 ho u r s , af t e r
s u f f e r i n g a t e n m i n u t e ex p os u r e to ai r .
2.2.6 Background gas compatibility
T he BDS oxygen sensor wi l l work in i ner t gas backgr ounds,
i ncludi ng ni t rogen, hydr ogen, ar gon, heli um and ethane. The sensor
out put, however, i s dif fer ent in di ff erent backgr ound gases. For exam pl e,
t he sensor output i n a hydr ogen background is twi ce as much as it woul d
be in a ni tr ogen background. Therefor e, i t is recom mended to cali br ate t he
analyzer wit h an oxygen standar d that has a sim il ar background as the
sam pl e gas. If an oxygen st andar d is unavai l able for a par ti cul ar
background, a Gas F act or which is det er mi ned at TAI coul d be used t o
cor rect the sensor out put in dif f er ent backgr ound (see sect ion 4.3.9) .
Note: the gas flow meter in the analyzer is calibrated for air. The
error for measuring nitrogen is usually negligible. But for
hydrogen, it reads 100% lower. For example, when the
float ball in the flow meter is at 0.5 SLPM, the actual flow
rate of hydrogen is about 1 SLPM.
Teledyne Analytical Instruments12
Oxygen AnalyzerOperational Theory
The BDS oxygen sensor can tolerate exposure to acidic gases. Up
to 0.2% CO
has no effect to ppb level oxygen measurement.
2
2.2.7 Stability
The BDS sensor is essentially drift free. Typically a BDS sensor
requires no re-calibration over an entire year period. However, there
may be some intrusion to the zero during the maintenance. See next
section for details.
2.2.8 Maintenance
The only maintenance required on the BDS sensor is to replenish
distilled or de-ionized water every three to four months. It is not
necessary to take the analyzer out of service while adding water to the
sensor but caution should be taken to avoid spilling water on the PC
boards or other area inside the analyzer.
Figure 2.5: Adding DI Water to the BDS Sensor
There is a Max line and Min Line clearly marked on the BDS
sensor body. It is a good practice to check the electrolyte level every
month and add de-ionized water into the sensor whenever it is
convenient.
When running dry gas through the sensor, the gas carries out
moisture from the sensor. Therefore, the electrolyte (10% KOH in
Teledyne Analytical Instruments13
Operational TheoryBDS 3000
water) inside the sensor is gradually concentrated during the sensor
operation. It typically takes about four months for the electrolyte level to
drop from the Max line to Min line. When adding water to increase the
electrolyte level from the Min line to the Max line, it is typical that the
oxygen reading will drift down about 10 ppb in an hour. If the oxygen
content in the sample gas is very close to zero, the analyzer may display
a negative reading during this period. The sensor will recover by itself
during the following week. This drift-down then recover-back
phenomenon is caused by the quick dilution of the electrolyte and reestablishment of a new equilibrium inside the sensor. To minimize this
effect, add a small amount of water each time and do this before the
electrolyte level reaches the Min line.
2.3Sample System
The sample system delivers gases to the BDS sensor from the
analyzer rear panel inlet. Depending on the mode of operation either
sample or calibration gas is delivered.
The Model BDS 3000 sample system is designed and fabricated to
ensure that the oxygen concentration of the gas is not altered as it travels
through the sample system.
The sampl e syst em for the standar d inst rument incor porates 1/4" VCR
fit tings for sample inl et and swagelock fittings for outl et tube connections at
the rear panel. The sample or cal ibrati on gas that flows through the system
is monitored by a flowmeter downstream from the sensor .
Figure 2-6 represents the flow diagram of the sampling system. In
the standard instrument, calibration gases can be connected directly to
the Sample In port by teeing to the port with appropriate valves.
Figure 2-6: Flow Diagram
Teledyne Analytical Instruments14
Oxygen AnalyzerOperational Theory
2.4Electronics and Signal Processing
T he Model BDS 3000 Oxygen Analyzer uses an 8031
m icrocontr ol l er wi th 32 kB of RAM and 128 kB of ROM to cont rol all
signal processi ng, i nput / output, and di splay functi ons f or the analyzer .
S ystem power is suppli ed fr om a universal power suppl y module desi gned
t o be compat i bl e wi t h any i nt er nat ional power source. F i gure 2- 7 shows
t he l ocati on of t he power suppl y and the mai n el ect roni c P C boards.
The signal processing electronics including the microprocessor,
analog to digital, and digital to analog converters are located on the
motherboard at the bottom of the case. The preamplifier board is
mounted on top of the motherboard as shown in the figure. These boards
are accessible after removing the back panel. Figure 2-8 is a block
diagram of the Analyzer electronics.
In the presence of oxygen the sensor generates a current. A current
to voltage amplifier converts this current to a voltage, which is further
amplified in the second stage amplifier.
The output from the second stage amplifier is sent to an 18 bit
analog to digital converter controlled by the microprocessor.
The digital concentration signal along with input from the control
panel is processed by the microprocessor, and appropriate control
signals are directed to the display, alarms and communications port. The
same digital information is also sent to a 12 bit digital to analog
converter that produces the 4-20 mA DC and the 0-1 VDC analog
concentration signal outputs, and the analog range ID outputs.
Signals from the power supply are also monitored, and through the
microprocessor, the system failure alarm is activated if a malfunction is
detected.
Teledyne Analytical Instruments15
Operational TheoryBDS 3000
Figure 2-7: Electronic Component Location
Teledyne Analytical Instruments16
Oxygen AnalyzerOperational Theory
Figure 2-8: BDS 3000 Electronics Block Diagram
Teledyne Analytical Instruments17
Operational TheoryBDS 3000
Teledyne Analytical Instruments18
Oxygen AnalyzerInstallation
Installation
Installation of the Model BDS 3000 Analyzer includes:
• Unpacking
• Mounting
• Gas connections
• Electrical connections
• Filling the Sensor with Electrolyte.
• Testing the system.
3.1Unpacking the Analyzer
Although the analyzer is shipped complete, certain parts, such as
the electrolyte, are wrapped separately to be installed on site as part of
the installation. Carefully unpack the analyzer and inspect it for damage.
Immediately report any damage or shortages to the shipping agent.
3.2Mounting the Analyzer
The Model BDS 3000 is for indoor use in a general purpose area. It
is NOT for hazardous environments of any type.
T he standard model is designed for f l ush panel m ounti ng. F igur e 3-1
i s an i l lust r at ion of the BDS 3000 st andard fr ont panel and mount ing
bezel . There ar e four mount ing hol es—one in each corner of t he ri gi d
f rame. The dr awings sect i on i n the r ear of thi s manual contai ns out l ine
dim ensi ons and mount ing hol e spaci ng di agram s.
On special order, a 19" rack-mounting panel can be provided. For
rack mounting, one BDS 3000 series analyzer is flush-panel mounted on
the rack panel. See Appendix for dimensions of the mounting panel.
Teledyne Analytical Instruments19
InstallationBDS 3000
Figure 3-1: Model BDS 3000 Front Panel
All operator controls are mounted on the control panel, which is
hinged on the left edge and doubles as the door that provides access to
the sensor and cell block inside the instrument. The door is spring
loaded and will swing open when the button in the center of the latch
(upper right corner) is pressed all the way in with a narrow gauge tool
(less than 0.18 inch wide), such as a small hex wrench or screwdriver
Allow clearance for the door to open in a 90-degree arc of radius 7.125
inches. See Figure 3-2.
Figure 3-2: Required Front Door Clearance
Teledyne Analytical Instruments20
Oxygen AnalyzerInstallation
3.3Rear Panel Connections
Figure 3-3 shows the Model BDS 3000 rear panel. There are ports
for gas inlet and outlet, power, communication, and both digital and
analog concentration output.
Figure 3-3: Rear Panel of the Model Ultra Trace 3000
3.3.1Gas Connections
The unit is manufactured with 1/4 inch VCR fittings. For a safe
connection:
SAMPLE IN: In the standard model, gas connections are made at the
SAMPLE IN and EXHAUST OUT connections. Calibration gases must be
tee'd into the sample inlet with appropriate valves. A VCR fitting is
provided for the inlet connection.
Teledyne Analytical Instruments21
InstallationBDS 3000
The inlet gas pressure should be regulated to pressures between 11
to 16 psig to maintain a flow between 0.5 to 1.0 SLPM. If pressure is too
low, the flow will drop below 0.5 SLPM at which the output of the
sensor is sensitive (see section 2.2.2). If pressure is too high, it will force
gas into the electrolyte and cause damage to the sensor. A pressure
regulator must be used if sample pressure varies farther than the
recommended range.
If greater sample flow is required for improved response time,
install a bypass in the sampling system upstream of the analyzer input.
EXHAUST OUT: Exhaust connections must be consistent with the
hazard level of the constituent gases. Check Local, State, and Federal
laws, and ensure that the exhaust stream vents to an appropriately
controlled area, if required
3.3.2Electrical Connections
For safe connections, no uninsulated wiring should be able to come
in contact with fingers, tools or clothing during normal operation.
CAUTION:USE SHIELDED CABLES. ALSO, USE PLUGS THAT
PROVIDE EXCELLENT EMI/RFI PROTECTION. THE
PLUG CASE MUST BE CONNECTED TO THE CABLE
SHIELD, AND IT MUST BE TIGHTLY FASTENED TO
THE ANALYZER WITH ITS FASTENING SCREWS.
