Onset MX1101 Operating Manual

HOBO® MX Temp/RH Data Logger (MX1101) Manual

The HOBO MX Temp/RH data logger records and transmits temperature and relative humidity
(RH) in indoor environments with its integrated sensors. This Bluetooth® Low Energy-enabled
logger is designed for wireless communication with a mobile device. Using the HOBOmobile®
app, you can easily configure the logger, read it out, and view data on your phone or tablet, or
export the data for further analysis. The logger can calculate minimum, maximum, average, and
standard deviation statistics and be configured to trip audible or visual alarms at thresholds you
specify. The logger also supports burst logging in which data is logged at a different interval
when sensor readings are above or below certain limits. This compact data logger also has a
built-in LCD screen to display the current temperature, relative humidity, logging status, battery
use, memory consumption, and more.

Specifications

Temperature Sensor

Range -20° to 70°C (-4° to 158°F)

HOBO MX Temp/RH
Data Logger

Models: MX1101

MX1101-01 (Japan
and Korea)

Included Items:

• Command™ strip

• Double-sided tape

• Hook & loop strap

• Two AAA 1.5 V alkaline

batteries

Required Items:

• HOBOmobile app

• Device with iOS or

Android™ and Bluetooth

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% (non-condensing)

Accuracy ±2% from 20% to 80% typical to a maximum of ±4.5% including

Resolution 0.01%

Drift <1% per year typical

Response Time

Temperature 7:30 minutes in air moving 1 m/s (2.2 mph)

RH 20 seconds 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 -20° to 70°C (-4° to 158°F); 0 to 95% RH (non-condensing)

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 Immediate, push button, date & time, or next interval

Stop Modes When memory full, push button, date & time, or after a set logging

Restart Mode Push button

Time Accuracy ±1 minute per month at 25°C (77°F), see Plot B

Battery Life 1 year, typical with logging interval of 1 minute. Faster logging and/or

Battery Type Two AAA 1.5 V alkaline batteries, user replaceable

Memory 128 KB (84,650 measurements, maximum)

Full Memory Download Time Approximately 60 seconds; may take longer the further the device is

*Per RH sensor manufacturer data sheet

hysteresis at 25°C (77°F); below 20% and above 80% ±6% typical

period

statistics sampling intervals, entering burst logging mode, and
remaining connected with HOBOmobile will impact battery life.
Excessive readouts, checking of Full Status Details, audible alarms,
and paging all impact battery life. Visual alarms and other events can
have a marginal impact on battery life.

from the logger

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HOBO MX Temp/RH Data Logger (MX1101) Manual

Specifications (continued)

LCD LCD is visible from 0° to 50°C (32° to 122°F); the LCD may react slowly

Size 3.66 x 8.48 x 2.29 cm (1.44 x 3.34 x 0.9 in.)

Weight 56 g (1.98 oz)

Environmental Rating IP50

*Per RH sensor manufacturer data sheet

or go blank in temperatures outside this range

The CE Marking identifies this product as complying with all relevant
directives in the European Union (EU).

See last page

Plot A: Temperature

Accuracy and Resolution

Plot B: Time Accuracy

Logger Components and Operation

Start/Stop Button

LCD Screen

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 in
HOBOmobile with a push button start or stop, and with Allow
Button Restart selected (see Setting up the Logger). You can
also press this button for 1 second to record an internal event
(see Recording Internal 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 Setting up
the Logger).

Press both the Start/Stop button and the Alarm/Stats button
simultaneously for 3 seconds to reset a logger password.

Alarm/Stats 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 was

Alarm/Stats Button

Temperature

Sensor

Mounting

Loop

RH Sensor (behind panel)

configured in HOBOmobile to maintain the visual alarm until
the alarm button was pressed (see Setting up Alarms).

Mounting Loops: Use the two mounting loops (only one visible
in the diagram) to mount the logger with the hook-and-loop
strap (see Mounting the Logger).

Temperature Sensor: This sensor is located in the lower left
corner of the raised panel to the right of the LCD screen.

RH Sensor: This sensor is located behind the vented panel in
the logger case to the right of the LCD screen and the
temperature sensor.

LCD Screen: This logger is equipped with an LCD screen that
displays details about the current status. This example shows all
symbols illuminated on the LCD screen followed by definitions
of each symbol in the table on the next page.

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LCD Symbol Description

The logger is waiting to be started or restarted.
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.

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 will be empty. In this example, the
logger memory is almost full (only one segment in
the memory bar is empty).

