Onset MX1102A User manual

HOBO® MX CO2Logger (MX1102A) Manual
22504-G
The HOBO MX CO2 data logger records carbon dioxide, temperature, and relative humidity (RH)
data in indoor environments using non-dispersive infrared (NDIR) self-calibrating CO2sensor
technology and integrated temperature and RH sensors. This Bluetooth® Low Energy (BLE)-
enabled logger is designed for wireless communication and supports a USB connection. Using the
HOBOconnect® app on your phone, tablet, or computer, or HOBOware® software on your
computer, you can easily configure the logger, download data from it, and view plotted data. The
logger can calculate minimum, maximum, average, and standard deviation statistics and can be
configured to trip audible or visual alarms at specified thresholds. In addition, it supports burst
logging in which data is logged at a different interval when sensor readings are above or below
certain limits. This logger also has a built-in LCD screen to display the current CO2level,
temperature, RH, logging status, battery use, memory consumption, and more.
Specifications
Temperature Sensor
Range 0° to 50°C (32° to 122°F)
Accuracy ±0.21°C from 0° to 50°C (±0.38°F from 32° to 122°F), see Plot A
Resolution 0.024°C at 25°C (0.04°F at 77°F), see Plot A
Drift <0.1°C (0.18°F) per year
RH Sensor*
Range 1% to 90% RH (non-condensing)
Accuracy ±2% from 20% to 80% typical to a maximum of ±4.5% including
hysteresis at 25°C (77°F); below 20% and above 80% ±6% typical
Resolution 0.01%
Drift <1% per year typical
C
O2Sensor
Range 0 to 5,000 ppm
Accuracy ±50 ppm ±5% of reading at 25°C (77°F), less than 90% RH (non-
condensing) and 1,013 mbar
Warm-up Time 15 seconds
Calibration Auto or manual to 400 ppm
Non-linearity <1% of FS
Pressure Dependence 0.13% of reading per mm Hg (corrected via user input for
elevation/altitude)
Operating Pressure Range 950 to 1,050 mbar (use Altitude Compensation for outside of this
range)
Compensated Pressure
Range
-305 to 5,486 m (-1,000 to 18,000 ft)
Sensing Method Non-dispersive infrared (NDIR) absorption
Response Time
Temperature 12 minutes to 90% in airflow of 1 m/s (2.2 mph)
RH 1 minute to 90% in airflow of 1 m/s (2.2 mph)
CO21 minute to 90% in airflow of 1 m/s (2.2 mph)
Logger
Radio Power 1 mW (0 dBm)
Transmission Range Approximately 30.5 m (100 ft) line-of-sight
Wireless Data Standard Bluetooth Low Energy (Bluetooth Smart)
Logger Operating Range 0° to 50°C (32° to 122°F); 0 to 95% RH (non-condensing)
*Per RH sensor manufacturer data sheet
Note: The HOBO U-Shuttle (U-DT-1) is not compatible with this logger.
HOBO MX CO2Logger
MX1102A
Included Items:
•Four AA 1.5 V alkaline
batteries
Required Items:
•Mobile device with
HOBOconnect app,
Bluetooth, OS, iPadOS®, or
Android™, or a Windows
computer with a native BLE
adapter or supported BLE
dongle
OR
•HOBOware 3.7.3 or later
and USB cable
Accessories:
•Mounting kit with
mounting brackets, screws,
tie wraps, and Command™
strip

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Specifications (continued)
Logging Rate 1 second to 18 hours
Logging Modes Fixed interval (normal, statistics) or burst
Memory Modes Wrap when full or stop when full
Start Modes Now, next interval, push button, date & time
Stop Modes When memory full, push button, date & time, or after a set logging
period
Time Accuracy ±1 minute per month at 25°C (77°F), see Plot B
Power Source 4 AA 1.5 Volt batteries (user replaceable) or USB power source (5 V
DC, 2 Watts)
Battery Life 6 months, typical with logging and sampling intervals of 5 minutes
or slower; 6 months or less with logging and sampling intervals
faster than 5 minutes while logging CO
2
. Entering burst logging
mode will impact battery life. With app use, battery life can be
reduced by remaining connected, excessive readouts, audible
alarms, and paging. Visual/audible alarms and other events can have
a marginal impact on battery life.
Memory 128 KB (84,650 measurements, maximum)
Download Type USB 2.0 interface or via Bluetooth Smart
Full Memory Download Time 20 seconds via USB; approximately 60 seconds via Bluetooth Smart,
may take longer the further the device is from the logger
LCD LCD is visible from 0° to 50°C (32° to 122°F); the LCD may react
slowly or go blank in temperatures outside this range
Size 7.62 x 12.95 x 4.78 cm (3.0 x 5.1 x 1.88 inches
Weight 267.4 g (9.43 oz)
Environmental Rating IP50
The CE Marking identifies this product as complying with all relevant
directives in the European Union (EU).
See last page
*Per RH sensor manufacturer data sheet
Note: The HOBO U-Shuttle (U-DT-1) is not compatible with this logger.
Plot A: Temperature
Accuracy and Resolution
Plot B: Time Accuracy

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Logger Components and Operation
USB Port: Use this port to connect the logger to a computer for
use with HOBOware or to power the logger for longer
deployments or if faster logging intervals are required.
Start/Stop Button: Press this button for 3 seconds to start or
stop logging data or to resume logging on the next even logging
interval. This requires configuring the logger with a push button
start or stop (see Choosing Logger Settings). You can also press
this button for 1 second to record an internal event (see Logger
Events), to silence a beeping alarm (see Setting up Alarms), or
to turn the LCD screen on if the option to turn off the LCD has
been enabled (see Choosing Logger Settings).
Press both the Start/Stop button and the Clear/Next button
simultaneously for 3 seconds to reset the logger password.
Clear/Next Button: Press this button for 1 second to switch
between statistics, alarm readings, and the current sensor
readings as applicable or to silence a beeping alarm. Press this
button for 3 seconds to clear a visual alarm if the logger is
configured to maintain the alarm until the button is pressed
(see Setting up Alarms).
