HOBO MX2300 Series Data Logger Manual
1-800-LOGGERS
5
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5.
Enable the Low Alarm if you want an alarm to trip when the
sensor reading falls below the low alarm value. Drag the
slider to the reading that will trip the alarm or 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 and tap Done in the Alarm Duration screen.
7.
Select either Cumulative or Consecutive Samples. 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 30-
minute period.
8.
Tap Done and repeat steps 3–8 for the other sensor if
desired.
9.
Back in the Configure screen, a setting to maintain the
alarm until the logger is reconfigured is enabled
automatically. This cannot be disabled.
10.
Tap Start in the Configure screen to load the alarm settings
onto the logger if you are ready to start.
When an alarm trips, the logger alarm LED blinks every 4
seconds (unless Show LED is disabled), an alarm icon appears in
the app, and an Alarm Out of Range event is logged. Even if the
reading returns to a normal range, the alarm indicator will not
clear in the app and the alarm LED will continue to blink.
Notes:
•
Alarms are checked <placeholder>.
•
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
0.04°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 0.04°C resolution).
•
When you read out the logger, alarm events can be
displayed on the plot or in the data file. See
Logger
Events
.
•
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 and tap the logger to connect to it. If
the logger was configured with Power Saving Mode
enabled, press the button on the logger to wake it up.
When working with multiple loggers, you can also press the
button on the logger to bring it to the top of the list.
2.
Once connected, tap Configure.
3.
Tap Logging Mode and then tap Burst Logging.
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.
