Xylem WS750 WASTEWATER/STORMWATER SAMPLER - Manual (Page 8)

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VII. Composite Sampling
A composite sample is a series of smaller samples put into the same bottle, thus showing
an “average” sample over time. Set the Interval control to the desired time between
samples (do not select the External Trigger position). Set the Size control for the
corresponding pump to the desired sample size. Note that the sample size settings are
approximate and apply to a head height of four feet. For heights other than four feet, refer
to the chart inside the front of the sampler. Each pump can have different size settings but
will share the same Sample Interval setting.
The sampler starts timing when both of the optional Rain and Water Sensors detect
moisture. If you do not have the optional water sensors or do not need them for your
application, defeat them by plugging one of the two shorting plugs supplied with the sampler
into their jack. If both inputs are defeated, the sampler starts up triggered when the power
switch is turned on. The Status LED starts blinking every 2 seconds once the sampler is
triggered.
The Start Delay timer begins running when the sampler is triggered by the Rain and Water
Sensors and the first sample is taken when the timer expires. If the Delay control is set to
zero, sampling begins immediately. The delay timer only applies to the first sample taken
by each pump. At the end of each sample, the pumps reverse for 15 seconds.
Sampling continues as Trigger-Delay-Sample-Reverse-Interval-Sample-Reverse-Interval-
Sample-Reverse … until the sample bottles are full. For each pump, the same amount of
Interval time is placed between samples, even if the size settings are different. When both
bottles are full, the Status LED remains lit constantly.
VIII. Discrete Sampling
A discrete sample is a single sample put into the same bottle, thus being a sample at one
point in time. Set the Size control for the corresponding pump to “Full”. Once started, the
pump will continue to run until the sample bottle if full.
As with composite sampling, the Start Delay timer begins when the sampler is trigger by the
Rain and Water Sensors and the first sample is taken when the timer expires. If the Delay
control is set to zero, sampling begins immediately. The Status LED blinks every 2 seconds
while the delay timer or the pumps are running and remains lit constantly once both of the
sample bottles have been filled. At the end of sampling, the pumps reverse for 15 seconds.