Hobo MX1104 User manual

HOBO® MX Analog/Temp/RH/Light (MX1104) and
MX 4-Channel Analog (MX1105) Data Logger Manual
23968-G
The HOBO MX Analog/Temp/RH/Light (MX1104) and HOBO MX 4-Channel Analog (MX1105)
data loggers measure and transmit data wirelessly from indoor environments to a mobile
device or computer using Bluetooth® Low Energy technology. The MX1104 model has
integrated temperature, relative humidity (RH), and light intensity sensors and one analog input
while the MX1105 model has four analog inputs. Both models support a wide variety of
external sensors (sold separately), including self-describing temperature, split-core AC current
transformer, 4-20 mA input, and DC voltage input sensors. The self-describing sensors are
designed with integrated strain relief for a secure connection to the loggers and are
automatically detected by the HOBOconnect® app for easy setup. Using the app, you can
configure the loggers, read out and view data, and export the data for further analysis. The
loggers can calculate minimum, maximum, average, and standard deviation statistics and can
also be configured to trip audible or visual alarms at thresholds you specify. In addition, both
loggers support burst logging in which data is logged at a different interval when sensor
readings are above or below certain limits. These compact loggers also have built-in LCD
screens to display current sensor readings, logging status, battery use, memory consumption,
and more.
Specifications
Temperature Sensor (MX1104)
Range -20° to 70°C (-4° to 158°F)
Accuracy ±0.20°C from 0° to 50°C (±0.36°F from 32° to 122°F)
Resolution 0.002°C at 25°C (0.004°F at 77°F)
Drift <0.1°C (0.18°F) per year
RH Sensor* (MX1104)
Range 0% to 100% at -20° to 70°C (-4° to 158°F); exposure to conditions
above 95% may temporarily increase the maximum RH sensor error
by an additional 1%
Accuracy ±2.5% from 10% to 90% (typical) to a maximum of ±3.5% including
hysteresis at 25°C (77°F); below 10% and above 90% ±5% typical
Resolution 0.01%
Drift <1% per year typical
Response Time (MX1104)
Temperature 11 minutes in air moving 1 m/s (2.2 mph)
RH 30 seconds to 90% in airflow of 1 m/s (2.2 mph)
Light Sensor (MX1104)
Range 0 to 167,731 lux (15,582 lum/ft2)
Accuracy ±10% typical for direct sunlight (see Light Measurement on page 4 for
more details)
Logger with
Cable Type
SD-MA-420 or
CABLE-4-
20mA
SD-VOLT-2.5
or CABLE-2.5-
STEREO
SD-VOLT-05
or CABLE-
ADAP5
SD-VOLT-10
or CABLE-
ADAP10
SD-VOLT-24
or CABLE-
ADAP24
Measurement
Range
0 to 20.1 mA 0 to 2.5 V 0 to 5.0 V 0 to 10 V 0 to 24 V
Accuracy ±0.001 mA
±0.2% of
reading
±0.1 mV
±0.1% of
reading
±0.2 mV
±0.3% of
reading
±0.4 mV
±0.3% of
reading
±1.0 mV
±0.3% of
reading
Resolution 0.3 µA 40 µV 80 µV 160 µV 384 µV
Logger
Operating Range -20° to 70°C (-4° to 158°F)
Radio Power 1 mW (0 dBm)
HOBO MX1104 and
MX1105 Data Loggers
Models:
•Analog/Temp/RH/Light
(MX1104)
•4-Channel Analog
(MX1105)
Included Items:
•Tie wraps
•Two AAA 1.5 V alkaline
batteries (installed)
Required Items:
•HOBOconnect app
•Mobile device with
Bluetooth and iOS,
iPadOS®, or Android™, or a
Windows computer with a
native BLE adapter or
supported BLE dongle
MX1105 Model Shown

HOBO MX Analog/Temp/RH/Light (MX1104) and MX 4-Channel Analog (MX1105) Manual
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1-800-LOGGERS (U.S. only)
Specifications (continued)
Transmission Range Approximately 30.5 m (100 ft) line-of-sight
Wireless Data Standard Bluetooth Low Energy (Bluetooth Smart)
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
period
Restart Mode Push button
Time Accuracy ±1 minute per month at 25°C (77°F)
Battery Type Two AAA 1.5 V alkaline batteries, user replaceable
Battery Life 1 year, typical with logging interval of 1 minute and Bluetooth Always
On enabled; 2 years, typical with logging interval of 1 minute and
Bluetooth Always On disabled; and temperatures between 0° and
50°C (32° and 122°F). Faster logging intervals and statistics sampling
intervals, burst logging, remaining connected with the app, excessive
downloads, and paging may impact battery life.