Calibrate Button: Press this button to start a five-minute
manual calibration process of the CO
2
sensor. This requires
configuring the logger with the manual calibration CO
2
sensor
setting enabled in the app or HOBOware and bringing the
logger into a fresh air environment (see Calibrating the Logger).
Temperature Sensor: This sensor is located to the right of the
LCD screen below the large CO
2
sensor.
RH Sensor: This sensor is located behind the vented panel in
the logger case to the right of the temperature sensor.
CO
2
Sensor: This sensor is located below the large vented
circular panel to the right of the LCD screen.
LCD Screen: This logger is equipped with an LCD screen that
displays details about the current status. The example shows all
symbols illuminated on the LCD screen followed by definitions
of each symbol in the table.
LCD Symbol Description
The logger Is currently communicating with the
app via Bluetooth. The more bars there are, the
stronger the Bluetooth signal.
The logger is currently communicating with
HOBOware via USB cable.
The logger is currently powered by the USB cable.
The battery indicator shows the approximate
battery power remaining.
The logger has been configured to stop logging
when memory fills. The memory bar indicates the
approximate space remaining in the logger to
record data. When first started, all five segments
in the bar are empty. In this example, the logger
memory is almost full (only one segment in the
memory bar is empty).
The logger is configured to never stop logging
(wrapping). The logger continues recording data
indefinitely, with newest data overwriting the
oldest data until the batteries die or the logger is
reconfigured. When first launched, all five
segments in the memory bar are empty. In this
example, the memory is full (all five segments are
filled in) and new data is now overwriting the
oldest data.
The logger is currently logging.
A sensor reading is above or below the high or low
alarm limit that you configured. Press and release
the Clear/Next button until the alm symbol
(described later in this table) is displayed on the
screen. This symbol at left clears depending on
how alarms are configured to be cleared in the
software. If the alarm is set to clear when the
logger is reconfigured or relaunched, this symbol
remains on the LCD until the next time the logger
is configured (see Setting up Alarms). Otherwise, it
clears when the sensor reading is back within the
alarm limits or by pressing the Clear/Next button
for 3 seconds.
The logger is waiting to be started. Press and hold
the Start/Stop button for 3 seconds to start the
logger.
The logger has been started with push button stop
enabled; press and hold the Start/Stop button for
3 seconds to stop the logger.
An alarm displayed on the LCD is ready to be
cleared. This appears only if the logger is
configured to maintain the alarm until the
Clear/Next button is pressed (for 3 seconds). Note
that an audible alarm can be silenced by pressing
the Start/Stop button or Clear/Next button for 1
second.
Clear/Next Button
Start/Stop Button
CO2Sensor
LCD Screen
RH Sensor
Temperature
Sensor
Calibrate Button
USB Port

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LCD Symbol Description
Press this button to view the latest statistics (if
enabled) or the sensor reading associated with a
tripped alarm.
Press this button for 5 seconds to manually
calibrate the CO
2
sensor (if enabled). Calibrate and
CO
2
blink on the LCD during the 5-minute manual
calibration process.
These symbols show the maximum, minimum,
average, and standard deviation values most
recently calculated by the logger (if enabled).
Press the Next/Clear button for 1 second to cycle
through the available statistics and then back to
the current sensor reading (or to the alarm value if
applicable).
This is the farthest out-of-range sample displayed
during the logger deployment. Press the
Clear/Next button to view this reading. Press the
Clear/Next button again to cycle through any
statistics (defined above) and ultimately back to
the current sensor reading.
This is an example of a CO
2
reading in parts per
million. If the logger is powered by battery: A new
segment appears in the status bar every 15
seconds to indicate how long until the display is
updated. In this example, there are 18 segments.
This means it has been 4 minutes and 30 seconds
since the CO
2
reading was updated on the LCD.
There are 30 seconds left (two segments) before
the reading is updated on the LCD. If the logger is
powered by USB cable: The segmented status bar
is not displayed and the current reading is updated
every second.
This is an example of a temperature reading.
Temperature units are determined by the settings
in the software. To switch between Celsius and
Fahrenheit, change the units in the software and
then reconfigure the logger. Temperature readings
are updated on the LCD every 15 seconds if the
logger is battery-powered or every second if it is
USB-powered regardless of logging interval.
This is an example of an RH reading. RH readings
are updated on the LCD every 15 seconds if the
logger is battery-powered or every second if it is
USB-powered regardless of logging interval.
The logger is configured to start logging on a
particular date/time. The display counts down in
days, hours, minutes, and seconds until logging
begins. In this example, 5 minutes and 38 seconds
remain until logging begins.
The configuration settings are being loaded onto
the logger from the software.
An error occurred while loading the configure
settings onto the logger from the software. Try
reconfiguring the logger.
The logger has been stopped with the software or
because the memory is full.
Notes:
•You can disable the LCD screen in the app. When the LCD
is turned off for logging, you can still temporarily view
the LCD screen by pushing the Start/Stop or Clear/Next
button. The LCD then remains on for 10 minutes.
•When the logger is connected to the computer with the
USB cable, the LCD screen refreshes every second
regardless of logging interval.
•When the logger has stopped logging, the LCD screen
remains on with STOP displayed until you download data
from the logger (unless the LCD screen was turned off in
the software). Once you have downloaded data from the
logger, the LCD turns off automatically after 2 hours.
•The LCD screen flashes HELLO when you page the logger
from the app (see Getting Started with the App).
•The LCD screen flashes CHIRP OFF when you clear an
audible alarm.
Setting up the Logger
Important: The CO
2
sensor within this logger can experience
measurement drift during storage and shipment. We strongly
recommend that you perform a manual calibration prior to
deploying the logger. Start the logger as described in this
section and perform a manual calibration. See Calibrating the
Logger for more details; follow the manual calibration steps in
that section. Improper manual calibration can cause incorrect
sensor readings.
Install the batteries in the logger. Use a Phillips-head
screwdriver to open the battery cover on the back of the logger
and insert four AA batteries observing polarity (see Battery
Information). Screw the cover back in place.