The logger has been configured to never stop
logging (wrapping). The logger will continue
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 will be empty.
In this example, the memory is full (all five
segments are filled in) and new data is now
overwriting the oldest data. This will continue until
the logger is stopped or the battery runs out.

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 Alarm/Stats button until the “alm” symbol
(described below) is displayed on the screen. This
symbol at left will clear depending on how visual
alarms were configured in HOBOmobile. If the
visual alarm was set to clear when the logger is
reconfigured, this symbol will remain on the LCD
until the next time new configure settings are
loaded onto the logger (see Setting up the Logger).
Otherwise, it will clear when the sensor reading is
back within the alarm limits or by pressing the
Alarm/Stats button for 3 seconds.

A visual alarm is ready to be cleared. This will only
appear if HOBOmobile was configured to maintain
the visual alarm until the alarm button is pressed.
Press the Alarm/Stats button for 3 seconds to
clear the visual alarm. Note that an audible alarm
can be silenced by pressing the Start/Stop button
or Alarm/Stats button for 1 second.

These symbols show the maximum, minimum,
average, and standard deviation values most
recently calculated by the logger (if the logging
mode has been set to Fixed Interval in
HOBOmobile and each statistic has been selected;
see Statistics Logging). Press the Alarm/Stats
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
Alarm/Stats button to view this reading. Press the
Alarm/Stats button again to cycle through any
statistics (defined above) and ultimately back to
the current sensor reading.

This is an example of a temperature reading.
Temperature units are determined by the settings
in HOBOmobile. To switch between Celsius and
Fahrenheit, change the units in the HOBOmobile
Settings (the logger must be reconfigured for units
changes to take effect).

LCD Symbol Description

This is an example of an RH reading.

The logger has been configured to start logging on
a particular date/time. The display will count down
in days, hours, minutes, and seconds until logging
begins. In this example, 5 minutes and 38 seconds
remain until logging will begin.

The configure settings are being loaded onto the
logger from HOBOmobile.

An error occurred while loading the configure
settings onto the logger from HOBOmobile. Try
reconfiguring the logger.

The logger has been stopped with HOBOmobile or
because the memory is full.

Notes:

• You can disable the LCD screen when logging. Deselect
“Show LCD” when setting up the logger as described in
the next section. When this option is disabled, you can
still temporarily view the LCD screen by pushing the
Start/Stop button for 1 second. The LCD will then remain
on for 10 minutes.

• The LCD screen refreshes every 15 seconds regardless of
the logging interval selected in HOBOmobile. If you
choose a logging interval less than 15 seconds, the data
will be recorded at the faster interval, but the sensor
readings will only be updated on the screen every 15
seconds.

• When the logger has stopped logging, the LCD screen will
remain on with “STOP” displayed until the logger is
offloaded to your mobile device (unless the logger was
configured with the “Show LCD” option disabled). Once
the logger has been offloaded, the LCD will turn off
automatically after 2 hours. The LCD will turn back on the
next time the logger connects with your device through
HOBOmobile.

• The LCD screen flashes “HELLO” when you page the
logger from HOBOmobile (see Downloading HOBOmobile
and Connecting to a Logger).

• The LCD screen flashes “CHIRP OFF” when an audible
alarm is cleared.

Downloading HOBOmobile and
Connecting to a Logger

Install the HOBOmobile app to connect to and work with the
logger.

1. Download HOBOmobile. Go to the App Store® or Google

Play™ and download the HOBOmobile app to your phone or
tablet.

2. Install the batteries. Open the battery door on the back of

the logger and insert two AAA batteries observing polarity
(see Battery Information). Reinsert the battery door and
snap it back into place.

3. Open HOBOmobile. Enable Bluetooth in your device
settings if prompted.

4. Connect to the logger. Tap the HOBOs icon (on Android
devices) or tap the Devices icon and then tap Loggers at the

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top of the screen (on Apple® devices). The logger should
appear in the In Range list as shown here.

Tap the row in the list to connect to the logger. If it does not
appear in the list, make sure the logger is within range of
your mobile device. Note that current sensor readings are
always visible in this list even if the logger is not logging.

Tips for connecting:

• Make sure the logger is within range of your mobile
device. 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.

• If the logger appears in the In Range list, but you cannot
connect to it, close HOBOmobile and power cycle the
mobile device. This forces the previous Bluetooth
connection to close.

Once connected to the logger you can select one of the
following actions:

• Configure. Select logger settings and load them onto the

logger to start logging. See Setting up the Logger.

