Bacharach DIOXOR II User manual

INSTRUCTION 0019-9166
COMBINED SERVICE MANUAL for:
DIOXOR®II
MONOXOR®II
MONOXOR®II H (High Range)
NONOXOR®II
Rev. 7 – May 2010
Bacharach, Inc.
621 Hunt Valley Circle, New Kensington, PA 15068
Phone: [phone] • Fax: [phone] • Web: www.mybacharach.com
Printed in the U,S.A.

® Bacharach, Dioxor, Monoxor, and Nonoxor are registered trademarks of Bacharach, Inc.
Copyright © Bacharach 1997-2010, all rights reserved.
A

TABLE OF CONTENTS
1.0 SERVICE MANUAL CONTENTS.................................................................4
2.0 MAINTENANCE............................................................................................5
2.1 Opening the Case..................................................................................5
2.2 Closing the Case....................................................................................6
2.3 Cleaning........................................................................................7
2.4 Sensor Replacement..............................................................................9
2.5 Printed Circuit Board Replacement.....................................................10
2.6 ChamberAssembly Servicing..............................................................11
3.0 SENSOR CALIBRATION............................................................................12
3.1 Monoxer II CO Calibration.................................................................12
3.2 Dioxor II SO2, Monoxor II H CO, and Nonoxor II NOx Calibration...13
4.0 TROUBLESHOOTING CHART ................................................................14
5.0 REPLACEMENT PARTS.............................................................................17
5.1 Probe Assembly .................................................................................17
5.2 Instrument Assembly ..........................................................................18
5.3 Miscellaneous Parts and Accessories.................................................20
5.4 BACHARACH Sales/Service Centers...............................................20

Single Gas Instrument Service Manual
Page 4 Bacharach, Inc. Instruction 0019-9166
1.0 SERVICE MANUAL CONTENTS
This manual contains the following service information for the . . .
DIOXOR II (Part No. 0019-7038 & 0019-7043)
MONOXOR II (Part No. 0019-7034 & 0019-7039)
MONOXOR II H (Part No. 0019-8015)
NONOXOR II (Part No. 0019-7036 & 0019-7042).
NOTE: The 0019-7039, 0019-7042, and 0019-7043 versions of these
instruments do not contain a probe, all non-probe related functions
remain the same in this instruction.
•Instrument maintenance, which includes information on how to:
• Open and close the case
• Clean the Fan Assembly and chamber assembly area
• Replace the sensor
• Replace the Printed Circuit Board (P.C.B.)
• Service the gas-sensing chamber assembly (chamber assembly)
•Sensor calibration
•Troubleshooting chart
•Replacement parts list
GENERAL NOTE
If excessive torque is applied to the instrument's
fasteners, poor performance or damage to components
may occur.
The torque specifications are as follows:
Screws Torque
Sensor Mounting 4 - 8 oz. in.
Motor Mounting 6-10 oz. in.
Chamber Sealing 16-20 oz. in.
Rear Cover/Case 18-24 oz. in.
Fan Assembly 32-40 oz. in.

Single Gas Instrument Service Manual
Instruction 0019-9166 Bacharach, Inc. Page 5
2.0 MAINTENANCE
2.1 Opening the Case
Figure 2-1.
Opening and
Closing the Case
Equipment Needed:
•Phillips-head screwdriver, No. 1
Procedure:
1. Lay the instrument face down on a workbench; then detach the metal clip
from the bottom of case and fold the elastic strap over top of the instrument
(Fig 2-1).
2. Slide off battery cover.
3. Remove batteries.
4. Using a No. 1 Phillips-head screwdriver, remove the two screws from the
rear of the case.
5. Lift up the bottom portion of the rear case and slide it forward until the case
clears the inlet port.
6. To gain better access to the components, remove the gas-sensing chamber as-
sembly (Chamber Assembly) and the Printed Circuit Board (P.C.B.) from the
front case by pulling them straight up from the front case (Fig 2-2); then lay
these items on your workbench.