You can use both the app and HOBOware software with this
logger. The following sections provide an overview for using the
logger with both programs. You can switch back and forth
between the two programs (for example, configure the logger
in HOBOware, and download its data in the app). However, you
can connect to only one program at a time. You cannot use the
app with the logger while it is connected to HOBOware. If you
attempt to use the logger in HOBOware while it is connected to
the app, the device will not be found. If you want to connect to
the app after using the logger with HOBOware, you must
disconnect the USB cable once you are done with HOBOware.
Getting Started with HOBOconnect
These steps provide an overview of setting up the logger with
the HOBOconnect app.
1. Download HOBOconnect to a phone or tablet from the App
Store® or Google Play™.
Download the app to a Windows computer from
www.onsetcomp.com/products/software/hoboconnect.
2. Open the app and enable Bluetooth in your device settings
if prompted.
3. Tap Devices and then tap the logger tile in the app to
connect to the logger.
If the logger does not appear or if it is having trouble
connecting, follow these tips:
•Make sure the logger is within range of your mobile
device or computer. The range for successful wireless
communication is approximately 30.5 m (100 ft) with full
line-of-sight.
•If your device can connect to the logger intermittently or
loses its connection, move closer to the logger, within
sight if possible.

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•If the logger appears in the app, but you cannot connect
to it, close the app and then power down your device to
force the previous Bluetooth connection to close.
4. Once connected, tap Configure & Start.
5. Specify your logger configuration settings. See Choosing
Logger Settings for details on the available settings.
6. Tap the CO
2
sensor and select manual and/or auto
calibration. Select Altitude Compensation and enter the
altitude above or below sea level. Tap Save. See Calibrating
the Logger for more details on calibration settings.
7. Tap Start to save the configuration settings and begin
logging.
Logging begins based on the settings you selected. Deploy the
logger using the included mounting materials (see Mounting
the Logger). After logging begins, you can download data from
the logger at any time (see Downloading Data From the Logger
for details).
Note: The sensor readings displayed within the app may not
match what is displayed on the logger.
When the logger is connected, you can:
Tap this: To do this:
Specify logger settings and save them onto the
logger to start logging. See Configuring the
Logger.
Tap to view live data.
Stop a beeping alarm on the logger if audible
alarms are enabled as described in Setting up
Alarms.
Lock the logger. Set a password for the logger so
that it is not mistakenly stopped or reconfigured.
Tap the icon, enter a password, and then tap Set.
Once a password is entered on a phone or tablet,
that mobile device is the only one to remember
it. This means you can connect to the logger
without entering a password on that mobile
device, but you must enter a password on all
other mobile devices. For example, if you set the
password for the logger with your tablet and
then try to connect to the device later with your
phone, you must enter the password on the
phone but not with your tablet. Similarly, if
others attempt to connect to the logger with
different devices, they are also required to enter
the password.
To reset a password:
•Simultaneously press both the Start/Stop
button and the Alarm/Stats button for 3
seconds, or
•Tap Manage Password and then tap Reset.
Manage Password. Reset your existing password
or set a new password for the logger.
Stop logging data (this overrides any Stop
Logging settings described in Configuring the
Logger).
Start logging if the logger was configured to start
with a button push. See Configuring the Logger.
Download logger data. See Downloading Data
From the Logger.
Mark the logger as a favorite. You can then filter
the list of devices to show only loggers marked as
favorites.
Make the logger beep one time to help you
locate it. HELLO also appears on the LCD when
the logger is paged.
Update the firmware on the logger. A logger
readout is completed automatically at the
beginning of the firmware update process.
Important: Before updating the firmware on the
logger, check the remaining battery level and
make sure it is no less than 30%. Make sure you
have the time to complete the entire update
process, which requires that the logger remains
connected to the device during the upgrade.
Getting Started with HOBOware
These steps provide an overview of setting up the logger with
HOBOware. For complete details, see the HOBOware Help.
1. Install HOBOware on your computer.
2. Connect the logger to the computer with a USB cable.
Important: USB 2.0 specifications do not guarantee operation
outside the range of 0°C (32°F) to 50°C (122°F).
3. From the device menu in HOBOware, select Launch.
4. Choose your logger settings. See Choosing Logger Settings
for details on the available settings.
5. Click the CO
2
Settings button and select manual and/or auto
calibration (both are selected by default). Select Use Carbon
Dioxide Sensor Altitude Compensation and enter the
altitude above or below sea level. Click OK. See Calibrating
the Logger for more details on calibration settings.

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6. Click the Start button when finished. Note that the Start
button text changes based on your Start Logging selection.
Logging begins based on the settings you selected. Deploy the
logger using the included mounting materials (see Mounting
the Logger). After logging begins, you can read out the logger at
any time (see Reading Out the Logger for details).
Choosing Logger Settings with HOBOconnect
The following table lists the available settings when configuring
the logger with the HOBOconnect app.
Logger Setting Action
Name Enter a name for the logger up to 20 characters.
This name will be used as the file name. A name
also helps identify the logger in the Loggers
screen in the app. If no name is entered, the
logger serial number is used.
Group Add the logger to a group to help identify the
logger.
Logging
Interval
Select how often the logger records data.
Start Logging
Options
Choose one of the following:
•Now. Logging will begin
immediately after
configuration settings are loaded on the
logger.
•On Next Logging Interval. Logging will begin
at the next even interval as determined by
the selected logging interval.
•On Button Push. Logging will begin 15
seconds after you press the Start/Stop
logging button on the logger for 3 seconds.
•On Date/Time. Logging will begin at a date
and time you specify.
Stop Logging
Options
Choose a memory option:
•When Memory Fills. The logger will continue
recording data until the memory is full.
•Never (Wrap When Full). The logger will
continue recording data indefinitely, with
newest data overwriting the oldest. This
option is not available if the Logging Mode is
set to Burst (see Burst Logging).
Choose this stop logging option if desired:
Logger Setting Action
•On Button Push. Select this if you want to be
able to stop logging by pushing the Start/Stop
button on the logger.
Choose a Stop Logging time-based option.
•Never. Select this if you do not want the
logger to stop at any predetermined time
frame.
•On Date/Time. Select this if you want the
logger to stop logging on a specific date and
time. Select the date and time.
•After. Select this if you want to control how
long the logger should continue logging once
it starts. Choose the amount of time you
want the logger to log data. For example,
select 30 days if you want the logger to log
data for 30 days after logging begins.