ULTIMATELY, IT IS THE INSTALLER WHO ENSURES
THAT THE CONNECTIONS PROVIDE ADEQUATE
EMI/RFI SIELDING.
3.3.2.1 PRIMARY INPUT POWER
The power cord receptacle and fuse block are located in the same
assembly. Insert the power cord into the power cord receptacle.
CAUTION:POWER IS APPLIED TO THE INSTRUMENT'S
CIRCUITRY AS LONG AS THE INSTRUMENT IS
CONNECTED TO THE POWER SOURCE. THE RED
SWITCH ON THE FRONT PANEL IS FOR SWITCHING
POWER ON OR OFF TO THE DISPLAYS AND
OUTPUTS ONLY.
The universal power supply requires 85–250 VAC, 47-63 Hz power
source.
Teledyne Analytical Instruments22
Oxygen AnalyzerInstallation
Fuse Installation: The fuse block, at the right of the power cord
receptacle, accepts US or European size fuses. A jumper replaces the
fuse in whichever fuse receptacle is not used. Fuses are not installed at
the factory. Be sure to install the proper fuse as part of installation. (See
Fuse Replacement in chapter 5, maintenance.)
3.3.2.2 50-PIN EQUIPMENT INTERFACE CONNECTOR
Figure 3-4 shows the pin layout of the Equipment Interface
connector. The arrangement is shown as seen when the viewer faces the
rear panel of the analyzer. The pin numbers for each input/output
function are given where each function is described in the paragraphs
below.
Analog Outputs: There are four DC output signal pins—two pins per
output. For polarity, see Table 3-1. The outputs are:
0–1 VDC % of Range:Voltage rises linearly with increasing
oxygen, from 0 V at 0 ppm to 1 V at
full scale ppm. (Full scale = 100% of
programmable range.)
0–1 VDC Range ID:0.25 V = Low Range, 0.5 V = Medium
Range, 0.75 V = High Range, 1 V =
100ppm.
4–20 mA DC % Range:Current increases linearly with
increasing oxygen, from 4 mA at 0
ppm to 20 mA at full scale ppm. (Full
scale = 100% of programmable range.)
4–20 mA dc Range ID:8 mA = Low Range, 12 mA = Medium
Range, 16 mA = High Range, 20 mA
= 100ppm.
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InstallationBDS 3000
Table 3-1: Analog Output Connections
PinFunction
3+ Range ID, 4-20 mA, floating
4– Range ID, 4-20 mA, floating
5+ % Range, 4-20 mA, floating
6– % Range, 4-20 mA, floating
8+ Range ID, 0-1 V dc
23– Range ID, 0-1 V dc, negative ground
24+ % Range, 0-1 V dc
7– % Range, 0-1 V dc, negative ground
Alarm Relays: The nine alarm-circuit connector pins connect to the
internal alarm relay contacts. Each set of three pins provides one set of
Form C relay contacts. Each relay has both normally open and normally
closed contact connections. The contact connections are shown in Table
3-2. They are capable of switching up to 3 amperes at 250 VAC into a
resistive load. The connectors are:
Threshold Alarm 1:
• Can be configured as high (actuates when concentration
is above threshold), or low (actuates when concentration
is below threshold).
• Can be configured as failsafe or nonfailsafe.
• Can be configured as latching or nonlatching.
• Can be configured out (defeated).
Threshold Alarm 2:
• Can be configured as high (actuates when concentration
is above threshold), or low (actuates when concentration
is below threshold).
• Can be configured as failsafe or nonfailsafe.
• Can be configured as latching or nonlatching.
• Can be configured out (defeated).
Teledyne Analytical Instruments24
Oxygen AnalyzerInstallation
System Alarm:
Actuates when DC power supplied to circuits is
unacceptable in one or more parameters. Permanently
configured as failsafe and latching. Cannot be defeated.
Actuates if self-test fails.
(Reset by pressing button to remove power. Then
press again and any other button EXCEPT System to
resume.
Further detail can be found in Chapter 4, Section 4-5.
Digital Remote Cal Inputs: Accept 0 V (off) or 24V dc (on) inputs for
remote control of calibration. (See Remote Calibration Protocol below.)
See Table 3-3 for pin connections.
Zero:
Floating input. 5 to 24 V i nput across the + and – pins puts
the analyzer into the Zero mode. Either side may be
grounded at the source of t he signal. 0 to 1 volt across the
ter minals allows Zero mode to ter minate when done. A
synchronous signal must open and close the external zero
val ve appropriately. See Remote P robe Connect or. (T he –C
opt ion internal valves oper ate automati cally) .
Teledyne Analytical Instruments25
InstallationBDS 3000
Span:
Floating input. 5 to 24 V input across the + and – pins
puts the analyzer into the Span mode. Either side may be
grounded at the source of the signal. 0 to 1 volt across the
terminals allows Span mode to terminate when done. A
synchronous signal must open and close external span
valve appropriately. See Figure 3-5 Remote Probe
Connector. (The –C option internal valves operate
automatically.)
Cal Contact:
This relay contact is closed while analyzer is spanning
and/or zeroing. (See Remote Calibration Protocol below.)
Table 3-3: Remote Calibration Connections
PinFunction
9+ Remote Zero
11– Remote Zero
10+ Remote Span
12– Remote Span
40Cal Contact
41Cal Contact
Remote Calibration Protocol: To properly time the Digital Remote Cal
Inputs to the Model BDS 3000 Analyzer, the customer's controller must
monitor the Cal Relay Contact.
When the contact is OPEN, the analyzer is analyzing, the Remote
Cal Inputs are being polled, and a zero or span command can be sent.
When the contact is CLOSED, the analyzer is already calibrating. It
will ignore your request to calibrate, and it will not remember that
request.
Once a zero or span command is sent, and acknowledged (contact
closes), release it. If the command is continued until after the zero or
span is complete, the calibration will repeat and the Cal Relay Contact
(CRC) will close again.
Teledyne Analytical Instruments26
Oxygen AnalyzerInstallation
For example:
1) Test the CRC. When the CRC is open, Send a zero command
until the CRC closes (The CRC will quickly close.)
2) When the CRC closes, remove the zero command.
3) When CRC opens again, send a span command until the
CRC closes. (The CRC will quickly close.)
4) When the CRC closes, remove the span command.
When CRC opens again, zero and span are done, and the sample is
being analyzed.
Note: The Remote Valve connections (described below) provides
signals to ensure that the zero and span gas valves will be
controlled synchronously.
Range ID Relays: Four dedicated Range ID relay contacts. The first
three ranges are assigned to relays in ascending order—Low range is
assigned to Range 1 ID, Medium range is assigned to Range 2 ID, and
High range is assigned to Range 3 ID. The fourth range is reserved for
the Air Cal Range (25%). Table 3-4 lists the pin connections.
Table 3-4: Range ID Relay Connections
PinFunction
21Range 1 ID Contact
38Range 1 ID Contact
22Range 2 ID Contact
39Range 2 ID Contact
19Range 3 ID Contact
18Range 3 ID Contact
34Range 4 ID Contact (Air Cal)
35Range 4 ID Contact (Air Cal)
Network I/O: A serial digital input/output for local network protocol.
At this printing, this port is not yet functional. It is to be used for future
options to the instrument. Pins 13 (+) and 29 (–).
Teledyne Analytical Instruments27
InstallationBDS 3000
Remote Valve Connections: The Ultra Trace 3000 is a single-chassis
instrument, which has no Remote Valve Unit. Instead, the Remote Valve
connections are used as a method for directly controlling external
sample/zero/span gas valves. See Figure 3-5.
Figure 3-5: Remote Probe Connections
The voltage from these outputs is nominally 0 V for the OFF and
15 V dc for the ON conditions. The maximum combined current that can
be pulled from these output lines is 100 mA. (If two lines are ON at the
same time, each must be limited to 50 mA, etc.) If more current and/or a
different voltage is required, use a relay, power amplifier, or other
matching circuitry to provide the actual driving current.
In addition, each individual line has a series FET with a nominal
ON resistance of 5 ohms (9 ohms worst case). This can limit the
obtainable voltage, depending on the load impedance applied. See
Figure 3-6.
3.4Electrolyte Refill of BDS Sensor
The BDS sensor was shipped dry. It must be filled with the
electrolyte before operation. The electrolyte is a caustic solution (10%
KOH), supplied in five 50 ml bottles. Review the Material Safety Data
Sheet (MSDS) in Section A-6 before handling the electrolyte.
Teledyne Analytical Instruments28
Oxygen AnalyzerInstallation
Figure 3-6: FET Series Resistance
To refill the BDS sensor:
1. Open the front door and swing it open.
2. Unscrew the sensor cap and disconnect sensor cable from the
BDS sensor.
3. Pour the electrolyte from the five small bottles into a larger
container.
4. Sparge the electrolyte with nitrogen gas at a flow of 100 CCM
for about 1/2 hour then pour into the provided wash bottle.
5. Ref. to Figure 3.7 for the method of adding electrolyte to the
sensor. It is important that as the sensor is being filled with the
electrolyte, filling is accomplished without trapping gas bubbles
in the lower part of the sensor.