• Readout. Offload logger data. See Reading Out the

Logger.

• Full Status Details. Check the battery level and view the

configuration settings currently selected for the logger.

• Start Logging or Restart Logging. These options appear

depending on the Start Logging and Stop Logging settings
selected in the next section.

• Stop Logging. Stop the logger from recording data (this

overrides any Stop Logging settings described in Setting
up the Logger).

• Page. Press and hold the Page icon and the logger will

beep to help you locate a deployed logger (tap the Page
icon if you only want the logger to beep once). “HELLO”
also appears on the LCD when the logger is paged.

• Clear Audible Alarm. If audible alarms are enabled as

described in Setting up Alarms, use this to clear a
beeping alarm on the logger.

• Logger Password. Select this to create a password for the

logger that will be required if another mobile device
attempts to connect to it. To reset a password,
simultaneously press both the Start/Stop button and the
Alarm/Stats button on the top of the logger for 3 seconds
or tap Reset to Factory Default in the Set Logger
Password screen.

• Update Firmware. When new logger firmware is

available, this action appears in the list. Select it and
follow the instructions on the screen. A logger readout
will be completed automatically at the beginning of the
firmware update process. If the connection is lost
between the logger and the mobile device during the
firmware update, a Firmware Update Pending Status

displays for the logger in the HOBOs list. Connect to the
logger and select Restore Logger (or Update Firmware if
that option is available) to continue updating the
firmware.

Important: Before updating the firmware on the
logger, check the remaining battery level by selecting
Full Status Details 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.

• Force Offload. This may appear if an error was

encountered when loading configure settings. Select this
to offload all the data on the logger before reconfiguring
the logger.

Setting up the Logger

Use HOBOmobile to set up the logger, including setting alarms,
selecting the options to start and stop logging, and choosing a
logging mode. These steps provide an overview of setting up
the logger. For complete details, see the HOBOmobile User’s
Guide.

1. Tap the HOBOs icon (on Android devices) or tap the Devices
icon and then tap Loggers at the top of the screen (on Apple
devices). Select a logger in the In Range list to connect to it.

2. Once connected, tap Configure.

3. Tap Name and type a name for the logger up to 20
characters (optional). Tap Done.

4. Tap Group to add the logger to the Favorites group, an
existing custom group, or create a new group name with up
to 20 characters (optional). Tap Done.

5. Tap Logging Interval and choose how frequently the logger
will record data unless operating in burst logging mode (see
Burst Logging).

6. Tap Start Logging and select when logging will begin:

• Now. Logging will begin immediately after tapping Start

in the Configure screen.

• 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 once 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. Select the Date and time

Tap Done.

7. Tap Stop Logging and select the options for when logging
will end.

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a. Choose one of two memory options:

• 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).

b. Select On Button Push if you want to be able to stop

logging by pushing the Start/Stop button on the logger
for 3 seconds. Note that if you also choose On Button
Push for the Start Logging option, then you will not be
able to stop logging until 30 seconds after logging begins.

If you select On Button Push for the Stop Logging option,
then you also have the option to select Allow Button
Restart. This allows you to stop and then resume logging
during the deployment by pushing the Start/Stop button
on the logger for 3 seconds.

Important: When Allow Button Restart is selected and
you use the Start/Stop button to stop and restart logging,
logging will restart on the next even logging interval, not
at the time the button was pushed. For example, a logger
started logging at 7:00 AM with a logging interval set to 1
hour. If you press the Start/Stop button to stop the logger
at 8:45 AM and then press the button again at 10:15 AM,
logging will not begin immediately at 10:15 AM. Instead,
logging will begin again at 11:00 AM, which is the next
even interval time based on your 1-hour logging interval.
Therefore, depending on the logging interval, the gap
between the time you press the button to resume logging
and the time actual logging begins could be significant.
The faster the logging interval, the less time will elapse
before logging resumes.

c. Select one of the following time options for when to stop

logging:

• 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 and then tap Done.

• 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
and then tap Done. For example, select 30 days if you
want the logger to log data for 30 days after logging
begins.

d. Tap Done.

8. Select the sensor measurement types that will be logged.
By default, both the temperature and RH sensors are
enabled. Both sensors are required to calculate dew point,
which is an additional data series available for plotting after
reading out the logger. You can also set up alarms to trip
when a sensor reading rises above or falls below a specified
value. See Setting up Alarms for details on enabling sensor
alarms and selecting the associated audible and visual
alarm settings.

