Bacharach N2O Portable Monitor User manual

N2O Portable Monitor
Portable Area Gas Monitor (PAGM) with
Infrared Sensor for N2O Gas
Instruction 3015-4787
Operation & Maintenance
Rev. 8 – February 2013
Product Leadership • Training • Service • Reliability
Patent 6,590,690

ii Instruction 3015-4787
WARRANTY
Bacharach, Inc. warrants to Buyer that at the time of delivery this Product will be free from defects in material and
manufacture and will conform substantially to Bacharach Inc.'s applicable specifications. Bacharach's liability and Buyer's
remedy under this warranty are limited to the repair or replacement, at Bacharach's option, of this Product or parts thereof
returned to Seller at the factory of manufacture and shown to Bacharach Inc.'s reasonable satisfaction to have been
defective; provided that written notice of the defect shall have been given by Buyer to Bacharach Inc. within two (2) years
after the date of delivery of this Product by Bacharach, Inc.
Bacharach, Inc. warrants to Buyer that it will convey good title to this Product. Bacharach's liability and Buyer's remedy
under this warranty of title are limited to the removal of any title defects or, at the election of Bacharach, to the
replacement of this Product or parts thereof that are defective in title.
The warranty set forth in paragraph 1 does not apply to parts the Operating Instructions designate as having a limited shelf-
life or as being expended in normal use (e.g., filters).
THE FOREGOING WARRANTIES ARE EXCLUSIVE AND ARE GIVEN AND ACCEPTED IN LIEU OF (I) ANY
AND ALL OTHER WARRANTIES, EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE: AND (II) ANY
OBLIGATION, LIABILITY, RIGHT, CLAIM OR REMEDY IN CONTRACT OR TORT, WHETHER OR NOT
ARISING FROM BACHARACH'S NEGLIGENCE, ACTUAL OR IMPLIED. The remedies of the Buyer shall be limited
to those provided herein to the exclusion of any and all other remedies including, without limitation incidental or
consequential damages. No agreement varying or extending the foregoing warranties, remedies or this limitation will be
binding upon Bacharach, Inc. unless in writing, signed by a duly authorized officer of Bacharach.
Register Your Warranty by Visiting
www.mybacharach.com
Product improvements and enhancements are continuous; therefore the specifications and information
contained in this document may change without notice.
Bacharach, Inc. shall not be liable for errors contained herein or for incidental or consequential damages in
connection with the furnishing, performance, or use of this material.
No part of this document may be photocopied, reproduced, or translated to another language without the prior
written consent of Bacharach, Inc.
Copyright © 2013, Bacharach, Inc., all rights reserved.
BACHARACH®is a registered trademark of Bacharach, Inc. All other trademarks, trade names, service marks
and logos referenced herein belong to their respective owners.

N2O Portable Monitor Table of Contents
Instruction 3015-4787 iii
Table of Contents
1INTRODUCTION ....................................................................................................................................... 1
1.1 How to Use This Manual ................................................................................................................. 1
1.2 Warning Statements ........................................................................................................................ 1
1.3 Caution Statements ......................................................................................................................... 1
1.4 Hazard Symbols on Monitor ............................................................................................................ 1
1.5 Safety Precautions ........................................................................................................................... 1
1.5.1 Hazardous Area Warning ................................................................................................. 1
1.5.2 Combustible/Flammable Gas Warning ............................................................................ 2
1.5.3 Explosive Atmosphere....................................................................................................... 2
1.5.4 Misuse and Modifications to Monitor............................................................................... 2
1.5.5 Altitude Limit .................................................................................................................... 2
1.5.6 Cleaning ............................................................................................................................. 2
1.6 Unpacking and Initial Checks......................................................................................................... 2
1.7 Shipping Precaution......................................................................................................................... 3
1.8 Features and Capabilities................................................................................................................ 3
1.9 Functional Overview ........................................................................................................................ 3
2SPECIFICATIONS.....................................................................................................................................4
3OPERATION..............................................................................................................................................5
3.1 Front Panel Display and Controls .................................................................................................. 5
3.2 Connecting Gas-Sample & Exhaust Lines ..................................................................................... 5
3.2.1 Overview ............................................................................................................................ 5
3.2.2 Connecting the Gas-Sample Line ..................................................................................... 5
3.2.3 Connecting the Exhaust Line (optional) .......................................................................... 6
3.3 Gas Detector Operation ................................................................................................................... 6
3.4 Time Weighted Average (TWA) Operation..................................................................................... 8
3.4.1 Overview ............................................................................................................................ 8
3.4.2 Starting a New or Continuing TWA/twa.......................................................................... 8
3.5 Peak Reading Operation.................................................................................................................. 9
3.6 Leak Detector Operation ................................................................................................................. 9
3.7 Standby Mode................................................................................................................................... 9
3.8 Battery – Charging and Using ...................................................................................................... 10
3.8.1 Charging the Battery ...................................................................................................... 10
3.8.2 Using the Battery ............................................................................................................ 10
3.9 Display Screens .............................................................................................................................. 10
3.9.1 Initial Power ON.............................................................................................................. 10
3.9.2 Filling the Purge-Air Bag................................................................................................ 10
3.9.3 Data Display Screen ........................................................................................................ 10
3.9.4 Function Screens ............................................................................................................. 11
3.10 Working with System Faults......................................................................................................... 14
3.10.1 Functional Overview ....................................................................................................... 14
3.10.2 Clearing / Silencing a Fault Alarm ................................................................................ 14
3.10.3 Viewing the Faults Log ................................................................................................... 14
3.10.4 Fault Codes ...................................................................................................................... 15
3.11 Working with the Gas Alarm ........................................................................................................ 16
3.11.1 Gas-Alarm Light .............................................................................................................. 16
3.11.2 Silencing a Gas Alarm..................................................................................................... 16
3.12 Clearing the PPM & Faults Data.................................................................................................. 16
3.13 Working with the DIAG Function................................................................................................. 16
3.13.1 Overview .......................................................................................................................... 16
3.13.2 Keypad Functions............................................................................................................ 16
3.13.3 First Diagnostic Screen ................................................................................................... 17
3.13.4 Second Diagnostic Screen ............................................................................................... 17
3.14 Working with the P-CHK Function .............................................................................................. 18
3.14.1 Overview .......................................................................................................................... 18