Figure 3.7: Adding Electrolyte to the BDS Sensor
Teledyne Analytical Instruments29
InstallationBDS 3000
Squirt electrolyte content into the sensor. Do it slowly until the
bottom parts of the sensor are fully immersed in the electrolyte.
4. Pour the rest of the electrolyte into the sensor. Gas bubbles in the
top portion of the sensor would not affect the sensor
performance. One bottle of electrolyte is sufficient to rise the
electrolyte level to the MAX line. For the rest of sensor life, no
further electrolyte addition is needed.
5. Install the sensor cap,
6. Do not connect the sensor's electric connector at this stage.
3.5Testing the System
Before plugging the instrument into the power source:
• Check the integrity and accuracy of the gas connections.
Make sure there are no leaks.
• Check the integrity and accuracy of the electrical
connections. Make sure there are no exposed conductors
• Purge the system for 3 minutes. Make sure the gas flow rate
is within 0.5-1 SLPM.
Power up the system, and conduct the Self-Diagnostic Test as
described in Chapter 4, Section 4.3.5. It takes two minutes for the
microprocessor to test various sections of the analyzer.
3.6 Sensor Protection Mode
The BDS sensor is a very sensitive device for measuring ultra trace
levels of oxygen. When the oxygen level in the gas exceeds 100 ppm (in
nitrogen background) for one minute, the analyzer will enter a selfprotection mode and show temporary shut down on the display. It
indicates a high level oxygen intrusion into the system. Check the gas
line and other related parts, and fix them if there is any leaks found.
The analyzer will try to reconnect with the sensor in one minute. If
it is still over range for one minute, the analyzer will enter a temporary
shut down mode again for three minutes. The analyzer will try the third
time to reconnect the sensor, and will enter a System Shut Down mode
to protect the sensor if it is still over range.
Pressing the ESCAPE key will return the analyzer to operation.
Teledyne Analytical Instruments30
Oxygen AnalyzerInstallation
For operations frequently encountering oxygen levels above 100
ppm, TAI’s Micro-Fuel-Cell type of oxygen sensor is recommended.
The maximum working range with a background of nitrogen gas is
100 ppm. The maximum working range is different for other gas
backgrounds. See Section 4.3.9.
Teledyne Analytical Instruments31
InstallationBDS 3000
Teledyne Analytical Instruments32
Oxygen AnalyzerOperation
Operation
4.1Introduction
Once the analyzer has been installed, it can be configured for your
application. To do this you will:
• Set system parameters:
• Establish a security password, if desired, which will require
the operator to log in.
• Establish and start an automatic calibration cycle, if desired.
• Calibrate the instrument.
• Define the three user-selectable analysis ranges, then choose
autoranging or select a fixed range of analysis, as required.
• Set alarm setpoints, and modes of alarm operation (latching,
failsafe, etc).
Before you configure your BDS 3000, these default values are in
effect:
Ranges:LO = 100ppb ppm, MED = 1000
ppb, HI = 10 ppm.
Auto Ranging: ON
Alarm Relays: Defeated, Alarm 1 at10.000 ppm,
Alarm 2 at 1.000 ppm HI, Not
failsafe, Not latching.
Zero: Auto, every 0 days at 0 hours.
Span: Auto, at 008.00 ppm, every 0 days
at 0 hours.
If you choose not to use password protection, the default password
is automatically displayed on the password screen when you start up,
and you simply press ENTER for access to all functions of the analyzer.
Teledyne Analytical Instruments33
OperationBDS 3000
4.2Using Data Entry and Function Buttons
Data Entry Buttons: The __ arrow buttons select options from the
menu currently being displayed on the VFD screen. The selected option
blinks.
When the selected option includes a modifiable item, the __ arrow
buttons can be used to increment or decrement that modifiable item.
The ENTER button is used to accept any new entries on the VFD
screen. The ESCAPE button is used to abort any new entries on the VFD
screen that are not yet accepted by use of the ENTER button.
Figure 4-1 shows the hierarchy of functions available to the
operator via the function buttons. The six function buttons on the
analyzer are:
•Analyze. This is the normal operating mode. The analyzer
monitors the oxygen content of the sample, displays the
percent of oxygen, and warns of any alarm conditions.
•System. The system function consists of several subfunctions
that regulate the internal operations of the analyzer:
• Auto-Cal setup
• Password assignment
• Self -Test initiation
• Checking software version
• Logging out
• Show negative readings
• Set digital filter
• Zero. Used to set up a zero calibration.
• Span. Used to set up a span calibration.
•Alarms. Used to set the alarm setpoints and determine
whether each alarm will be active or defeated, HI or LO
acting, latching, and/or failsafe.
•Range. Used to set up three analysis ranges that can be
switched automatically with auto-ranging or used as
individual fixed ranges.
Teledyne Analytical Instruments34
Oxygen AnalyzerOperation
Figure 4-1: Hierarchy of Functions and Subfunctions
Teledyne Analytical Instruments35
OperationBDS 3000
Any function can be selected at any time by pressing the
appropriate button (unless password restrictions apply). The order as
presented in this manual is appropriate for an initial setup.
Each of these functions is described in greater detail in the
following procedures. The VFD screen text that accompanies each
operation is reproduced, at the appropriate point in the procedure, using
ARIAL NARROW bolded type style. Pushbutton names are printed in
Oblique type.
4.3The System Function
The subfuctions of the System function are described below.
Specific procedures for their use follow the descriptions:
•Auto-Cal: Used to define an automatic calibration sequence
and/or start an Auto-Cal.
•PSWD: Security can be established by choosing a 5 digit
password (PSWD) from the standard ASCII character set. (See
Installing or Changing the Password, below, for a table of ASCII
characters available.) Once a unique password is assigned and
activated, the operator MUST enter the UNIQUE password to
gain access to set-up functions which alter the instrument's
operation, such as setting the instrument span or zero setting,
adjusting the alarm setpoints, or defining analysis ranges.
After a password is assigned, the operator must log out to
activate it. Until then, anyone can continue to operate the
instrument without entering the new password.
Only one password can be defined. Before a unique password
is assigned, the system assigns TETAI by default. This allows
access to anyone. After a unique password is assigned, to defeat
the security, the password must be changed back to TETAI.
•Logout: Logging out prevents unauthorized tampering with
analyzer settings.
•More: Select and enter More to get a new screen with
additional subfunctions listed.
•Self–Test: The instrument performs a self-diagnostic test to
check the integrity of the power supply, output boards and
amplifiers.
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Oxygen AnalyzerOperation
•Version: Displays Manufacturer, Model, and Software
Version of instrument.
•Xout: This function provides the capability for the analog
output to track negative readings, by introducing an offset on
the zero baseline.
•Neg: The operator selects whether display can show
negative oxygen readings or not.
•TRAK/HLD: The oper ator sets whether the instrument analog
out puts t rack t he concentration change during calibration and
set s a ti me del ay for the concentration alar ms aft er cal ibrati on.
•Filter: This is to set the response time of the digital filter in
the LO range.
•GasBkgn: Set the gas correction factor. This function adjusts
the calibration of the sensor when the background gas is changed.
•Trbsht: Displays useful information for troubleshooting
purposes.
•TempComp: Compensates the zero baseline temperature
drift by setting the temperature coefficient of the sensor in
ppb/degrees C.
•Temperature: Displays sensor temperature.
4.3.1Tracking Oxygen Readings During
Calibration and Alarm Delay
The user has the option of setting the preference as to whether the
analog outputs track the display readings during calibration or not. To
set the preference, press the System key once and the first System menu
will appear in the VFD display:
TRAK/HLD Auto-Cal
PSWD Logout More
TRAK/HLD
the ENTER key once:
should be blinking. To enter this system menu press
Output Sttng: TRACK
Alarm Dly: 10 min
Teledyne Analytical Instruments37
OperationBDS 3000
Or
Output Sttng: HOLD
Alarm Dly: 10 min
In the first line, TRACK or HOLD should be blinking. The operator
can toggle between
When
TRACK is selected, the analog outputs (0-1 VDC and 4-20 mA)
TRACK and HOLD with the Up or Down keys.
and the range ID contacts will track the instrument readings during
calibration (either zero or span). TRACK is the factory default.
When HOLD is selected, the analog outputs (0-1 VDC and 4-20
mA) and the range ID contacts will freeze on their last state before
entering one of the calibration modes. When the instrument returns to
the Analyze mode, either by a successful or an aborted calibration, there
will be a three-minute delay before the analog outputs and the range ID
contacts start tracking again.
The concentration alarms freeze on their last state before entering
calibration regardless of selecting HOLD or TRACK. But, when HOLD
is selected the concentration alarms will remain frozen for the time
displayed in the second line of the
TRAK/HLD menu after the analyzer
returns to the Analyze mode.
The factory default is three minutes, but the delay time is
programmable. To adjust to delay time use the Left or Right arrow keys.
When the time displayed on the second line blinks, it can be adjusted by
Pressing the Up or Down keys to increase or decrease its value. The
minimum delay is 1 minute, the maximum is 30.
This preference is stored in non-volatile memory so that it is
recovered if power is removed from the instrument.
4.3.2Setting up an Auto-Cal
When proper automatic valving is connected (see Chapter 3,
Installation), the Analyzer can cycle itself through a sequence of steps
that automatically calibrates the instrument.