Single Gas Instrument Service Manual
Page 6 Bacharach, Inc. Instruction 0019-9166
2.2 Closing the Case
Figure 2-2.
P.C.B. and
Chamber Assem-
bly
Removal and
Installation
Equipment Needed:
• Phillips-Head Screwdriver, No. 1
Procedure:
CAUTION
When replacing the P.C.B. and chamber assembly, the P.C.B. must
be installed FIRST. The P.C.B. switches could be damaged if the
P.C.B. is installed after the chamber assembly is in place.
1. Ensure that the P.C.B. is properly positioned face down over its locating-tab
on the front case (Fig 2-2).
2. Properly position the chamber assembly between the ribs of the front case.
3. Slide the rear case over the inlet port and properly join the two case halves
together.
4. Secure the case halves to each other using the two screws removed in Sec-
tion 2.1, Step 4 (Tighten to 18–24 oz. in.).
5. Reinstall the batteries (observe proper battery polarity); replace the battery
cover; and attach the elastic strap’s metal clip to the bottom of the instru-
ment.

Single Gas Instrument Service Manual
Instruction 0019-9166 Bacharach, Inc. Page 7
2.3 Cleaning
The inside of the chamber assembly is the only part of the instrument that needs
to be cleaned. To clean the chamber assembly, proceed as follows:
Equipment Needed:
•Screwdriver, No. 1 Phillips head •Clean rags
•Screwdriver, 1/8" flat-blade •Cotton Swabs
•Warm soapy water •Pipe cleaners
•Allen Wrench, .05 in.
Procedure:
1. Open the case as described in Section “2.1 Opening the Case.”
2. Using a flat-blade screwdriver, remove the three screws and nuts that secure
the Sensor to the chamber assembly; DO NOT remove the sensor wires.
Then remove the Sensor along with its O-ring and Membrane from the
chamber assembly.
3. Using a No. 1 Phillips-head screwdriver, disassemble the chamber assembly
by removing the two screws and nuts that secure the Chamber to the Motor
Assembly
(Fig 2-3).
NOTE: Do not remove the Fan Assembly unless it's absolutely neces-
sary for cleaning or repair purposes.
4. If it is necessary to remove the Fan Assembly, first loosen the set screw on
the Fan Assembly with the .05 in. Allen wrench, and then pull off the assem-
bly.
NOTE: It is not necessary to disassemble the Motor Assembly. If
motor replacement is required, refer to Section 2.6, Step 5.
5. Clean the Fan Assembly, Chamber & Motor Assembly (see Fig 2-3) using
cotton swabs and clean rags dampened with warm, soapy water. After clean-
ing, dry all parts with clean dry rags and cotton swabs.
NOTE: Replace, DO NOT CLEAN, the Membrane (Fig 2-2) if dirty.
6. Clean the Chamber’s inlet and outlet ports using pipe cleaners dipped in
warm, soapy water. After cleaning, dry them with clean dry pipe cleaners.
7. Reassemble the chamber assembly as follows:
NOTE: DO NOT overtighten any screws; damage to plastic parts
will result.

Single Gas Instrument Service Manual
Page 8 Bacharach, Inc. Instruction 0019-9166
Figure 2-3.
Chamber As-
sembly, Exploded
View
Figure 2-3A.
Fan-blade assem-
bly set screw
a. If disassembled, push the Fan Assembly onto the Motor shaft until it seats
(Fig 2-3). Be sure the set screw (Fig 2-3A) is not screwed in so far that it
prevents the adapter from seating fully. Tighten the set screw to approxi-
mately 32–40 ounce-inches using the .05 in. Allen wrench. Spin the Fan
Assembly to be sure it will run in the chamber.
b. Mate and secure the Chamber and Motor Assembly together with the
two screws and nuts removed in Step 3 (Tighten to 16–20 oz. in.).
8. Reinstall the Membrane (mesh side toward the chamber assembly), O-ring,
and Sensor on the chamber assembly (Fig 2-2); then secure the Sensor using
the three screws and nuts removed in Step 2 (Tighten to 4–8 oz. in.).
9. Close the case as per Section “2.2 Closing the Case.”