9. Tap Logging Mode. Select either fixed interval logging or
burst logging. With fixed interval logging, the logger records
data for all enabled sensors and/or selected statistics at the
logging interval selected (see Statistics Logging for details

on choosing statistics options). In burst mode, logging
occurs at a different interval when a specified condition is
met. See Burst Logging for more information. Tap Done.

10. Enable or disable Show LCD, which controls whether the
LCD on the logger will remain illuminated while the logger is
logging. If you disable Show LCD, the LCD on 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. In addition,
you can always view the status of any in-range logger on
your mobile device regardless of the logger’s LCD setting
(may require a logger password as applicable).

11. Tap Start in the upper right corner of the Configure screen
to load the settings onto the logger if you are ready to start.

Logging will begin based on the settings you selected.
Deploy the logger using the 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).

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. This can
alert you to problems so you can take corrective action. To set
an alarm:

1. Tap the HOBOs icon (on Android devices) or tap the Devices
icon and then tap Loggers at the top of the screen (on Apple
devices). Select a logger in the In Range list to connect to it.

2. Once connected, tap Configure.

3. In Sensor & Alarm Setup, tap an enabled sensor.

4. 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 tap the value
field and type a specific reading. In this example, an alarm
will trip when the temperature rises above 85°F.

5. Enable the Low Alarm if you want an alarm to trip when the
sensor reading falls below the low alarm value. Drag the

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HOBO MX Temp/RH Data Logger (MX1101) Manual

slider to the reading that will trip the alarm or tap the value
field and type a specific reading. In the example, an alarm is
configured to trip when the temperature falls below 32°F.

Note: The actual values for the high and low alarm limits are
set to the closest value supported by the logger.

6. Under Raise Alarm After, select the duration before an
alarm is tripped.

7. If you select Cumulative Samples, then the alarm will trip
when the time the sensor is out of range over the course of
the deployment is equal to the selected duration. If you
select Consecutive Samples, then the alarm will trip when
the time the sensor is continuously out of range is equal to
the selected duration. For example, the high alarm for
temperature is set to 85°F and the duration is set to 30
minutes. If Cumulative is selected, then an alarm will trip
once a sensor reading has been at or above 85°F for a total
of 30 minutes since the logger was configured; specifically,
this could be 15 minutes above 85°F in the morning and
then 15 minutes above 85°F again in the afternoon. If
Consecutive is selected, then an alarm will trip only if all
sensor readings are 85°F or above for a continuous 30­minute period.

8. Tap Done and repeat steps 3–8 for the other sensor if
desired.

9. Back in the Configure screen, enable Audible Alarms if you
want a beep to sound on the logger every 30 seconds when
the sensor alarm trips. The beeping will continue until the
alarm is cleared from HOBOmobile, either button on the
top of the logger is pressed, or 7 days have passed. Battery
life will be slightly reduced when this setting is enabled. It is
recommended that you only enable this feature if you have
regular access to the logger so that you can easily turn off
the beeping.

10. Also in the Configure screen, select one of the following
options to determine how long the alarm icon will remain
illuminated on the logger LCD screen after an alarm trips:

• Logger Reconfigured. The alarm icon will remain visible

on the LCD until the next time the logger is reconfigured.

• Sensor in Limits. The alarm icon will remain 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 will remain visible

until you press the Alarm/Stats button on the logger.

11. Tap Start in the Configure screen to load the alarm settings
onto the logger if you are ready to start.

Notes:

• The alarm icon will be illuminated on the logger LCD

when the alarm trips. You can also press the Alarms/Stats
button on the logger to view the farthest out-of-range
value during the deployment. Alarm limits are checked
when the logger’s LCD screen refreshes every 15
seconds.

• The actual values for the high and low alarm limits are set

to the closest value supported by the logger. For
example, the closest value to 85°F that the logger can
record is 84.990°F and the closest value to 32°F is

32.043°F. In addition, alarms can trip or clear when the
sensor reading is within the logger specifications of

0.02°C resolution. This means the value that triggers the

alarm may differ slightly than the value entered. For
example, if the High Alarm is set to 75.999°F, the alarm
can trip when the sensor reading is 75.994°F (which is
within the 0.02°C resolution).

• When you read out the logger, alarm events can be
displayed on the plot or in the data file. See Recording
Internal Logger Events.

• Once cleared, an audible alarm will start 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 HOBOmobile depending on the
settings selected for maintaining visual alarms or because
the alarm condition may still be in effect. In addition, an
audible alarm will continue beeping when the sensor
values have returned to the normal range until it is
cleared as described in step 9.