Logging Mode Choose a logging mode:
•Fixed Logging. The logger will record data for
all enabled sensors at the selected logging
interval.
•Burst Logging. In burst mode, logging occurs
at a different interval when a specified
condition is met. See Burst Logging for more
information.
•In the app, select Fixed if you want the logger
to log current readings. Select each statistic
you want the logger to log.
In HOBOware, select Statistics and then
select Current Reading if you want sensor
readings to be logged. Select each statistic
you want the logger to log.
Current readings and statistics are logged at
the logging interval rate. See Statistics
Logging for more information.
Show LCD Enable or disable to control whether the LCD
remains illuminated while the logger is logging.
If you disable the LCD, the logger will not show
the current reading, status, or other
information while the logger is logging. You will,
however, be able to temporarily turn the LCD
screen on by pressing the Start/Stop button on
the logger for 1 second.
Sensor &
Alarm Setup
Enable the sensor measurement types that will
be logged: temperature, RH, and/or CO
2
. Both
temperature and RH are required to calculate
dew point, which is an additional data series
available for plotting after reading out the
logger. You can configure alarms for sensors.
See Setting up Alarms. If logging CO
2
, you can
select calibration settings. See Calibrating the
Logger.
Choosing Logger Settings with HOBOware
The following table lists the available settings when configuring
the logger with HOBOware.
Logger Setting Action
Name Enter a name for the logger up to 20 characters.
This name will be used as the file name. A name
also helps identify the logger in the Loggers
screen in the app. If no name is entered, the
logger serial number is used.

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Logger Setting Action
Logging
Interval
Select how often the logger will record data.
Start Logging
Options
Choose one of the following:
•Now. Logging will begin immediately after
configuration settings are loaded on the
logger.
•On Next Logging Interval. Logging will begin
at the next even interval as determined by
the selected logging interval.
•On Button Push. Logging will begin 15
seconds after you press the Start/Stop
logging button on the logger for 3 seconds.
•On Date/Time. Logging will begin at a date
and time you specify.
Stop Logging
Options
Choose a memory option:
•When Memory Fills. The logger will continue
recording data until the memory is full.
•Never (Wrap When Full). The logger will
continue recording data indefinitely, with
newest data overwriting the oldest. This
option is not available if the Logging Mode is
set to Burst (see Burst Logging).
Choose this stop logging option if desired:
•On Button Push. Select this if you want to be
able to stop logging by pushing the Start/Stop
button on the logger.
Choose a Stop Logging time-based option.
•Never. Select this if you do not want the
logger to stop at any predetermined time
frame.
•On Date/Time. Select this if you want the
logger to stop logging on a specific date and
time. Select the date and time.
•After. Select this if you want to control how
long the logger should continue logging once
it starts. Choose the amount of time you
want the logger to log data. For example,
select 30 days if you want the logger to log
data for 30 days after logging begins.
Logging Mode Choose a logging mode:
•Fixed Logging. The logger will record data for
all enabled sensors at the selected logging
interval.
•Burst Logging. In burst mode, logging occurs
at a different interval when a specified
condition is met. See Burst Logging for more
information.
•In the app, select Normal if you want the
logger to log current readings. Select each
statistic you want the logger to log.
In HOBOware, select Statistics and then
select Current Reading if you want sensor
readings to be logged. Select each statistic
you want the logger to log.
Current readings and statistics are logged at
the logging interval rate. See Statistics
Logging for more information.
Show LCD Enable or disable to control whether the LCD
remains illuminated while the logger is logging.
If you disable the LCD, the logger will not show
Logger Setting Action
the current reading, status, or other
information while the logger is logging. You will,
however, be able to temporarily turn the LCD
screen on by pressing the Start/Stop button on
the logger for 1 second.
Sensor &
Alarm Setup
Enable the sensor measurement types that will
be logged: temperature, RH, and/or CO2. Both
temperature and RH are required to calculate
dew point, which is an additional data series
available for plotting after reading out the
logger. You can configure alarms for sensors.
See Setting up Alarms. If logging CO2, you can
select calibration settings. See Calibrating the
Logger.
Calibrating the Logger
The CO2sensor in the logger requires altitude compensation
and regular calibration to ensure the logger is taking accurate
readings where it is deployed. When you first configure the
logger, both auto and manual calibration are selected by
default. Use altitude compensation if you are monitoring CO2 at
elevations above or below 305 meters (1,000 feet).
Some CO2measurement drift may occur during shipment and
storage. We recommend manual calibration immediately after
logging begins for best accuracy.
Important: If you perform a manual calibration, be sure to
follow the instructions later in this section. Improper manual
calibration can result in incorrect sensor readings.
The following CO2settings are available in both the app and
HOBOware:
•Manual calibration. Manual calibration is the best way to
calibrate your logger. Use this option to manually calibrate
the logger to 400 ppm using the Calibrate button on the
logger. This requires taking the logger outside in fresh air
on a dry day or to an indoor location that is unoccupied
and has no connection to a ventilation system for five
minutes on a regular basis. Press the Calibrate button on
the logger for 5 seconds to manually calibrate the CO2
sensor. Calibrate and CO2blink on the LCD during the 5-
minute manual calibration process in which 300
measurements are taken to get the average and create the
offset from 400 ppm. (See the steps later in this section for
more details on manual calibration.) This is recommended
if the logger is deployed in a building that is always
occupied, if you want the logger to be calibrated more
frequently than every eight days (the normal auto
calibration schedule), or if you want to calibrate the logger
immediately after logging begins. Note: Once you perform
a manual calibration, the 24-hour auto calibration is
canceled and an auto calibration is performed eight days
from the time the manual calibration occurred.
•Auto calibration. Use this option if you want the logger to
automatically calibrate within the first 24 hours after
logging begins and then every eight days thereafter. The
logger is calibrated based on the average of the three CO2
measurements that follow the lowest CO2value identified
during the 24-hour or 8-day time period as applicable.

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Important: Accurate auto-calibration requires the building
or location where the logger is deployed to be empty at
least once during the eight-day period (for example, an
empty office building during the weekend or overnight
typically has background CO2levels of 400 to 450 ppm).