Table of Contents N2O Portable Monitor
iv Instruction 3015-4787
3.14.2 Keypad Functions............................................................................................................ 18
3.14.3 Screen Display ................................................................................................................. 18
3.15 Print/Plot Logged Gas Levels........................................................................................................ 19
3.16 Downloading Stored Data to a Personal Computer..................................................................... 20
3.17 Importing Saved Data Into a Spreadsheet................................................................................... 21
4MAINTENANCE...................................................................................................................................... 22
4.1 Disassembly.................................................................................................................................... 22
4.2 Internal Particulate / Hydrophobic Filter Replacement ............................................................. 23
5PARTS AND SERVICE........................................................................................................................... 24
5.1 Replacement Parts & Optional Items........................................................................................... 24
Replacement Parts...................................................................................................................... 24
Item Description ......................................................................................................................... 24
Part Number ............................................................................................................................... 24
Item Description ......................................................................................................................... 24
Part Number ............................................................................................................................... 24
5.2 Service Centers .............................................................................................................................. 25
6DECLARATION OF CONFORMITY....................................................................................................... 26

N2O Portable Monitor Introduction
Instruction 3015-4787 1
1 Introduction
1.1 How to Use This Manual
This manual provides important information on how to operate and service Bacharach’s Nitrous Oxide
(N2O) Portable Monitor.
To assure operator safety and the proper use of the monitor, please read, understand, and follow the
contents of this manual.
If you have a working knowledge of gas monitors, you will find this manual useful as a reference tool. If
you are new to the use of gas monitors, you can educate yourself about the principles of gas detection and
the proper operation of this device by reading this manual thoroughly.
1.2 Warning Statements
The use of the word WARNING in this manual denotes a potential hazard associated with the use of this
equipment. It calls attention to a procedure, practice, or condition, or the like, which if not correctly
performed or adhered to, could result in personal injury or death.
1.3 Caution Statements
The use of the word CAUTION in this manual denotes a potential hazard associated with the use of this
equipment. It calls attention to a procedure, practice, condition, or the like, which if not correctly
performed or adhered to, could result in damage to the equipment.
1.4 Hazard Symbols on Monitor
This symbol indicates the need to consult this operating instruction
manual when opening the enclosure.
WARNING: A potential risk exists if the operating instructions are
not followed.
This symbol indicates the presence of electric shock hazards when
the enclosure is opened.
WARNING: To avoid risk of injury from electric shock, do not open
the enclosure when power is applied.
1.5 Safety Precautions
1.5.1 Hazardous Area Warning
Hazardous Area Warning: This instrument has not been
designed to be intrinsically safe for use in areas classified as
hazardous locations. For your safety, DO NOT use it in hazardous
(classified) locations.

