User Manual

HOBO 4-Channel Thermocouple Data Logger (UX120-014M) Manual
1-800-LOGGERS 6 www.onsetcomp.com
For example, the high alarm for temperature is set to 300°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 300°F for a total of 30 minutes since the
logger was configured; specifically, this could be 15 minutes
above 300°F in the morning and then 15 minutes above
300°F again in the afternoon. If Consecutive is selected,
then an alarm will trip only if all sensor readings are 300°F
or above for a continuous 30-minute period.
7. Repeat steps 2 through 6 for any additional thermocouple
sensors.
8. Choose how long the logger should maintain the sensor
alarm once it has tripped. Select “Host has relaunched
logger” if you want the alarm to remain visible on the LCD
until the next time you relaunch the logger. Select “Sensor
reading within limits” if you want the alarm to clear once
the sensor reading returns to the normal range between
the high and low alarm limits. Select “Cleared with button
press” if you want the alarm to remain on until you press
the Alarm/Stats button on the logger.
9. Click OK to save alarm settings.
Notes:
• Once the logger is launched, alarms will trip as
determined by these settings. Logger alarms will display
on the LCD screen. Note that the alarm limits are only
checked when the logger’s LCD screen refreshes every 15
seconds.
• The actual values for the high and low alarm limits are set
to the closest values supported by the logger based on
the thermocouple type. In addition, alarms can trip or
clear when the sensor reading is within the resolution
specification for each thermocouple type. This means the
value that triggers the alarm may differ slightly than the
value entered.
• When you read out the logger, high and low alarm levels
will be displayed on the plot along with “Chan <#> Alarm
Tripped” and “Chan <#> Alarm Cleared” events showing
when the temperature alarm tripped and cleared. The
“Chan <#> Alarm Cleared” event contains the value that
was furthest out of range for the sensor before the alarm
cleared (see the Points table for the actual value).
• Alarms can only be configured on thermocouple
channels; they are not available for the internal 10K
thermistor (temperature) channel.
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, let’s say the logger is recording data at a 5-minute
logging interval and burst logging is configured to log every 10
seconds on one thermocouple when the temperature goes
above 2,000°F (the high limit) or falls below -200°F (the low
limit. This means the logger will record data every 5 minutes as
long as the temperature remains between 2,000°F and -200°F
on that channel. Once the temperature reaches 2,100°F, for
example, the logger will switch to the faster logging rate and
record data every 10 seconds until the temperature falls back
below the high limit (or 2,000°F in this case) on that channel. At
that time, logging then resumes every 5 minutes at the normal
logging interval. Similarly, if the temperature falls to -250°F on
that channel, for example, then the logger would switch to
burst logging mode again and record data every 10 seconds.
Once the temperature rises back to -200°F, the logger will then
return to normal mode, logging every 5 minutes. To set up
burst logging:
1. Select Burst for Logging Mode in the Launch Logger
window. If Burst has already been configured for this
logger, click the Edit button in the Launch Logger window.
2. In the Burst Logging window, select a thermocouple from
the list.
3. Select the High Limit checkbox if you want to set up a
condition in which burst logging will occur when the sensor
reading rises above the high limit value. Type in the value or
drag the red upper slider.
4. Select the Low Limit checkbox if you want to set up a
condition in which burst logging will occur when the sensor
reading falls below the low limit value. Type in the value or
drag the blue lower slider.