Note: If you require highly accurate Auto-Cal timing, use external
Auto-Cal control where possible. The internal clock in the
Model BDS 3000 is accurate to 2-3 %. Accordingly,
internally scheduled calibrations can vary 2-3 % per day.
To setup an Auto–Cal cycle:
Teledyne Analytical Instruments38
Oxygen AnalyzerOperation
CAUTION:FREQUENT ZERO ADJUSTMENTS OF THE CELL IS
NOT RECOMMENDED. A NEWLY INSTALLED CELL
MAY TAKE 7-10 DAYS OF OPERATION TO REACH A
STEADY ZERO (TYPICALLY LESS THAN 5 PPB). IF
REQUIRED, THE INSTRUMENT MAY BE ZEROED
AFTER THIS INITIAL STABILIZING PERIOD AND MAY
BE CHECKED AGAIN AFTER AN ADDITIONAL 7-10
DAY PERIOD. THE FREQUENCY OF ZERO
ADJUSTMENT IS AT THE DISCRETION OF THE
USER (ONCE A MONTH IS SUGGESTED).
Choose System from the Function buttons. The LCD will display
five subfunctions.
TRAK/HLD Auto—Cal
PSWD Logout More
Use < > arrows to blink Auto—Cal, and press Enter. A new screen
for Span/Zero set appears.
Span OFF Nxt: 0d 0h
Zero OFF Nxt: 0d 0h
Press < > arrows to blink Span (or Zero), then press ENTER again.
(You won’t be able to set OFF to ON if a zero interval is entered.) A
Span Every ... (or Zero Every ...) screen appears.
Span Every 0 d
Start 0 h from now
Use __ arrows to set an interval value, then use __ arrows to move
to the start-time value. Use DÑ arrows to set a start-time value.
To turn ON the Span and/or Zero cycles (to activate Auto-Cal):
Press System again, choose
Auto—Cal, and press ENTER again. When
the Span/Zero values screen appears, use the < > arrows to blink the
Span (or Zero) OFF/ON field. Use _ arrows to set the OFF/ON field to
ON. You can now turn these fields ON because there is a nonzero span
interval defined.
4.3.3Password Protection
If a password is assigned, then setting the following system
parameters can be done only after the password is entered: span and zero
settings, alarm setpoints, analysis range definitions, switching between
autoranging and manual override, setting up an auto-cal, and assigning a
Teledyne Analytical Instruments39
OperationBDS 3000
new password. However, the instrument can still be used for analysis or
for initiating a self-test without entering the password.
If you have decided not to employ password security, use the
default password TETAI. This password will be displayed automatically
by the microprocessor. The operator just presses the ENTER key to be
allowed total access to the instrument’s features.
Note: If you use password security, it is advisable to keep a copy
of the password in a separate, safe location.
4.3.3.1 ENTERING THE PASSWORD
To install a new password or change a previously installed
password, you must key in and ENTER the old password first. If the
default password is in effect, pressing the ENTER button will enter the
default TETAI password for you.
Press System to enter the System mode.
TRAK/HLD Auto—Cal
PSWD Logout More
Use the __arrow keys to scroll the blinking over to PSWD, and
press ENTER to select the password function. Either the default TETAI
password or AAAAA place holders for an existing password will appear
on screen depending on whether or not a password has been previously
installed.
T E T A I
Enter PWD
or
A A A A A
Enter PWD
The screen prompts you to enter the current password. If you are
not using password protection, press ENTER to accept TETAI as the
default password. If a password has been previously installed, enter the
password using the < > arrow keys to scroll back and forth between
letters, and the __ arrow keys to change the letters to the proper
password. Press ENTER to enter the password.
If the password is accepted, the screen will indicate that the
password restrictions have been removed and you have clearance to
proceed.
Teledyne Analytical Instruments40
Oxygen AnalyzerOperation
PSWD Restrictions
Removed
In a few seconds, you will be given the opportunity to change this
password or keep it and go on.
Change Password?
<ENT>=Yes <ESC>=No
Press ESCAPE to move on, or proceed as in Changing the
Password, below.
4.3.3.2 INSTALLING OR CHANGING THE PASSWORD
If you want to install a password, or change an existing password,
proceed as above in Entering the Password. When you are given the
opportunity to change the password:
Change Password?
<ENT>=Yes <ESC>=No
Press ENTER to change the password (either the default TETAI or
the previously assigned password), or press ESCAPE to keep the
existing password and move on.
If you chose ENTER to change the password, the password
assignment screen appears.
T E T A I
<ENT> To Proceed
or
A A A A A
<ENT> To Proceed
Enter the password using the __ arrow keys to move back and forth
between the existing password letters, and the __ arrow keys to change
the letters to the new password. The full set of 94 characters available
for password use are shown in Table 4-1 below.
When you have finished typing the new password, press Enter. A
verification screen appears. The screen will prompt you to retype your
password for verification.
A A A A A
Retype PWD To Verify
Teledyne Analytical Instruments41
OperationBDS 3000
Wait a moment for the entry screen. You will be given clearance to
proceed.
A A A A A
<ENT> TO Proceed
Table 4-1: Characters Available for Password Definition:
Use the arrow keys to retype your password and press ENTER
when finished. Your password will be stored in the microprocessor and
the system will immediately switch to the Analyze screen, and you now
have access to all instrument functions.
If all alarms are defeated, the Analyze screen appears as:
0.0 ppm Anlz
Range: 0 — 100
If an alarm is tripped, the second line will change to show which
alarm it is:
0.0 ppm Anlz
AL—1
Note: If you log off the system using the logout function in the
system menu, you will now be required to re-enter the
password to gain access to Span, Zero, Alarm, and Range
functions.
Teledyne Analytical Instruments42
Oxygen AnalyzerOperation
4.3.4Logout
The Logout function provides a convenient means of leaving the
analyzer in a password protected mode without having to shut the
instrument off. By entering
instrument leaving the system protected against use until the password is
reentered. To log out, press the System button to enter the System
function.
Use the __ arrow keys to position the blinking over the Logout
function, and press ENTER to Log out. The screen will display the
message:
Logout, you effectively log off the
TRAK/HLD Auto—Cal
PSWD Logout More
Protected Until
Password Reentered
4.3.5System Self-Diagnostic Test
The Model BDS 3000 has a built-in self-diagnostic testing routine.
Pre-programmed signals are sent through the power supply, output board
and sensor circuit. The return signal is analyzed, and at the end of the
test the status of each function is displayed on the screen, either as OK
or as a number between 1 and 3. (See System Self Diagnostic Test in
Chapter 5 for number code.)
The self diagnostics are run automatically by the analyzer
whenever the instrument is turned on, but the test can also be run by the
operator at will. To initiate a self diagnostic test during operation:
Press the System button to start the System function.
TRAK/HLD Auto—Cal
PSWD Logout More
Use the < > arrow keys to blink More, then press Enter.
Version Diag Xout
Neg-Y Filter-10 More
Use the __arrow keys again to move the blinking to the Self–Test
function. The screen will follow the running of the diagnostic.
RUNNING DIAGNOSTIC
Testing Preamp — 83
Teledyne Analytical Instruments43
OperationBDS 3000
During preamp testing there is a countdown in the lower right
corner of the screen. When the testing is complete, the results are
displayed.
Power: OK Analog: OK
Preamp: 3
The module is functioning properly if it is followed by OK. A
number indicates a problem in a specific area of the instrument. Refer to
Chapter 5 Maintenance and Troubleshooting for number code
information. The results screen alternates for a time with:
Press Any Key
To Continue . . .
Then the analyzer returns to the initial System screen.
4.3.6Version Screen
Move the __arrow key to More and press Enter. With Version
blinking, press Enter. The screen displays the manufacturer, model, and
software version information.
4.3.7Filter Function
The response time on the most sensitive range (ppb range) is user
definable from approximately 1-60 minutes. The adjustable filter allows
the user to tune the response of the analyzer to best balance sensor noise
and response time requirements. The factory default setting is 5 minutes.
The actual response time will depend on the user’s sample system (the
length and size the tubing of tubing as well as the sample flow rate).
The filter setting can be accessed by selecting SYSTEM on the
keypad followed by MORE on the display with the __keys. The filter
function is then selected and changed using the arrow keys. Press
ENTER and ANALYZE to return to analyze mode.
In the event of an over-range condition, the filter rate will
automatically switch to a faster setting (approximately 45 sec. response
time) for the duration of the over-range or upset condition. This feature
allows the analyzer to quickly respond to and track an upset condition.
Teledyne Analytical Instruments44
Oxygen AnalyzerOperation
4.3.8Negative Value Display
The operator is able to set the display not to show negative
readings. To access this option, Press the SYSTEM key and access the
second screen of the System menu:
Version Diag Xout
Neg-N Filter-5 More
By using the Left or Right keys, the Neg- field can be accessed.
Once that field is selected, use the Up or Down keys to toggle from
Y or Y to N. Setting to N means that when the reading of the sensor
N to
drifts negative, the display will stay at zero. To follow negative upsets,
set this field to Y. The default setting is N.
