Functional Operation; Cell And Characterization Board Assembly - ABB Platinum standard Series Product Instruction

DESCRIPTION AND OPERATION

FUNCTIONAL OPERATION

Cell and Characterization Board Assembly

FUNCTIONAL OPERATION
2 - 2
The Type PTSD pressure transmitter has two major sections: a
cell and characterization board assembly, and an electronics
assembly. The Type STT Smart Transmitter Terminal commu-
nicates with the Type PTSD pressure transmitter. The EZ CAL
option provides a way to validate the zero and span of the
transmitter without using the Type STT terminal.
Type PTSD pressure transmitters use an electrically isolated
differential reluctance cell as the sensing device. The cell has
two half-shells clasping a measuring diaphragm, centered and
welded at the edges under stress. A core is welded to each side
and at the center of the diaphragm. The diaphragm has spiral
ridges for pressures ≤90 kilopascals (≤360 inches of water) or
is flat and trimmed for pressures >90 kilopascals (>360 inches
of water). These distinctive diaphragms provide symmetry,
flexibility, and accuracy under static pressure (Fig. 2-2).
C H A R AC T E R IZ ATIO N
B O A R D
Figure 2-2. Cell and Characterization Board Assembly
Two inductive coils are at each side of the cores in the two
half-shells. Two welded walls isolate them from the fill fluid.
Two isolating diaphragms, welded to the edges, isolate the
measuring diaphragm to protect against corrosion and
overloads.
LE A D W IR E S
IS O L AT IN G
IS O L AT IN G
D IA P H R AG M D IA P H R AG M
C O IL S
M AG N E T IC
C O R E S
F ILL FL U ID
M E AS U R IN G
D IA P H R AG M
T 02 2 09 A
WBPEEUI110504A0