Thermo Scientific STD5000, Руководство пользователя

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Chapter 3
Operation
General neral
Operation is outlined in the flow chart displayed in Figure 1–1 . The
electric to pneumatic conversion takes place in the E-Pi valve. A
conditioned 4–20 mA input signal provides an electric current to the E-Pi
coil, creating a magnetic field that magnetizes the valve. The magnetization
is proportional to the input current signal and positions the membrane
relative to the valve seat. The pneumatic output is modulated relative to the
input current. Further conditioning of the pneumatic output is achieved
with a volume booster.
Final conditioning of the boosted pneumatic output signal occurs by
measuring the output with a pressure sensor. This signal is then compared
with the current to the E-Pi, resulting in exact pneumatic output relative to
the input signal.
Programming Programming
Programming is selectable via internal jumpers located on the circuit board.
A label on the E-Pi module shows the location and position of these
jumpers (shown in
Figure 3–1 ).
To select the operating mode, plug in the jumpers according to the
following table. The table also displays the part number of the E-Pi module
required to achieve the desired outputs and the necessary supply pressure.
Note We recommend that you select the mode PRIOR TO final
installation. ▲
Note When switched from direct to reverse or into split range, the span
remains within ±1%. ▲
Thermo Fisher Scientific STD5000 & STD6000 User Guide 3-1