SERIES ZrO
2000
FAST RESPONSE OXYGEN ANALYZER
The Series ZrO
help ensure the long life of the product, care should be taken to operate it as prescribed in this manual.
Refer to Section 7.1.2 on page 7 of this manual for important information in preparation of start-up.
Please take the time to read the manual before starting to use this product.
Fast Response Oxygen Analyzer is a high performance analytical instrument and in order to
2000
CAUTION
Alpha Omega Instruments Corp.
40 Albion Road, Lincoln, RI, USA 02865
Tel: (001) (401) 333-8580
Fax: (001) (401) 333-5550
Email: salescontact@aoi-corp.com
Website: www.aoi-corp.com
Rev 3.1109, November 2018
© COPYRIGHT 2018.
Alpha Omega Instruments Corp.
All rights reserved including the right to
reproduce this manual or any portion thereof in
any form.
TABLE OF CONTENTS
Section 1.0
Table of Contents
i
Section 2.0
Tables and Figures
ii
Section 3.0
Cautions
iii
Section 4.0
General Specifications
1
Section 5.0
Introduction
2
Section 6.0
Installation Procedures
3
Section 7.0
Operation
7
Section 8.0
Calibration Procedures
16
PAGE
3.1 Explanation of Graphic Symbols iii
3.2 Important Warnings iv
5.1 General Description 2
5.2 Optional Equipment Descriptions 2
5.2.1 Pressure Regulator Option 2
5.2.2 Sample Pump Option 2
6.1 Unpacking the Instrument 3
6.2 Electrical Installation 3
6.3 Mechanical Configuration 3
6.3.1 Oxygen Sensor 5
6.3.2 Wiring Alarm Relays 5
6.3.3 Wiring the mA DC Outputs 6
7.1 Preparation for Operation 7
7.1.1 Mounting Configurations 7
7.1.2 Initial Check 7
7.2 Operating Procedures 7
7.2.1 Power On 7
7.2.2 Front Panel Controls and Indicators 8
7.2.3 Scaling Analog Outputs of the Analyzer 8
7.3 Alarm System 10
7.3.1 General Description of Alarm Processing 10
7.3.2 Default / User Settings 11
7.3.3 Fail Safe 11
7.3.4 Oxygen Alarm Type 11
7.3.5 Output Type 11
7.3.6 Manual Clear / Auto Clear 11
7.3.6.1 Manual Clear Operation 12
7.3.6.2 Auto Clear Operation 12
7.3.7 Setting the Alarm Levels 12
7.3.8 Timing Out During Alarm Setting 12
7.4 Sample Gas Handling 13
7.4.1 Positive Pressure Sampling 13
7.4.2 Negative Pressure Sampling 13
7.4.3 Gas System Pressure and Flow Limits 14
7.4.4 Corrosive Gases 15
7.4.5 Orientation 15
7.4.6 Condensable Gas Constituents 15
7.4.7 Sample Gas Moisture Limits 15
8.1 Routine Calibration Check 16
8.2 Calibration Gas 16
8.3 Procedure for Checking Calibration Span 17
8.4 Procedure for Checking Calibration Zero 19
8.5 Timing Out During Calibration Checks 19
i
Section 9.0
Menu System
20
9.1 Main Menu 20
Section 10.0
Maintenance and Troubleshooting
22
Section 11.0
Appendix A
– Bench Top Configuration Drawings
Section 12.0
WARRANTY
24
Tables and Figures
9.2 Factory Sub-Menu 21
10.1 User Maintenance 22
10.2 Serviceable Items 22
10.3 Troubleshooting 22
Part Number BTP 23
Figure 6.0 Main Printed Circuit Board 4
Figure 6.1 Rear View 5
Table 6.0 Relay Configurations 6
Table 6.1 Customer Wiring 6
Figure 7.0 SW6 Switch Settings 10
Figure 7.1 Typical Sampling System 14
Nernst Equation 16
Table 9.0 Main Menu 20
Table 9.1 Factory Sub-Menu 21
Table 10.0 Troubleshooting 22
ii
ALPHA OMEGA INSTRUMENTS CORP.
WARNING: ELECTRICAL SHOCK HAZARD:
SERIES ZrO
FAST RESPONSE OXYGEN ANALYZER Instruction Manual
2000
SECTION 3.0
CAUTIONS
The cautions listed here are important for the proper operation of the analyzer. Please read the
following carefully as there are several items to be aware of while operating the instrument.
3.1 Explanation of Graphic Symbols
To avoid the risk of fire or electric shock, do not expose the Series ZrO
GENERAL WARNING/CAUTION: Refer to the instructions associated with
that section of the manual for specifics on the potential danger.
2000
Fast Response Oxygen
Analyzer to rain or water spray.
Dangerous voltages are
present within the instrument. This particular warning symbol is specific
to an electrical hazard existing at or nearby the component and/or
procedure under discussion, Failure to heed the warnings may result in
injury and/or death. Remove all power sources when installing or
removing AC power or data signal connections and when
performing any work inside the instrument.
HOT SURFACE WARNING: When powered, the sensor is
extremely HOT (750 °C). DO NOT TOUCH!
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ALPHA OMEGA INSTRUMENTS CORP.
SERIES ZrO
FAST RESPONSE OXYGEN ANALYZER Instruction Manual
2000
Potentially Hazardous AC voltages exist within the analyzer. All
servicing should be performed by a qualified service technician.
Disconnect all sources of power and external connections before
removing the cover.
This system is designed for use with inert gases. The sample going
into the analyzer must not contain any oils, combustibles (i.e. thread
sealants), particulates > 3 microns (i.e. dust), reducing agents (i.e.
hydrocarbons, CO, hydrogen, etc.), gases containing H2S, SOX, or
gases containing solvents. These gases will have adverse effects on
the sensor. Flammable gases or gases containing halogen atoms
(such as Freon) must be removed prior to analysis. Gases
containing silicon vapors or adhesives must be avoided. Also,
gases with thermal conductivities that are significantly different than
nitrogen may cause changes in the output of the sensor and therefore
produce measurement errors.
3.2 Important Warnings
RF Disclaimer
This instrument generates and uses small amounts of radio frequency energy, and there is no guarantee
that interference will not occur in a particular installation. If this equipment does cause interference to
radio or television reception, try to correct the interference by one of more of the following steps:
1. Reorient the receiving antenna.
2. Relocate the instrument with respect to the receiver.
3. Change the AC outlet of the instrument so the instrument and receiver are on
different branch circuits
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ALPHA OMEGA INSTRUMENTS CORP.
Measurement Ranges
Resolution
Accuracy
Percent
: ±2% of reading or 0.05% absolute
Trace
Sensor Type
Maximum Sample Pressure
Response Time
Display
Input Power
Standard Outputs
Audible Alarm
Audible Alarm Cancel
Oxygen Alarm Relays
Operating Temperature
Sample Gas Moisture Limits
Enclosure
Enclosure Dimensions
Weight (Bench top Configuration)
SERIES ZrO
FAST RESPONSE OXYGEN ANALYZER Instruction Manual
2000
Section 4.0
General Specifications1
0% to 100%
0.01 on highest reading and 0.001 ppm on lowest reading
whichever is greater.
: ±2% of reading or ±0.5ppm absolute
whichever is greater.
Zirconia
0.1 to 0.5 pounds per square inch gauge (PSIG)
< 5 seconds at 0.15 liters per minute (LPM) over 1 decade
0.7” (17.8 mm) high 6 digit liquid crystal display
Universal 90-264 VAC, 50 or 60 Hz
(2) Selectable 0-20 mA DC or 4-20 mA DC, both scalable
by the user
Internal Audible Alarm
Front Panel Switch
Two (2) SPDT Form C contacts rated 10 A @ 30V DC /
115/230 VAC. Alarms may be cleared manually or
automatically, by user selection.
50° to 104°F (10° to 40°C)
80% RH at 68°F (40°C) which represents a dew point
temperature equivalent of 61.6°F (16.5°C)
Aluminum, rated NEMA 1
13 inches (330 mm) – length
10.71 inches (272 mm) – width
6.3 inches (160 mm) – height
9.4 pounds (4.26 kg.) / 10.4 pounds (4.72 kg.) with pump.
Alpha Omega Instruments Corp. reserves the right to change or modify its product specifications without notice
1
All specifications are based on a temperature of 77°F (25°C) at standard pressure of 29.9 inches of mercury (1 atmosphere).
1
ALPHA OMEGA INSTRUMENTS CORP.
