Theory Of Operation - YZ Systems DynaPak DP-2020N Manual

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3. Theory of Operation

DynaPak 2020 Gas Sampler
The DynaPak 2020 Sampler is a pipeline mounted system
which uses the pneumatically operated, positive
displacement DynaPak 2000N pump, the Z-200 timer/
controller, the YZ filter/regulator and a low power solenoid
valve to obtain gas samples. The 2020 has two modes of
operation:
A. Proportional-to-flow sampling: in this mode of operation, the
2020 extracts a gas sample from the pipeline at time
intervals proportional to the pipeline flow rate. The volume
of the sample is set by the operator using the volume
adjustment feature of the DP-2000 pump. The Z-200
periodically energizes a low power solenoid valve, which
allows actuation gas to stroke the DP-2000 pump.
The Z-200 operates as a recycling timer with exception that
the off time is adjusted to account for variations in pipeline
flow conditions. In the event that flow increases in the
pipeline the time between solenoid actuations will be
shortened. If the flow in the pipeline decreases the time
between solenoid actuations will lengthen. This allows the
time between solenoid actuations to be directly propor-
tional-to-flow in the pipeline.
The Z-200 controller uses a customer supplied 1 - 5 VDC
analog signal to determine the percentage of flow that is
present in the pipeline.
B. Proportional-to-time sampling: in this mode of operation, the
Z-200 controller operates as a recycling timer, energizing
the solenoid valve at an interval pre-selected by the opera-
tor. As in the other mode of operation, solenoid actuation
allows the DP-2000 pump to stroke.
In either mode of operation, the number of solenoid
actuations is recorded by the onboard LCD indicator. The
Z-200 timer/counter operates using a replaceable internal
battery pack. The battery pack condition is monitored using
two indicator LEDs. When the battery pack needs replace-
ment, the red LED will illuminate when the solenoid output
is activated. If the battery pack is good, the green LED will
illuminate when the solenoid is activated.
The External Power Option can be used in lieu of the
internal battery pack. The External Power Option (model No.
EPO-120) consists of an AC to DC convertor and intrinsically
safe barrier to convert 120 AC power to 28 VDC to operate
the controller without the use of the internal battery pack.
The Solar Power Option would be used in lieu of the
internal battery pack. The Solar Power Option (model
#SPO-12) consists of a 5 watt solar panel with RM-12
charger regulator module and internal 12V, 5 Amp hour
battery pack.