Michell Instruments XZR250 User manual

XZR250 User’s Manual
Michell Instruments 1
PRODUCT OVERVIEW
XZR250
Oxygen Analyzer
User’s Manual
97528 Issue 5
May 2019

XZR250 User’s Manual
ii 97528 Issue 5, May 2019
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XZR250 User’s Manual
Michell Instruments iii
XZR250
For Michell Instruments' contact information please go to
www.michell.com

XZR250 User’s Manual
iv 97528 Issue 5, May 2019
Contents
Safety ................................................................................................................................vi
Electrical Safety ...........................................................................................................vi
Pressure Safety ............................................................................................................vi
Toxic Materials .............................................................................................................vi
Repair and Maintenance ...............................................................................................vi
Calibration ...................................................................................................................vi
Safety Conformity ........................................................................................................vi
Abbreviations .....................................................................................................................vii
Warnings .......................................................................................................................... viii
1 PRODUCT OVERVIEW ........................................................................................1
1.1 Components ....................................................................................................... 1
2 INSTALLATION ..................................................................................................2
2.1 General Guidelines .............................................................................................. 2
2.2 Electrical Connections ......................................................................................... 3
2.3 Mounting Instructions ......................................................................................... 6
2.4 Probe Installation ............................................................................................... 8
3 INITIAL STARTUP ............................................................................................10
3.1 Commissioning Checks ...................................................................................... 10
3.2 Switching ON ................................................................................................... 10
3.3 First-time Calibration (field adjustment) ............................................................. 10
4 SYSTEM ELEMENTS .........................................................................................11
4.1 Human Machine Interface (HMI) ........................................................................ 11
4.2 On-Screen Settings ........................................................................................... 13
4.3 Menu Structure ................................................................................................ 14
4.4 Configurable Options ........................................................................................ 15
4.5 Security Password ............................................................................................ 15
4.6 Analog Output Ranges ...................................................................................... 17
4.6.1 Display Output ............................................................................................ 18
5 OPERATIONAL CONSIDERATIONS .....................................................................20
5.1 Environments ................................................................................................... 20
5.1.1 Operating in Aggressive and Humid Environments ......................................... 20
5.1.2 Protecting from Excessive Moisture ............................................................... 20
5.1.3 Using the Sensor with Silicones .................................................................... 20
5.2 Cross Sensitivity ............................................................................................... 20
5.2.1 Combustible Gases ...................................................................................... 21
5.2.2 Heavy Metals .............................................................................................. 21
5.2.3 Halogen and Sulphur Compounds ................................................................. 21
5.2.4 Reducing Atmospheres ................................................................................ 21
5.2.5 Other ......................................................................................................... 21
6 MAINTENANCE ................................................................................................22
6.1 Cleaning .......................................................................................................... 22
6.1.1 Outer Surfaces ............................................................................................ 22
6.1.2 Inner (sampling) tubes ................................................................................ 22
6.2 Calibrating ....................................................................................................... 23
6.2.1 Calibration gas requirements ........................................................................ 24