4.3.9The Gas Correction Factor
When the background gas is changed. this function can adjust the
calibration of the instrument to compensate for the sensor change of
output. This is helpful when the gas background needs to be changed
and only a calibration bottle with nitrogen background is used. The
default setting is 1.00, for nitrogen gas background. To set this factor,
press the System key and access the third screen:
GasBkgnd TempComp
o
Trbsht temp: 21.0
C
Select GasBkgnd and press the ENTER key to see the function
screen:
Gas Background
Correction: 1.00
Use the Up or Down keys to adjust the value. The working range is
0.25 to 2.50. This factor will divide the output. For example if the factor
is set to 2.00, the output of the sensor, when read by the electronics will
be divided by two.
Special consideration on the working range: Changing the gas
correction factor has an effect on the maximum working range of the
analyzer, e.g.: if a gas factor of 2.00 is selected the maximum working
range of the analyzer is 50 ppm. Any reading above this, may saturate
the amplifier. The automatic sensor shutdown function will become
Teledyne Analytical Instruments45
OperationBDS 3000
active automatically when the reading goes over 50 ppm as described in
Section 3.6.
4.3.10 Troubleshooting Screen
This System function provides access to troubleshooting
information. This information will be helpful to TAI technical support
staff.
Note: To use this function, it is recommended that known span
gas be flowing through the system before entering this
function.
Once the span gas has been flowing for at least five minutes, Press
the SYSTEM key and access the
Trbsht on the third screen.
GasBkgnd TempComp
Trbsht
Press the ENTER key. The VFD display will scroll through four
screens with a five seconds delay each. The values shown are frozenfrom the moment the System key was pressed (that is why is
important not to enter the System menu until span gas has flowed for a
while).
First Screen:
FCalib_factor = 4.581(slope calibration, default value
shown)
AtoD_Ave =115810(Average ADC count reading of
sensor amplifier on the span gas,
range: 0 to 260,000)
Second Screen:
lOffset[0] = 2480(ADC count of offset of the first
gain of sensor amplifier)
lOffset[1] = 2430(ADC count of offset of the second
gain of sensor amplifier)
Third Screen:
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Oxygen AnalyzerOperation
lOffset[2] = 2327(ADC count of offset of the third
gain of sensor amplifier)
lOffset[3] = 2330(ADC count of offset of the fourth
gain of sensor amplifier)
Fourth Screen:
tempOffset = 2190(ADC count of offset of
temperature amplifier)
Current_gain= 1(current gain of sensor amplifier on
span gas)
4.3.11 Temperature
The temperature of the sensor is displayed on the third screen or
system menu, and is shown in degrees centigrade. If sensor cable is
disconnected, the display will show either “> 50” or “ < 0”.
4.3.12 Extended Analog Output Function
To access this function, press the SYSTEM key to enter it’s menu.
Select the More function to move on to the second screen of the system
menu.
Version Diag Xout
Neg-Y Filter-10 More
Select Xout and press ENTER to get to the extended output setup
menu.
Output Offst: 10% FS
Neg. Analog Offset
The number on the first line is adjustable using the Up and Down
keys between 0 and 50. This function makes it possible to track negative
readings in the analog output, since the analog outputs do not go below
zero volts or 4 mA DC. Provided that negative readings are allowed (
this is set in the system menu as well ).
If the value is set to zero of FS (full scale), the analog outputs work
in standard form and this is the default.
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OperationBDS 3000
Reading on0 to 1 VDC4-20 mA DC
DisplayOutputOutput
0 % of FS0.04.0
100 % of FS1.020.0
If the value is set to 10% of FS:
Reading on0 to 1 VDC4-20 mA DC
DisplayOutputOutput
-10 % of FS0.004.0
0 % of FS0.915.45
100 % of FS1.0020.0
4.3.13 Zero Baseline Temperature Compensation
The BDS Sensor is temperature compensated when not on zero gas.
The “Span” temperature coefficient from sensor to sensor is not very
different. The software will do this temperature compensation without
the need to enter a coefficient. The BDS Sensor baseline exhibits
temperature dependency too and it is different from sensor to sensor. A
temperature coefficient must be entered into the analyzer in order to
compensate for diurnal temperature drifts. The coefficient ranges from
0.50 to 1.75 ppb/°C.
To access this function, press the SYSTEM key to enter it’s menu. Select
the More function to move on to the second screen of the system menu.
Select More one more time to go on to the third screen of the system menu.
GasBKgnd TempComp
Trbsht Temp: 24.3 C
Select TempComp and press ENTER to get to the temperature
coeficient setup menu:
Set BDS sensor temp
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Oxygen AnalyzerOperation
0.00 ppb/degree C
The number on the second line is adjustable using the Up and
Down arrow keys between 0.00 and 10.0. The coefficient is different
from sensor to sensor and it’s entered into the analyzer at the factory
before shipping. If the sensor is replaced, a new coefficient must be
entered. TAI can give the coefficient or it may be estimated.
To estimate it in the field:
1. Set the coefficient to zero.
2. Run the analyzer on “Zero” calibration gas for two weeks or
once stability of its baseline is reached.
3. After the sensor has been purged for at least two weeks and it’s
baseline is stable, monitor the reading and ambient temperature
over a minimum period of 24 hours.
Take the maximum and minimum readings, and the maximum
and minimum temperature readings.
4. Calculate the coefficient using the relation:
Coefficient = (O2 max - O2 min) ÷ (Temp max - Temp min)
For example:
In a 24 hour run:
O
max = 3.55 ppb
2
O2 min = 1.75 ppb
Temp max = 24.5 degrees C.
Temp min = 22.1 degrees C.
Coefficient = (3.55-1.75)ppb ÷ (24.5-22.1) °C = 0.75 °C.
4.4Calibration of the Analyzer
The analyzer must be calibrated prior to its use. For most
applications where the desired range of measurement is 0 to 10 ppm, or
less we recommend the analyzer be calibrated using a span gas with a
concentration between 7.0 to 9.0 ppm oxygen in nitrogen. This will
require that calibration be performed in the 0-10 ppm analyzer range.
Before the cell is ready for calibration, it must be purged with
sample gas to a low oxygen level—preferably below 0.1 ppm. If the
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OperationBDS 3000
oxygen content of the sample gas is higher than 0.1 ppm, a zero gas such
as nitrogen having an oxygen concentration below 0.1 ppm may be
required.
4.4.1Zero Cal
The BDS Sensor has a zero offset of less than 5 ppb oxygen.
Normally, the offset slowly decreases during the first 7 to 10 days of
operation, and is expected to reach a steady value after this time.
Generally, the value of the zero offset is part of the oxygen reading
of the sample gas as shown by the analyzer readout. As an example, a
reading of 5 ppb oxygen may include 0.4 ppm oxygen in the sample gas
and a 5 ppb zero offset.
The determination of the zero offset requires the use of oxygen free
gas to the analyzer. We recommend the use of nitrogen gas with a
scrubber to assure oxygen levels below 0.1 ppb.
The user may decide to eliminate the zero offset for improved
accuracy. If so desired, the analyzer is equipped to provide this
function. However, we do not recommend carrying out the cal zero
during the first 10 days of the operation of the cell.
The ZERO button on the front panel is used to enter the zero
calibration function. Zero calibration can be performed in either the
automatic or manual mode. In the automatic mode, an internal algorithm
compares consecutive readings from the sensor to determine when the
output is within the acceptable range for zero. In the manual mode, the
operator determines when the reading is within the acceptable range for
zero. Make sure the zero gas is connected to the instrument. If you get a
CELL FAILURE message skip to section 4.4.1.3.
4.4.1.1 AUTO MODE ZEROING
Press ZERO to enter the zero function mode. The screen allows you
to select whether the zero calibration is to be performed automatically or
manually. Use the
zero settling. Stop when AUTO appears, blinking, on the display.
arrow keys to toggle between AUTO and MAN
__
Zero: Settling: AUTO
<ENT> To Begin
Press ENTER to begin zeroing.
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Oxygen AnalyzerOperation
#### PPM Zero
Slope = #### ppm/s
The beginning zero level is shown in the upper left corner of the
display. As the zero reading settles, the screen displays and updates
information on slope (unless the slope starts within the acceptable zero
range and does not need to settle further).
Then, and whenever slope is less than 0.08 for at least 3 minutes,
instead of slope you will see a countdown: 5 Left, 4 Left, and so fourth.
These are five steps in the zeroing process that the system must
complete, AFTER settling, before it can go back to Analyze.
#### PPM Zero
4 Left = ### ppm/s
The zeroing process will automatically conclude when the output is
within the acceptable range for a good zero. Then the analyzer
automatically returns to the Analyze mode.
Because the reading of the slope is not very sensitive, it is
recommended that zero gas be purging a few minutes before starting the
Auto mode zeroing. This will ensure cell stability on the new Zero
settings.
4.4.1.2 MANUAL MODE ZEROING
Press ZERO to enter the Zero function. The screen that appears
allows you to select between automatic or manual zero calibration. Use
the
keys to toggle between AUTO and MAN zero settling. Stop when
__
MAN appears, blinking, on the display.
Zero: Settling: Man
<ENT> To Begin
Press ENTER to begin the zero calibration. After a few seconds the
first of five zeroing screens appears. The number in the upper left-hand
corner is the first-stage zero offset. The microprocessor samples the
output at a predetermined rate. It calculates the differences between
successive samplings and displays the rate of change as slope= a value
in parts per million per second (ppm/s).
#### ppm Zero
Slope = #### ppm/s
Note: It takes several seconds for the true slope value to display.
Wait about 10 seconds. Then, wait until Slope is
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OperationBDS 3000
sufficiently close to zero before pressing ENTER to finish
zeroing .