• Although an audible alarm and a visual alarm can occur
at the same time when a sensor alarm is tripped, they are
cleared in different ways. The audible alarm can be
cleared as described in step 9. Meanwhile, a visual alarm
is cleared as determined by the setting selected for
Maintain Visual Alarm Until in the Configure screen. This
means you could clear a beeping audible alarm and the
visual alarm will remain on the LCD and in HOBOmobile
until the logger is reconfigured, the sensor is in limits, or
the alarm button is pressed--whichever setting you
selected.

• If the logger was configured to stop logging with a button
push, any tripped alarms will be cleared automatically
when logging is stopped and no Alarm Cleared event will
be logged in the data file. This ensures that the logger will
start checking for alarm conditions when logging resumes
(if the logger was configured with Allow Button Restart
selected).

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 will record
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 will switch 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, then the logger would switch to burst logging mode again
and record data every 30 seconds. Once the temperature rises
back to 32°F, the logger will then return to normal mode,
logging every 5 minutes. Note: Sensor alarms, statistics, and the
Stop Logging option “Wrap When Full” are not available in
burst logging mode.

To set up burst logging:

1. Tap the HOBOs icon (on Android devices) or tap the Devices
icon and then tap Loggers at the top of the screen (on Apple
devices). Select a logger in the In Range list to connect to it.

2. Once connected, tap Configure.

3. Tap Logging Mode and then tap Burst Logging.

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4. Tap a sensor under Burst Sensor Limits.

5. 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 tap the
value field and type a specific reading. In this example, the
logger will switch to burst logging when the temperature
rises above 85°F.

6. 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 tap the
value field and type a specific reading. In the example, the
logger will switch to burst logging when the temperature
falls below 32°F.

7. Tap Done and repeat steps 4–7 for the other sensor if
desired.

8. Tap Burst Logging Interval and 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. Tap Done.

9. Tap Done to exit the Logging Mode screen.

10. Tap Start in the Configure screen to load the burst settings
onto the logger if you are ready to start.

Notes:

• Once the logger is configured, the high and low burst

limits are only checked when the logger's LCD screen
refreshes once every 15 seconds. Therefore, if you set
the logging interval to less than 15 seconds and the
sensor reading falls outside the levels, the burst logging
will not begin until the next 15-second refresh cycle.

• If high and/or low limits have been configured for more

than one sensor, then burst logging will begin when any
high or low condition goes out of range. Burst logging will
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. For example,
the closest value to 85°F that the logger can record is

84.990°F and the closest value to 32°F is 32.043°F.

• Burst logging mode can begin or end when the sensor

reading is within the logger specifications of 0.02°C
resolution. This means the value that triggers burst
logging may differ slightly than the value entered. For
example, if the high limit for a temperature alarm is set
to 75.999°F, burst logging can start when the sensor
reading is 75.994°F (which is within the 0.02°C
resolution).

• Once the high or low condition clears, the logging

interval time will be calculated using the last recorded
data point in burst logging mode, not the last data point

recorded in “normal mode.” For example, let’s assume
the 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 Recording
Internal 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. The logger will check the high
and low conditions when logging resumes (if the logger
was configured with Allow Button Restart selected).

Statistics Logging

During fixed interval 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, and

• The standard deviation from the average for all sampled

values.

For example, a logger is configured with both the temperature
and RH sensors enabled, and the logging interval set to 5
minutes. The logging mode is set to fixed interval logging with
Normal and all four statistics enabled and with a statistics
sampling interval of 30 seconds. Once logging begins, the logger
will measure and record the actual temperature and RH sensor
values every 5 minutes. In addition, the logger will take a
temperature and RH sample every 30 seconds and temporarily
store them in memory. The logger will then calculate the
maximum, minimum, average, and standard deviation using the
samples gathered over the previous 5-minute period and log
the resulting values. When reading out the logger, this would
result in 10 data series (not including any derived series, such
as dew point): two sensor series (with temperature and RH
data logged every 5 minutes) plus eight maximum, minimum,
average, and standard deviation series (four for temperature
and four for RH with values calculated and logged every 5
minutes based on the 30-second sampling).

To log statistics:

1. Tap the HOBOs icon (on Android devices) or tap the Devices
icon and then tap Loggers at the top of the screen (on Apple
devices). Select a logger in the In Range list to connect to it.