Memory 4 MB (1.9 million measurements, maximum)
Full Memory Download Time Approximately 4 to 15 minutes depending on the mobile device; 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 11.28 x 5.41 x 2.92 cm (4.44 x 2.13 x 1.15 in.)
Weight 123 g (4.34 oz)
Environmental Rating IP54
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
Logger Components and Operation
RH Sensor: This sensor is located in the upper left corner and to
the left of the LCD screen in the MX1104 model.
Light Sensor: This sensor is located below the RH sensor and to
the left of the LCD screen in the MX1104 model.
Temperature Sensor: This sensor is located in the bottom left
corner and to the left of the LCD screen in the MX1104 model.
A small pipe protrudes from the bottom side of the logger case
to vent the temperature sensor.
Analog Sensor Port: Use this 2.5 mm jack to connect a self-
describing sensor or other analog sensor. The MX1104 model
has one port and the MX1105 model has four ports.
Top 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 the app with a
push button start or stop, and with Allow Button Restart
selected (see Configuring the Logger).
MX1104 Model
Analog Sensor
Port
Bottom
Button
Top Button
Light Sensor
Temperature
Sensor (internal)
and Venting Pipe
Mounting
Loop
Self-Describing Sensor
Plug
LCD Screen
MX1105 Model
RH Sensor

HOBO MX Analog/Temp/RH/Light (MX1104) and MX 4-Channel Analog (MX1105) Manual
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1-800-LOGGERS (U.S. only)
You can also press the top button for 1 second to wake up the
logger, bring the logger to the top of the list in the app, cycle
through each channel on the LCD, silence a beeping alarm (see
Setting up Alarms), and turn the LCD screen on if the option to
turn off the LCD has been enabled (see Configuring the Logger).
Bottom Button: When statistics are being logged, press this
button for 1 second to switch between the latest sensor
reading, statistics, and an alarm reading (if applicable) for the
channel currently displayed. If no statistics are being logged
and a sensor alarm trips, press this button for 1 second to view
the alarm reading for the channel currently displayed. You can
also press this button for 1 second to wake up the logger,
silence a beeping alarm, or turn the LCD screen on if the option
to turn off the LCD has been enabled. Press this button for 3
seconds to clear a visual alarm if the logger was configured in
the app to maintain the visual alarm until the alarm button was
pressed (see Setting up Alarms). Press both the top and bottom
buttons simultaneously for 10 seconds to reset a logger
password.
Self-Describing Sensor: This is a type of external sensor
available for MX1104 and MX1105 loggers. Turn the sensor
plug one-quarter clockwise when inserting it into an analog
sensor port to secure it in place. This sensor also features
automatic detection by the logger (see Working with Sensors).
Plug: Use this Santoprene® (TPE) plug to fill an empty analog
sensor port.
Mounting Loops: Use the two mounting loops (only one visible
in the diagrams) to mount the logger with tie wraps (see
Mounting the Logger).
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.
LCD Symbol Description
The logger is waiting to be started or restarted.
Press and hold the top button for 3 seconds to
start the logger; HOLD will also be displayed
during this time.
The logger has been started with push button stop
enabled. Press and hold the top button for 3
seconds to stop the logger; HOLD will also be
displayed during this time.
This is displayed while pressing the top button for
3 seconds to start, stop, or restart the logger, or
while pressing the bottom button for 3 seconds to
clear an alarm.
This is displayed when there is more than one
channel being logged. Press the top button to
cycle through each channel to view sensor
measurements.
LCD Symbol Description
Statistics are being logged. Press the bottom
button to switch between the current sensor
readings, statistics, and any alarm readings for
each channel.
