Xylem EXO Series User Manual page 57

Samples Per Wipe - Wiping Interval
In most deployments the user will choose to use the EXO2 central wiper to wipe the sensors preceding each
logging interval. We recommend a wiping interval of 1 for 15-minute and 30-minute sampling intervals; 1
wipe will occur just prior to a sample being taken. Set the wiping interval to 2 and one wipe will occur every
other sample. If you have a short sampling interval, such as 5 minutes, and biofouling is not aggressive, then
you may not need to wipe the sensors prior to every sampling interval. In this case, you can set the wiping
interval to 4, in which case it will wipe every fourth time a sample is taken, or approximately every 20 minutes.
This action can help conserve battery life.
Setting Samples Per Wipe to 0 will disable the central wiper.
Sampling Rates
The sensors output data to the EXO sonde in real time, this data transfer rate varies by sensor and processing
conditions but generally it can be assumed the sensor transfers data to the sonde twice a second (2 Hz). In
high speed unattended sampling applications, like vertical profiling, the sonde can be deployed to log data as
fast as 4 times a second (4 Hz). The user can set the sampling interval, and the real time transfer between the
sensors and sonde will automatically adjust to an appropriate output rate. The user can not manually control
the output rate of the sensors themselves.
Sampling rates can vary significantly depending on application, and a sampling rate will have a significant
impact on memory usage and battery consumption. An EXO2 sonde with a full payload can be expected to
log more than 90 days at a 30-minute sampling interval, but the same sonde set to profile at 4 Hz (four times
Stop deployment
This Stop Deployment button appears when an attached
EXO device is actively logging. After stopping a
deployment, the button disappears and the icon in the
upper right changes state to indicate the sonde is not
actively logging data.
Advanced sampling and logging
Access the following functions in the in the Deploy | Open
Template | Edit Template menu and click on the Advanced
tab.
Logging Intervals
When deploying a sonde, data is logged and time-stamped
at a routine sampling interval. A typical sampling interval
for unattended logging is 15 minutes. If the sonde logs
at 00:15:00, the sonde will wake up early to activate the
sensors and start processing data. Typically this will be 12-
15 seconds before the time-stamp. If an averaging interval
were activated, then the sonde would wake up 15 seconds
early plus the averaging interval to start averaging the data.
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