Introduction N2O Portable Monitor
2Instruction 3015-4787
1.5.2 Combustible/Flammable Gas Warning
Combustible/Flammable Gas Warning: This is NOT a safety
device. Some gases which this instrument can detect may be
combustible/ flammable. When properly configured, this instrument
is designed to alarm at concentrations that are lower than the
explosive limit of the gas. As such, it is the buyer’s responsibility to
initiate an immediate planned response to any gas leaks as soon as
they are detected. This equipment should NEVER be used to
measure or sample gases at or above their respective lower explosive
limits.
1.5.3 Explosive Atmosphere
Explosive Atmosphere: Do not operate this equipment in the
presence of flammable liquids, vapors or aerosols. Operation of any
electrical equipment in such an environment constitutes a safety
hazard.
1.5.4 Misuse and Modifications to Monitor
The protection provided by the monitor may be impaired if the monitor is used in a manner not specified
by these instructions. Changes or modifications to this monitor will void the warranty.
1.5.5 Altitude Limit
6,562 ft (2,000 m)
1.5.6 Cleaning
Clean the outside of the monitor’s case using a dry cloth — DO NOT use soap and water.
1.6 Unpacking and Initial Checks
Your N2O Portable Monitor was carefully inspected at the factory before shipment, and packed so as to be
highly resistant to damage while in transport. When you receive the instrument, however, please unpack
it promptly and make a visual inspection to make sure that no damage has occurred during shipment. Also
check that all the following items have been received.
Item
Qty.
Part Number
N
2
O Portable Monitor
1
3015-4790
External Filter Assembly
1
3015-5324
Soft Carrying Case with
Shoulder Strap
1 3015-5700
Battery Pack & Charger
1
3015-5739
Stainless Steel Probe
1
3015-5326
Instruction Manual
1
3015-4787
Elbow
1
3015-3234
Tubing (3 ft)
1
0003-6182
If damage was found, immediately file a claim with the carrier. If an item is missing, please contact
Bacharach’s Service Department for assistance (refer to Section 5.2 Service Centers).

N2O Portable Monitor Introduction
Instruction 3015-4787 3
1.7 Shipping Precaution
When shipping the instrument by air, deflate the purge-air bag to prevent it from bursting due to changes
in air pressure. Deflate the bag by selecting the EMTYBAG function as described on page 11.
1.8 Features and Capabilities
•Detects, measures, and displays the level of N2O gas in the area being monitored
•Measurement range of 0–1,000 ppm with a resolution of 1 ppm
•Self contained purge-air bag, allowing the monitor to be used in a contaminated atmosphere
•Automatically logs up to 200 gas readings that can be printed / plotted for analysis
•Eliminates false alarms with use of non-dispersive IR source and sample draw system
•Visual and audible gas alarm indictors that are turned ON when the detected gas level exceeds
a user defined trip-point
•Extensive self diagnostics, providing both visual and audible indications when a fault occurs
•Battery powered, providing 8–12 hours of operation
1.9 Functional Overview
The Bacharach Nitrous Oxide (N2O) Portable Monitor is designed to detect, measure, and display the
concentration of N2O gas in the area being monitored. To ensure accurate gas measurements, the monitor
self-zeros every 4 minutes using its internal supply of fresh air.
During normal operation the N2O Monitor displays both the current gas level and the peak gas level
detected on its front panel LCD. The monitor retains a log of previous readings that can be easily accessed
at a later time for analysis.
Front panel indicators and an audible alarm are provided to signal gas alarm and instrument fault
conditions. The audible alarm can temporarily be silenced by a push of a button, but will reactivate if the
gas level is still above the alarm trip point after a user-defined time period has elapsed.
The N2O Monitor requires only minor periodic maintenance such as the occasional replacement of filters.
The monitor incorporates active diagnostics that continuously check the system for proper operation. A
front panel indicator is provided to alert an operator of system malfunctions, and fault codes are generated
that enable the operator to quickly identify the cause of the fault.

Specifications N2O Portable Monitor
4Instruction 3015-4787
2 Specifications
Product Type..................... Portable N2O Gas Monitor
Measuring Range ............. 0 to 1,000 ppm
Warm-Up Time................. 15 minutes
Detector Type.................... Infrared, Non-Dispersive
Sensitivity ......................... 1 ppm
Accuracy............................ ±1 ppm ±5% of reading from 0 to 100ppm
and ±10% of reading from 101 to 1000ppm.
Response Time.................. 90% of response within 3 seconds; 100% in 5 seconds
Temperature Drift............ 1.5 ppm per °C between purge cycles
System Noise .................... Less than 40dB(A) at 10 ft (3 m)
Operating Temp................ 32 to 122°F (0 to 50°C)
Ambient Humidity ........... 5 to 90% RH (non-condensing)
Altitude Limit ................... 6,562 ft (2,000 m)
Power................................. DC power pack, provides 8–12 hours of operation
Power Consumption ......... 15 Watts
Front Panel ....................... 3 Indicator lights:
ON – Green LED flashes during warm-up, and then glows steady
during normal operation
FAULT – Yellow LED flashes when there is a system fault
ALARM – Red LED flashes when the gas level is above its alarm setting
Audible Alarm .................. Internal audible alarm programmable for any of the following conditions:
OFF, FAULT/ALARM, ALARM
Dimensions ....................... 9D x 14.5L x 5W inches (229 x 368 x 127 mm)
Weight ............................... Less than 9 lbs (4 kg) including battery
Valid Calibration Period
to Specifications................ 12 months
Warranty........................... 2 Years from date of shipment

N2O Portable Monitor Operation
Instruction 3015-4787 5
3 Operation
3.1 Front Panel Display and Controls
3.2 Connecting Gas-Sample & Exhaust Lines
3.2.1 Overview
A single gas-sample line needs to be run from the N2O Monitor to the area to be monitored. If desired, an
optional exhaust line can be installed to vent N2O gas away from the monitor.
3.2.2 Connecting the Gas-Sample Line
To connect the gas-sample line to the monitor, simply push the tubing onto the elbow connector and attach
the elbow onto the Gas Sample Port on the front of the monitor as shown in the illustration below.
The gas-sample line can be up to 50 ft (15.2 m) in length. All tubing bends should have a radius of no less
than 5" to insure proper airflow. If kinks or obstructions occur in the line the monitor may not function
properly.
The end of this line should be placed near the potential leak source and positioned to reduce the possibility
of mists, aerosols, oil, water, dust, or other contaminates being drawn into the monitor.
An external filter (P/N 3015-5324) should be attached to the end of this line. See figure below.