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 the app and
each statistic has been selected; see Statistics
Logging). Press the bottom button to cycle
through the available statistics and then back to
the current sensor reading (or to the alarm value if
applicable).
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 battery
voltage is depleted 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.
The logger is currently logging.
This indicates a sensor alarm has tripped. Press
the top button to view the channel with the alarm
icon. Press the bottom button to view the reading
that tripped the alarm. The “alm” symbol
(described below) is displayed on the screen with
the reading (or dashes if the alarm has already
cleared). This symbol at left will clear depending
on how visual alarms were configured in the app.
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 Configuring the
Logger). Otherwise, it will clear when the sensor
reading is back within the alarm limits or by
pressing the bottom button for 3 seconds.
This is displayed with the reading that tripped the
alarm. While viewing the channel with the alarm,
press the bottom button to see the reading (you
may need to cycle through statistics readings first
if applicable). If the alarm cleared, dashes (- - - -)
will display instead of a reading.
A visual alarm is ready to be cleared. This will only
appear if the app was configured to maintain the
visual alarm until the alarm button is pressed.
While viewing the channel with the alarm on the
LCD, press the bottom button for 3 seconds to
clear the visual alarm. Note that an audible alarm
can be silenced by pressing the top or bottom
button for 1 second.
This indicates a problem with an external sensor.
See Working with External Sensors for more
details.

HOBO MX Analog/Temp/RH/Light (MX1104) and MX 4-Channel Analog (MX1105) Manual
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1-800-LOGGERS (U.S. only)
LCD Symbol Description
This is an example of a sensor reading, with the
latest reading displayed above the unit type for
that sensor. To switch between US and SI units,
change the units in the app Settings (the logger
must be reconfigured for units changes to take
effect). Note: If the sensor value exceeds five
digits, then the scientific notation E3 is appended
to the value on the LCD to signify that the
displayed digits are multiplied by 1,000. For
example, a value of 100,000 is displayed as 100E3
on the LCD. This only affects the LCD; logged data
contains all digits.
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 the app.
The logger has been stopped with the app 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 top
or bottom button for 1 second. The LCD will then remain
on for 10 minutes.
•The LCD screen refreshes at the same rate as the logging
interval.
•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 1 hour. The LCD will turn back on the
next time you press the top or bottom button to wake up
the logger.
•The LCD screen flashes “HELLO” when you page the
logger from the app (see Downloading the App and
Connecting to a Logger).
•The LCD screen flashes “BOOT” when a firmware upgrade
is underway.
•The LCD screen flashes “CHIRP OFF” when an audible
alarm is cleared.
Button Functionality Quick Reference
Button Press for 1 second to:
Press and
hold for
3 seconds to:
Press and
hold for 10
seconds to:
Top
button
•Cycle through each
channel to view the
latest sensor readings
•Wake up the logger
•Bring the logger to the
top of the list in the
app
•Silence a beeping
alarm
•Turn on LCD
Start, stop, or
resume
logging
(depending on
settings
chosen in the
app)
NA
Button Press for 1 second to:
Press and
hold for
3 seconds to:
Press and
hold for 10
seconds to:
Bottom
button
•Cycle through any
statistics and alarm
readings for the
channel currently
displayed (if
applicable)
•Wake up the logger
•Silence a beeping
alarm
•Turn on LCD
Clear an alarm
for the
channel
currently
displayed
(depending on
the settings
chosen in the
app)
NA
Both
buttons
NA NA Reset a
password
Light Measurement (MX1104)
The MX1104 logger measures light intensity in units of
lumens/ft
2
or lux. The light sensor in the MX1104 has a spectral
response that tightly matches the photopic response of the
human eye. This is shown in Plot A.
The light sensor has range of 0 to 167,731 lux (15,582 lum/ft
2
).
The resolution of the light measurement varies from 1 unit of
lux or lum/ft
2
in very dim light to 40 lux (4 lum/ft
2
) for a full
scale measurement.