If the logger is deployed in an area where the CO2level
does not go down to 400 ppm during the eight-day time
period, perform manual calibration regularly instead or
the logger will report inaccurate CO2readings. If you plan
to use auto calibration but the building will be occupied
during the first day after logging begins, use the manual
calibration option as well. You can manually calibrate the
logger immediately after logging begins and use auto
calibration thereafter. Note: Every time the logger is
started, auto calibration begins after 24 hours and then
again after eight days unless you perform a manual
calibration first.
•Altitude compensation. The CO2sensor must compensate
for locations above or below 305 meters (1,000 feet) to
provide an accurate reading. You must enter the altitude
above or below sea level in either meters or feet when
configuring the logger if it is deployed at a location above
or below sea level. In normal use, the CO2measurement
varies by approximately 0.135% of the reading for each
mbar change in barometric pressure (the sensor is
calibrated at 1,013 mbar). Use altitude compensation
when deploying the logger for the best CO2accuracy
possible.
To access calibration and altitude compensation settings in
the app:
1. Tap Devices and then tap the logger tile in the app to
connect to the logger.
2. Tap Configure & Start.
3. Tap the CO2sensor.
4. Select auto calibration, manual calibration, or both.
5. Select Altitude Compensation and enter the altitude (in
either meters or feet) above or below sea level where the
logger will be deployed.
To access calibration and altitude compensation settings in
HOBOware:
1. Connect the logger to the computer with the USB cable.
2. From the Device menu in HOBOware, select Launch.
3. Click the CO2Settings button.
4. Select auto calibration, manual calibration, or both.
5. Select Use Carbon Dioxide Sensor Altitude Compensation
and enter the altitude above or below sea level where the
logger will be deployed in either meters or feet.
6. Click OK.
7. Click Start in the Launch Logger window to load settings to
the logger.
Note: If both auto calibration and manual calibration are
selected, the logger automatically calibrates within 24 hours
after logging begins unless you perform a manual calibration
during that time period. In addition, when both calibration
settings are selected, the eight-day calibration cycle is reset any
time a manual calibration is performed.
To manually calibrate the CO2sensor:
Important: If you do not follow these manual calibration
instructions as described, the sensor readings will be incorrect
and you will need to manually calibrate the logger again.
1. Take the logger outside in fresh air on a dry day where the
carbon dioxide level is 400 ppm. You can also use an indoor
location for manual calibration if it is unoccupied and is not
exposed to a ventilation system.
2. Press the Calibrate button on the logger for 5 seconds until
it beeps. The logger calibrates for 5 minutes. The CO2and
Calibrate symbols on the LCD flash while calibration is
underway. A time- and date-stamped manual calibration
event is logged in the data at the end of the 5-minute
calibration sequence.
3. Once the Calibration process is complete, return the logger
to its deployment location. Repeat this process at least once
every eight days for best accuracy.
Setting up Alarms
You can set an alarm to trip on the logger when a sensor
reading rises above or falls below a specified value. Alarms alert
you to problems so you can take corrective action. To set up a
sensor alarm:
1. In the app: Connect to the logger and tap Configure & Start.
In HOBOware: From the Device menu, select Launch. Click
the Alarms button in the Launch Logger window.
2. Select the sensor that you want to set up with an alarm
condition.
3. Enable the High Alarm if you want an alarm to trip when the
sensor reading rises above the high alarm value. Drag the
slider to the reading that will trip the alarm or type a
specific reading.
4. Enable the Low Alarm if you want an alarm to trip when the
sensor reading falls below the low alarm value. Drag the
slider to the reading that will trip the alarm or type a
specific reading.
5. Set the duration before an alarm is tripped and select one
of the following:
•Cumulative. The alarm trips once the sensor reading is
out of the acceptable range for the selected duration any
time during logging. For example, if the high alarm is set
to 85°F and the duration is set to 30 minutes, the alarm
trips once the sensor readings have been above 85°F for
a total of 30 minutes since the logger was configured.
•Consecutive. The alarm trips once the sensor reading is
out of the acceptable range continuously for the selected
duration. For example, the high alarm is set to 85°F and
the duration is set to 30 minutes, the alarm trips only if
all sensor readings are 85°F or above for a continuous 30-
minute period.
6. Repeat steps 2–5 for any other sensors if desired..
7. Enable Audible Alarms if you want a beep to sound on the
logger every 30 seconds when the sensor alarm trips (in the
app, enable this in the configuration settings screen; in
HOBOware, select the Use Audible Alarm checkbox in the
Configure Alarms window). The beeping continues until the
alarm is cleared from the software, a button on the logger is

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pressed, or 7 days have passed. Battery life is slightly
reduced when this setting is enabled. We recommend that
you enable this feature only if you have regular access to
the logger so that you can easily turn off the beeping.
8. Select one of the following options for when to clear the
alarm symbol that appears on the LCD (in the app, enable
this in the configuration settings screen; in HOBOware,
select the checkbox in the Configure Alarms window).
•Logger Reconfigured. The alarm icon remains visible on
the LCD until the next time the logger is reconfigured.
•Sensor In Limits. The alarm icon remains visible on the
LCD until the sensor reading returns to the normal range
between any configured high and low alarm limits.
•Alarm Button Pressed. The alarm icon remains visible
until you press the Clear/Next button on the logger.
9. In the app: Tap Start.
In HOBOware: Click OK in the Configure Alarms window and
then click Start in the Launch Logger window when ready.
Notes about alarms:
•The alarm icon is illuminated on the logger LCD when the
alarm trips. You can also press the Clear/Next button on
the logger to view the farthest out-of-range value during
the deployment.
•The logger checks alarm limits for temperature and RH
sensors every 15 seconds. The logger checks CO2alarm
limits every 15 seconds if the logger is powered by USB
cable or every 5 minutes if it is powered by batteries. If
you are configuring a CO2sensor alarm for a battery-
powered logger, we recommend that you select a
duration that is divisible by 5 and a minimum of 5
minutes.
•For USB-powered loggers, CO2alarms are not tripped for
the first 15 seconds after logging begins as the CO2
sensor requires a 15-second warmup period.