Operation N2O Portable Monitor
6Instruction 3015-4787
3.2.3 Connecting the Exhaust Line (optional)
The optional exhaust line carries the exhausted gas sample away from the monitor.
The exhaust line can be up to 50 ft (15.2 m) in length. Ideally this line should terminate outdoors in a
location that is not exposed to the elements.
Connect the exhaust line to the monitor by firmly pushing the tubing into the Exhaust Port’s push-to-
connect (PTC) fitting. If the exhaust line terminates outside the building, position the tubing so that no
water or moisture can enter the line. Note that this line does not require a termination filter.
To connect the exhaust line to the exhaust
port’s PTC fitting, firmly push the appropriate
tubing into the hole in the center of the
connector until it seats in the connector. Refer
to the figures at the left.
To remove tubing from a PTC connector, push
and hold the spring-loaded collar inwards, then
simultaneously withdraw the tubing. Refer to
the figures at the right.
3.3 Gas Detector Operation
CAUTION:Operate the monitor in its horizontal position (handle facing upwards).
Tilting the monitor to a vertical position while in operation may cause inaccurate
measurements to occur.
Turn ON the monitor as follows:
1. Lift up the shield located in front of the handle
2. Press the red power ON/OFF toggle switch.
3. Observe monitor’s firmware version is briefly displayed.
BACHARACH
VERSION x.xx
PRESS ENTER FOR
NEW TWA/twa

N2O Portable Monitor Operation
Instruction 3015-4787 7
4. Observe that the NEW TWA/twa screen may appear, depending on
the configuration of the monitor’s TWA/twa function (refer to
Section 3.4 for detailed TWA operation).
5. Observe the monitor starts counting down its warm-up period of
900 seconds (15 minutes).
6. At the end of warm up, take the monitor to an area than contains
fresh air and press the ENTER button to fill the monitor’s internal
purge-air bag with clean, fresh air that is of the same temperature
and humidity as the area being monitored for gas. DO NOT fill the
purge-air bag in an area that is contaminated with N2O gas.
After the purge-air bag is filled, observe the following as the monitor makes
gas measurements in the area being sampled:
•MEASURE indicates when the monitor is actively measuring the
level of N2O gas at the sampling point. The screen to the right shows
that currently 100 ppm is being measured. The measurement cycle
runs for 4 minutes.
A log of up to 200 previous measurements can be viewed using the
PPM LOG function (page 12), or printed as described in 3.15.
The 2ndUNIT value (Blank, Peak PPM, Continuous TWA, or 8 Hr
TWA) is user-selected (refer to 2ndUNIT function on page 13).
•PURGE indicates when the monitor is resetting its infrared detector
to a baseline of 0 ppm using the air contained in the monitor’s
internal purge-air bag. The purge cycle runs for 10 seconds.
The monitor will operate for approximately 40 minutes before the purge-air bag needs refilled.
When the message "PURGE AIR EMPTY" appears, take the monitor to a clean, fresh-air
environment and press the ENTER button to refill the bag.
Work with gas alarms and system faults as follows:
ALARM (red) light turns ON if the detected gas level exceeds a programmed alarm point. An audible
alarm also sounds if the AUDALRM function is activated (page 11) Pressing the front panel
SILENCE button turns OFF the audible alarm, but the ALARM light will continue to flash for as
long as the detected gas level is above the alarm point. The audible alarm will reactivate if the gas-
alarm condition is not cleared within the time period set by the SILENCE function (page 12).
FAULT (yellow) light turns ON if a fault occurs (see Fault Code list on page 15). An audible alarm
also sounds if the AUDALRM function is activated (page 11). Pressing the front panel SILENCE
button turns OFF the audible alarm, but the FAULT light continues to flash for as long as the fault is
present. The audible alarm will reactivate if the fault condition is not cleared within the time period
set by the SILENCE function (page 12). Both the FAULT light and audible alarm will automatically
turn OFF after the cause of the fault has been eliminated. A log of the last 30 fault events can be
viewed using the monitor’s FAULTS function (page 12).
MEASURE 2ndUNIT
100ppm N2O
PURGE 2ndUNIT
100ppm N2O
PURGE AIR EMPTY
(ENTER) TO FILL
PURGE AIR EMPTY
<ENTER> TO FILL
WARM UP
900