SERIES ZrO
FAST RESPONSE OXYGEN ANALYZER Instruction Manual
2000
SECTION 5.0
INTRODUCTION
5.1 General Description
The Series ZrO2000 Fast Response Oxygen Analyzer is a microprocessor based instrument designed
to measure gas phase oxygen concentrations over a range of 0-100%. The sensor used in the Series
ZrO2000 Fast Response Oxygen Analyzer is a Zirconia based type that exhibits fast response times
and due to its inherent design, a low frequency of re-calibration.
The analyzer is housed in a NEMA 1 enclosure rated for general purpose use. The front panel
contains five switches that provide access to the analyzer's settings. Oxygen values are displayed
on a 0.7"
(17.8 mm) high 6 digit liquid crystal display (LCD). The instrument is equipped with two oxygen alarm
relays. Both relays are Form C (SPDT) types rated at 10 amps at 115/230 VAC/ 30 VDC and are user
configurable for fail-safe operation. In addition to the alarm relays, the Series ZrO 2000 Fast Response
Oxygen Analyzer has a built-in audible alarm and red LEDs for visual indication of an oxygen alarm
condition. There are also two green LEDs to indicate whether the LCD is displaying parts per million
(PPM) or percent (%). The audible alarm may be manually canceled at anytime. If the audible alarm
is canceled and the alarm event continues, indications of this condition will still be available through
the front panel LEDs and relay contact(s). Two flowmeters are standard equipment for the Series
ZrO2000 Fast Response Oxygen Analyzer, one for the “Sample Flow” and another for the “Bypass
Flow”.
The Series ZrO2000 Fast Response Oxygen Analyzer comes equipped with two standard analog
outputs. These can be configured for 0-20 mA DC or 4-20 mA DC separately. Both are scalable by
the user. The analyzer accepts a universal input of 90VAC to 264VAC @ 50-60Hz.
5.2 Optional Equipment Descriptions1
The Series ZrO2000 Fast Response Oxygen Analyzer incorporates standard features that make it
immediately suitable for many applications. However, for certain requirements, the user may
desire to augment the capabilities of the instrument by equipping it with one or more of the
available options, as described below.
5.2.1 Pressure Regulator Option P/N ZR-PRR
Stainless steel pressure regulator with a 3,000 PSIG inlet capacity and an adjustable outlet
pressure range of 0-5 PSIG. The regulator does not include a gauge.
5.2.2 Sample Pump Option P/N ZR-PMP
Sample pump designed for applications where the sample pressure is insufficient to transport the
sample through the sensor housing. Not to be used with any restrictions up stream (i.e. sample filter,
pressure regulator, flowmeter, etc.).
1
Please contact the factory for other options and accessories
2
ALPHA OMEGA INSTRUMENTS CORP.
ELECTICAL INSTALLATION SHOULD BE PERFORMED BY A
SERIES ZrO
FAST RESPONSE OXYGEN ANALYZER Instruction Manual
2000
SECTION 6.0
INSTALLATION PROCEDURES
6.1 Unpacking the Instrument
Upon opening the shipping container, carefully unpack the instrument to check if the outer surfaces
have been damaged. If so, report the findings immediately to Alpha Omega Instruments who will, in
turn, provide further instructions.
NOTE: IF DAMAGE HAS BEEN FOUND, DO NOT PROCEED
FURTHER, BUT INSTEAD, CONTACT THE FACTORY.
If there is no apparent damage, check the contents to ensure all items were shipped. In some cases,
items may be back ordered. All damage and shortage claims must be made known to Alpha
Omega Instruments within 10 days after receipt of shipment. Carefully rotate the analyzer and
check to make sure no components have been loosened or dislodged. If there are loose or
dislodged components (rattling of any kind), contact the factory for further instructions. If
nothing is rattling around, the installation procedure can begin.
6.2 Electrical Installation
CERTIFIED ELECTRICIAN AND SHOULD COMPLY WITH
APPLICABLE FEDERAL, STATE, OR LOCAL ELECTRICAL
SAFETY CODES.
The Series ZrO2000 Fast Response Oxygen Analyzer is shipped with a standard North American
power cord, however this cord can be used to power the analyzer from a universal input of 90 VAC
to 264 VAC @ 50/60 Hz.
6.3 Mechanical Configuration
The Series ZrO2000 Fast Response Oxygen Analyzer has a switch bank located on the main system
board that allows a number of options to be selected by the user. Please reference Figure 6.0 for the
location of the switch bank (labeled “SW6”).
WHEN POWERED, THE SENSOR IS VERY HOT! DO NOT
TOUCH ANYWHERE NEAR IT UNLESS THE INSTRUMENT HAS
BEEN POWERED OFF AND GIVEN SUFFICIENT TIME TO
COOL!
To access the switch bank SW6, it is required to remove the cover to the analyzer. To accomplish
this, first turn down the bail so the analyzer is not in the tilted configuration. Then carefully turn the
analyzer upside down and remove the four screws on the outer edge holding on the cover. Once
removed, carefully turn the analyzer back to its upright position and slowly slide the cover off towards
the front. The SW6 switch bank is located towards the front of the analyzer on the right hand side
down toward the bottom of the printed circuit board shown in Figure 6.0.
Note: It is not necessary to change the switch settings unless a specific condition must be
controlled upon startup or unexpected power cycling. See section 7.3.2 for details on the
Default / User settings.
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ALPHA OMEGA INSTRUMENTS CORP.
SW6
SERIES ZrO
FAST RESPONSE OXYGEN ANALYZER Instruction Manual
2000
Note: The analyzer is configured at
the factory to allow the user to
save all settings via battery backed
RAM. This eliminates the need to
open the cover and change the
switch settings.
FIGURE 6.0
In some rare cases where it is necessary to have a default configuration of the switch settings, then
the analyzer can be set up to read the switch settings of SW6 while turning on the analyzer or when
initiating a “warm boot” (see section 7.2). In this mode, any changes made via the front panel will be
remembered only until the next power cycle or “warm boot”. A full description of this option can be
found in section 7.3.
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ALPHA OMEGA INSTRUMENTS CORP.
Figure 6.0
Figure 6.1
FOR THE SENSOR TO WORK PROPERLY, THE OXYGEN ANALYZER
ADVERSELY EFFECT THE READINGS,
SERIES ZrO
6.3.1 Oxygen Sensor
FAST RESPONSE OXYGEN ANALYZER Instruction Manual
2000
Wiring of the oxygen sensor has been done at the factory. For information regarding sensor wiring
or replacement, please contact the factory. Proper use of the analyzer requires that the sensor be
exposed to a reference gas of 20.9% (ambient air). To accomplish this, the analyzer must not be
placed in an environment where the air around the outside of the enclosure is not 20.9% (i.e. a
glove box).
6.3.2 Wiring Alarm Relays
Access to the control signals generated from the Series ZrO
MUST BE PLACED IN AN ENVIRONMENT WITH CLEAN FRESH
AMBIENT AIR (20.9% OXYGEN). NEVER PLACE THE ANALYZER IN
AN ENVIRONMENT WHERE THE OXYGEN CONCENTRATION
COULD BE LOWER OR HIGHER THAN NORMAL BREATHING AIR
(20.9%). PLACING THE ANALYZER IN A GLOVE BOX OR OTHER
CONFINED AREA WHERE OXYGEN LEVEL IS NOT 20.9% WILL
2000
Fast Response Oxygen Analyzer is
accomplished using the user interface connectors on the rear panel of the analyzer. These
connectors are shown below labeled “I/O”. There are three (3) connectors labeled “A”, “B”, and “C”
as shown. Each connector has 6 pins. Reference Table 1.1 for details on the connector pin outs.
Rear View
Rear View
The Series ZrO
2000
Fast Response Oxygen Analyzer is equipped with two single pole double throw
(SPDT) relays with Form C contacts rated at 10 amperes @ 30 VDC and 115/230 VAC. Each oxygen
alarm relay can be configured by the user and both alarms default to a factory setting of low oxygen
alarms. To configure either of the oxygen alarm relays to act as a high alarm, please refer to Section
7.3.
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ALPHA OMEGA INSTRUMENTS CORP.