•The actual values for the high and low alarm limits are set
to the closest value supported by the logger. In addition,
alarms can trip or clear when the sensor reading is within
the resolution specifications.
•When you download data from the logger, alarm events
can be displayed on the plot or in the data file. See
Logger Events.
•Once cleared, an audible alarm starts beeping again if the
sensor values go out of the normal range. Even if an
audible alarm is cleared, a visual alarm may remain on
the logger LCD and in the app (if applicable) depending
on the settings selected for maintaining visual alarms or
because the alarm condition may still be in effect. In
addition, an audible alarm continues beeping when the
sensor values have returned to the normal range until it
is cleared.
•Although an audible alarm and a visual alarm can occur
at the same time when a sensor alarm is tripped, you
clear them in different ways. Clear the audible alarm
from within the software, by pressing a button on the
logger, or wait until 7 days have passed. Meanwhile, a
visual alarm is cleared as determined by the setting
selected for maintaining an alarm in the software. This
means you could clear a beeping audible alarm and the
visual alarm remains on the LCD and in the app (if
applicable) until you reconfigure the logger, the sensor is
in limits, or you press the alarm button--whichever
setting you select.
•If the logger is configured to stop logging with a button
push, tripped alarms clear automatically when logging is
stopped and no Alarm Cleared event is logged in the data
file.
Burst Logging
Burst logging is a logging mode that allows you to set up more
frequent logging when a specified condition is met. For
example, a logger is recording data at a 5-minute logging
interval and burst logging is configured to log every 30 seconds
when the temperature rises above 85°F (the high limit) or falls
below 32°F (the low limit). This means the logger records data
every 5 minutes as long as the temperature remains between
85°F and 32°F. Once the temperature rises above 85°F, the
logger switches to the faster logging rate and record data every
30 seconds until the temperature falls back to 85°F. At that
time, logging then resumes every 5 minutes at the normal
logging interval. Similarly, if the temperature falls below 32°F,
the logger switches to burst logging mode again and records
data every 30 seconds. Once the temperature rises back to
32°F, the logger then returns to normal mode, logging every 5
minutes.
To set up burst logging:
1. In the app: Connect to the logger and tap Configure & Start.
In HOBOware: From the Device menu, select Launch.
2. Set the Logging Mode to Burst logging. (If already selected
in HOBOware, click the Edit button.)
3. Select the sensor that you want have burst limits.
4. Enable High Limit if you want burst logging to occur when
the sensor reading rises above a specific reading. Drag the
slider to the reading that will trigger burst logging or type a
specific reading.
5. Enable Low Limit if you want burst logging to occur when
the sensor reading falls below a specific reading. Drag the
slider to the reading that will trigger burst logging or type a
specific reading.
6. Set the burst logging interval. Select an interval faster than
the logging interval. Keep in mind that the more frequent
the burst logging rate, the greater the impact on battery life
and the shorter the logging duration.
7. Repeat steps 3–6 for any other sensors if desired (tap Save
in the app first).
8. In the app: Tap Start.
In HOBOware: Click OK in the Burst Logging window and
then click Start in the Launch Logger window when ready.
Notes about Burst Logging:
•Sensor alarms, statistics, and the Stop Logging option in
HOBOware, Never (Wrapping) and in HOBOconnect
Never Stop (Overwrites Old Data) are not available in
burst logging mode.
•Once you configure the logger, the logger checks the high
and low burst limits every 15 seconds. If you set the
logging interval to less than 15 seconds and the sensor

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reading falls outside the levels, burst logging does not
begin until the next 15-second cycle.
•If high and/or low limits are configured for more than
one sensor, burst logging begins when any high or low
condition goes out of range. Burst logging does not end
until all conditions on all sensors are back within normal
range.
•The actual values for the burst logging limits are set to
the closest value supported by the logger.
•Burst logging mode can begin or end when the sensor
reading is within the resolution specifications.
•Once the high or low condition clears, the logging
interval time is calculated using the last recorded data
point in burst logging mode, not the last data point
recorded in fixed mode. For example, a logger has a 10-
minute logging interval and logged a data point at 9:05.
Then, the high limit was surpassed and burst logging
began at 9:06. Burst logging then continued until 9:12
when the sensor reading fell back below the high limit.
Now back in normal mode, the next logging interval will
be 10 minutes from the last burst logging point, or 9:22
in this case. If burst logging had not occurred, the next
data point would have been at 9:15.
•A New Interval event is created each time the logger
enters or exits burst logging mode. See Logger Events for
details on plotting and viewing the event. In addition, if
the logger is stopped with a button push while in burst
logging mode, then a New Interval event is automatically
logged and the burst condition is cleared, even if the
actual high or low condition has not cleared.
Statistics Logging
During fixed logging, the logger records data for enabled
sensors and/or selected statistics at the logging interval
selected. Statistics are calculated at a sampling rate you specify
with the results for the sampling period recorded at each
logging interval. The following statistics can be logged for each
sensor:
•The maximum, or highest, sampled value
•The minimum, or lowest, sampled value
•An average of all sampled values
•The standard deviation from the average for all sampled
values
For example, a logger is configured with the temperature and
CO2sensors enabled and the logging interval set to 5 minutes.
The current reading and all four statistics are enabled. The
statistics sampling interval is set to 30 seconds. Once logging
begins, the logger measures and records the actual
temperature and CO2sensor values every 5 minutes. In
addition, the logger takes a temperature and CO2sample every
30 seconds and temporarily stores them in memory. The logger
then calculates the maximum, minimum, average, and standard
deviation using the samples gathered over the previous 5-
minute period and logs the resulting values. When downloading
data from the logger, this results in the following 10 data series
(not including any derived series): two sensor series (with
temperature and CO2current readings logged every 5 minutes)
plus eight maximum, minimum, average, and standard
deviation series (four for temperature and four for CO2with
values calculated and logged every 5 minutes based on the 30-
second sampling rate).
To set up statistics in HOBOconnect
1. Tap Devices. Press the button on the logger to wake it up, if
necessary.
2. Tap the logger tile in the app to connect to it and tap
Configure & Start.
3. Tap Logging Mode and select Fixed Logging Mode.
4. Tap to turn on Statistics.
Note: Fixed Logging Mode records sensor measurements
taken at each logging interval. The selections you make in
the Statistics section add measurements to the recorded
data.
