HOBO MX pH and Temperature Logger (MX2501) Manual
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9.
Tap Pause Options, then select Pause On Button Push to
specify that you can pause the logger by pressing its switch
for 3 seconds.
10.
Tap Logging Mode. Select either Fixed Logging Mode or
Burst Logging. With fixed logging, the logger records data
for all 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.
11.
Enable or disable Show LED. If Show LED is disabled, the
alarm and status LEDs on the logger are not illuminated
while logging (the alarm LED does not blink if an alarm
trips). You can temporarily turn on LEDs when Show LED is
disabled by pressing the button on the logger for 1 second.
12.
Select the power saving mode, which determines when the
logger advertises or regularly sends out a Bluetooth signal
for the mobile device or computer to find via the app.
•
Bluetooth Always Off.
The logger advertises only during
logging when you push the switch on the logger. This
wakes up the logger when you need to connect to it. This
option uses the least battery power.
•
Bluetooth Always On.
The logger always advertises. You
never need to push a switch to wake up the logger. This
option uses the most battery power.
13.
Set up an optional alarm to trip when the pH and/or
temperature sensor reading rises above or falls below a
specified value. See
Setting up Alarms
for details on
enabling sensor alarms.
14.
Tap Start to save the configuration settings.
Logging begins based on the settings you selected. See
Deploying and Mounting the Logger
for details on mounting
and see
Reading Out the Logger
for details on downloading.
Setting up Alarms
You can set up alarms for the logger so that if a sensor reading
rises above or falls below a specified value, the red logger LED
blinks and an alarm icon appears in the app. Alarms alert you to
problems so you can take corrective action.
To set an alarm:
1.
Tap Devices. If the logger was configured with Bluetooth
Always Off enabled, push the switch on the logger to wake
it up.
2.
Tap the logger tile to connect to the logger and tap
Configure & Start.
3.
Tap a Sensor/Channel.
4.
Tap Enable Logging, if necessary.
5.
Tap Alarms to open that area of the screen.
6.
Select Low if you want an alarm to trip when the sensor
reading falls below the low alarm value. Enter a value to set
the low alarm value.
7.
Select High if you want an alarm to trip when the sensor
reading rises above the high alarm value. Enter a value to
set the high alarm value.
8.
For the Duration, select how much time should elapse
before the alarm trips and select one of the following:
•
Cumulative. The alarm trips 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, the alarm
trips once the sensor readings have been above 85°F for
a total of 30 minutes since the logger was configured.
•
Consecutive. The alarm trips 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, the alarm trips only if
all sensor readings are 85°F or above for a continuous 30-
minute period.
When an alarm trips, the red logger LED blinks every 4 seconds
(unless Show LED is disabled), an alarm icon appears in the app,
and an Alarm Tripped event is logged. The alarm state clears
when the readings return to normal if you selected Sensor in
Limits in step 9. Otherwise, the alarm state remains 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, the logger checks 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. In addition, alarms can trip or clear
when the sensor reading is within the specified
resolution specifications.
•
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 records 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 switches to the faster logging rate and records data
every 30 seconds until the temperature falls back to 85°F. At
that time, logging then resumes every 5 minutes at the fixed
logging interval. Similarly, if the temperature falls below 32°F,
then the logger switches to burst logging mode again and
record data every 30 seconds. Once the temperature rises back
to 32°F, the logger then returns to fixed mode, logging every 5
minutes.
Note:
Sensor alarms, statistics, and the Stop Logging
option Never Stop (Overwrites Old Data) are not available in
burst logging mode.
To set up burst logging:
1.
Tap Devices. Remove the logger from water. If the logger is
configured with Bluetooth Always Off enabled, press the
button on the logger to wake it up.
2.
Tap the logger tile to connect to the logger and tap
Configure & Start.
3.
Tap Logging Mode and then tap Burst Logging.
