Onset MX2300 Operating Manual

HOBO® MX2300 Series Data Logger Manual

The HOBO MX2300 series data loggers record and transmit temperature and/or relative
humidity (RH) in outdoor or indoor environments. These Bluetooth® Low Energy-enabled
loggers are 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 indicate alarms at thresholds you specify. The
logger also supports burst logging in which data is logged at a faster interval when sensor
readings are above or below certain limits. The Temp and Temp/RH models have internal
sensors while the External Temp/RH, External Temp, and 2x External Temp include built-in
external sensors, offering a wide range of solutions for monitoring temperature and RH in
numerous applications.

Specifications

Temperature Sensor

HOBO MX2300 Series
Data Logger

Models:

• MX2301, temp/RH

• MX2302, ext temp/RH

• MX2303, 2 ext temp

• MX2304, ext temp

• MX2305, temp

Included Items:

• Screws

• Cable ties

Required Items:

• HOBOmobile app

• Device with iOS and

Bluetooth

Accessories:

• Solar radiation shield (RS3
for use with MX2302,
MX2303, and MX2304
models; RS1 or M-RSA for
use with MX2301 and
MX2305 models)

• Mounting bracket for solar
radiation shield (MX2300­RS-BRACKET), for use with
MX2301 and MX2305
models

• Replacement battery
(HRB-2/3AA)

Range MX2301 and MX2305 internal sensors: -40 to 70°C (-40 to 158°F)

Accuracy ±0.25°C from -40 to 0°C (±0.45 from -40 to 32°F)

Resolution 0.04°C (0.072°F)

Drift <0.01°C (0.018°F) per year

Relative Humidity Sensor* (MX2301, MX2302 only)

Range 0 to 100% RH, -40° to 70°C (-40° to 158°F); exposure to conditions below

Accuracy ±2.5% from 10% to 90% (typical) to a maximum of ±3.5% including

Resolution 0.05%

Drift <1% per year typical

Response Time (typical, to 90% of change)

Temperature MX2301 and MX2305 internal sensors: 17 minutes in air moving 1 m/sec

RH MX2301: 1 minute in air moving 1 m/sec

Logger

Operating Range -40° to 70°C (-40° to 158°F)

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)

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

Time Accuracy ±1 minute per month 0° to 50°C (32° to 122°F)

Battery Type 2/3 AA 3.6 Volt lithium, user replaceable

MX2302 external temperature sensor: -40 to 70°C (-40 to 158°F)
MX2303 and MX2304 external sensors: -40 to 100°C (-40 to 212°F), with
tip and cable immersion in fresh water up to 50°C (122°F) for one year

±0.2°C from 0 to 70°C (±0.36 from 32 to 158°F)
±0.25°C from 70 to 100°C (±0.45 from 158 to 212°F), MX2303 and
MX2304 only

-20°C (-4°F) or above 95% RH may temporarily increase the maximum RH
sensor error by an additional 1%

hysteresis at 25°C (77°F); below 10% RH and above 90% RH ±5% typical

MX2302 external sensor: 2 minutes, 30 seconds in air moving 1 m/sec
MX2303 and MX2304 external sensors: 3 minutes in air moving 1 m/sec;
20 seconds in stirred water

MX2302: 4 minutes in air moving 1 m/sec

20923-A

HOBO MX2300 Series Data Logger Manual

Specifications (continued)

Battery Life 2 years, typical with logging interval of 1 minute and Power Saving Mode

Memory 128 KB (84,650 measurements, maximum)

Full Memory Download
Time

Dimensions Logger housing: 10.8 x 5.08 x 2.24 cm (4.25 x 2.0 x 0.88 in.)

Weight Logger: 75.5 g (2.66 oz)

Materials Acetal, silicone gasket, stainless steel screws

Environmental Rating NEMA 6 and IP67

*Per RH sensor manufacturer data sheet

disabled; 5 years, typical with logging interval of 1 minute and Power
Saving Mode enabled. Faster logging intervals and statistics sampling
intervals, burst logging, remaining connected with the app, excessive
downloads, and paging may impact battery life.

Approximately 60 seconds; may take longer the further the device is from
the logger

External temperature sensor diameter: 0.53 cm (0.21 in.)
External temperature/RH sensor diameter: 1.17 cm (0.46 in.)
External sensor cable length: 2 m (6.56 ft)
Solar radiation shield bracket: 10.8 x 8.3 cm (4.25 X 3.25 in.)