XZR250 User’s Manual
Michell Instruments v
Figures
Figure 1 Main Components .......................................................................................1
Figure 2 Front Panel ................................................................................................3
Figure 3 Cable Shielding ..........................................................................................4
Figure 4 Connector Pins ...........................................................................................5
Figure 5 Gas Flow Alignment ....................................................................................6
Figure 6 Mounting Adaptor Details ............................................................................7
Figure 7 Mounting Examples ....................................................................................7
Figure 8 Probe Installation .......................................................................................8
Figure 9 Insert Sensing Module ................................................................................9
Figure 10 Fit sensor Sensor head to Probe Body ..........................................................9
Figure 11 HMI .........................................................................................................11
Figure 12 LCD Layout ..............................................................................................13
Figure 13 Components .............................................................................................30
Figure 14 Insert Sensor block ...................................................................................33
Figure 15 External Dimensions .................................................................................37
Figure 16 2” ANSI Class 150 lb. Flange .....................................................................37
Appendices
Appendix A Technical Specications ..............................................................................36
Appendix B Theory of Operation ..................................................................................39
Appendix C Quality, Recycling & Warranty Information ................................................... 43
Appendix D Analyzer Return Document & Decontamination Declaration ..........................45
7 RELAY AND CURRENT TESTING ........................................................................26
7.1 Relay test ........................................................................................................ 26
7.2 Current Test ..................................................................................................... 27
8 ERROR CONDITIONS .......................................................................................29
8.1 O2 Error and Warning Codes .............................................................................. 29
8.2 Pressure Error and Warning Codes ..................................................................... 29
8.3 Temperature Error and Warning Codes ............................................................... 29
9 REPLACING PARTS ...........................................................................................30
9.1 Removing the Sensor head from the Probe ......................................................... 31
9.2 Replacing the Sensor head onto the Probe ......................................................... 31
9.3 Replacing the Zirconia Sensor block ................................................................... 32
9.4 Removing / Replacing the Front Panel ............................................................... 33
9.5 Disposal ........................................................................................................... 34
Tables
Table 1 HMI .......................................................................................................... 11
Table 2 Operator Panel Multifunctional Buttons ........................................................ 12
Table 3 Menu Structure .........................................................................................14

XZR250 User’s Manual
vi 97528 Issue 5, May 2019
Safety
The manufacturer has designed this equipment to be safe when operated using the procedures
detailed in this manual. The user must not use this equipment for any other purpose than that
stated. Do not apply values greater than the maximum value stated.
This manual contains operating and safety instructions, which must be followed to ensure the safe
operation and to maintain the equipment in a safe condition. The safety instructions are either
warnings or cautions issued to protect the user and the equipment from injury or damage. Use
qualified personnel and good engineering practice for all procedures in this manual.
Electrical Safety
The instrument is designed to be completely safe when used with options and accessories supplied
by the manufacturer for use with the instrument. The input power supply voltage is 24 V ±10% via
limited power supply.
Pressure Safety
The XZR250 is designed to be operated at atmospheric pressures.
Toxic Materials
The use of hazardous materials in the construction of this instrument has been minimized. During
normal operation it is not possible for the user to come into contact with any hazardous substance
which might be employed in the construction of the instrument. Care should, however, be exercised
during maintenance and the disposal of certain parts.
Repair and Maintenance
The instrument must be maintained either by the manufacturer or an accredited service agent. Refer
to www.michell.com for details of Michell Instruments’ worldwide offices contact information.
Calibration
The recommended calibration interval for the XZR250 is between one and three months. This
duration may be shorter or longer dependent on installation, application and customer preferences.
Safety Conformity
This product meets the essential protection requirements of the relevant EU directives.

XZR250 User’s Manual
Michell Instruments vii
Abbreviations
The following abbreviations are used in this manual:
°C degrees Celsius
°F degrees Fahrenheit
DC direct current
EU European Union
kg kilogram(s)
l/min liters per minute
lb pound
mA milliampere
max maximum
min minute(s)
scfh standard cubic feet per hour
Td cycle time to evacuate and re-pressurize the sealed cell
Td averaging counting x number of cycles and averaging the result
V Volts
% Percentage
" Inches

XZR250 User’s Manual
viii 97528 Issue 5, May 2019
Warnings
The following definitions apply to WARNINGS, CAUTIONS and NOTES used throughout
this manual.
!
Where this hazard warning symbol appears in the following
sections, it is used to indicate areas where potentially hazardous
operations need to be carried out.
NOTE:
Highlights an essential operating procedure, condition or statement.
CAUTION
Do not exceed maximum ratings and
ensure sensor(s) are operated in
accordance with their requirements.
Carefully follow all wiring instructions.
Incorrect wiring can cause permanent
damage to the device.
Zirconium oxide sensors are damaged by
the presence of silicone. Vapors (organic
silicone compounds) from RTV rubbers
and sealants are known to poison oxygen
sensors and MUST be avoided. Do NOT
use chemical cleaning agents.
Failure to comply with these
instructions may result in product
damage.
INFORMATION
As customer applications are outside of
Michell Instruments Ltd.’s control, the
information provided is given without legal
responsibility. Customers should test under
their own conditions to ensure that the
equipment is suitable for their intended
application.
For technical assistance or advice, please
contact the manufacturer.
General Note: The manufacturer reserves the right to make changes to product
specifications without notice or liability.
All information is subject to the manufacturer's own data and considered
accurate at time of going to print.