5. Select the statistics you want the logger to record at each
logging interval: Maximum, Minimum, Average, and
Standard Deviation (average is automatically enabled when
selecting Standard Deviation). Statistics are logged for all
enabled sensors. In addition, the more statistics you record,
the shorter the logger duration and the more memory is
required.
6. Enter a value in Statistics Sampling Interval to use for
calculating statistics. The rate must be less than, and a
factor of, the logging interval. For example, if the logging
interval is 1 minute and you select 5 seconds for the
sampling rate, the logger takes 12 sample readings between
each logging interval (one sample every 5 seconds for a
minute) and use the 12 samples to record the resulting
statistics at each 1-minute logging interval. Note that the
faster the sampling rate, the greater the impact on battery
life. Because measurements are being taken at the statistics
sampling interval throughout the deployment, the battery
usage is similar to what it would be if you had selected this
rate for the normal logging interval.
7. Tap Start.
To set up statistics in HOBOware:
1. From the Device menu, select Launch.
2. Select Statistics for the logging mode.
3. Select Current Reading to record the current reading for
each enabled sensor at the logging interval selected. Do not
select this if you only want to log statistics.
4. Select the statistics you want the logger to record at each
logging interval: Maximum, Minimum, Average, and
Standard Deviation (average is automatically enabled when
selecting Standard Deviation). Statistics will be logged for all
enabled sensors. In addition, the more statistics you record,
the shorter the logger duration and the more memory is
required.
5. Set the statistics sampling interval. The rate selected must
be less than, and a factor of, the logging interval. For
example, if the logging interval is 1 minute and you select 5
seconds for the sampling rate, then the logger will take 12
sample readings between each logging interval (one sample
every 5 seconds for a minute) and use the 12 samples to
record the resulting statistics at each 1-minute logging
interval. Note that the more frequent the sampling rate, the
greater the impact on battery life.

HOBO MX CO
2
Data Logger (MX1102A) Manual
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6. Click OK in the Burst Logging window and then click Start in
the Launch Logger window when ready.
Once logging begins, press the Clear/Next button on the logger
to cycle through the current maximum, minimum, average, and
standard deviation data on the LCD screen. Note that the logger
always displays the current sensor readings in the app (If
applicable) even if they are not being logged. You can plot the
statistics series once you read out the logger.
Setting a Password
You can create an encrypted password for the logger that is
required if another device attempts to connect to it. This is
recommended to ensure that a deployed logger is not
mistakenly stopped or purposely altered by others. This
password uses a proprietary encryption algorithm that changes
with every connection.
To set a password:
1. Tap Devices and tap the logger in the app to connect to it.
2. Tap the three-dot button (if applicable) and then tap Lock
Logger.
3. Type a password and then tap Set.
Only the device used to set the password can then connect to
the logger without entering a password; all other devices will
be required to enter the password. For example, if you set the
password for the logger with your tablet and then try to
connect to the logger later with your phone, you will be
required to enter the password on the phone but not with your
tablet. Similarly, if others attempt to connect to the logger with
different devices, then they would also be required to enter the
password. To reset a password, Press both the Start/Stop
button and the Clear/Next button simultaneously for 3 seconds
to reset a logger password, or connect to the logger and tap the
three-dot button (if applicable), then Manage Password, and
tap Reset.
Downloading Data From the Logger
To download data from the logger to the app:
1. Tap Devices and tap the logger tile in the app to connect to
the logger.
2. Tap Download Data. The logger reads out the data to the
phone, tablet, or computer.
3. Once the readout is complete, tap Data and select the file
to view it. Tap (if applicable) and to export the data.
You can also upload data automatically to HOBOlink, Onset’s
web-based software, using the app or the MX gateway. For
details, see the HOBOconnect User’s Guide and see the
HOBOlink help for details on working with data in HOBOlink.
To offload date from the logger to HOBOware:
1. Connect the logger to the computer with the USB cable.
2. From the Device menu, select Readout.
3. Save the data file when prompted. See the HOBOware Help
for details on plotting and exporting data in HOBOware.
Note: Data files read out from the logger in one program are
not automatically available in the other. To open app files in
HOBOware, share the HOBO file via email and open it on the
computer with HOBOware. Files in HOBOware cannot be
viewed in the app. You can, however, export data in HOBOware
to a text or Excel file that you can open on your mobile device.
See the app user’s guide and HOBOware Help for details on
sharing or exporting data.
HOBOconnect Logger Events
The logger records the following internal events to track logger
operation and status. Select events to plot when opening the
data file in HOBOconnect. To plot events in the app, tap Data
Files and select a file to open. Tap (if applicable) and then tap
. Select the events you want to plot and tap OK.
Internal Event
Name Definition
Host Connected The logger was connected to the mobile
device or computer as applicable.
Started The Start/Stop button was pressed to
begin or resume logging.
Stopped The logger received a command to stop
recording data (from the software or by
pushing the Start/Stop button).
Button Up/Button
Down
The Start/Stop button was pressed for
1 second.
Chan <#> Alarm
Tripped
A sensor alarm has tripped; <#> is the
sensor number, where 1 is CO
2
, 2 is
temperature, and 3 is RH.
Chan <#> Alarm
Cleared
A sensor alarm has cleared; <#> is the
sensor number, where 1 is CO
2
, 2 is
temperature, and 3 is RH. This event also
contains the value that was furthest out of
range for the sensor before the alarm
cleared, which is only available in a shared
or exported file.
New Interval The logger has entered or exited burst
logging mode.
Automatic
Calibration
The CO
2
sensor has been calibrated
automatically; the data file will show the
offset calculated in PPM during the
calibration.
Manual Calibration The CO
2
sensor has been manually
calibrated; the data file will show the
offset calculated in PPM during the
calibration.
Safe Shutdown The battery level dropped below 3.7 V; the
logger performs a safe shutdown.
Mounting the Logger
There are several ways to mount the logger using the materials
included:
•Attach Command strips to the back of the logger to
mount it to a wall or other flat surface.
•Screw in the brackets onto both sides of the logger using
the two small holes labeled in the diagram below and
then use tie wraps to mount it to a pole or pipe.