Fail-safe ON
Fail-safe OFF
TABLE 6.1
SERIES ZrO
FAST RESPONSE OXYGEN ANALYZER Instruction Manual
2000
Contacts shorted for each Alarm Relay
Alarm ON
High or Low O2 NC (C-1) to NO (C-2) to
Alarm1 /
Relay 1
COM (C-3) COM (C-3)
High or Low O2 NC (C-4) to NO (C-5) to
Alarm2 /
TABLE 1.0 illustrates the various wiring configurations for the four alarms in the Series ZrO2000 Fast
Response Oxygen Analyzer based on whether the alarms are going to be configured for fail-safe or
non fail-safe operation.
6.3.3 Wiring the mA DC Outputs
Terminal-Pin # Description Notes
A-1 Optional Pump Ground Factory wired
A-2 Optional Pump Adjust Factory wired
A-3 Optional Pump 24V Factory wired
A-4 Future Use Do not connect
A-5 Future Use Do not connect
A-6 Future Use Do not connect
B-1 Analog Output 1 0/4 to 20 mA
B-2 Analog Output 1 Return
B-3 Analog Output 2 0/4 to 20 mA
B-4 Analog Output 2 Return
B-5 Future Use Do not connect
B-6 Future Use Do not connect
C-1 Alarm 1 Normally Closed Contact
C-2 Alarm 1 Normally Open Contact
C-3 Alarm 1 Common Contact
C-4 Alarm 2 Normally Closed Contact
C-5 Alarm 2 Normally Open Contact
C-6 Alarm 2 Common Contact
The Series ZrO2000 Fast Response Oxygen Analyzer is equipped with two analog outputs, both of
which can be user set to output 0-20 mA DC or 4-20 mA DC from the front panel. In addition, each of
the two analog outputs can be scaled over a user selectable range. Reference Table 1.1 above to
wire to one or both of the mA DC output(s).
Note: Do not connect anything to the unused outputs of the analyzer. These are for future
use only.
Relay 2
COM (C-6) COM (C-6)
TABLE 6.0
RELAY CONFIGURATIONS
Customer Wiring
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ALPHA OMEGA INSTRUMENTS CORP.
SERIES ZrO
FAST RESPONSE OXYGEN ANALYZER Instruction Manual
2000
SECTION 7.0
Operation
7.1 Preparation for Operation
7.1.1 Mounting Configurations
Bench Top / Portable (BTP Configuration) The BTP is the basic configuration for the Series
ZrO2000 Fast Response Oxygen Analyzer, designed for either bench top or portable applications. All
gas and electrical connections are located on the instrument's rear panel for ease of access. See
Appendix A for detailed dimensional drawings.
7.1.2 Initial Check
The Series ZrO2000 Fast Response Oxygen Analyzer is ready to be used out of the shipping
container. The analyzer has been calibrated at the factory and re-calibration is not required at initial
startup. Please refer to Section 8.0 for details regarding routine calibration. Note: All gas lines used
to supply sample gas to the analyzer must be free of oil and rated for oxygen service.
Residual oils can damage the sensor and this will not be covered under warranty. If uncertain
where to obtain the proper tubing, we recommend contacting Winter Technologies (636-271-
6400) and order their part number WT-304C-1/4. This is 304 SS tubing that has been cleaned
of all residual oil.
7.2 Operating Procedures
7.2.1 Power ON
Power to the instrument is applied when the power cord is plugged into an AC outlet and the power
switch on the rear of the instrument is switched ON. The Series ZrO2000 Fast Response Oxygen
Analyzer has battery backed RAM so that when the instrument is initialized, all values set by the user
via the front panel will be maintained if switch #8 of SW6 is set to the "ON" position, otherwise referred
to as the “User Settings” configuration mode (See section 7.3). Initialization gives the user the
opportunity to make sure the microprocessor, internal memory, front panel LEDs, and the audible
alarms are functioning normally. During an initialization sequence, the instrument's front panel liquid
crystal display (LCD) will display a series of dashes like [¯ ¯ ¯ ¯ ][- - - -][_ _ _ _], each of the front panel
LED's will blink simultaneously for approximately 5 seconds, and the audible alarm will sound
intermittently for as long as the LEDs are blinking. After this, the display will briefly show the on board
switch settings such as [| | | | | | | |]. This is the factory default. Switches #5-8 of SW6 are in the ON
positions and switches # 1-4 are in the OFF positions. Finally, the instrument will start to warm up the
sensor and indicate this on the LCD in the form of a scrolling message [sensor Heating up]. The
measured sensor temperature is shown briefly at the end of the message to give an indication of
whether or not the system is heating up. Allow for at least 10 minutes to stabilize after warming up.
DO NOT HANDLE THE OXYGEN SENSOR WITH HANDS AS IT
WILL CAUSE SEVERE BURNS.
To initialize without the power cycling (referred to in the industry as a “warm boot”), and read the
switch bank settings (as opposed to saved RAM variables), check that SW6 - switch # 8 is set to
"OFF" and push the front panel UP, DOWN, and Alarm 2 buttons simultaneously. This causes the
analyzer to perform a “warm boot” and initialize just as if the power had been cycled. Do not hold the
buttons down very long after the display shows the dashes described above. The LCD will show the
same sequence as above, however, switch #8 will indicate low. Powering on with switch #8 in the
"OFF" position as described will cause the Series ZrO2000 Fast Response Oxygen Analyzer to read
the actual switch settings of SW6 as opposed to using the saved RAM settings. See the description
for SW6 in section 7.3 for details on user settings.
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ALPHA OMEGA INSTRUMENTS CORP.
SERIES ZrO
7.2.2 Front Panel Controls and Indicators
FAST RESPONSE OXYGEN ANALYZER Instruction Manual
2000
The front panel of the Series ZrO2000 Fast Response Oxygen Analyzer contains a 6 digit liquid crystal
display (LCD), five (5) membrane switches (“Alarm 1”, “Alarm 2”, up, down, and “Enter”) , and two (2)
alarm LEDs. An Audible Alert Indicator is located behind the front panel of the instrument. There are
also two LEDs that indicate whether the LCD is displaying ppm or percent (%) oxygen. Note that the
“ppm” and “%” LEDs only have meaning when showing oxygen values in the LCD. The 6 digit LCD
display shows the concentration of oxygen in the sample being measured in terms of percent or ppm
oxygen by volume and also displays messages or alerts from the microprocessor. Within
approximately 15- 25 minutes after the analyzer is powered on and the sensor is heated sufficiently,
the Series ZrO2000 Fast Response Oxygen Analyzer will measure and display the oxygen
concentration of the sample gas being exposed to the sensor. Note: for calibrations of any kind, the
analyzer should be running longer for better accuracy. See Section 8.0 (Calibration Procedures) for
more details. If the concentration of oxygen should go below 1%, the LCD will convert the readings to
ppm and the “ppm” LED will illuminate. When the concentration of oxygen is equal or greater than 1%
then the LCD will convert the reading into percent and the “%” LED will illuminate.
The Series ZrO2000 Fast Response Oxygen Analyzer alarms are set at the factory as low alarms. Any
one of these alarms can be set by the user for operation as high alarms also. Please refer to Section
7.3, Alarm System, for instructions on how to set Alarms for either high or low operation and how to
adjust the levels of the alarms.
7.2.3 Scaling the Analog Outputs of the Analyzer
The Series ZrO2000 Fast Response Oxygen Analyzer is equipped with two non-isolated analog outputs,
both of which can be user set to an output of 0 -20 mA DC or 4- 20 mA DC. Each output can also
have a user selectable oxygen range set to anywhere from 0.000 ppm to 100%. The analyzer is
shipped from the factory with Output 1 set from 0.000 ppm to 100% oxygen and Output 2 is set from
0.000 ppm to 25.0% oxygen. These ranges are scaled to the user selected output current ranges of 0
to 20mA or 4 to 20mA. These options provide great flexibility in controlling the range over which the
mA outputs control.
For certain applications, it may be desirable to change the analog output of the Series ZrO2000 Fast
Response Oxygen Analyzer over a narrower range of measurement. For instance, if operating
over the range of 0 to 10,000 ppm most of the time, it may be useful to scale the output for that
oxygen range instead of the default of 0 to 100% or 0 to 25%.
Setting the Analog Output Range
To adjust the analog outputs, the instrument must be placed into the “menu mode” by pressing the
“Enter” key while displaying the oxygen value. After pressing the “Enter” key the analyzer will be in
the “menu mode” and the LCD will display the first menu item. Simply press the up or down buttons a
number of times until the option [
Ot1 lo
] shows in the LCD. At this point, pressing “Enter” again will
allow the arrow keys to adjust the Output 1 Low setting. Adjust this value either up or down by using
the front panel up and down arrow keys until the desired value is achieved. When the desired value is
shown simply press “Enter” again to save the setting to RAM and automatically increment to the next
menu item. Continually pressing the “Enter” key will cycle through the various menu items / settings
by auto incrementing the menu items. At any time the user may arrow up or down to the menu item
[
] and press “Enter” to return to the main screen to display the oxygen value. A quick alternative
DONE
when displaying a menu item is to press the “Alarm 2” button to immediately exit the menu and return
to the main screen. The [
Ot2 lo
] setting works exactly the same as described above.