XZR250 User’s Manual
Michell Instruments 1
PRODUCT OVERVIEW
1 PRODUCT OVERVIEW
The XZR250 is a pressure compensated oxygen analyser designed to monitor the oxygen
concentration of the gas during combustion in boilers and industrial furnaces.
The XZR250 is designed to allow direct installation of the probe in the wall of a flue or
furnace to measure the concentration of oxygen in the stack gas with temperatures up to
700°C. The sensor is located in the sensor head and not the probe, this ensures a more
stable measurement and longer sensor life.
The XZR250 uses a zirconium oxide (ZrO2) sensor which should last for up to 7 years in
natural gas fired boilers. It can be replaced without the need to remove the probe from
its installation.
Single-point calibration can be simply performed using fresh air or a known reference gas.
1.1 Components
1. Sensor Head
2. Clamp
3. Mounting flange
4. Probe body
5. Gas sampling tubes
6. Gasket (see figure 8)
Figure 1 Main Components
The instrument is supplied with a quick start guide, however this full manual should be
read carefully before work commences: XZR250 97529 Quick Start Guide.

XZR250 User’s Manual
297528 Issue 5, May 2019
INSTALLATION
2 INSTALLATION
To ensure the best performance from your equipment, it must be installed correctly.
2.1 General Guidelines
Mount the probe so that the tip is in the main stream of gas (within the flue), as close
to the burner as possible, but not within the flame. Ensure the maximum temperature
is within the temperature limits of the probe.
!
WARNING: All wiring MUST be in accordance with the national
and/or any local codes, ordinances, and regulations.
Disconnect and lock out power before connecting the equipment
to the power supply.
!
CAUTION:
• Do NOT install the device suspended from the cable.
• Do NOT twist the cable(s).
• Avoid exerting excessive tensile force on the cable
(e.g. tugging).
• Do NOT leave any wires loose: accidental shorting
may cause product damage.
• Make sure the terminals are wired as shown in
Figure 4 as failure to connect power correctly could
result in irreversible product damage that is NOT
covered by warranty.
!
Always handle the interface board using the correct ESD
handling precaution

XZR250 User’s Manual
Michell Instruments 3
INSTALLATION
2.2 Electrical Connections
1. Remove the front panel:
a. If fitted, carefully remove the two screw covers (2) from the front panel (1).
b. Remove the four screws securing the front panel (1) to the housing.
c. Carefully ease the front panel (1) from the housing.
!
CAUTION: Do NOT pull forcefully.
d. Disconnect the ribbon cable from the panel and remove panel.
Figure 2 Front Panel
2. Select a suitable cable with the correct number of cores for your model that conforms
to site standards. The cable gland fitted as standard is M20 x 1.5, which will accept
cables with diametres from 7.0 mm to 12.5 mm.
3. Ensure your cable is prepared and ready for connection: shielding should be
exposed and wire ends trimmed.
4. Carefully feed the cable through the cable gland at the bottom of the sensor head:
pull through enough length to allow easy fitting of the terminal block connector.

XZR250 User’s Manual
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INSTALLATION
!
CAUTION: Make sure the shielding is intact and correctly
positioned to ensure the device is grounded properly as shown
below.
Figure 3 Cable Shielding
5. Using a 20mm spanner, tighten the cable gland to secure the cable in place.
NOTE:
Be careful not to over-tension the wires or over-tighten the gland.
6. Reconnect the ribbon cable to the front panel (1).
7. Re-fit the front panel (1) to the housing and secure in place using the four screws.
8. Fit the two screw covers (2).
!
CAUTION: Do NOT force the module otherwise you may damage
the terminals or other components within the housing.