Operation N2O Portable Monitor
8Instruction 3015-4787
3.4 Time Weighted Average (TWA) Operation
3.4.1 Overview
In addition to displaying the current N2O level, the monitor can also calculate and display a Time
Weighted Average ppm value. This value is available in two formats (8 Hour or Continuous). This provides
users with the most appropriate data on their average ppm N2O exposure in the working environment.
TWA operation is selected by using the 2ndUNIT function (page 13).
The two TWA formats are identified by the appearance of either “TWA” or ‘twa” in the upper-right corner
of the Data Display screen.
•TWA (upper case letters) is calculated over an 8-hour period. This format is designed to show the
user’s average ppm N2O exposure level during a typical work day. After 8 hours has expired, an
asterisk (*) will be displayed but the TWA will continue to be updated.
•twa (lower case letters) is continuously calculated over the operating time of the monitor. This
mode is useful for monitoring an area for a few minutes or more and is the preferred mode of
operation for checking operating room atmospheres.
3.4.2 Starting a New or Continuing TWA/twa
When the monitor is turned ON the following message appears if the monitor is set up to display
TWA/twa.
Press either . . .
•ENTER to start a new TWA/twa
•ESC to continue with the current TWA/twa.
Tip: If NO button is pressed within 60 seconds the monitor automatically continues
with the current TWA/twa.
Note:During the time the monitor is OFF, the gas measurement is assumed to be zero
and will be factored into the TWA/twa calculation.
After selecting whether to start or continue a TWA/twa, the next screen shows the current elapsed
TWA/twa time.
Where: xx is the accumulated time used by the monitor in calculating the TWA/twa.
PURGE 00TWA
100ppm N2O
PURGE 00twa
100ppm N2O
PRESS ENTER FOR
NEW TWA/twa
ELAPSED TWA TIME
IS xx MINUTES

N2O Portable Monitor Operation
Instruction 3015-4787 9
3.5 Peak Reading Operation
In addition to displaying the current N2O level, the monitor can also be set up to display its peak ppm
measurement.
The peak reading display is selected by using the 2ndUNIT function (page 13).
The display above shows that currently the monitor is detecting 100 ppm N2O and that a peak
measurement of 500 ppm has occurred.
The peak reading is reset by pressing the ENTER button.
3.6 Leak Detector Operation
The monitor can be configured to operate as a Leak Detector by setting the AUDALRM function (page 11)
to LEAK DETECTOR.
When configured as a Leak Detector, the monitor will produce a leak detector type of audible feedback. At
zero ppm there will be a tic every 2 seconds with the tic rate increasing up to 20 tics/second when the ppm
level reaches the ALRMLVL (page 11) setting.
3.7 Standby Mode
After becoming operational, the monitor can be placed into a Standby Mode. When taken out of standby
the monitor is ready for operation without waiting an additional 15 minutes to warm up. While in standby
the monitor will stop taking gas samples and stops purging itself from the purge-air bag.
Place the monitor into its Standby Mode by pressing both the ENTER and ESC buttons at the same time.
Take the monitor out of standby by again pressing both the ENTER and ESC buttons.
When the monitor is taken out of standby the operator must refill the purge-air bag by pressing the
ENTER button. Refilling the bag after coming out of standby re-establishes the monitor’s ambient
pressure reading and ensures that the purge-air bag is filled at the start of taking gas measurements.
WARNING: Fill the purge-air bag in a clean, fresh-air environment that is at the
same temperature and humidity as the area being checked for gas. DO NOT fill the
bag in an area that is contaminated with N2O gas.
.
As soon as the purge-air bag has been refilled with fresh air, the Data Display screen appears and the
monitor resumes normal operation.
PURGE 500pk
100ppm N2O
STAND BY
PURGE AIR EMPTY
<ENTER> TO FILL
RECHARGING PURGE
AIR...

Operation N2O Portable Monitor
10 Instruction 3015-4787
3.8 Battery – Charging and Using
3.8.1 Charging the Battery
The monitor is powered by a rechargeable battery pack located in a pouch on the side of the monitor’s soft
carrying case. The battery pack can be recharged at any time, regardless of the battery’s current charge state.
The AC adapter provided accepts voltage inputs of 100 to 240 VAC. Plug the adapter into the wall, then into
the battery. Disconnect the adapter when the battery is fully charged. A fully charged battery pack will power
the monitor for approximately 8-12 hours.
3.8.2 Using the Battery
The PAGM is designed for a 16VDC input. Following the instructions for the particular battery in use, set the
output voltage to 16V. Plug the battery into the instrument's battery input port and the instrument is ready for
use.
3.9 Display Screens
3.9.1 Initial Power ON
When the monitor is first powered ON, all front panel lights turn ON and a splash screen appears showing
the monitor’s current firmware revision level. After a brief moment the Warm Up screen is displayed
along with the front panel ON light (green) blinking.
The monitor requires 15 minutes to warm up from a cold start; after which, the ON light glows steady and
the Data Display screen appears.
If the monitor is turned OFF and then turned back ON, the latter warm-up time may be less than
15 minutes depending on the temperature of the IR detector.
3.9.2 Filling the Purge-Air Bag
CAUTION: Fill the purge-air bag in a clean, fresh-air environment that is at the
same temperature and humidity as the area being checked for gas. DO NOT fill the
bag in an area that is contaminated with N2O gas.
The following message is displayed and an audible alarm is sounded when the monitor’s purge-air bag is
empty. This message appears immediately after warm-up, and approximately every 40 minutes during
normal operation. Press the ENTER button to start the refill process.
After the air bag has been filled, the monitor starts or resumes normal operation by displaying the
Data Display screen.
3.9.3 Data Display Screen
BACHARACH
VERSION x.xx
WARM UP
MEASURE 2ndUNIT
100ppm N2O
PURGE 2ndUNIT
100ppm N2O
PURGE AIR EMPTY
<ENTER> TO FILL
RECHARGING PURGE
AIR...