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ALPHA OMEGA INSTRUMENTS CORP.
SERIES ZrO
FAST RESPONSE OXYGEN ANALYZER Instruction Manual
2000
To adjust the span points of the two analog outputs of the Series ZrO2000 Fast Response Oxygen
Analyzer, select the appropriate menu item [
Ot1 Hi
] / [
Ot2 HI
] and press “Enter”. The instrument will
display the value. Adjust as necessary and press “Enter” when finished. The span in our example
corresponds to 10,000 ppm. The scaling software in the Series ZrO2000 Fast Response Oxygen
Analyzer has built- in safeguards that will not allow the analyzer to be adjusted so that the “Lo” value
is set above that of the current “Hi” value, or have the “Hi” value set below that of the current “Lo”
value. When the proper scaling values have been set, press the “Enter” key to auto increment to the
next menu item.
Setting the Analog Output Type
Both analog output ranges can be selected to scale the user range over one of two types of current
outputs. One type is 0 to 20 mA DC. The other type is 4 to 20 mA DC. The type corresponds to the
low end of the mA DC signal output. This is typically set to 4.00 mA (default), which means that when
the LCD is displaying the “Low” value (0.00 oxygen in our example), the output will read 4.00 mA. This
can be changed to 0.0 depending on the [
Ot1Typ
] / [
Ot2Typ
] setting. The [
Ot1Typ
] / [
Ot2Typ
]
settings determine whether or not the associated mA output has a “live” zero or not. The “live” zero
allows the equipment monitoring the current loop to know that something is wrong when the current
falls below 4.00 mA. The 0.00 mA setting on the other hand allows for easy scaling when using a
resistor to convert the current to voltage. To select the offset type, toggle between the two options of
0.00 mA or 4.00 mA by pressing the up and down arrows. Pressing “Enter” will save the information
into battery backed RAM. If switch #8 of SW6 is ON (default), then this setting will be remembered
during a power cycle. Otherwise the system will default to the 4.00 mA option.
NOTE: Regardless of how the analog outputs are scaled, the analyzer will always maintain the
capability of displaying oxygen concentrations over the instrument’s standard range of 0-100%.
Scaling the outputs does not scale the front panel digital display. Furthermore, oxygen alarm relays
can be expected to change state if the oxygen values they are set to should meet or exceed the
alarm setting (independent of the output scaling). Both alarms are set at the factory to values of 0.000
and set for a low alarm (see next section for more details).
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ALPHA OMEGA INSTRUMENTS CORP.
O
N
SERIES ZrO
FAST RESPONSE OXYGEN ANALYZER Instruction Manual
2000
7.3 Alarm System
The Series ZrO2000 Fast Response Oxygen Analyzer incorporates an alarm system that can be
controlled by the user from both the front panel and the on board switch settings. This section
describes the function and control of each alarm type.
7.3.1General Description of Alarm Processing
The Series ZrO2000 Fast Response Oxygen Analyzer is equipped with two (2) single pole double
throw (SPDT) relays with Form C contacts rated at 10 amperes @ 30 VDC and 115/230 VAC. All
alarm relays are user configurable with the front panel controls of the instrument and the
configuration switch SW6. When an alarm event takes place, several indications are provided by
the Series ZrO2000 Fast Response Oxygen Analyzer:
1. The LED associated with the oxygen alarm in question will illuminate.
2. An audible alarm will sound.
3. The relay associated with the oxygen alarm in question will change state.
If the alarm event was associated with the instrument status, only the relay associated with
the instrument status alarm will change state. Alarm processing and behavior is controlled
via SW6 (Figure 7.0) and/or the user settings saved in the battery backed-up RAM
associated with the microprocessor.
USER CONFIGURATION
OUTPUT 2 4/20 MA
AUTO-CLEAR ALARMS
OUTPUT 1 4/20 MA
OXYGEN ALARM 2 (HI)
OXYGEN ALARM 1 (HI)
RELAY 2 - FAIL-SAFE
RELAY 1 - FAIL-SAFE
SW6
1 2 3 4 5 6 7 8
SWITCH SETTINGS
OUTPUT 2 0/20 MA
MANUALLY CLEAR ALARMS
OUTPUT 1 0/20 MA
OXYGEN ALARM 2 (LO)
OXYGEN ALARM 1 (LO)
RELAY 2 - NORMAL
RELAY 1 - NORMAL
FIGURE 7.0
SW6 SWITCH SETTINGS
Note: The factory setting for switch #8 is set to “User Configuration” or ON. This allows
the instruments settings to be fully controlled by the user via the front panel menu
system and remembered even after the power is turned off.
If switch #8 is changed to “Switch Settings” or OFF, then every time the analyzer is turned on, the
settings will be read from the switch bank instead of the battery backed RAM. Therefore, any settings
that were changed via the front panel menu system will be overwritten with the settings read from the
switch bank. This is useful in certain situations that require a failsafe mode of operation, since every
time the analyzer is turned on or re-booted, the settings will be restored even if inadvertently changed
via the front panel menu system.
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7.3.2 Default / User Settings
As described above, with switch #8 of SW6 in the "OFF" position, the Series ZrO
2000
Fast
Response Oxygen Analyzer reads switches #1 through #7 to configure all options. With switch
#8 in the "ON" position, all user settings1 will be retained. The factory default is the latter and
allows full control form the front panel menu. Note: to read the switches without turning off the
instruments, initiate a "warm boot" with switch #8 in the OFF position or “Switch Settings”
mode (See Figure 7.0).
7.3.3 Fail Safe
IF ANY ALARM IS NOT GOING TO BE USED, IT SHOULD BE
DISABLED (FACTORY DEFAULT). TO DO SO, CHOOSE THE ALARM
TO BE DISABLED AND SET THE ALARM AS A LOW ALARM
(SECTION 7.3.4), AND THEN SET THE ALARM TO 0.00 (SECTION
7.3.7).
Switches #1 and #2 control the fail- safe operation for each of the alarm relays. Each switch must be
turned "ON" to be fail-safe (refer to FIGURE 7.0). In the fail-safe mode, the normal or non-alarm
state of each of the alarm relays is energized. When an alarm signal is generated, the respective
relay for the alarm is not energized. This would be the same relay state (not energized) that would
be achieved if the power source were interrupted. The factory default setting for switches #1 and #2
is "OFF" (normal operation or non fail-safe). These settings are also available via the menu as
[
FS1sEt
] & [
FS2sEt
].
7.3.4 Oxygen Alarm Type
Switches #3 and #4 control whether the corresponding alarms are “high” alarms or “low” alarms. A
“high” alarm will be indicated if the oxygen level is GREATER THAN the alarm setting. A “low” alarm
will be indicated if the oxygen level is LESS THAN the alarm setting. These settings are also
available via the menu as [
7.3.5 Output Type
AL1sEt
] & [
AL2sEt
] by pressing the up and down buttons
simultaneously.
Switches #5 and #7 control whether the corresponding analog output has a 4.00 milliamp offset or
not. This results in two options for the analog outputs. Setting either of the switches to “ON” will
enable the 4 milliamp offset and result in a 4.00 to 20.00 mA output for the corresponding output.
Conversely, setting either switch to “OFF” will result in an analog output of 0.00 to 20.00 mA. These
settings are also available via the menu as [
7.3.6 Manual Clear / Auto Clear
OT1TYP
] & [
OT2TYP
].
There are two possible conditions that effect the way the instrument will respond to alarm
cancellation. One is Auto-Clear operation and the other is Manual Clear. The mode of operation is
determined by the setting of switch #6 of SW6. This setting is also available via the menu as
[
AuTCLr
1
If the user should change any of the settings via the front panel controls (i.e. Low to high alarm) and cycle the power,
switch #8 being “ON” causes the analyzer to ignore the switch settings #1 through #7 and use the settings currently stored in
battery backed RAM.
].
