Nominal span: the pressure interval between the minimum
ａnd maximum values of the sensor nominal range. The
span is a number.
Measuring range: the pressure range between minimum
ａnd maximum for which the transmitter has been calibrated.
Measuring span: the pressure interval between minimum
ａnd maximum values of the measuring range.
Input scale initial value or zero input: minimum pressure
value included in the measuring range.
Input full scale value: maximum pressure value included in
the measuring range.
1) Transmitter Parameters.
The parameters that are available for display and setting
are:
Measuring Span: possibility to change by 0.05% steps from
120% to 7% of the nominal span. (see table).
Zero Adjustment: by 0.1% steps from -9.9% to +9.9% of
measuring span
Span Adjustment: by 0.1% steps from -9.9% to +9.9% of
measuring span
Suppression/Elevation: by 0.05% steps of nominal span
from 0 to 99% for elevation and from 0 to 93% for
suppression
Damping : adjustable by 1 sec steps from 0 to 15 sec.
Reverse Output : obtained via software
Measuring Units : for the measuring span display, one of
the following units may be selected:
mbar, bar, kPa, mmH20, mH2O, / . mmHg㎏ ㎠ .
GENERAL
The transmitter SMART-250 measures a differential pressure
in spans between 175 and 48000 mmH2O with a static
pressure up to 100 bar. The pressure measuring element is a
piezoresistive sensor. It is possible to choose between sensors
to satisfy the process conditions.
The sensor generates a signal corresponding to the actual
pressure and it is complete with a PTC thermistor which also
transmits the temperature of the measuring cell to the
electronic system. On the basis of these two values and of the
configured parameters the electronic system generates a
standard output signal (4 to 20mA, two wires system) and
displays all the necessary data on the LCD display. The
operating parameters can be changed by means of the four
pushbuttons that are below the LCD display.
Among the relevant characteristics of this microprocessor
based transmitter, are the following:
- wide rangeability for the measuring span (abt. 1 to 17)
- square root extraction selectable
- automatic temperature compensation in the measuring cell
FUNCTIONAL DATA
With reference to the following, please note these
definitions:
Nominal range:(referred to the sensor mounted on the
instrument) the pressure range (included between a
minimum and a maximum values) to measure which the
sensor has been designed.
REF.
NOM. RANGE
mmH2O
min./max.
㎏ /㎠
RANGE LIMITS
min. (㎏ /㎠ ) max.
D 0 / 2500 175 / 3000 -2500 / +2500
E 0 / 6000 420 / 7200 -6000 / +6000
F 0 / 16000 1120 / 19200 -16000 / +16000
G 0 / 40000 2800 / 48000 -40000 / +40000
General
Specifications M o del SMART-250
Diaphragm Seal Type Level Transmitter
GT-S/325
12 - 99
(Intelligent Transmitters)

Physical Characteristics.
Power supply : 12.35 - 30 Vdc with no load
Supply voltage to permissible load relation:
0/250 Ohm for 17.35 Vdc (HART DIGITAL 21.5V)
0/582.5 Ohm for 24 Vdc
0/882.5 Ohm for 30 Vdc
Output signal : 4 -20mA, 2 wires,with superimposed digital
communication (Vell 202-HART protocol)
Settling time : 150ms (at 27 ℃ )
Static pressure and overpressure measuring element
nominal limits : 100bar
Applicable pressure limit : see flange rating
Displacement : 0.2㎠ at span max.
ENVIRONMENT AND CONDITIONS
Temperature
Process fluid : -20 ~ + 120℃
Housing : -20 ~ + 80℃
Handling and storage : -20 ~ + 90℃
Relative Humidity : 0 ~ 99% R.H.
LCD display reading : -10 ~ + 65℃
Performance
Unless otherwise stated performance specifications are
referred at atmospheric pressure, nominal span, silicone oil
filling and are given as a percent of span.
Accuracy rating: it is assured within the following limits
Non linearity : resettable with 0.1% accuracy
Repeatability : = 0.10%
Hysteresis : = 0.10%
Dead bａnd : negligible
OPERATING INFLUENCES
Thermal drift : It is referred to -10 ~ + 65℃ range.
Zero: ± 0.1%/10。K. Span: ± 0.1%/10。K at nominal range.
Static pressure effect :
Zero: ± 0.2%/10 bar. Span: ± 0.2% / 10 bar
Over range effect :
Zero: on either side ± 1%at 100 bar
Power supply effect :
Negligible between 12.35 and 30 V d.c.
Intelligent Transmitters
PHYSICAL SPECIFICATIONS
Process wetted parts :
Diaphragm SUS316 L / Hastelloy C - drain and vent plugs
SUS 316 - extension SUS 316 - gaskets PTFE + Viton.
Mounting flange : process wetted locking ring SUS 316
rotable
Mounting collar : carbon steel / SUS 316.
Housing : Die cast aluminium alloy AL UNI 4514 finished
with epoxy resin (RAL 5014). Buna N gaskets.
Filling fluid : Silicon oil.
Nameplate : Stainless steel, fixed on housing.
Calibration
Standard: at nominal range, direct action, transmitter mode.
Optional: at the conditions specified with the order.
Environmental protection: The transmitter is dust and sand
tight and protected against sea waves effects as defined by
IEC IP 66. Complis with electromagnetic compatability
requirements (RFI, EMI, Voltage Surges). Suitable for
tropical climate operation as defined in DIN 50.015.
Process connections: See table 1.
Bolts : SUS 304
Electrical connections : Two cable entries on electronic
housing, 1/2" NPT and cable glａnd PG 13.5 for 7 to 12mm
diameter cable.
Terminal board : 2 terminals for signal wiring up to 1.5 ㎟
(14 AWG). Connection for ground and cable shield.
Mounting position : any position.
Net weight : 10 Kg approx.
EXPLOSION PROTECTION
Classification.
Type: intrinsic safety Ex ia IIC T6, T5, T4 .
Explosion proof feature Exd IIc T6, T5, T4.
Max Amb. temp.: 40℃ for T6, 55℃ for T5, 80℃ for T4.
Condition A
No-load voltage: = 30 V d.c.
Short circuit current: = 120 mA.
Max transferred power: 0.75 W.
Condition B
No-load voltage: = 25.2 V d.c.
Short circuit current: = 152 mA.
Max transferred power: 0.95 W.
Green SenSor
F-4-1