XZR250 User’s Manual
Michell Instruments 5
INSTALLATION
9. Connect the wires as follows (refer to Figure 4 below):
Figure 4 Connector Pins
Power Supply
PIN 1: 24V DC
PIN 2: OV
RS485 Output
PIN 3: A
PIN 4: B
Analog Output
The mA outputs are powered with 24V excitation voltage and the maximum loop load
resistance for mA output 550 Ω
PIN 5: Analog GND
PIN 6: Analog Out1
PIN 7: Analog Out2 (If fitted)
Relay (alarm) Contacts
PIN 8: Relay 1 N/O
PIN 9: Relay 1 Common
PIN 10: Relay 2 (Fault alarm) N/O
PIN 11: Relay 2 (Fault alarm) Common
NOTE:
Relays are supplied normally open (N/O) as standard but can be ordered as normally
closed (N/C) if preferred.
10. Carefully pull the cable back though the gland until the connector and board are
aligned.
11. Fit the connector to the board.

XZR250 User’s Manual
697528 Issue 5, May 2019
INSTALLATION
2.3 Mounting Instructions
The probe should be mounted such that the alignment arrow on the flange is in the
same direction as the sample gas flow. Refer to Figure 5 showing alignment arrow.
Avoid positions where:
• Obstructions or bends create turbulence in the gas flow and/or hinder probe
insertion and removal.
• Excessive vibration induced by other equipment could result in damage or
mechanical failure of the product.
• Excessive contamination or dust flows are likely. A particulate shield to
prevent contamination build-up in the gas sampling tubes may be required.
Select a position that is accessible for maintenance purposes and make allowances for
access to the wiring and piping inlets, which are at the base of the sensor head.
The device must be securely fitted to a suitable surface using the 2" 150lb ANSI mounting
flange incorporated into the probe.
Figure 5 Gas Flow Alignment
The device should be installed in a suitable location, taking into account factors including
those detailed in Section 2.1 General Guidelines.
The probe must be installed in a horizontal or slightly downward angled position.
Do:
• Ensure the sensor head is oriented so that the cable gland is facing
downwards.
• Ensure the sensor head is shielded from radiated heat in excess of 55°C
Do Not:
• Mount with the probe vertically or with the tip higher than the sensor head
(i.e. angled upwards) as this can lead to condensate entering the probe.
• Allow the gas flow straight into the gas sampling tubes: refer to figure 7.

XZR250 User’s Manual
Michell Instruments 7
INSTALLATION
Figure 6 Mounting Adaptor Details
NOTE:
The probe should be mounted horizontally, or ideally at an angle of approximately 5° to the
flue wall as shown in figure 6.
Figure 7 Mounting Examples
!
CAUTION: The gas temperature must not exceed 700°C for
prolonged periods. Short term excursions (less than 30 min) to
750oC will not damage the probe.

XZR250 User’s Manual
897528 Issue 5, May 2019
INSTALLATION
2.4 Probe Installation
I
!
CAUTION: Do not mount the probe at an angle that would allow
liquid to run down towards the sensor head, as this may cause
blockage or damage.
NOTE:
A suitable 2” ANSI flange mounting adaptor is required. If the application temperatures
will exceed 200°C, use an anti-seize compound on any mounting threads to ease future
removal of the probe.
1. Cut a 50mm (2” nom. pipe) diameter hole in the flue wall (or other mounting position).
2. Either:
• Weld the mounting adaptor into place, concentric with the hole in the flue.
• Drill and bolt the mounting adaptor to the flue.
3. Before bolting in place, fit a suitable gasket between the adaptor and the flue wall.
A gasket is supplied with each analyzer. (Order code: XZR250A1-GASKET01)
4. Carefully insert the probe into the hole in the flue (or other mounting position).
5. Ensure the probe is in the correct orientation using the flow direction indicator on
the probe's flange.
6. Secure the probe into place using suitable bolts and washers.
Figure 8 Probe Installation
!
CAUTION: Always install a suitable gasket between the mating
flanges to prevent gas leakage. The wrong type of gasket may
lead to accidental poisoning of the zirconia sensor: refer to 5.1.3