When switch 6 of DIP Switch SW6 is placed in the “Off” or ‘”Manually Clear Alarms” position, the user
is required to manually clear the alarm indication from the analyzer even if the original alarm condition
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has returned to a non-alarm level. When the switch is in the “On” or “Auto-Clear Alarms” position, the
analyzer will automatically clear the three (3) alarm indications (LED, Audible Alarm, and Relay) when
the original alarm condition returns to a non-alarm level.
7.3.6.1 Manual Clear Operation
In the Manual Clear mode (SW6, switch #6 is "OFF), the analyzer will not automatically clear the
alarm indicators. The user must first cancel the audible alarm by pushing the appropriate alarm
button. Only after the audible alarm has been canceled can the user clear the alarm condition by
again pushing the appropriate alarm button. If the set-point is to remain the same, simply push the
appropriate alarm button a third time.
Note: If the audible alarm is activated, pressing any alarm button that is not associated with an
alarm condition will temporarily quiet the audible alarm. Upon exiting the alarm set condition or if
the monitor times out because of no user input, the audible alarm will resume awaiting a manual
clear operation as described above.
7.3.6.2 Auto Clear Operation
In the Auto Clear mode (SW6, switch #6 is ON), the Series ZrO2000 Fast Response Oxygen Analyzer
will automatically reset the alarm indications mentioned above when the alarm condition clears.
Under Auto-Clear operation, the silenced audible alarm may automatically come back on if the O2
reading should go out of alarm range and then back into alarm condition. Also, after silencing the
audible alarm, all alarms must be cleared to re-enable the audible alarm.
7.3.7 Setting the Alarm Levels
Assuming that no alarms are currently activated (no alarm LEDs are illuminated), press the desired
alarm switch on the front panel, "Alarm 1" or "Alarm 2". The numerical value in the LCD is the existing
alarm value associated with that alarm channel. When the alarm switch is pressed, the LED directly
above the switch will light indicating that channel is in the alarm set mode. Each of the oxygen alarms
can be changed from low to high level or vice versa by pressing the UP and DOWN arrows
simultaneously. To set the oxygen alarm values, press the DOWN arrow to lower the oxygen alarm
value or the UP arrow to increase the value. The longer either arrow is held down, the more rapidly
the alarm values will scroll in the display. When the value in the display is close to the desired oxygen
set point value, it is recommended that pressure be released from the switch. To obtain the final
value, apply momentary pressure to the switch to change values in small increments. When finished
setting the alarm, press the associated alarm switch. The LED will go off, and the display will indicate
the actual oxygen concentration. If more than one alarm value or level is to be changed, repeat this
procedure on the desired alarm channel.
An alternate method of setting the alarms is through the use of the menu by pressing “Enter” while
the LCD is displaying the oxygen value. Simply select the appropriate menu item ([AL1Set] or
[AL2Set]) and adjust as necessary. Note: The menu also supports toggling from “L” to “H” while
setting the alarms by simultaneously pressing the up & down buttons.
7.3.8 Timing Out During Alarm Setting
If the user is adjusting the alarm values and other settings in the Series ZrO2000 Fast Response
Oxygen Analyzer and no adjustment has been made for approximately 2 minutes, the analyzer will
automatically revert back to displaying the oxygen value in the LCD. NOTE: If the user is in an alarm
setting sequence and the instrument times out, the alarm value will be that which was last
displayed in the LCD. This feature helps to prevent the user from inadvertently keeping the analyzer
off-line for a prolonged period of time.
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7.4 Sample Gas Handling
The Series ZrO2000 Fast Response Oxygen Analyzer is shipped with stainless steel 1/4” sample gas
fittings on the sample inlet and quick connect style for the outlet port of the analyzer. Both fittings are
designed to be used with 1/4” OD stainless/plastic tubing respectively. The most critical item to pay
close attention to is the delta pressure across the sensor. Other than the supplied factory pump,
particular attention should be paid to ensure that there are no sample restrictions or sources of back
pressure to the analyzer. The oxygen sensor used in the Series ZrO2000 Fast Response Oxygen
Analyzer is a partial pressure measuring device and any changes to the total pressure will affect each
of the partial pressures, oxygen being one. Fluctuations in sample back pressure are not corrected for
and could lead to a significant error in the oxygen measurement. Typically the instrument is either
monitoring a pressure regulated source or drawing a sample from a source at atmospheric pressure.
For low ppm oxygen measurements, it is imperative to scrutinize the entire plumbing system including
the analyzer to determine the suitable components for measuring low ppm oxygen concentrations. For
instance, stainless steel tubing is recommended to minimize oxygen adsorption on the walls of the
tubing. Using tubing material other than stainless steel can adversly effect response time of the
analyzer. Be sure to check all components in the sampling system for leaks (i.e. filters, valves, etc).
7.4.1 Positive Pressure Sampling
The standard Series ZrO2000 Fast Response Oxygen Analyzer does not come equipped with a
sample pump. In this case, the sample must be under positive pressure and the “Sample Flow
Adjust” and “Bypass Flow” adjustments would be used to control the sample flow. The factory
strongly recommends the sample gas to be allowed to vent to atmosphere to avoid errors in the
measument due to back pressure.
7.4.2 Negative Pressure Sampling
The Series ZrO2000 Fast Response Oxygen Analyzer can be ordered with a sample pump that mounts
directly to the instrument on the rear panel. Alpha Omega Instruments Corp. strongly recommends
using the optional pump supplied at the factory when drawing a sample from a source at
atmosphere. The pump draws a slight vacuum from the “Sample Out” port which in turn will draw a
sample from the “Sample IN” port. It is important to keep the “Sample Flow Adjust” control knob fully
open (counter-clock wise) in this configuration. To adjust the proper flow rate, use the front panel
controls to control the pump via the main menu item [FloSet] (Pump). The “Bypass Flow” adjustment
knob can also be used to make final adjustments to achieve the proper flow rate of 0.15 LPM for the
sample flowmeter. Again, drawing a sample using a pump requires that the “Sample Flow
Adjust” knob be OPEN (FULLY COUNTER-CLOCKWISE). DO NOT turn the “Sample Flow Adjust”
knob clockwise, otherwise this will cause a significant error in the oxygen readings due to the
induced delta pressure drop. Instead, use the [FloSet] menu item or the “Bypass Flow” control knob
to finely adjust the sample flow rate to the optimal 0.15 LPM. Note: ideally the pump should be
disconnected when a positive pressure sample is being used (i.e., Calibration gas cylinder)1.
To disconnect the pump from the “Sample OUT” port, simply disconnect the “quick-connect” fitting by
depressing the ring and pulling the tube out when necessary. The other end will remain attached to
the pump until the calibration gas is removed and the pump tube is pushed back into the “quickconnect” fitting for drawing the sample as described above.
1
For best results, optionally apply the positive pressure sample to the “Sample IN” using a 1/4” stainless steel TEE and attach
an 8” piece of tubing to the opposite side of the tee to minimize any back diffusion. This allows the calibration to be done while
using the pump to draw the sample and minimize errors associated with switching from a positive pressure to calibrate and
then a negative pressure to analyze the source sample.
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It is recommended that the sampling lines be kept as short as possible to minimize the response time.
Keep all sample lines leak tight and avoid the use of the gases listed in section 3.2.
For specific sampling system questions, please contact the factory.
7.4.3 Gas System Pressure and Flow Limits
FAST RESPONSE OXYGEN ANALYZER Instruction Manual
2000
Figure 7.1
Typical Sampling System
For sample gases and/or calibration gases that are under positive pressure, it is imperative that the
input pressure to the sensor be kept under 2.0 PSIG. If the pressure is expected to be in excess of
2.0 PSIG it is advisable to use a pressure regulator (Alpha Omega Instruments model number ZRPRR). The flow rate to the analyzer should be set to 0.15 LPM (± 0.03 LPM). Higher flow rates will
cause errors due to a cooling effect on the sensor. For repeatability, always use 0.15 LPM (± 0.03
LPM).
Warning: When applying a calibration gas from a pressurized cylinder,
the possibility exists that a high pressure pulse may be introduced into the
sample system. To avoid any damage, it is highly recommended to turn
the “Sample Adjust” control valve OFF (fully clockwise) until a reasonable
flow rate of about 0.25 LPM flow is established in the “Bypass Flow”
meter. Although the valves are rated at 100 PSI or greater, the sensor
and or plumbing will dislodge and/or possibly damage the analyzer or
sensor. It is highly recommended to check the sample flow rate
before connecting the sample to the analyzer.