Plot A
Light Measurement Accuracy
Although the MX1104 is factory calibrated to account for the
light attenuation of the plastic enclosure, you may notice a
difference in the MX1104 reading compared to a commercially
available lux meter. Ideally, a light meter’s response should be
proportional to the cosine of the angle at which the light is
incident. The MX1104 does not collect light exactly according to
this rule. Plot B illustrates the difference between an ideal
cosine response and the approximate response of the MX1104.
The MX1104 is calibrated to give best results for direct
illumination, but this is not always the case.

HOBO MX Analog/Temp/RH/Light (MX1104) and MX 4-Channel Analog (MX1105) Manual
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1-800-LOGGERS (U.S. only)
Plot B
The MX1104 is also calibrated to give best results in the
sunlight. Because artificial indoor and outdoor lights have
different spectral properties than sunlight, the MX1104 may
show an error of greater than ±10% when compared to a
commercially available lux meter in these situations. Multiple
MX1104 loggers, however, will typically exhibit ±10%
agreement with each other in any type of light.
Downloading the App and
Connecting to a Logger
Install the app to connect to and work with the logger.
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. Press either button on the logger to wake it up.
4. Tap Devices and then tap the logger in the app to connect
to it.
If the logger does not appear or if it is having trouble
connecting, follow these tips:
•If the logger was configured with Bluetooth Always On
disabled (see Configuring the Logger), make sure the
logger is “awake” by pressing the top or bottom button.
Press the top button again to bring the logger to the top
of the list if you are working with multiple loggers.
•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.
•Change the orientation of your device to ensure the
antenna is pointed toward the logger. Obstacles between
the antenna in the device and the logger may result in
intermittent connections.
•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.
Once the logger is connected, you can:
Tap this: To do this:
Select logger settings and save them onto the
logger to start logging. See Configuring the
Logger.
Read out (offload) logger data. See Reading Out
the Logger.
Start or restart logging depending on the
configuration settings selected in Configuring the
Logger.
Stop the logger from recording data (this
overrides any Stop Logging settings described in
Configuring the Logger).
Make the logger beep one time to help you
locate it. “HELLO” also appears on the LCD when
the logger is paged.
Stop a beeping alarm on the logger if audible
alarms are enabled as described in Setting up
Alarms.
Set 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 top and bottom
button for 10 seconds or tap and tap Reset.
Mark the logger as a favorite. You can then filter
the list of devices to only show loggers marked as
favorites.
Update the firmware on the logger. A logger
readout will be 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.
Note: Tapping this icon is only required when using the
app on an iPhone®, iPad®, or Android device.
Configuring the Logger
Use the app 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 app user’s guide.
1. If you are using an analog sensor, insert the sensor plug into
the sensor port. For self-describing sensors, turn the sensor
plug one-quarter clockwise until it stops. See Working with
External Sensors for more details.
2. In the app, tap Devices. If the logger was configured with
Bluetooth Always On disabled, press a button on the logger
to wake it up. When working with multiple loggers, you can
>
>
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HOBO MX Analog/Temp/RH/Light (MX1104) and MX 4-Channel Analog (MX1105) Manual
1-508-759-9500 (U.S. and International) 6 www.onsetcomp.com
1-800-LOGGERS (U.S. only)
press the top button on the logger to bring it to the top of
the list.
3. Tap the logger in the app to connect to it and then tap
to configure the logger.
4. Tap Name and type a name for the logger (optional). If no
name is selected, the logger serial number is used as the
name.
5. Tap Group to add the logger to a group (optional). Tap Save.
6. Tap Logging Interval and choose how frequently the logger
will record data unless operating in burst logging mode (see
Burst Logging).
7. Tap Start Logging and select when logging will begin:
•Now. Logging will begin immediately after the
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 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.
Tap Save.
8. Tap Stop Logging and select the options for when logging
will end.
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 top button on the logger for 3
seconds.
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 top button on the
logger for 3 seconds.
Important: When Allow Button Restart is selected and
you use the top button on the logger 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 top 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.
•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.
d. Tap Save.
9. Tap Logging Mode. Select either fixed or burst logging. With
fixed 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 Save.
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 either
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. Enable or disable Bluetooth Always On. If Bluetooth Always
On is enabled, the logger will “advertise” or regularly send
out a Bluetooth signal for the phone, tablet, or computer to
find via the app while it is logging, which uses battery
power. When Bluetooth Always On is disabled, the logger
will only advertise during logging when you press the
button on the logger to wake it up, thereby preserving as
much battery power as possible.