•Mount the logger to the wall or a flat surface using two
screws and the included template. The dimensions are
also shown in the following example.

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2
Data Logger (MX1102A) Manual
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Protecting the Logger
The logger is designed for indoor use and can be permanently
damaged by corrosion if it gets wet. Protect it from
condensation. If the message FAIL CLK appears on the LCD
screen, there was a failure with the internal logger clock
possibly due to condensation. Remove the battery immediately
and dry the circuit board.
Note: Static electricity may cause the logger to stop logging.
The logger has been tested to 8 KV, but avoid electrostatic
discharge by grounding yourself to protect the logger. For more
information, search for “static discharge” on onsetcomp.com.
Battery Information
The logger requires four user-replaceable AA 1.5 V alkaline or
optional lithium batteries for operation at the extreme ends of
the logger operating range. Expected battery life varies based
on the ambient temperature where the logger is deployed, the
logging or sampling interval, frequency of offloading and
connection to a mobile device, number of channels that are
active, audible alarms duration, use of burst mode or statistics
logging, and battery performance. New batteries typically last 6
months with logging and sampling intervals greater than 5
minutes.
Deployments in extremely cold or hot temperatures, or a
logging or sampling interval faster than 5 minutes can impact
battery life. Estimates are not guaranteed due to uncertainties
in initial battery conditions and operating environment.
The logger can also be powered by the USB cable if faster
logging intervals are desired or when the remaining battery
voltage is too low for it to continue logging. Connect the logger
to the computer, click the Readout button on the toolbar in
HOBOware, and save the data as prompted. Replace the
battery before launching the logger again.
To install or replace the batteries:
1. Use a Phillips-head screwdriver to unscrew the battery
cover on the back of the logger.
2. Remove any old batteries.
3. Insert four new batteries observing polarity.
4. Screw the battery cover back in place.
WARNING: Do not cut open, incinerate, heat above 85°C
(185°F), or recharge the lithium batteries. The batteries may
explode if the logger is exposed to extreme heat or conditions
that could damage or destroy the battery case. Do not dispose
of the logger or batteries in fire. Do not expose the contents of
the batteries to water. Dispose of the batteries according to
local regulations for lithium batteries.
Note: CO
2
sensor readings may temporarily appear as 0 ppm in
the app when replacing the batteries until the logger begins
logging again.
9.53 cm (3.75 inches)
Bracket
mounting
hole
Bracket
mounting
hole
Wall
mounting
hole
Wall
mounting
hole
Remove this
screw to
replace the
batteries

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U.S. and International Sales: 1-508-759-9500
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© 2015–2022 Onset Computer Corporation. All rights reserved. Onset, HOBO, HOBOware, HOBOlink, and
HOBOconnect are registered trademarks of Onset Computer Corporation. App Store, iPhone, iPad, and iPadOS are
service marks or registered trademarks of Apple Inc. Android and Google Play are trademarks of Google LLC. Windows
is a registered trademark or Microsoft Corporation. Bluetooth and Bluetooth Smart are registered trademarks of
Bluetooth SIG, Inc. All other trademarks are the property of their respective companies.
Patent #: 8,860,569 22504-G
Federal Communication Commission Interference Statement
This equipment has been tested and found to comply with the limits for a Class B digital device, pursuant to Part 15 of the FCC Rules. These limits are designed to provide
reasonable protection against harmful interference in a residential installation. This equipment generates uses and can radiate radio frequency energy and, if not installed and
used in accordance with the instructions, may cause harmful interference to radio communications. However, there is no guarantee that interference will not occur in a
particular installation. If this equipment does cause harmful interference to radio or television reception, which can be determined by turning the equipment off and on, the user
is encouraged to try to correct the interference by one of the following measures:
•Reorient or relocate the receiving antenna
•Increase the separation between the equipment and receiver
•Connect the equipment into an outlet on a circuit different from that to which the receiver is connected
•Consult the dealer or an experienced radio/TV technician for help
This device complies with Part 15 of the FCC Rules. Operation is subject to the following two conditions: (1) This device may not cause harmful interference, and (2) this device
must accept any interference received, including interference that may cause undesired operation.
FCC Caution: Any changes or modifications not expressly approved by the party responsible for compliance could void the user's authority to operate this equipment.
Industry Canada Statements
This device complies with Industry Canada license-exempt RSS standard(s). Operation is subject to the following two conditions: (1) this device may not cause interference, and
(2) this device must accept any interference, including interference that may cause undesired operation of the device.
Avis de conformité pour l’Industrie Canada
Le présent appareil est conforme aux CNR d'Industrie Canada applicables aux appareils radio exempts de licence. L'exploitation est autorisée aux deux conditions suivantes : (1)
l'appareil ne doit pas produire de brouillage, et (2) l'appareil doit accepter tout brouillage radioélectrique subi, même si le brouillage est susceptible d'en compromettre le
fonctionnement.
To comply with FCC and Industry Canada RF radiation exposure limits for general population, the HOBO MX logger must be installed to provide a separation distance of at least
20 cm from all persons and must not be co-located or operating in conjunction with any other antenna or transmitter.
NCC Statement
經型式認證合格之低功率射頻電機，非經許可，公司、商號或使用者均不得擅自變更頻率、加大功率或變更原設計之特性及功能。
低功率射頻電機之使用不得影響飛航安全及干擾合法通信；經發現有干擾現象時，應立即停用，並改善至無干擾時方得繼續使用。前項合法通信，指依電信法規定作
業之無線電通信。低功率射頻電機須忍受合法通信或工業、科學及醫療用電波輻射性電機設備之干擾。
Translation:
Article 12
Without permission granted by the NCC, any company, enterprise, or user is not allowed to change frequency, enhance transmitting power or alter original characteristic as well
as performance to an approved low power radio-frequency device.
Article 14
The low power radio-frequency devices shall not influence aircraft security and interfere with legal communications. If found, the user shall cease operating immediately until no
interference is achieved. The said legal communications means radio communications is operated in compliance with the Telecommunications Act. The low power radio-
frequency devices must be susceptible with the interference from legal communications or ISM radio wave radiated devices.