Xylem WS705 IMPROVED COMPOSITE/DISCRETE WATER SAMPLER - Manual (Page 9)

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IX. External Trigger Mode
When the Sample Interval control is set to the “External Trigger” position, the sampler can
be triggered externally by either the Trigger In jack or the Rain Sensor input. This mode is
useful in applications where sampling occurs based on readings from a process controller,
SCADA system, flow monitor, auto-dumping rain gauge or other remote monitoring devices.
Using the Rain Sensor as a trigger source:
This mode is normally used with an auto-dumping rain gauge that empties itself every 24
hours. Set the Sample Interval control to External Trigger. Set each pumps Size control
based on desired composite sample size or set to Full for a discrete sample.
The sampler will be triggered when both the Rain and Water Sensors detect moisture. If the
Water Sensor is not needed, use one of the shorting plugs supplied with the sampler to
defeat it by plugging it into the Water Sensor input jack. Place the Rain Sensor at the
desired height in the rain gauge. When the Rain Sensor detects moisture, the sampler will
start.
Once triggered by the Rain Sensor, the Start Delay timer begins running and the Status
LED begins blinking every 2 seconds. When the timer expires, the pump takes a sample
based on the Sample Size settings. When the sample is complete, the pump reverses for
15 seconds, then stops. The sampler cannot be re-triggered until the rain gauge empties
itself and the Rain Sensor goes dry. The next time the sensor detects moisture, the Start
Delay timer will start over again and another sample will be taken when it expires.
If the pump’s Sample Size control is set to take a full-bottle discrete sample, further triggers
will have no affect. If the pump is set to take composite samples, each one will represent
the conditions at the time of that “qualified rain event”. This process will continue until the
sample bottle is full and the Status LED remains lit all the time.
Using the Trigger Input as a source:
This input is generally used for connecting to a flow monitor, processor controller, or other
external monitoring device.
When using the Trigger In input jack, leave the Rain Sensor input jack disconnected.
Upon being triggered by the Trigger Input, the Start Delay timer begins running. When the
delay timer has expired, the pump takes a sample based on the Sample Size setting.