12. Make sure all channels you want to log are enabled and
then do the following:
•For self-describing sensors, the sensor type will be
automatically detected. Tap the sensor if you want to
enter a label, set up alarms, or add scaling.
•For other external sensors, the sensor type will not be
automatically detected. Enable the channel (if necessary)
and then tap it to enter a label (optional). Select the type
of sensor or cable from the list. Set up alarms and add
scaling if needed and then tap Save.
•See Working with External Sensors and Setting up Alarms
for additional details.
13. Tap to save the configuration settings.
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). Note: If an
“Error Configuring Logger” message appears in the app, an

HOBO MX Analog/Temp/RH/Light (MX1104) and MX 4-Channel Analog (MX1105) Manual
1-508-759-9500 (U.S. and International) 7 www.onsetcomp.com
1-800-LOGGERS (U.S. only)
error occurred while loading the configure settings onto the
logger. Try reconfiguring the logger.
Working with External Sensors
The MX1104 has one analog sensor port and the MX1105 has
four analog sensor ports that can accept self-describing and
other external sensors. Refer to www.onsetcomp.com for a
current list of supported sensors.
To connect an external sensor:
1. Make sure the logger is stopped.
2. For self-describing sensors, insert the plug into an analog
sensor port as shown.
3. For other external sensors, insert the sensor into an analog
sensor port and make sure it is firmly seated.
4. If you need to connect a sensor to the sensor cable,
complete any wiring before logging begins. Refer to the
sensor or cable manual for more information on connecting
the sensor and wiring, if applicable.
5. Tap Devices. Press the button on the logger to wake it up (if
necessary).
6. Tap the logger in the app to connect to it and tap .
7. Under Sensor & Alarm Setup, make sure all external sensor
channels are enabled.
8. For self-describing sensors, the sensor type will be
automatically detected. Tap the sensor to enter a label
(optional). To set up scaling, tap Scaling and then enter the
Series Name, Unit, and values for High and Low and then
tap Save. See Setting up Alarms for details on adding
alarms.
For other external sensors, the sensor type will not be
automatically detected. Tap the sensor and enable the
channel (if necessary). Enter a label (optional). Select the
type of sensor or cable from the list. To set up scaling, tap
Scaling and then enter the Series Name, Unit, and values for
High and Low and then tap Save. See Setting up Alarms for
details on adding alarms.
9. Tap .
Notes:
•For MX1104 loggers, an external sensor is channel 1. For
MX1105 loggers, the sensor channel number is listed
above the analog sensor port where the external sensor
is connected.
•The configuration screen in the app will automatically
update to show when a sensor is disconnected or
connected.
•Make sure you select the correct sensor type in the app if
you are not using self-describing sensors. If you select the
wrong type, then incorrect data will be logged. The app
can only automatically detect the sensor type for self-
describing sensors.
•If you disconnect a sensor or if it is not fully inserted into
the analog sensor port while the logger is logging, a
warning icon appears on the LCD and the logger will beep
once. Use the top button on the logger to view the
channel with the warning, which also displays dashes
instead of a valid current reading. Erroneous readings will
be displayed in the app and logged depending on the
logging interval while the sensor is disconnected (e.g. if a
sensor is disconnected for 5 minutes and the logging
interval is set to 1 minute, then there will be 5 erroneous
data points while the sensor was disconnected). When
the sensor is reconnected, the warning icon will clear, the
correct value will replace the dashes for the channel on
the LCD, and the correct readings will be logged.
•Do not swap out sensors or move sensors to empty ports
while the logger is logging. Stop the logger before making
any physical changes to the sensors.
•If a warning icon appears for a self-describing sensor and
you have checked that the correct sensor is properly
installed, then the sensor might be faulty. Contact Onset
Technical Support.
•The 4-20mA input cable (SD-MA-420 or CABLE-4-20mA)
measures current from 0 to 20.1 mA. Do not expose to
current above 20 mA or to negative current. Do not cut
off the end of the gray cable where it connects to the
blue and yellow wires as it contains the precision resistor
required for current measurement.