Generally, you have a good zero when sl ope is less than 0.05 ppm/s
for about 30 seconds. When slope is close enough to zero, press ENT ER. In
a f ew seconds, the screen will update.
Once zero settling is completed, the information is stored in the
microprocessor, and the instrument automatically returns to the Analyze
mode.
4.4.2Span Cal
The SPAN button on the front panel is used to span calibrate the
analyzer. Span calibration can be performed using the automatic mode,
where an internal algorithm compares consecutive readings from the
sensor to determine when the output matches the span gas concentration.
Span calibration can also be performed in manual mode, where the
operator determines when the span concentration reading is acceptable
and manually exits the function.
4.4.2.1 AUTO MODE SPANNING
Press SPAN to enter the span function. The screen that appears
allows you to select whether the span calibration is to be performed
automatically or manually. Use the
AUTO and MAN span settling. Stop when AUTO appears, blinking, on
the display.
Span: Settling: AUTO
<ENT> For Next
Press ENTER to move to the next screen.
Calib. Holding time
Cal hold: 5 min
This menu allows the operator to set the time the analyzer should
be held in the AUTO span mode, after the readings of the analyzer settle.
Five minutes is the default, but it could be adjusted anywhere from 1 to
60 minutes by using the UP or DOWN keys.
Press ENTER to move to the next screen.
Span Val: 008.00 ppm
<ENT>Span <UP>Mod #
arrow keys to toggle between
__
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Oxygen AnalyzerOperation
Use the
arrow keys to enter the oxygen-concentration mode
__
(999.99 ppm is maximum value of span gas allowed). Use the__arrow
keys to blink the digit you are going to modify. Use the
arrow keys
__
again to change the value of the selected digit. When you have finished
typing in the concentration of the span gas you are using, press ENTER
to begin the Span calibration.
#### ppm Span
Slope = #### ppm/s
The beginning span value is shown in the upper left corner of the
display. As the span reading settles, the screen displays and updates
information on slope. Spanning automatically ends when the span output
corresponds, within tolerance, to the value of the span gas concentration.
Then the instrument automatically returns to the analyze mode.
4.4.2.2 MANUAL MODE SPANNING
Press SPAN to start the Span function. The screen that appears
allows you to select whether the span calibration is to be performed
automatically or manually.
Span: Settling: MAN
<ENT> For Next
Use the
keys to toggle between AUTO and MAN span settling.
__
Stop when MAN appears, blinking, on the display. Press ENTER to
move to the next screen.
Press ENTER to move to the next screen.
Calib. Holding time
Cal hold: 5 min
This menu allows the operator to set the time the analyzer should
be held in the AUTO span mode. It does not have any effect in the
MANual mode. Just press ENTER key to continue.
Span Val: 008.00ppm
<ENT>Span <UP>Mod #
Press _(<UP>) to permit modification (Mod #) of span value.
Use the arrow keys to enter the oxygen concentration of the span
gas you are using (999.99 is maximum value of span gas). The
__
choose the digit, and the __arrows choose the value of the digit.
Teledyne Analytical Instruments53
arrows
OperationBDS 3000
Press ENTER to enter the span value into the system and begin the
span calibration.
Once the span has begun, the microprocessor samples the output at
a predetermined rate. It calculates the difference between successive
samplings and displays this difference as a slope on the screen. It takes
several seconds for the first slope value to display. Slope indicates the
rate of change of the span reading. It is a sensitive indicator of stability.
#### % Span
Slope = #### ppm/s
When the span value displayed on the screen is sufficiently stable,
press ENTER. (Generally, when the Span reading changes by 1 % or less
of the full scale of the range being calibrated, for a period of ten minutes
it is sufficiently stable.) Once ENTER is pressed, the span reading
changes to the correct value. The instrument then automatically enters
the Analyze function.
4.4.3 Span Failure
The analyzer checks the output of the cell at the end of the span. If
the raw output of the cell is less than 1.5 nA/ppb or more than 13.5
nA/ppb O2, the span will not be accepted. The analyzer will return to
the previous calibration values, trigger the System Alarm, and display in
the VFD:
Span Failed!!
This message will be shown for five seconds and the instrument
shall return to the Analyze mode. In the upper right hand corner of the
VFD display
operator troubleshoot in case calibration was initiated remotely. To
reset the alarm and the flag message, the analyzer must be properly
spanned.
A trace cell is unlikely to fail span. As explained before, when the
sensor reaches the end of its useful life, the zero offset begins to rise
until the analyzer finds the zero unsatisfactory. Nevertheless, feeding the
wrong span gas or electronics failure could set this feature off at the end
of the span. Consider this before replacing the cell.
FCAL will be shown. This message flag will help the
4.5The Alarms Function
The Model BDS 3000 is equipped with 2 fully adjustable
concentration alarms and a system failure alarm. Each alarm has a relay
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Oxygen AnalyzerOperation
with a set of form “C" contacts rated for 3 amperes resistive load at 250
VAC. See Figure 3-5 in Chapter 3, Installation and/or the
Interconnection Diagram included at the back of this manual for relay
terminal connections.
The system failure alarm has a fixed configuration as described in
Chapter 3 Installation.
The concentration alarms can be configured from the front panel as
either high or low alarms by the operator. The alarm modes can be set as
latching or non-latching, and either failsafe or non-failsafe, or, they can
be defeated altogether. The setpoints for the alarms are also established
using this function.
Decide how your alarms should be configured. The choice will
depend upon your process. Consider the following four points:
1. Which if any of the alarms are to be high alarms and which if
any are to be low alarms?
Setting an alarm as HIGH triggers the alarm when the oxygen
concentration rises above the setpoint. Setting an alarm as LOW
triggers the alarm when the oxygen concentration falls below
the setpoint.
Decide whether you want the alarms to be set as:
• Both high (high and high-high) alarms, or
• One high and one low alarm, or
• Both low (low and low-low) alarms.
2. Are either or both of the alarms to be configured as failsafe?
In failsafe mode, the alarm relay de-energizes in an alarm
condition. For non-failsafe operation, the relay is energized in
an alarm condition. You can set either or both of the
concentration alarms to operate in failsafe or non-failsafe mode.
3. Are either of the alarms to be latching?
In latching mode, once the alarm or alarms trigger, they will
remain in the alarm mode even if process conditions revert back
to non-alarm conditions. This mode requires an alarm to be
recognized before it can be reset. In the non-latching mode, the
alarm status will terminate when process conditions revert to
non-alarm conditions.
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OperationBDS 3000
4. Are either of the alarms to be defeated?
The defeat alarm mode is incorporated into the alarm circuit so
that maintenance can be performed under conditions which
would normally activate the alarms.
The defeat function can also be used to reset a latched alarm.
(See procedures, below.)
If you are using password protection, you will need to enter your
password to access the alarm functions. Follow the instructions in
section 4.3.3 to enter your password. Once you have clearance to
proceed, enter the Alarm function.
Press the ALARM button on the front panel to enter the Alarm
function. Make sure that AL–1 is blinking.
AL—1 AL—2
Choose Alarm
Set up alarm 1 by moving the blinking over to AL–1 using the
arrow keys. Then press ENTER to move to the next screen.
AL—1 10.000 ppm HI
Dft—N Fs—N Ltch—N
Five parameters can be changed on this screen:
• Value of the alarm setpoint, AL–1 #### ppm (oxygen);
value can be set from 0 to 999 ppb + 1.000-1000.00 ppm.
• Out-of-range direction, HI or LO
• Defeated? Dft–Y/N (Yes/No)
• Failsafe? Fs–Y/N (Yes/No)
• Latching? Ltch–Y/N (Yes/No).
• To define the setpoint, use the < > arrow keys to move the
blinking over to AL–1 ####. Then use the __arrow keys to
change the number. Holding down the key speeds up the
incrementing or decrementing. (Remember, the setpoint units
are ppm O2).
• To set the other parameters use the
arrow keys to move the
__
blinking over to the desired parameter. Then use the __ arrow keys
to change the parameter.
__
Teledyne Analytical Instruments56
Oxygen AnalyzerOperation
• Once the parameters for alarm 1 have been set, press ALARMS
again, and repeat this procedure for alarm 2 (AL–2).
• To reset a latched alarm, go to Dft– and then press either D two
times or Ñ two times. (Toggle it to Y and then back to N.)
–OR –
Go to
Ltch– and then press either
two times or _ two times.
_
(Toggle it to N and back to Y).
Alarm Hysterisis: There is alarm hysterisis to prevent chatter of
the alarm contacts. It is set to 0.2 ppm for alarms set above 1 ppm, and
10 ppb for alarms set below 1 ppm.
4.6The Range Function
The Range function allows the operator to program up to three
concentration ranges to correlate with the DC analog outputs. If no
ranges are defined by the user, the instrument defaults to:
Low = 0–100 ppb
Med = 0–1 ppm
High = 0–10 ppm.
The Model BDS 3000 is set at the factor y to default to autoranging. I n
thi s mode, the microprocessor aut omatically r esponds to concent ration
changes by swit ching ranges for optimum readout sensitivi ty. If the current
range lim its ar e exceeded, the instrument wil l automatically shift to the next
higher range. I f the concentration fall s to below 90% of full scale of the
next lower range, the instr ument will switch to that range. A corresponding
shi ft in the DC percent-of- range output , and in the range ID outputs, will be
not iced.