Solar radiation shield bracket: 20.4 g (0.72 oz)

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

See last page

Logger Components and Operation

Mounting

Holes

Vent

Alarm LED

Status LED

Start Button

External Sensor

MX2303 model shown

Mounting Holes: Use the holes at the top and bottom of the

logger to mount it (see Deploying and Mounting the Logger).

Alarm LED: This LED blinks red every 4 seconds when an alarm
is tripped (unless Show LED is disabled as described in
Configuring the Logger). If the logger is logging faster than 4
seconds, the LED blinks at the logging rate when an alarm is
tripped.

Status LED: This LED blinks blue every 4 seconds when the
logger is logging (unless Show LED is disabled as described in
Configuring the Logger). If the logger is logging faster than 4
seconds, the LED blinks at the logging rate. If the logger is

MX2301 model shown

waiting to start logging because it was configured to start “On
Button Push” or with a delayed start, it will blink every 8
seconds.

Start Button: Press this button to wake up the logger; both the
alarm and status LEDs will blink. Once the logger is awake,
press this button to move it to the top of the loggers list in
HOBOmobile. Press this button for 3 seconds to start or stop
the logger when it is configured to start or stop “On button
push” (see Configuring the Logger). Both LEDs will blink four
times when you press the button to start or stop logging. Press
this button for 10 seconds to reset a password (see Setting a
Password).

External Sensor: This is the external probe attached to the
bottom of the logger that measures temperature or
temperature/RH. The MX2302 logger has one external sensor
that measures both temperature and RH and the MX2304
logger has one sensor that measures temperature only. The
MX2303 logger (shown at left) has two external temperature
sensors; the left sensor is channel 1 and the first temperature
shown in HOBOmbile, and the right sensor is channel 2 and the
second in HOBOmobile.

Vent: The RH sensor is located behind the vent (MX2301 model
only).

Downloading HOBOmobile and
Connecting to a Logger

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

1. Download the HOBOmobile app from the App Store.

1-800-LOGGERS 2 www.onsetcomp.com

HOBO MX2300 Series Data Logger Manual

2. Open the app and enable Bluetooth in the device settings if
prompted.

3. Press the button on the logger to wake it up.

4. Tap the HOBOs icon at the bottom of the screen. Tap the
logger in the list to connect to it.

If the logger does not appear in the list or if it is having trouble
connecting, follow these tips:

• Make sure the logger is “awake” by pressing the start

button. The alarm and status LEDs will blink once when
the logger wakes up. You can also press the button a
second time to bring it to the top of the list if you are
working with multiple loggers.

• 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 there are several loggers in the area, move the logger

to a location with fewer loggers. Interference can
sometimes occur when numerous loggers are in one
location.

• 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 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:

Update Firmware. When new logger firmware is
available, this action appears in the list. Select it and
follow the instructions on the screen. 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, always read out the logger first. 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 configuration settings. Select
this to offload all the data on the logger before
reconfiguring it.

Configuring the Logger

Use HOBOmobile to set up the logger, including selecting the
logging options, configuring alarms, and enabling Power Saving
Mode. These steps provide an overview of setting up the
logger. For complete details, see the HOBOmobile User’s Guide.

1. Press the button on the logger to wake it up.

2. Find the logger in the list and tap it to connect to it. If you
are working with multiple loggers, you can press the button
on the logger a second time to bring it to the top of the list.
The logger name (or serial number if no name has been
assigned) turns green when the logger moves to the top of
the list. Note that the current readings are displayed even
when the logger is not logging.

• Configure. Select logger settings and load them onto the

logger to start logging. See Configuring the Logger.

• Readout. Download 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. Select this option to begin logging (if the

logger is configured to start “On Button Push” as
described in Configuring the Logger).

• Stop Logging. Stop the logger from recording data. This

overrides any Stop Logging settings described in
Configuring the Logger.

• Page Logger LED. Press and hold this option to illuminate

the alarm and status LEDs for 4 seconds.

• 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, connect
to the logger, tap Set Logger Passkey, and select Reset to
Factory Default. You can also press the button on the
logger for 10 seconds to reset a password.

1-800-LOGGERS 3 www.onsetcomp.com

3. Once connected, tap Configure.

4. Tap Name and type a name for the logger up to 20
characters (optional). Tap Done. If no name is selected, the
logger serial number is used as the name.

5. 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.