N2O Portable Monitor Operation
Instruction 3015-4787 11
During normal operation the Data Display screen shows when the monitor is performing the following
two functions:
MEASURE indicates that the monitor is actively measuring gas. In the screen shown above the monitor is
currently detecting 100 ppm of N2O gas. The 2ndUNIT value (Blank, Peak PPM, Continuous TWA, or
8 Hr TWA) is user-selected (refer to 2ndUNIT function on page 13). The measurement cycle runs for
4 minutes.
PURGE is displayed when the monitor is resetting its infrared detector to a baseline of 0 ppm using the
fresh air in the monitor’s internal purge-air bag. The purge cycle runs for 10 seconds.
3.9.4 Function Screens
The Function screens are used to set up the monitor and display stored data.
From the Data Display screen, press both the Keypad Left and Right buttons at the same time to
display the first Function Menu screen. Next, use the Keypad buttons to move the arrow (>) until it
points to the desired function, and then press the ENTER button to select that function.
Once a function has been selected, use the Keypad to scroll through the displayed data or to change a
parameter associated with that function. Press ENTER to save any newly entered parameters. Press the
ESC button to return to the previous screen without saving.
Note that if no buttons are pressed within 90 seconds after selecting a function, the unit returns to the
Data Display screen.
FILLBAG – Press ENTER to manually fill the purge-air bag.
WARNING: Fill the purge-air bag in a clean, fresh-air environment
that is at the same temperature and humidity as the area being
checked for gas. DO NOT fill the bag in an area that is
contaminated with N2O gas.
EMTYBAG – Press ENTER to manually empty the purge-air bag. Use
this function to drain the bag if it becomes contaminated with gas.
ALRMLVL – Detected gas level that causes the front panel ALARM
(red) light to turn ON and the audible alarm to sound (if AUDALRM
function is set to ALARM or ALARM/FAULT).
AUDALRM – The internal audible alarm is programmable to function as
follows:
•OFF – Audible alarm is disabled.
•ALARM – Alarm sounds when detected gas level exceeds the ALRMLVL level as evidenced by the front
panel ALARM (red) light turning ON.
>FILLBAG EMTYBAG
ALRMLVL AUDALRM
>PPM LOG LOG INT
FAULTS DIAG
>SILENCE P-CHK
GAS CLOCK
FILLING BAG...
DRAINING BAG...
AUDIBLE ALARM IS
ALARM
EDIT ALARM LEVEL
0300 ppm
>2ndUNIT PRINT
PLOT PC-DUMP

Operation N2O Portable Monitor
12 Instruction 3015-4787
•ALARM/FAULT – Alarm sounds when either the detected gas level exceeds the ALRMLVL value, or if
a system fault occurs, as evidenced by the front panel ALARM (red) light or FAULT (yellow) light
turning ON.
•LEAK DETECTOR – When selected, the monitor will produce a leak detector type of audible feedback.
At zero ppm there will be a tic every 2 seconds with the tic rate increasing up to 20 tics/second when the
ppm level reaches the ALRMLVL setting.
•TWA ALARM – Audible alarm sounds when the TWA or twa, whichever is selected by the 2ndUNIT
Function, exceeds the ALARMLVL value.
The audible alarm can be temporarily silenced by pressing the SILENCE button (page 12).
PPM LOG – Contains records of the last 200 measurements. Each
record shows the measurement’s date, time, and ppm level.
Measurements are logged at an interval determined by the LOG INT
function.After all 200 locations are filled the newest entries overwrite
the oldest entries.
Use the Keypad Up and Down buttons to change the record number by
a factor of 1. Use the Right and Left buttons to change the record
number by a factor of 10. Press ESC to return to the previous screen.
To the right, record #025 shows that a gas level of 7 ppm was measured
on 07/11/05 at 15:35.
The PPM Log can be cleared per Section 3.11.
LOG INT – Sets the interval at which measurements are logged to
memory from 1 to 9999 minutes. Factory default is 1 minute. The logged
measurements can be viewed using the PPM LOG function. Use the
Keypad to enter the desired value, and then press ENTER to save that
value and return to the previous screen.
FAULTS – Contains records of the last 30 fault events. The most recent
event is displayed when the Fault screen is first displayed. After 30
events have been recorded, the newest record overwrites the oldest. Each
record lists an event’s numeric fault code (refer to Section 3.10) plus the
date and time at which the event occurred. Use any of the Keypad
buttons to scroll through the other fault events. Press ESC to return to
the previous screen.
To the right, record #15 shows that a Purge Flow Fault (fault code
<1000>) occurred on 07/11/05 at 12:37.
DIAG – Enters the diagnostic function. Refer to Section 3.13.
SILENCE – Sets the length of time the internal audible alarm is turned
OFF when the front panel SILENCE button is pressed. The factory default
is 30 seconds. If the cause of the gas-alarm has not been cleared at the end of
this time period, the internal audible alarm will reactivate. Use the Keypad
to enter the desired time period, and then press ENTER to save that value
and return to the previous screen.
#025 7PPM @
07/11/05 15:35
LOG INTERVAL IS
0001 min
4.2159v <0000>
29.05cD 14.58psi
SILENCE TIMEOUT
0030 sec
#15 <1000> @
07/11/07 12:37