If the sample pressure is insufficient to move the gas through the sensor housing, a diaphragm
sample pump may be required (Alpha Omega Instruments P/N ZR-PMP). The ZR-PMP has been
designed to provide dampening of the sample to eliminate fluctuations in oxygen readings due to
pump pulsation. Alpha Omega Instruments does not recommend the use of any other type of
diaphragm pump unless provisions for dampening have been included1.
1
It is possible to pump the sample into the “Sample IN” port, however the performance of the analyzer will be directly
affected by the performance of the pump. Any leaks in the pump will cause significant errors in the readings
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Another precaution is to ensure that the pressure differential across the sensor is minimized. Excess
pressure differential may occur if the sample flow is either restricted or shutoff ahead of the analyzer
(i.e. filter or valve) and simultaneously a sample pump was left on drawing a vacuum from the
“Sample Out”, therefore creating a delta pressure condition across the oxygen sensor. This condition
should be avoided as large measurements errors will occur. Under normal conditions the differential
pressure should be almost nil - less than 0.2 pounds per square inch differential (PSID). Maximum
differential pressure should be kept to below 2.0 PSID. In general, as long as one side of the
analyzer is at or about ambient pressure, the pressure differential (including the factory supplied
pump) will be satisfactory.
7.4.4 Corrosive Gases
For applications where the sample contains corrosive gases, please check with the factory prior to
startup.
7.4.5 Orientation
Never mount the analyzer upside down or sideways. This could damage the sensor and will result in
erroneous oxygen readings. The analyzer comes equipped with a bail on the front two feet to allow for
better viewing at a slight angle. Please note that any calibrations should be done with the analyzer
laying horizontally to allow for the correct flow showing in the meter. Using the bail to tilt the analyzer
will not effect the output significantly, however the flowmeter will show a lower flow due to the design
of the flowmeter. This flow error can be ignored and is only a result of the angle that the flow meter is
in. To check the flow rate, simply put the bail down and lay the analyzer flat. Note: Do not readjust the
flow rate when the bail is in use as this will cause significant errors in the reading due to an incorrect
flow rate.
7.4.6 Condensable Gas Constituents
The Series ZrO2000 Fast Response Oxygen Analyzer should not be used for applications where
there is a likelihood that one or more gas constituents will condense (liquefy). Usually, sample gases
with high dew point temperatures (water vapor concentration) can pose a problem. If the sample gas
temperature is allowed to cool to the dew point temperature of the sample gas, condensation will take
place. If the sensor is exposed to liquids, even in small amounts, erroneous oxygen readings will
result. If the problem is severe enough, there may be permanent damage to the sensor. A water trap
or absorbent system can be used to eliminate the condensate for some applications.
7.4.7 Sample Gas Moisture Limits
The Series ZrO2000 Fast Response Oxygen Analyzer should not be used when the
dewpoint temperature of the gas exceeds 61.6°F (16.5°C). This is equivalent to a relative
humidity level of 80% at an ambient temperature of 68°F (40°C). Dewpoints higher than the
aforementioned concentrations may cause erroneous oxygen readings particularly in the
parts per million ranges.
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Ecell
= Sensor output
SERIES ZrO
FAST RESPONSE OXYGEN ANALYZER Instruction Manual
2000
SECTION 8.0
CALIBRATION PROCEDURES
8.1 Routine Calibration Check
The Series ZrO2000 Fast Response Oxygen Analyzer is fully calibrated at the factory prior to shipment.
Alpha Omega Instruments oxygen sensors feature high accuracy and excellent long term stability
characteristics. As a result, routine maintenance is kept to a minimum. As is the case with all gas
analyzers, it is advisable to periodically check the overall system calibration [CALSPN]. The
frequency of these checks is often determined by in-house calibration protocols. If none exists, Alpha
Omega Instruments Corp. recommends that a calibration check be made on an average of twice
every year. It is also recommended to check the calibration just before taking any high precision
measurements. A ZERO calibration [CALAIr] is also recommended when taking any measurements
at or around ambient air (20.9%).
8.2 Calibration Gas
The oxygen sensor in the Series ZrO2000 Fast Response Oxygen Analyzer has a logarithmic output
based upon the Nernst equation shown below.
E
= E
cell
offset
+
(R*T)
(n*F)
* ln
(Reference)
(Sample)
Where:
Eoffset =
Sensor offset at ambient (209000 PPM oxygen)
R = universal gas constant (8.314510)
T = Temperature in Kelvin (~1023.15°K / 750°C)
n = 4 (number of electrons transferred)
F = Faraday’s constant (96485.3415 Coulomb/mol)
ln = natural log
Reference = 209000 PPM
Sample = Oxygen sampled at “Sample In”
Nernst Equation
As a result, it can be calibrated using a single calibration gas. The Series ZrO2000 Fast Response
Oxygen Analyzer removes any complexity by using ambient air as the reference gas, controlling the
sensor temperature accurately, and removing any sensor offset at the factory. This is accomplished
by calibrating the Series ZrO2000 Fast Response Oxygen Analyzer at the factory with ambient air
(20.9% oxygen) and an NIST traceable standard (typically 2.0% oxygen) at the specified flow rate of
0.15 LPM. This is called a “two point calibration” and need not be repeated by the customer unless
specific conditions exist that would warrant it (see section 8.0 – Calibration Procedures).
When shipped from the factory, the Series ZrO2000 Fast Response Oxygen Analyzer is ready to
measure any oxygen concentration from 0.001 ppm to 100%. After some time (often many months)
it may be necessary to re-calibrate the Series ZrO2000 Fast Response Oxygen Analyzer. Since the
sensor offset is already calibrated and canceled out, a simple single point calibration is all that is
required to compensate for any changes in the system output over time.
The single point calibration should be performed at or around the desired operating point for
best accuracy. For example, if the expected operating level of Oxygen is around 100 ppm, the
calibration standard gas of 70 to 100 ppm (70-100% of reading) should be used.
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The calibration gas should contain a defined concentration of oxygen with a balance of nitrogen
(N 2). Alpha Omega Instruments recommends a calibration gas at or around 2.0% oxygen (NIST
traceable). Note: the factory will perform a calibration on a specific NIST traceable gas. The
[
CALgAS
] variable will also be set at the factory via the main menu to reflect this NIST traceable
calibration gas. Using a gas in the 2.0% range will give the best results over the whole range of
the instrument for general use. For specific ranges of operation, the analyzer may be factory
calibrated to a different gas concentration.
Note: The Series ZrO
2000
Fast Response Oxygen Analyzer is very repeatable and accurate as long as
the flow rate is maintained to the designated flow rate of 0.15 LPM. When using a calibration gas to
verify the analyzer, DO NOT recalibrate the instrument if the reading is not exact but falls within the
uncertainty of specification of the calibration gas1 . Doing so may result in poor readings on other
gases due to the error in the calibration gas. Many times the reading of the Series ZrO
2000
Fast
Response Oxygen Analyzer is more accurate than the specified calibration gas. To verify a
calibration, simply apply a second calibration standard gas to insure that the gain of the system has
not been changed significantly. The second gas should be withing the specified tolerance of the
calibration standard gas.
If the analyzer is to be used primarily for the measurement of oxygen concentrations in the range of
ambient air (20.9% O2), make sure that a ZERO calibration is done [
CALAIr
] while sampling a source
of ambient air at 0.15 LPM If there is any reason to question the composition of the ambient air to be
used for calibration, the analyzer should be calibrated next to an open door or window where there is
an ample exchange of fresh air from an outside environment. If the location of the analyzer precludes
the use of a fresh air supply for calibration, compressed air from a cylinder source is the next best
choice (do not use plant or shop air as oil vapors and/or water mist that may be entrained in the gas
stream could damage the sensor).
8.3 Procedure for Checking Calibration Span
1. Power up the Series ZrO
7.2. Make sure that the analyzer is warmed up for at least 2 hours for best results.
2. Select a cylinder or source of calibration gas as described in Section 8.2.
2000
Fast Response Oxygen Analyzer as described in Section
3. When selecting a pressure regulator to use with the cylinder gas, it is advisable to use
a two-stage regulator with the second stage capable of delivering a gas sample at a
pressure at under 2.0 PSIG.
4. In addition to the selection of the pressure regulator, care must be given to choose
the correct sample tubing materials. For oxygen measurements below 1%,
stainless steel metal tubing is recommended.
DO NOT USE RUBBER OR PLASTIC TUBING for calibration
checks below 1%. Air contains 20.9% oxygen. A small leak of
air into either the calibration gas or sample gas line can cause
sizable errors in readings. Leakage can be through cracks in
the tubing or by diffusion through the tubing.
