Siemens technical specifications Sitrans P250 for differential pressure, Technische Daten

© Siemens AG 2008

SITRANS P measuring instruments for pressure

Transmitters for gage, absolute and differential pressure

SITRANS P250 for differential pressure

■Mode of operation

Overview

2

p1	p2
	U
	const.
	U	I0, UB
	I

SITRANS P250 transmitter for differential pressure

The SITRANS P250 transmitter measures the differential pres- sure of liquids and gases.

■Benefits

•High measuring accuracy

•Sturdy stainless steel enclosure

•For aggressive and non-aggressive media

•For the measurement of the differential pressure of liquids and gases

•Temperature-compensated measuring cell

•Compact design

■Application

The SITRANS P250 transmitter for differential pressure is prima- rily used in the following industries:

•Chemical industry

•Pharmaceutical industry

•Food industry

•Mechanical engineering

•Shipbuilding

SITRANS P250 pressure transmitter, function diagram

The piezo-resistive ceramic measuring cell (membrane) has a Wheatstone bridge circuit, on which the operating pressure P1 and P2 of the media acts at both ends.

The voltage output from the measuring cell is converted by an amplifier into an output current of 4 to 20 mA or an output voltage of 0 to 5 or 10 V DC.

The output current and voltage are linearly proportional to the in- put pressure.

■Technische Daten

SITRANS P250 differential pressure transmitter

Application
Differential pressure transmitter	Liquids and neutral gases
Mode of operation
Measuring principle	Piezo-resistive measuring cell
	(ceramic diaphragm)
Input
Measured variable	Differential pressure
Measuring range	0 ... 0.1 to 0 ... 25 bar
	(0 ... 1.45 to 0 ... 363 psi)
Operating pressure	≤ 25 bar (363 psi) at a differential
	pressure range < 6 bar (87 psi)
	≤ 50 bar (725 psi) at a differential
	pressure range > 10 bar (145 psi)
Burst pressure	1.5 x operating pressure
Output
Output signal

• Water supply • Current output signal 4 ... 20 mA

■Design

Main components:

• Stainless steel enclosure with piezo-resistive ceramic measur-

ing cell and (temperature-compensated) electronics module.

• Voltage output signal	0 ... 5 V and 0 ... 10 V DC
Load
3-wire	> 10 kΩ
2-wire	≤ (UH - 11 V) / 0.02 A
Measuring accuracy

• Process connection made of stainless steel in diverse designs

(see Selection and ordering data)

• Electrical connection through connectors acc. to EN 175301-

803-A and round connectors M12, as well as with permanently

fixed cable

■Function

The pressure transmitter measures the differential pressure of

liquids and gases.

Dynamic behavior (at 25°C (77°F), including conformity error, hystere- sis and repeatability)

Long-term drift acc. to IEC 60770

Influence of ambient temperature

•Start of scale

•Full-scale value

≤1 % of typical full-scale value, see "Measuring range" table

≤0.5 % of full-scale value/year

≤0.6 %/10 K of full-scale value

(≤ 1.2 %/10 K for measuring cell 0 ... 0.1 bar (1.45 psi))

≤0.22 %/10 K of full-scale value

(≤ 0.37 %/10 K for measuring cell 0 ... 0.1 bar (1.45 psi))

Dynamic behavior	Suitable for static and dynamic
	measurements
Response time T99	< 5 ms
Load variation	< 50 Hz

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Siemens FI 01 · 2009