N2O Portable Monitor Operation
Instruction 3015-4787 13
P-CHK – The Pressure Check function displays the current manifold
pressure and the stored ambient pressure in psia, along with the difference
between these two pressures and the current fault code. Refer to
Section 3.14.
GAS – Displays Nitrous Oxide (N2O) as the gas being monitored. No other
gas types are available for selection.
CLOCK – Sets the monitor’s date and time. Use the Keypad to enter
the correct date and time, and then press ENTER to save those values
and return to the previous screen. Note that time is displayed in a
24 hour format, while the date is displayed as mm/dd/yy.
2ndUNIT – One of following second measurements can be selected to
appear in the upper-right hand corner of the Data Display Screen:
•NONE – Blank
•Peak PPM – Peak gas reading
•Cont twa – Time Weighted Average calculated on a continuous basis
•8hr TWA – Time Weighted Average calculated over an 8 hour period
PRINT – Refer to Section 3.15 Print/Plot Logged Gas Levels.
PLOT – Refer to Section 3.15 Print/Plot Logged Gas Levels.
PC-DUMP – A personal computer can be connected to the monitor’s DB9
RS-232 connector (refer to illustration in Section 3.15) for the purpose of
downloading logged ppm measurements. These measurements can later be
analyzed using any common spreadsheet program. Refer to Section 3.17 for
detailed instructions on how to transfer stored data to a personal computer.
14.07 * AMB14.05
-0.02dif <1000>
SET DATE & TIME
07/11/05 15:30
SELECT GAS TYPE
N2O
MEASURE 00500pk
100ppm N2O
2ndUNIT >PRINT
PLOT PC-DUMP
2ndUNIT PRINT
>PLOT PC-DUMP
2ndUNIT PRINT
PLOT >PC-DUMP

Operation N2O Portable Monitor
14 Instruction 3015-4787
3.10 Working with System Faults
3.10.1 Functional Overview
If a system malfunction occurs (see Fault Code list, page 15), the front panel FAULT light will flash and
the audible alarm, if activated (refer to AUDALRM function page 11), will start beeping.
3.10.2 Clearing / Silencing a Fault Alarm
The FAULT light and audible alarm will automatically turn OFF after the cause of the fault has been
eliminated.
Pressing the SILENCE button while a fault condition still exists causes the internal audible alarm to turn
OFF for a period of time as set by the SILENCE function (page 12). The front panel FAULT light will
continue to flash as a reminder that a fault condition still exists. At the end of the silence period if the
cause of the fault has not been corrected the audible-alarm circuit will reactivate.
3.10.3 Viewing the Faults Log
From the Data Display screen, press any of the Keypad buttons to display the first Function Menu
screen. Next, use the Keypad buttons to move the arrow (>) until it points to the FAULTS function, and
then press the ENTER button to display the Faults Log screen.
The Faults Log screen shows the monitor’s current fault status. If the
fault is still present when the FAULTS function is selected, then the
current cause of the fault is displayed along with the date and time it
occurred. If the cause of the fault has been cleared, then the Faults Log
screen will show <0000> along with the date and time the fault was
cleared. Use the Keypad buttons to scroll through the fault log. In the
screens shown to the left, record #03 shows that a Sample Flow Fault (fault
code <0800>) occurred on 07/11/05 at 08:17, while record #04 shows that
the fault was cleared on 07/11/05 at 9:00.
The cause of the fault is identified by a numeric fault code. To convert the
fault code into a text description of the fault, first press the ENTER button
and then use the Keypad buttons to scroll through the display until the
text description of the fault appears. If the fault code is a combination of
two or more faults, then continue to use the Keypad buttons until all fault
text descriptions have been displayed. For example, the fault code <1800>
represents the combination of both a Sample Flow <0800> and a Purge
Flow <1000> fault as shown to the left.
The Fault Log can be cleared as described in the “Working with the Gas Alarm" section.
Gas-Alarm Light
If the detected gas level reaches the gas-alarm level as set by the ALRMLVL function, the front panel
ALARM (red) light will flash and the audible alarm, if activated (refer to AUDALRM function on page
11), will start beeping. The ALARM light and audible alarm will automatically turn OFF once the
detected gas level drops below the gas-alarm level.
Silencing a Gas Alarm
Pressing the SILENCE button while the alarm circuit is activated causes the audible alarm to turn OFF
for a period of time as set by the SILENCE function (page 12). The front panel ALARM light will continue
to flash as an indication that an alarm condition still exists. At the end of the silence period if the detected
gas level is still above the gas-alarm level the audible alarm will reactivate.
FAULT CODE <1800>
12 SAMPLE FLOW
FAULT CODE <1800>
13 PURGE FLOW
#03 <0800> @
07/11/05 08:17
#04 <0000> @
07/11/05 09:00