5. To protect the sensor from accidental pressure pulses, turn the “Sample Flow Adjust”
1
Note that the uncertainty of the standard gas is around ±2% at an oxygen level of 20,000 ppm (or 2% oxygen)
knob fully clockwise to close the valve.
6. Adjust the “Bypass Flow” adjustment knob so that it’s FULL counter-clock wise or OPEN
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7. Apply the calibration sample gas and slowly adjust the regulator so that the “Bypass
Flow” meter reads 0.5 LPM. At this point, adjust the “Bypass Flow” control valve down
to between 0.15 and 0.2 LPM.
8. Open the “Sample Flow Adjust” control valve until 0.15 LPM is flowing1.
9. The reading in the LCD will now display the oxygen concentration of the calibration
gas. If the oxygen value read on the LCD differs from the calibration gas, a calibration
offset adjustment should be made so that the value displayed in the LCD is identical to
that of the calibration gas. If an offset adjustment is to be made, the instrument must
be placed in the calibration mode. Before going into calibration mode, first monitor the
analyzer response to the calibration gas, waiting until a stable reading has been
established (minimum of 5 minutes). If the displayed reading does not stabilize, check
your plumbing for leaks or other obvious problems. Be sure to allow the oxygen
reading to come into equilibrium before making any adjustments.
10. With a stable oxygen sample being supplied, the calibration sample gas concentration
needs to be entered into the analyzer. To do so, press the front panel button labeled
“Enter”. This enters the main menu and the LCD will display the first menu item. Press
the up or down buttons to cycle to the [
CALGAs
] entry and press “Enter” again. Adjust
the value with the up and down buttons. Make sure the appropriate green LED is
illuminated (PPM or %) by simply ramping up or down the number in the display. The
threshold for ppm to % is 1.00% and the analyzer will automatically toggle the range
and the appropriate ppm / % LED will illuminate. For instance, if using a ppm level gas
and the % LED is illuminated, simply press the down arrow until the LED switches to
PPM and continue adjusting the value to the desired PPM. When finished adjusting
the value, press “Enter” again. The firmware will automatically auto-increment to the
[
CALSPN
] option. The [
CALGAs]
entry will be remembered so that if at a later date
the analyzer is re-calibrated, it is not necessary to reenter this information. At
this point proceed directly to the span calibration by pressing “Enter” or double check
the oxygen reading by exiting the menu by pressing the “Alarm 2” button. Optionally
scroll to the menu item titled “Done” and press “Enter” to exit the menu.
11. If the previous step exited the menu and the LCD is displaying the oxygen reading,
simply press “Enter” to get back to the menu and arrow to [
already at the menu item [
display [
], then display [
CAL
CALSPN
YES
then proceed by pressing “Enter” again. If [
display [
-Hold-
] and then go through a series of tests and if there are any problems,
], simply press “Enter”. The firmware will briefly
] in the LCD. Using the arrows, select [
] was selected, the analyzer will first
YES
CALSPN
] again, otherwise, if
] or [No],
YES
the LCD will show an error message. Note: Error messages will not time out!
Pressing any key will acknowledge the error. The firmware will revert to the
previous calibration to avoid strange readings. It is strongly recommended to
investigate the cause of the error and re-calibrate. Otherwise, the LCD will indicate a
successful calibration and return to the next menu item.
During a [
CALSPN
±20% of the [
] calibration, the analyzer will determine if the calibration being performed is within
CALGAs
] setting. As an example, if the user should be monitoring ambient air (20.9%
oxygen) and accidentally enter a calibration gas of 2% and then forget to apply the calibration gas
to the analyzer, the system will show an error that it is out of range. In this case the analyzer will
revert to the old calibration settings to avoid gross errors on the display. It is recommended to recalibrate any time there is an error displayed on the screen after checking to see if the procedure
was followed correctly. If the errors persist despite following the procedure correctly, please contact
the factory for further instructions.
1
Higher flow rates could cause cooling of the sensor resulting in errors.
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8.4 Procedure for Checking Calibration Zero
Calibration Zero is misleading since the calibration is really performed at the level where there is no
output from the sensor. This occurs when the reference gas (which is ambient air or 20.9% oxygen) is
equal to the sampled gas. Therefore, all that is needed to check the Calibration at Zero is a source of
fresh air or clean compressed instrument air. Make sure the analyzer is reading the oxygen value on
the LCD, then follow these steps to complete the zero calibration:
1. Make sure the analyzer is sampling 0.15 LPM of fresh air or clean compressed
instrument air. If the analyzer is equipped with a pump, simply open the “Sample
Adjust” control valve fully and use the front panel menu item [
FloSET
]1 to adjust the
flow2. Otherwise, apply the pressurized sample being careful to keep the inlet pressure
to below 2.0 PSIG. Use the “Bypass Flow” control valve along with the “Sample Adjust”
control valve to achieve the proper flow of 0.15 LPM.
Warning: Do not apply instrument air without first checking
that the instrument air is free of any oils. Having oils
present in the sample system could damage the sensor and
2. Press the “Enter” button to enter the main menu.
3. Using the up and down buttons, scroll through until the LCD reads [
4. Press “Enter”. The firmware will briefly display [
Using the arrows, select [
may result in permanent damage to the analyzer.
], then display [
CAL
] or [No], then proceed by pressing “Enter” again. If [No]
YES
was selected, the calibration is canceled and the LCD will show [
CALAir
] in the LCD.
YES
CANCeleD
].
]. If [
YES
]
was selected, this initiates the calibration on ambient air. The analyzer will first go
through a series of tests and if there are any problems the LCD will show an error
message. Note:
Any error message will not time out! Pressing any key will acknowledge the
error. The firmware will revert to the previous calibration to avoid strange
readings. It is strongly recommended to investigate the cause of the error and re-
During a [
calibrate. Otherwise, the LCD will display [
and return to the next menu item
CALAir
] calibration, the analyzer will determine if the calibration being performed is
] to indicate a successful calibration
CALd
within ±20mV offset. As an example, if the user should be monitoring a calibration gas (i.e. 2%
oxygen) and accidentally initiate a [
CALAir
], the system will show an error that it is out of range.
In this case the analyzer will revert to the old calibration settings to avoid gross errors on the
display.
8.5 Timing Out During Calibration Checks
If the calibration check process is not completed in approximately 2 minutes, the analyzer will
automatically revert back to the previous calibration offset settings. NOTE: If the user is in a
calibration setting sequence and the instrument times out, the calibration is canceled and the
display will indicate this. This feature helps to prevent the user from inadvertently keeping the
analyzer off-line for a prolonged period of time. The one exception to this is when an “Error” has
occurred. You must press “Enter” to acknowledge the error and it is recommended to correct the
error immediately.
1
After entering the [FloSET] menu item, the firmware will wait until the up or down arrows are pushed. While waiting, the LCD will indicate
the following: “[FlosEt] >>> [Enter] >>>[IF] >>>[d one] >>>[up-dn] >>>[to] >>>[change] “. Simply press and hold Enter until it beeps.
This will auto increment to the next menu item.
2
The “Bypass Flow” control valve can only be closed when drawing a sample via the pump. Under positive pressure, the “Bypass Flow”
control valve should never be closed completely. This would create a “dead” volume of air that could adversely affect the readings.
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ALPHA OMEGA INSTRUMENTS CORP.
To Descriptions
Note: Enter to exit and save
UP/DN to
change
UP/DN to change
Yes
Auto
Auto Clearing of alarms (set to
Yes Fail Safe for
Alarm 1 Setting
UP/DN to change
Yes Fail Safe for Alarm 2 Setting
UP/DN to change
Explanation shown
Flow Set
using the pump (use the
Sub-Menu
Sub-Menu
SERIES ZrO
FAST RESPONSE OXYGEN ANALYZER Instruction Manual
2000
SECTION 9.0
MENU SYSTEM
The menu system is comprised of a simple rotating menu that shows the individual items that can be
set or viewed by the user. There is only one menu - the Main Menu, however there is also a submenu called the Factory menu. The following sections document the items available in each menu.