XZR250 User’s Manual
Michell Instruments 9
INSTALLATION
Figure 9 Insert Sensing Module
1. Ensure housing is wired correctly; refer to section 2.2 Electrical Connections.
2. Hold the sensor head with the display facing downwards.
3. Fit sensing module to the sensor head and gently push to secure the module in
place; refer to Figure 9. The connector is keyed to aid alignment.
4. Keep the sensor head oriented with the sensor upwards until just before fitting the
probe to avoid dropping the sensor during installation.
5. With the clamp fitted over the sensor head shoulder carefully slide the head onto
the probe; refer to Figure 10. Ensuring the probe is inserted fully.
6. Ensuring the display is correctly oriented, tighten the clamp: torque to 5Nm.
!
CAUTION: Take care not to bump or shock the probe and ensure
the gasket is not damaged when inserting the probe.
Figure 10 Fit sensor Sensor head to Probe Body

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INITIAL STARTUP
3 INITIAL STARTUP
3.1 Commissioning Checks
Before commissioning the equipment please read safety instructions.
Complete the following essential tasks BEFORE switching the system ON for the first time:
• Ensure the analyzer is installed in the correct orientation.
• Verify the device is mounted securely and sealed correctly.
• Verify the device, wiring connector and calibration gas inlet port are all undamaged.
• Ensure the cables are strain-free and not twisted.
• Ensure the device is connected properly, with all its inputs and outputs complete.
All screw terminals are properly tightened.
!
CAUTION: Test the power supply to ensure it is 24VDC ±10%
via a limited power supply before wiring to the probe. Failure to
do so may result in damage to the product and invalidate your
warranty
3.2 Switching ON
When the device is powered up, the screen below is displayed on the LCD until the
internal zirconia sensing element reaches operating temperature. This should take
approximately 90 seconds:
3.3 First-time Calibration (field adjustment)
Calibration is required when the device is powered ON for the first time
or when the sensing module is replaced. Refer to 6.2 Calibrating.

XZR250 User’s Manual
Michell Instruments 11
SYSTEM CONFIGURATION
4 SYSTEM ELEMENTS
The XZR250 combustion control analyzer consists of three main elements:
• A probe to extract the sample.
• A sensor block to measure the gas (contains O2, pressure & temperature sensors)
• A sensor head to house the sensor, provides electrical outputs and an HMI for local
configuration.
4.1 Human Machine Interface (HMI)
Figure 11 HMI
Number Description
1 Front panel
2 Screw cover
3 Backlit LCD screen
4 Left / Down button
5 Enter / Back / Home button
6Right / Up button
Table 1 HMI

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12 97528 Issue 5, May 2019
SYSTEM CONFIGURATION
The buttons are multifunctional:
Primary Secondary Tertiary
Scroll left Scroll down n/a
Scroll right Scroll up n/a
Enter
Back one level.
Press and hold until screen
flashes twice
Return to the home screen.
Press and hold until screen
flashes three times
Table 2 Operator Panel Multifunctional Buttons
NOTE:
Screen flashes once on every button press unless otherwise specified.
Throughout this guide the following conventions apply:
• Left / Down button press is shown as <LEFT> or <DOWN>
• Right / Up button press is shown as <RIGHT> or <UP>
• Enter / Back / Home button press is shown as <ENTER>, <BACK> or <HOME>
The following on-screen conventions are used:
*Menu option can be edited.
>Additional options available within the menu structure; press the right arrow
button to scroll through the menu options.
<Last entry of the menu structure has been reached; press the left arrow
button to scroll back through the menu options.
<> Cursor position, i.e. digit is highlighted.
<<>> Digit is in edit mode.
NOTE:
The numeric value given before the “>” denotes the menu number for that option