N2O Portable Monitor Operation
Instruction 3015-4787 15
3.10.4 Fault Codes
FAULT CODES ARE ADDITIVE. For example:
A fault code of <0003> indicates that both a Box
Temperature Fault <0001> and a Bench Temper-
ature Fault <0002> have occurred.
<0001> Box Temperature Fault: Enclosure
temperature is outside normal range (or IR detector
has failed). Check that the monitor is not being
subjected to extreme temperatures. Use the DIAG
function to check the Box Temperature.
<0002> Bench Temperature Fault: Optical
bench is outside normal operating range (or IR
detector has failed). Check that the monitor is not
being subjected to extreme temperatures.
<0004> Manifold Pressure Fault: The manifold
pressure is outside its normal operating range (or
IR detector has failed). Enter the DIAG function and
record ALL data. Call the factory with this
information for further instructions.
<0040> Fill Flow: The purge-air bag’s pressure
drop is outside expected limits. Use the EMTYBAG
and FILLBAG functions to refill the purge-air bag. If
the fault still occurs, check for a punctured bag or
disconnected tubing.
<0080> Over Range Fault: Monitor exposed to a
gas level that exceeded 65,000 ppm.
<0100> Zero Filter Fault: The air-purge bag is
contaminated with gas. Take monitor to a clean-air
area and use the EMTYBAG and FILLBAG functions
several times to decontaminate the purge-air bag.
<0200> Gain Set Fault: The digipot autotune
sequence has failed. This fault will only occur on
first boot up or after a firmware upgrade. Call the
factory for further instructions.
<0400> A/D Fault: A fault has occurred in the
analog-to-digital circuitry. Contact the factory with
this information for further instructions.
<0800> Sample Flow Fault: Check for:
A restriction in the gas-sample inlet or exhaust; a
blocked internal filter; or a failed pump.
<1000> Purge Flow Fault: Check for:
A restriction in the gas-sample exhaust; a blocked
internal filter; or a failed pump. Once the purge air
stream has been restored, the monitor will return to
normal operation after it completes a purge cycle.
<2000> Bag Fill Time: The purge-air bag did not
fill within the expected time allotment, or too many
purge cycles occurred indicating a leak in the purge-
air system. Check for a punctured bag or
disconnected tubing.
<4000> Zero Range Fault: The IR detector’s
output voltage is out of tolerance. Enter the DIAG
function and record all data. Call the factory with
this information for further instructions.
<8000> Clipping Fault: The detector voltage may
be out of tolerance. Use the DIAG function to check
the IR detector voltage. Call the factory with this
information for further instructions.

Operation N2O Portable Monitor
16 Instruction 3015-4787
3.11 Working with the Gas Alarm
3.11.1 Gas-Alarm Light
If the detected gas level reaches the gas-alarm level as set by the ALRMLVL function, the front panel
ALARM (red) light will flash and the audible alarm, if activated (refer to AUDALRM function on page
11), will start beeping. The ALARM light and audible alarm will automatically turn OFF once the
detected gas level drops below the gas-alarm level.
3.11.2 Silencing a Gas Alarm
Pressing the SILENCE button while the alarm circuit is activated causes the audible alarm to turn OFF
for a period of time as set by the SILENCE function (page 12). The front panel ALARM light will continue
to flash as an indication that an alarm condition still exists. At the end of the silence period if the detected
gas level is still above the gas-alarm level the audible alarm will reactivate.
3.12 Clearing the PPM & Faults Data
Up to 200 gas measurements and 30 fault events are stored by the monitor.
To clear stored data, first display the data to be cleared by selecting the PPM LOG or FAULTS function
per Section 3.9.4. Next, press both the ENTER and Keypad Right buttons at the same time. A single,
long tone should be heard when the data has been successfully cleared.
3.13 Working with the DIAG Function
3.13.1 Overview
The DIAG function displays sensor data and status information useful to a service technician for
troubleshooting various fault conditions. Explanations of the data shown in these screens are given below.
3.13.2 Keypad Functions
From the Data Display screen, press any one of the Keypad buttons to display the first Function Menu
screen. Next, use the Keypad buttons to move the arrow (>) until it is next to the DIAG function, and
then press ENTER to display the first of two Diagnostic screens.
Press the Keypad Up button to toggle between the First and Second Diagnostic screen.