HOBO MX pH and Temperature Logger (MX2501) Manual
8
Limits in step 9. Otherwise, the alarm state will remain in place
until the logger is reconfigured.
Notes:
•
Alarm limits are checked at every logging interval unless
burst logging is configured. For example, if the logging
interval is set to 5 minutes, then the logger will check the
sensor readings against your configured high and low
alarm setting every 5 minutes.
•
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 specified 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 specified
resolution).
•
When you read out the logger, alarm events can be
displayed on the plot or in the data file. See
Logger
Events
.
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 Bluetooth Always Off
enabled, push the switch on the logger to wake it up. If the
logger was configured with Bluetooth Off Water Detect and
is currently underwater, remove it from the water.
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.
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 faster the burst
logging rate, the greater the impact on battery life and the
shorter the logging duration. Because measurements are
being taken at the burst logging interval throughout the
deployment, the battery usage is similar to what it would be
if you had selected this rate for the normal logging interval.
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:
•
The high and low burst limits are checked at the burst
logging interval rate whether the logger is in normal or
burst condition. For example, if the logging interval is set
to 1 hour and the burst logging interval is set to 10
minutes, the logger will always check for burst limits
every 10 minutes.
•
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 can begin or end when the sensor reading is
within the specified 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 specified
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 at the normal logging rate. For example, the
logger has a 10-minute logging interval and logged a data
point at 9:05. Then, the high limit was surpassed and