Siemens P technical specifications Measuring cell for gage pressure, function chart

© Siemens AG 2008

SITRANS P measuring instruments for pressure

Transmitters for food, pharmaceuticals and biotechnology

SITRANS P300 for gage and absolute pressure

Measuring cell for gage pressure Measuring cell for gage pressure, front-flush diaphragm

6
5
4
3		1
		2
		3
		4
		5
	pe	6
		pe

1

2

Reference pressure Measuring cell Process connection Seal diaphragm Filling liquid

Relative pressure sensor Pressure as input variable

1

5

2

4

1Reference pressure

2 Measuring cell

3 Seal diaphragm

4	Filling liquid	3
5	Relative pressure sensor
p Pressure as input variable

2

Measuring cell for gage pressure, function chart

The input pressure (pe) is transferred to the gage pressure sen- sor (6) via the seal diaphragm (4) and the filling liquid (5), dis- placing its measuring diaphragm. The displacement changes the resistance value of the four piezo resistors in the measuring diaphragm in a bridge circuit. The change in the resistance causes a bridge output voltage proportional to the input pres- sure.

The transmitters with spans ≤ 63 bar measure the input pressure against atmosphere, those with spans ≥ 160 bar against vacuum.

Measuring cell for absolute pressure

e

SH

Measuring cell for gage pressure, front-flush diaphragm, function chart

The input pressure (pe) is transferred to the gage pressure sen- sor (6) via the seal diaphragm (4) and the filling liquid (5), dis- placing its measuring diaphragm. The displacement changes the resistance value of the four piezo resistors in the measuring diaphragm in a bridge circuit. The change in the resistance causes a bridge output voltage proportional to the input pres- sure.

The transmitters with spans ≤ 63 bar measure the input pressure against atmosphere, those with spans ≥ 160 bar against vacuum.

5

4

3

2

pe

1

1Measuring cell

2Process connection

3 Seal diaphragm

4 Filling liquid

5 Absolute pressure sensor

pe Pressure as input variable

Measuring cell for absolute pressure, front-flush diaphragm

4

1

3

1Measuring cell

2 Seal diaphragm

Measuring cell for absolute pressure, function chart

The input pressure (pe) is transferred to the absolute pressure sensor (5) via the seal diaphragm (3) and the filling liquid (4), displacing its measuring diaphragm. The displacement changes the resistance value of the four piezo resistors in the measuring diaphragm in a bridge circuit. The change in the re- sistance causes a bridge output voltage proportional to the input pressure.

3	Filling liquid
4	Absolute pressure sensor	2
pe	Pressure as input variable

SH

Measuring cell for absolute pressure, front-flush diaphragm, function chart

Siemens FI 01 · 2009

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