The autoranging feature can be overridden so that analog output
stays on a fixed range regardless of the oxygen concentration detected. If
the concentration exceeds the upper limit of the range, the DC output
will saturate at 1 VDC (20 mA at the current output).
However, the digital readout and the RS-232 output of the
concentration are unaffected by the fixed range. They continue to read
accurately with full precision. See Front Panel description in Chapter 1.
The automatic fourth range is always 0-1000 ppm and is not
programmable.
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OperationBDS 3000
4.6.1Setting the Analog Output Ranges
To set the ranges, enter the range function mode by pressing the
RANGE button on the front panel.
L—100 ppb M—1 ppm
H—10 ppm Mode—AUTO
Use the __arrow keys to blink the range to be set: low (L), medium
(M), or high (H).
Use the __ arrow keys to enter the upper value of the range (all
ranges begin at 0). Repeat for each range you want to set. Press ENTER
to accept the values and return to Analyze mode. (See note below.)
Note: The ranges must sequentially increase from low to high, for
example, if range 1 is set as 0–500 ppb and range 2 is set
as 0–10 ppm, range 3 cannot be set as 0– 5 ppm since it is
lower than range 2.
Ranges, and alarms, are set in ppb or ppm units depending on
concentration. All concentration-data outputs change from ppb units to
ppm when the concentration is above 1.0 ppm. Range Low (L) is always
a ppb range and cannot be set higher than 1000 ppb nor lower than 10
ppb. The medium (M) and High (H) ranges can only be set in ppm. The
Medium (M) range can be set between 1 and 10 ppm, while the high (H)
range can be set between 10 and 1000 ppm.
Note: Refer to Section 4.3.9 to find maximum working range.
4.6.2Fixed Range Analysis
The autoranging mode of the instrument can be overridden, forcing
the analyzer DC outputs to stay in a single predetermined range.
To switch from autoranging to fixed range analysis, enter the range
function by pressing the RANGE button on the front panel.
Use the
Use the __ arrow keys to switch from AUTO to FX/L, FX/M, or
FX/H to set the instrument on the desired fixed range (low, medium, or
high).
arrow keys to move the blinking over AUTO.
__
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Oxygen AnalyzerOperation
4.7The Analyze Function
Normally, all of the functions automatically switch back to the
Analyze function when they have completed their assigned operations.
Pressing the ESCAPE button in many cases also switches the analyzer
back to the Analyze function. Alternatively, you can press the ANALYZE
button at any time to return to analyzing your sample.
4.8Signal Output
The standard Model BDS 3000 Oxygen Analyzer is equipped with
two 0–1 VDC analog output terminals accessible on the back panel (one
concentration and one range ID), and two isolated 4–20 mA DC current
outputs (one concentration and one range ID).
See Rear Panel in Chapter 3, Installation, for illustration.
The signal output for concentration is linear over the currently
selected analysis range. For example, if the analyzer is set on a range
that was defined as 0–100 ppm O2, then the output would be as shown in
Table 4-2.
Table 4-2: Linear Output for a 0-100 ppm O2 Range
Voltage SignalCurrent Signal
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OperationBDS 3000
ppm O
2
00.04.0
100.15.6
200.27.2
300.38.8
400.410.4
500.512.0
600.613.6
700.715.2
800.816.8
900.918.4
1001.020.0
Output (VDC)Output (mA DC)
The analog output signal has a voltage which depends on the
oxygen concentration AND the currently activated analysis range. To
relate the signal output to the actual concentration, it is necessary to
know what range the instrument is currently on, especially when the
analyzer is in the autoranging mode.
To provide an indication of the range, a second pair of analog
output terminals are used. They generate a steady preset voltage (or
current when using the current outputs) to represent a particular range.
Table 4-3 gives the range ID output for each analysis range.
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Oxygen AnalyzerOperation
Table 4-3: Range ID Output
RangeVoltage (V)Current (mA)
LO0.258
MED0.5012
HI0.7516
(0-1000) ppm1.0020
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OperationBDS 3000
Figure 4-2: Analyzer Power-up Sequence
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Oxygen AnalyzerOperation
Figure 4-3: Analyzer Span Sequence
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OperationBDS 3000
Figure 4-4: Analyzer Zero Sequence
Teledyne Analytical Instruments64
Oxygen AnalyzerMaintenance
Maintenance
5.1Routine Maintenance
Aside from normal cleaning and checking for leaks at the gas
connections, routine maintenance is limited to refilling sensor with
deionized water replace burned fuses, and recalibration. For
recalibration, see Section 4.4 Calibration.
WARNING: SEE WARNINGS ON THE TITLE PAGE OF THIS
MANUAL.
5.2Adding Water to the BDS Sensor
When running dry gas through the sensor, water is extracted from
the electrolyte. Therefore, the electrolyte level should be checked
periodically. When the electrolyte level is low, only de-ionized water or
distilled water should be added into the sensor. It typically takes about
four months to dry the electrolyte from the MAX line to the MIN line
when the sensor is operated on a bone dry gas line.
It is not necessary to turn off the power to the analyzer while
adding water, but care should be taken that no water is splashed outside
the sensor. Spilling water on the PC board could cause serious damage
to the analyzer and electric shock to the personal.
Unscrew and take the sensor cap off. Use the wash bottle provided
to squeeze de-ionized water into the sensor, as shown in Figure 5.1. It is
a good practice that water is added before reaching the MIN line.
Reinstall the cap after adding water.
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MaintenanceBDS 3000
Figure 5.1 Adding water into the BDS sensor
WARNING:THE SENSOR USED IN THE MODEL BDS 3000
OXYGEN ANALYZER USES ELECTROLYTE WHICH
CONTAINS POTASSIUM HYDROXIDE, THAT CAN BE
HARMFUL IF TOUCHED, SWALLOWED, OR
INHALED. AVOID CONTACT WITH ANY FLUID OR
POWDER IN OR AROUND THE UNIT. WHAT MAY
APPEAR TO BE PLAIN WATER COULD BE THE
ELECTROLYTE. IN CASE OF EYE CONTACT,
IMMEDIATELY FLUSH EYES WITH WATER FOR AT
LEAST 15 MINUTES. CALL PHYSICIAN. (SEE
APPENDIX, MATERIAL SAFETY DATA SHEET.)
5.3Fuse Replacement
1. Place small screwdriver in notch, and pry cover off, as shown in
Figure 5-2.
2. To change between American and European fuses, remove the
single retaining screw, flip Fuse Block over 180 degrees, and
replace screw.
3. Replace fuse as shown in Figure 5-3.
4. Reassemble Housing as shown in Figure 5-2.
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Oxygen AnalyzerMaintenance
Figure 5-2: Removing Fuse Block from Housing
American FusesEuropean Fuses
Figure 5-3: Installing Fuses
5.4System Self Diagnostic Test
1. Press the SYSTEM button to enter the system mode.
2. Use the __arrow keys to move to More, and press ENTER.
3. Use the__arrow keys to move to Self-Test, and press ENTER.
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MaintenanceBDS 3000
The following failure codes apply:
Table 5-1: Self-Test Failure Codes
Power
0OK
15 V Failure
215 V Failure
3Both Failed
Analog
0OK
1DAC A (0–1 V Concentration)
2DAC B (0–1 V Range ID)
3Both Failed
Preamp
0OK
1Zero too high
2Amplifier output doesn't match test input
3Both Failed
5.5Major Internal Components
T he S ensor i s accessed by unl at chi ng and swi nging open the f r ont
panel , as descr ibed earl i er . Ot her i nternal component s are accessed by
r em oving t he rear panel and sli ding out t he enti r e chassis. See F igure 5- 4,
bel ow. The gas pi pi ng is il lust r at ed in F igure 2- 3, and the maj or el ectr oni c
com ponents l ocati ons are shown in Fi gur e 2- 7, in Chapter 2.
WARNING:SEE WARNINGS ON THE TITLE PAGE OF THIS
MANUAL.
The BDS 3000 contains the following major components:
• Analysis Section
Sensor with stainless steel wetted parts
Sample system
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Oxygen AnalyzerMaintenance
• Power Supplies
• Microprocessor
• Displays
5 digit LED meter
2 line, 20 character, alphanumeric, VFD display
• RS-232 Communications Port.
See the drawings in the Drawings section in back of this manual for
details.
Figure 5-4: Rear Panel Screws
To detach the rear panel, remove only the 14 screws marked with
an X.
Teledyne Analytical Instruments69
MaintenanceBDS 3000
5.6Cleaning
If the instrument is unmounted at time of cleaning, disconnect the
instrument from the power source. Close and latch the front-panel access
door. Clean outside surfaces with a soft cloth dampened slightly with
plain clean water. Do not use any harsh solvents such as paint thinner or
benzene.
For panel-mounted instruments, clean the front panel as prescribed
in the above paragraph. DO NOT wipe front panel while the instrument
is controlling your process.
5.7Troubleshooting
SymptomsPossible causes and Solutions
Read higher than expected(1), (2), (3)
Read lower than expected(2), (3)
Read negative(3), (4)
Noise signal(3), (5)
Slow response(5)
Causes and solution keys:
(1) Gas leak: Make sure to use new VCR gaskets, high quality
valves and gas regulator for the sampling system. Tighten each
connection.