•If you are using the SD-VOLT-2.5 or CABLE-2.5-STEREO
voltage input cable, the input line must not be exposed
to signals below 0 V or above 2.5 V. The voltage input
cable connections are as follows:
Wire Connection
Red Switched 2.5 V output
White Voltage input
Black Ground
•The external input channels have a switched 2.5 V
output. This signal can be used to power a sensor directly
or to trigger an external circuit. External sensors should
draw no more than 4 mA total when powered.
The switched 2.5 V output turns on about 5 ms before
the external channels are measured as shown in the
following diagram for an MX1105 logger. The shaded
Using the diagram on the
logger housing shown above as
reference, insert the plug into
the analog sensor port.
Turn the plug one-
quarter clockwise.
The flat part of the plug will be
facing up when properly installed.
a. b.
c. d.

HOBO MX Analog/Temp/RH/Light (MX1104) and MX 4-Channel Analog (MX1105) Manual
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1-800-LOGGERS (U.S. only)
area shows the 100 ms period for each enabled channel
during which the logger samples the input signals.
When using multiple voltage and/or current inputs, the
(-) from the current source(s) and the 0 V line from the
voltage source(s) are tied together at the logger. If these
lines are at different voltage potentials, this may cause
inaccurate readings or even damage your logger.
WARNING: Analog channel input cannot exceed 2.5
V DC. For sensor outputs up to 24 V DC, use the
appropriate voltage adapter cable (SD-VOLT-xx or
CABLE-ADAPX).
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 Devices. Press the button on the logger to wake it up (if
necessary).
2. Tap the logger in the app to connect to it and tap .
3. Tap a sensor (tap the Enable Logging toggle if necessary).
4. Select High if you want an alarm to trip when the sensor
reading rises above the high alarm value. Drag the slider or
type a value to set the high alarm value.
5. Select Low if you want an alarm to trip when the sensor
reading falls below the low alarm value. Drag the slider or
type a value to set the low alarm value.
6. For the Duration, select how much time should elapse
before the alarm trips and select one of the following:
•Cumulative. The alarm will trip 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, then the
alarm will trip once the sensor readings have been above
85°F for a total of 30 minutes since the logger was
configured.
•Consecutive. The alarm will trip 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, then the
alarm will only trip if all sensor readings are 85°F or
above for a continuous 30-minute period.
7. Tap Save and repeat steps 3–7 for any other sensors if
desired.
8. In the configuration settings, 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 the app, either button on 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.
9. For Maintain Visual Alarms Until, 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 bottom button on the logger.
10. Tap .
Notes:
•The alarm icon will be illuminated on the logger LCD
when the alarm trips. You can also press the bottom
button on the logger to view the farthest out-of-range
value during the deployment. Dashes will appear instead
of a value once the alarm is cleared on the channel.
Alarm limits are checked at the same rate as the logging
interval.
•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 reading is within the
resolution specifications. This means the value that
triggers the alarm may differ slightly than the value
entered.
•When you read out the logger, alarm events can be
displayed on the plot or in the data file. See 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 in the app 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 configuration setting. This
means you could clear a beeping audible alarm and the
visual alarm will remain on the LCD and in the app until
the logger is reconfigured, the sensor is in limits, or the
bottom button on the logger 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).

HOBO MX Analog/Temp/RH/Light (MX1104) and MX 4-Channel Analog (MX1105) Manual
1-508-759-9500 (U.S. and International) 9 www.onsetcomp.com
1-800-LOGGERS (U.S. only)
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
for a temperature sensor 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 32°F and 85°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 Devices and press the button on the logger to wake it
up (if necessary).
2. Tap the logger in the app to connect to it and tap .
3. Tap Logging Mode and then tap Burst Logging.
4. Select Low and/or High and either type or drag the slider to
set the low and/or high values.
5. Repeat step 4 for other sensors if desired.
6. Set the burst logging interval, which must be 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. Tap Save.
8. Tap .
Notes:
•Burst limits are checked at the same rate as the logging
interval. When the logger enters burst logging mode, the
LCD will update at the same rate as the new burst logging
interval.