Single Gas Instrument Service Manual
Instruction 0019-9166 Bacharach, Inc. Page 9
2.4 Sensor Replacement
When the instrument can no longer be spanned, as described in Section “3.0 Sen-
sor Calibration,” the Sensor has reached the end of its useful life, and should be
replaced. The life of a Sensor is typically two years. The Sensor may also need
to be replaced if the instrument will not zero properly, or if erratic gas readings
occur. Refer to Section “4.0 Troubleshooting Chart.”
Equipment Needed (Refer to Section “5.0 Replacement Parts” for Part
Nos.):
•Phillips-head screwdriver, No. 1 •Replacement Sensor:
•Nutdriver, 4mm (5/32") •Dioxor II - SO2
•Screwdriver, 1/8" flat blade •Monoxor II - CO
•O-Ring and Membrane, if required •Nonoxor II - NOX
•Monoxor II H - CO
Procedure:
WARNING!
Burn hazard! The Sensors contain corrosive chemicals,
DO NOT puncture or take the sensors apart.
1. Open the case as described in Section “2.1 Opening the Case.”
2. Using a nutdriver, loosen the nuts that secure the sensor wires to the Sen-
sor terminals R, S and C; then remove the wires. If the Sensor has pin and
socket connections, simply pull the sockets from the sensor pins.
3. Using a flat-blade screwdriver, remove the three screws and nuts that secure
the Sensor to the chamber assembly; then remove the Sensor along with its
O-ring and Membrane from the chamber assembly.
4. Remove and discard of the old Sensor in accordance with local and federal
regulations. DO NOT discard the sensor’s O-ring and Membrane, unless you
intend to replace these items.
NOTE: Replace the O-ring if it looks deformed, and replace the
Membrane if it is contaminated with oil or dirt. We recommend
that both the O-ring and Membrane be replaced at the same time.
5. Remove the new Sensor from its shipping canister. Do not remove the short-
ing wire (across the R & S terminals) from the Sensor (SO2& CO only, the
NOXdoes not have a shorting wire) until you are ready to make the electrical
connection.
6. Position the Membrane, O-ring, and new Sensor on the chamber assembly
as per Fig 2-2. Ensure that the sensor terminals are positioned as shown.
Secure these items to the chamber assembly using the screws and nuts re-
moved in Step 3 (Torque to 4–8 oz. in.). DO NOT overtighten the screws!
7. Remove the shorting wire from the R & S terminals (SO2& CO only). Con-
nect the blue (S), red (R), and black (C) wires from the P.C.B. to their as-
sociated sensor terminals (See Fig 2-4). If the Sensor uses nuts to secure the
Sensor wires, DO NOT overtighten these connections!
8. Close the case as per Section “2.2 Closing the Case.”
9. Calibrate the new Sensor as per Section “3.0 Sensor Calibration.”

Single Gas Instrument Service Manual
Page 10 Bacharach, Inc. Instruction 0019-9166
2.5 Printed Circuit Board (P.C.B.) Replacement
Figure 2-4.
Sensor & Motor
Wiring Diagram
Equipment Needed (Refer to Section “5.0 Replacement Parts” for Part
Nos.):
•Phillips-head screwdriver, No. 1
•Printed Circuit Board (P.C.B.)
Procedure:
1. Open the case as described in Section “2.1 Opening the Case.”
2. Unplug the motor connector from the P.C.B.
3. Unplug the sensor connector from the P.C.B.
NOTE: (For SO2& CO Sensors only) If the Sensor is not going to
be immediately plugged into the new P.C.B., place a shorting wire
between sensor terminals R and S.
4. Remove the Switch Covers from the old P.C.B. and place them on the new
P.C.B., then replace the old P.C.B. with the new one.
5. Plug the motor connector into the P.C.B.
6. Remove the shorting wire from sensor terminals R & S (if installed); then
plug the sensor connector into the P.C.B.
7. Close the case as per Section 2.2 Closing the Case.”
8. Calibrate the Sensor with the new P.C.B. as per Section “3.0 Sensor Calibra-
tion.”
9. Discard the old P.C.B.