2. Once connected, tap Configure.

3. Tap Logging Mode and then select Fixed Interval Logging.

4. Select Normal to record the current reading for each
enabled sensor at the logging interval shown at the top of

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HOBO MX Temp/RH Data Logger (MX1101) Manual

the screen. Do not select this if you only want to log
statistics.

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 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.

6. Tap Statistics Sampling Interval and select the rate 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, 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.

7. Tap Done.

8. Tap Done again to exit the Logging Mode screen.

9. Tap Start in the Configure screen to load the statistics
settings onto the logger if you are ready to start.

Once logging begins, click the Alarm/Stats button on the logger
to cycle through the current maximum, minimum, average, and
standard deviation data on the LCD screen. Note that the logger
will always display the current sensor readings in HOBOmobile
even if they are not being logged. You can plot the statistics
series once you read out the logger.

Reading Out the Logger

To offload data from the logger:

1. Tap the HOBOs icon (on Android devices) or tap the Devices
icon and then tap Loggers at the top of the screen (on Apple
devices).

2. Find the logger you wish to offload in the In Range list and
tap that row.

3. Once connected, tap Readout.

4. Tap the Data Files icon to view a mini-graph of the
offloaded data.

5. Tap the mini-graph to view a larger version of the graph or
to share the file.

Data can also be uploaded automatically to HOBOlink, Onset’s
web-based software, via HOBOmobile or the HOBO MX
Gateway. For details on uploading data to HOBOlink, see the
HOBOmobile User’s Guide.

Recording Internal Logger Events

The logger records the following internal events to track logger
operation and status. To plot events in HOBOmobile, tap a

mini-graph and then tap . Select the events you wish to plot

and then tap again. You can also view events in shared or
exported data files.

Internal Event Name Definition

Host Connected

Started

Stopped The logger received a command to stop

Button Up/Button
Down

Chan <#> Alarm
Tripped

Chan <#> Alarm
Cleared

New Interval

Safe Shutdown The battery level dropped below 1.85 V; the

The logger was connected to the mobile
device.

The Start/Stop button was pressed to begin
or resume logging.

recording data (from HOBOmobile or by
pushing the Start/Stop button).

The Start/Stop button was pressed for
1 second.

A sensor alarm has tripped; <#> is the sensor
number, where 1 is temperature and 2 is RH.

A sensor alarm has cleared; <#> is the sensor
number, where 1 is temperature and 2 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.

The logger has entered or exited burst
logging mode.

logger performs a safe shutdown.

Mounting the Logger

There are several ways to mount the logger using the materials
included:

• Use the four magnets on the back of the logger case to
mount it to a magnetic surface.

• Attach Command strips to the back of the logger to
mount it a wall or other flat surface. Double up the two
Command strips so that they protrude past the magnets.

• Use the double-sided tape to affix the logger to a surface.

• Insert the hook-and-loop strap through the mounting

loops on both sides of the logger to mount it to a curved
surface, such as a pipe or tubing.

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.

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HOBO MX Temp/RH Data Logger (MX1101) Manual

Battery Information

The logger requires two user-replaceable AAA 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 the 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 1
year with logging intervals greater than 1 minute. Deployments
in extremely cold or hot temperatures, a logging interval faster
than 1 minute, or a sampling interval faster than 15 seconds
can impact battery life. Estimates are not guaranteed due to
uncertainties in initial battery conditions and operating
environment.

Note: Make sure the batteries installed have flat negative
terminals. There should be no indent in the bottom of the
batteries. Batteries with indents in the negative terminals may
become loose and prevent proper operation.

Only use batteries
with flat negative
terminals

Do not use batteries with an
indent in the negative terminal

To install or replace the batteries:

1. Open the battery door on the back of the logger.

Mounting

magnet

Battery door

2. Remove any old batteries.

3. Insert two new batteries observing polarity.

4. Reinsert the battery door and snap it back into 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.

Mounting
magnets

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HOBO MX Temp/RH Data Logger (MX1101) Manual

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 MX1101 loggers must be installed to provide a separation distance of at
least 20cm 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 radio­frequency devices must be susceptible with the interference from legal communications or ISM radio wave radiated devices.

© 2014–2019 Onset Computer Corporation. All rights reserved. Onset, HOBO, HOBOmobile, and HOBOlink
are registered trademarks of Onset Computer Corporation. Apple is a registered trademark and App Store is a

1-800-LOGGERS (564-4377) • 508-759-9500
www.onsetcomp.com/support/contact

service mark of Apple Inc. Android and Google Play are trademarks of Google LLC. 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 17840-P