9.1 Main Menu
The Main Menu is where all of the important settings will be changed or viewed. The following table
shows the main menu and the options available. Press the Enter key while in the normal operating
mode of displaying the oxygen concentration value to display the menu as shown below:
Main Menu
UP/DN Select Items
ENTER to change
A2 to exit
[AL1Set]
[AL2Set]
[CALGAS]
[CALSPN]
[Ot1`lo]
[Ot1`Hi]
[Ot2`lo]
[Ot2`Hi]
[Ot1typ]
[Ot2typ]
[autCLr]
[FS1SET]
[FS2SET]
[FLoSET]
[CaLair]
[FACtry]
[done``]
Press Enter
Adjust
0.000 ppm to 100% Alarm 1 Set point
0.000 ppm to 100% Alarm 2 Set point
0.000 ppm to 100% Calibration Gas UP/DN to change
No
0.000 ppm to 100% Output 1 Low output UP/DN to change
0.000 ppm to 100% Output 1 High output UP/DN to change
0.000 ppm to 100% Output 2 Low output UP/DN to change
0.000 ppm to 100% Output 2 High output UP/DN to change
4-20 or 0-20 Output 1 Type UP/DN to change
4-20 or 0-20 Output 2 Type UP/DN to change
Man Automatic or Manual mode)
No (Yes = Failsafe, No = Not Failsafe) Enter to save
No (Yes = Failsafe, No = Not Failsafe) Enter to save
on LCD flowmeter for visual feedback)
Yes or No Calibrate on Ambient Air UP/DN to change
See next table
See next table
Keys available after Enter:
UP&DN toggles LO/HI
UP&DN toggles LO/HI
Calibrate to “Cal Gas” UP/DN to change
UP/DN to change
UP/DN to change
Factory diagnostic readings UP/DN to change
Factory diagnostic readings UP/DN to change
TABLE 9.0
Main Menu
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ALPHA OMEGA INSTRUMENTS CORP.
ENTER to view and
SERIES ZrO
FAST RESPONSE OXYGEN ANALYZER Instruction Manual
2000
9.2 Factory Sub-Menu
The [FACtry] sub-menu is used for diagnostic purposes only. This menu will not be accessed under
normal operation as it has no means of making any changes. To change to this sub-menu, simply
select it with the Enter key from the Main Menu.
The following table shows the Factory Sub-Menu and the options available:
Factory Sub Menu
UP/DN Select Items
Units or Descriptions
return to factory menu Type
A2 to exit
[TCdegc]
[2out-U]
[2out-2]
[2out-C]
[2ero-f]
[2ero-t]
[2ero-s]
[GAIN-F]
[GAIN-t]
[GAIN-p]
[2ero-U]
[SPAN-U]
[Code-b]
[Code-S]
°C Thermocouple Sensor temperature
mV “Zout-U” - Uncompensated sensor output
mV “Zout-Z” - Zero Compensated sensor output
mV “Zout-C” - Zero & Spane Compensated sensor output
mV Sensor factory zero offset stored in ROM (Read Only Memory)
mV Sensor zero offset stored in volatile memory
mV Sensor zero offset sum
Number Sensor factory gain stored in ROM
Number Sensor gain stored in volatile memory
Number Gain product
Number User calibrated zero offset stored in non-volatile memory
Number User calibrated gain stored in non-volatile memory
Text Base code version #
Text Sensor code version #
TABLE 9.1
Factory Sub-Menu
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ALPHA OMEGA INSTRUMENTS CORP.
WARNING: ELECTRICAL SHOCK HAZARD:
Dangerous
Delivery system leaks on gases
Check the integrity of the sample lines
Erroneous readings
Flow rate too high or too low
Use recommended flow
rate of
Delivery system leaks on gases
Check the integrity of the sample lines
SERIES ZrO
FAST RESPONSE OXYGEN ANALYZER Instruction Manual
2000
SECTION 10.0
MAINTENANCE AND TROUBLESHOOTING
10.1 User Maintenance
The Series ZrO2000 Fast Response Oxygen Analyzer requires minimum. The user should check
the calibration of the analyzer in accordance with established protocol. If no protocol exists, Alpha
Omega Instruments recommends that the analyzer be calibrated twice a year.
10.2 Serviceable Items
There are no end user serviceable items located inside the chassis. Do not open the chassis except
in rare cases when the switch settings will need to be changed from their default settings described
earlier in this manual.
voltages are present within the instrument. This particular warning
symbol is specific to an electrical hazard existing at or nearby the
component and/or procedure under discussion. Failure to heed
the warnings may result in injury and/or death. Remove all power
sources when installing or removing AC power or data signal
connections and when performing any work inside the
instrument enclosure.
10.3 Troubleshooting
In the case that readings are incorrect, use this table to try and determine a possible solution:
Condition Possible Problem Notes
Low readings
High readings
Reducing gases in the sample gas This can damage the sensor
Calibration error Check on traceable gas standard
above ambient
0.15 LPM
Gas source contamination Check the integrity of the sample lines
below ambient
TABLE 10.0
Troubleshooting
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ALPHA OMEGA INSTRUMENTS CORP.
BENCH TOP
SERIES ZrO
FAST RESPONSE OXYGEN ANALYZER Instruction Manual
2000
SECTION 11.0
APPENDIX A
CONFIGURATION
PART NUMBER “BTP”
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ALPHA OMEGA INSTRUMENTS CORP.
SERIES ZrO
FAST RESPONSE OXYGEN ANALYZER Instruction Manual
2000
SECTION 12.0
WARRANTY
Alpha Omega Instruments Corp. warrants the products delivered to be free from defects in material and workmanship at the
time of delivery to the FOB point specified in the purchase order, its liability under this warranty being limited to repairing or
replacing, at Alpha Omega Instruments' option, items which are returned to it prepaid within two years (one year for sensor)
from the date of shipment and found to Seller’s satisfaction to have been so defective.
Alpha Omega Instruments’ one (1) year sensor warranty offers protection for one year from the date of shipment of the
Series ZrO2000 Fast Response Oxygen Analyzer. Any sensor from a Series ZrO2000 Fast Response Oxygen Analyzer that
fails under normal use must be returned to Seller prepaid and, if such sensor is determined by Seller to be defective, Seller
shall provide Buyer a replacement sensor. Buyer must provide the serial number of the analyzer from which the sensor has
been removed. If a sensor is found to be defective and a new one issued, the warranty of the replacement sensor(s) is for a
period of one year from the date of shipment. In no event shall Alpha Omega Instruments Corp. be liable for consequential
damages.
This warranty applies only if:
(i) the items are used solely under the operating conditions and manner recommended in this
manual, specifications, or other literature;
NO PRODUCT IS WARRANTED AS BEING FIT FOR A PARTICULAR
PURPOSE AND THERE IS NO WARRANTY OF MERCHANTABILITY.
(ii) the items have not been misused or abused in any manner or repairs attempted thereon;
(iii) written notice of the failure within the warranty period is forwarded to Alpha Omega Instruments
Corp. and the directions received for properly identifying items returned under warranty are
followed;
(iv) the return notice authorizes Alpha Omega Instruments Corp. to examine and disassemble returned
products to the extent the Company deems necessary to ascertain the cause of failure.
The warranties stated herein are exclusive. THERE ARE NO OTHER WARRANTIES, EITHER EXPRESSED OR IMPLIED,
BEYOND THOSE SET FORTH HEREIN, and Alpha Omega Instruments Corp. does not assume any other obligation or
liability in connection with the sale or use of said products.
Disclaimer of Warranty
The Series ZrO2000 Fast Response Oxygen Analyzer is designed to provide valuable operating data. The
information gathered from the analyzer may be used to help eliminate or diminish potentially hazardous
conditions associated with the process environment. However, it is imperative that personnel involved with the
operation of the analyzer be properly trained and fully acquainted with the process as well as the analyzer.
Personnel safety is the responsibility of those in charge of the process and the surrounding environment. Though
this analyzer should, under the correct operating conditions, provide early detection of a process upset or
disruption, it cannot overcome operational deficiencies that could lead to the creation of a hazardous situation.
The purchaser is responsible for the process and any and all hazardous conditions that may result from normal or
abnormal operating conditions. The purchaser has the added responsibility of training personnel involved in the
application for which the analyzer is used. Alpha Omega Instruments makes no representation or warranties,
either expressed or implied, by or with respect to anything in this manual, including, but not limited to, implied
warranties of merchantability or fitness for a particular purpose. In no event will Alpha Omega Instruments Corp.
be held liable for any damages, whether direct or indirect, special, consequential, or incidental arising from the
use of this manual. Some states in the USA do not allow the exclusion of incidental or consequential damages.
Alpha Omega Instruments Corp. also reserves the right to make any changes to improve the performance of its
products at any time and without notice.
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