•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.
•Burst logging mode can begin or end when the sensor
reading is within the resolution specifications. This means
the value that triggers burst logging may differ slightly
than the value entered.
•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 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 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, the MX1104 logger is configured with only 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 Devices and press the button on the logger to wake it
up (if necessary).
2. Tap the logger in the app to connect to it and tap .
3. Tap Logging Mode and then select Fixed Logging.
4. Select Normal to record the current reading for each
enabled sensor at the logging interval shown at the top of
the screen. Do not select this if you only want to log
statistics.

HOBO MX Analog/Temp/RH/Light (MX1104) and MX 4-Channel Analog (MX1105) Manual
1-508-759-9500 (U.S. and International) 10 www.onsetcomp.com
1-800-LOGGERS (U.S. only)
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 Save.
8. Tap .
Once logging begins, click the bottom button on the logger to
cycle through the current maximum, minimum, average, and
standard deviation data for the current channel displayed on
the LCD. Note that the logger will always display the current
sensor readings for some channels in the app 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 will
be 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 press the button on the logger to wake it
up (if necessary). Tap the logger in the app to connect to it.
2. Tap (if applicable) and then .
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 the button on the logger
for 10 seconds or connect to the logger and tap (if
applicable), then , and tap Reset.
Reading Out the Logger
To offload data from the logger:
1. Tap Devices and press the button on the logger to wake it
up (if necessary).
2. Tap the logger in the app to connect to it and tap . The
logger will read out the data to the phone, tablet, or
computer.
3. Once the readout is complete, tap HOBO Files and select
the file to view it. Tap (if applicable) and to export
the data.
Data can also be uploaded automatically to HOBOlink, Onset’s
web-based software, via the app or the MX gateway. For
details, see the app user’s guide and see the HOBOlink help for
details on working with data in HOBOlink.
Logger Events
The logger records the following internal events to track logger
operation and status. You can view events in exported files or
plot events in the app.
To plot events, tap HOBO 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.
Started The top button on the logger was pressed to
begin or resume logging.
Stopped The logger received a command to stop
recording data (from the app or by pushing
the top button on the logger).
Chan <#> Alarm
Tripped
A sensor alarm has tripped; <#> is the sensor
number, 1 through 4.
Chan <#> Alarm
Cleared
A sensor alarm has cleared; <#> is the sensor
number, 1 through 4. 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.
Safe Shutdown The battery level dropped below 1.6 V; the
logger performs a safe shutdown.
Mounting the Logger
Use the four magnets on the back of the logger to mount it to a
magnetic surface or insert the tie wraps through the mounting
loops to attach it to other surfaces. Insert a Santoprene plug
into any empty analog sensor ports if necessary.
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.
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.

HOBO MX Analog/Temp/RH/Light (MX1104) and MX 4-Channel Analog (MX1105) Manual
1-508-759-9500 (U.S. and International)
1-800-LOGGERS (564-4377) (U.S. only)
www.onsetcomp.com/support/contact
© 2019–2021 Onset Computer Corporation. All rights reserved. Onset, HOBO, HOBOconnect, and HOBOlink 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 of 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 23968-G
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. Battery life is 1 year, typical with a
logging interval of 1 minute, but may be extended to 2 years
when the logger is configured with Bluetooth Always On
disabled. 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. 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.
To replace the batteries:
1. Use a Phillips-head screwdriver to unscrew the four screws
on the front of the logger.
2. Carefully separate the top and bottom of the logger
enclosure.
3. Remove any old batteries and insert new batteries
observing polarity.
4. Make sure the rubber seal on the bottom part of the logger
enclosure is clean and free of any debris.
5. Carefully reassemble the logger enclosure and screw in the
four screws.
WARNING: Do not cut open, incinerate, heat above 85°C
(185°F), or recharge lithium batteries. The batteries may
explode if the logger is exposed to extreme heat or conditions
that could damage or destroy the battery cases. 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.
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 logger 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.
KC Statement
해당 무선설비는 전파혼신 가능성이 있으므로 인명안전과 관련된 서비스는 할 수 없음
Translation:
The service related to human safety is not allowed because this device may have the possibility of the radio interference.