(2) Improper gas flow rate: adjust the inlet pressure to obtain 0.5 –
1 SLPM flow rate.
(3) Improper calibration of the analyzer: Turn the analyzer off,
then turn back on again. Press the SYSTEM key when prompted
by the analyzer “Press the System for default Values”. This will
return the analyzer to its defaults settings in calibration and zero
values. Recalibrate the analyzer with a high quality standard gas
if it is necessary.
(4) Just after adding water: The analyzer will recover by itself.
(5) Gas entered and is trapped in the sensor: This could happen if
the sensor is filled with the electrolyte improperly, or the sensor
is pressurized because of a clogged vent. To remedy this
Teledyne Analytical Instruments70
Oxygen AnalyzerMaintenance
situation, uninstall the sensor and take off the cap carefully, then
apply a vacuum degas process as shown in the Figure 5-5.
Degassing in a 28 inch mercury vacuum for 5 minutes is
sufficient to remove the gas bubbles. Reinstall the sensor into the
analyzer.
Note: A low cost vacuum degas kit (TAI P/N B72098) is available
from Teledyne Analytical Instruments.
Figure 5-5: Vacuum Degassing for the BDS Oxygen Sensor
Teledyne Analytical Instruments71
MaintenanceBDS 3000
Teledyne Analytical Instruments72
Oxygen AnalyzerAppendix
Appendix
A-1 Specifications
Packaging: General Purpose
• Flush panel mount (Standard).
• Relay rack mount. Contains one
instrument in one 19" relay rack
mountable plate (Optional).
Sensor: Teledyne BDS Sensor, patent pending.
Sample System: All wetted parts of 316 stainless steel with
built-in restrictor.
90 % Response Time: Less than 90 seconds at 25 °C (77 °F) on
10, and 100 ppm range. 90 seconds on
1000ppb range.
Software programmable response in 100
ppb range from 1 minute to 60 minutes.
Default is 5 minutes response time.
Ranges: Three user definable ranges from
0–100 ppb to 0–100 ppm, plus over range
of 0-100 ppm.
Autoranging with range ID output.
Alarms: One system-failure alarm contact to detect
power failure or sensor-zero and span
failure.
Two adjustable concentration threshold
alarm contacts with fully programmable
setpoints.
Displays: 2-line by 20-character, VFD screen, and
one 5 digit LED display.
Teledyne Analytical Instruments73
AppendixBDS 3000
Digital Interface: Full duplex RS-232 communications port.
Power: Universal power supply 85-250 V ac, at
47-63 Hz.
Operating Temperature: 5-40 °C
Accuracy: ±2% of full scale for all ranges at constant
temperature.
All accuracy specifications are contingent
upon the completion of zero and span
calibration.
All accuracy is established at constant
pressure and equilibrium has been
established.
Analog outputs: 0-1 V dc percent-of-range,
0-1 V dc range ID.
4-20 mA dc (isolated) percent-of-range,
4-20 mA dc (isolated) range ID.
Slow Blow
1CP179850 pin D-sub interface connector
50CP1799Pins for CP1798 connector
1B597125ml wash bottle for DI water
1B598125ml electrolyte bottle
1P1076Pipet
1B72098BDS sensor recovery kit
Note: Orders for replacement parts should include the part
number (if available) and the model and serial number of
the instrument for which the parts are intended.
Orders should be sent to:
TELEDYNE Analytical Instruments
16830 Chestnut Street
City of Industry, CA 91749-1580
Phone (626) 934-1500, Fax (626) 961-2538
Web: www. teledyne-ai. com
or your l ocal r epresentative.
Teledyne Analytical Instruments75
AppendixBDS 3000
A-3Drawing List
D-71902 Outline Diagram
A-419-inch Relay Rack Panel Mount
Figure A-1: Single 19" Rack Mount (dimensions in mm)
Teledyne Analytical Instruments76
Oxygen AnalyzerAppendix
A-5Application notes
Pressure and flow recommendations:
3000 series analyzers require reasonably regulated sample
pressures. While the 3000 analyzers are not sensitive to variations of
incoming pressure (provided they are properly vented to atmospheric
pressure), the pressure must be maintained so as to provide a useable
flow rate through the analyzer. Any line attached to sample vent should
be 1/4" or larger in diameter.
Flow rate recommendations:
A usable flow rate for a 3000 series analyzer is one which can be
measured on the flowmeter. This is basically 0.5 - 1.0 SLPM . The
optimum flow rate is 1 SLPM (mid scale). Note: response time is
dependent on flow rate, a low flow rate will result in slow response to
O2 changes in the sample stream. The span flow rate should be the
approximately same as the sample flow rate.
Cell pressure concerns:
The sensors used in 3000 series analyzers are optimized to
function at atmospheric pressure.
Bypass:
To improve the system response, a bypass can be added to
increase the sample flow rate to the analyzer by a factor of ten. A bypass provides a sample flow path around the analyzer of 2 - 18 SCFH.
typically.
Potential for fire and explosion: The electrolyte in the Micro-fuel Cells is not
flammable. There are no fire or explosion hazards associated with Micro-fuel
Cells.
Potential for reactivity: The sensors are stable under normal conditions of
use. Avoid contact between the sensor electrolyte and strong acids.
Section IV - Health Hazard Data
Primary route of entry:
Exposure limits: OSHA PEL:
ACGIH TLV:
Effects of overexposure
Ingestion:The electrolyte could be harmful or fatal if
Eye:The electrolyte is corrosive; eye contact could
Dermal:The electrolyte is corrosive; skin contact could
Inhalation:Liquid inhalation is unlikely.
Signs/symptoms of exposure:
Medical conditions
aggravated by exposure:None
Ingestion, eye/skin contact
0.05 mg./cu.m. (Pb)
2 mg/ cu.m. (KOH)
swallowed.
Oral LD50 (RAT) = 3650 mg/kg
result in permanent loss of vision.
result in a chemical burn.
Contact with skin or eyes will cause a burning
sensation and/or feel soapy or slippery to
touch.
Carcinogenicity:
Other health hazards:Lead is listed as a chemical known to the State
NTP Annual Report on Carcinogens: Not
listed
LARC Monographs: Not listed
OSHA: Not listed
of California to cause birth defects or other
reproductive harm.
Teledyne Analytical Instruments80
MSDSAppendix
Section V - Emergency and First Aid Procedures
Eye Contact:Flush eyes with water for at least 15 minutes
and get immediate medical attention.
Skin Contact:Wash affected area with plenty of water and
remove contaminated clothing. If burning
persists, seek medical attention.
Ingestion:
Give plenty of cold water. Do not induce
vomiting. Seek medical attention. Do not
administer liquids to an unconscious person.
Inhalation:Liquid inhalation is unlikely.
Section VI - Handling Information
NOTE:The o xy g en s e ns or s a re s e aled , a nd u n de r no r ma l c ir cu ms tan ce s , th e
c on te nts o f the s en s or s d o no t p re se n t a he a lth h az ar d. Th e follo win g
infor ma tio n is give n a s a g uide in th e ev en t tha t a c ell lea k s.
Protective clothing:
Clean-up procedures:Wipe down the area several times with a wet
Protective measures
during cell replacement:
Disposal:Should be in accordance with all applicable
NOTE:The above information is derived from the MSDS provided by the
manufacturer. The information is believed to be correct but does not
purport to be all inclusive and shall be used only as a guide.
Teledyne Analytical Instruments shall not be held liable for any
damage resulting from handling or from contact with the above
product.
Rubber gloves, chemical splash goggles.
paper towel. Use a fresh towel each time.
Before opening the bag containing the sensor
cell, check the sensor cell for leakage. If the
sensor cell leaks, do not open the bag. If there
is liquid around the cell while in the
instrument, put on gloves and eye protection
before removing the cell.
state, local and federal regulations.
Teledyne Analytical Instruments81
AppendixMSDS
Teledyne Analytical Instruments82
Oxygen AnalyzerIndex
Index
abort entry, 34
acces s d oo r, 4, 20
accuracy, 74
adding electrolyte, 29
adding water, 66
address, 75. See company address
Ag/Ag
calibration, 12
flowrate, 10, 22, 77
form C relay contacts, 24
front panel, 2, 20
frozen display. See display
function key, 2
fuse, 67
fuse block, 22
fuse installation, 23
gas correction factor. See gas factor
g as f actor , 12, 37, 45
gas inlet, 5, 9
gas outlet, 5, 9
GasBkgn, 37GasBkgnd, 45
hierarchy of functions, 35HOLD, 38
inlet, 14, 21
input
digital, 6, 25
inp ut/o u tp ut, 15
installation, 19
KOH, 8, 13, 28
latch , 4, 20
latching, 24
LED, 4
log out, 36
logout function, 43Ltch, 57
maintenance, 65
manual span mode, 52, 53
manual zero mode, 51
manuals, additional, v
maximum working range, 31
membrane switches, 2
meter, 4
m icro co n tr oller , 15
microprocessor, 2, 7
model information, iii
More, 36
motherboard, 15
m ou ntin g , 19
moving contact, 25
MSDS, 79
Neg, 37, 45
negative display, 45
negative reading, 14
network I/O, 6, 27
nonfailsafe, 24
nonlatching, 24
normally closed, 24, 25
normally open, 24, 25