Pressure Transponder With Surface Accoustic Wave Sensor

• US 20080307889A1
• Filed: 12/23/2005
• Published: 12/18/2008
• Est. Priority Date: 01/08/2005
• Status: Active Grant

• Current Assignee: ABB AG (ABB Limited)
• Original Assignee: ABB Patent GmbH (ABB Limited)
• Inventors: Scholz, Wolfgang, Gasch, Armin, Milanovic, Raiko, Riegler, Peter
• Granted Patent: US 7,694,571 B2
• Time in Patent Office: Days
• US Class Current: 73/703
• CPC Class Codes: G01L 19/0092 Pressure sensor associated with other sensors, e.g. for measuring acceleration or temperature G01L9/025, G01L9/045, G01L9/065, G01L9/085, G01L9/105, G01L9/125, G01L19/02, G01L19/04 take precedence; measuring two or more variable G01D21/02; temperature sensors with pressure compensation G01K1/26
• CPC Class Codes: G01L 19/0645 using isolation membranes, specially adapted for protection
• CPC Class Codes: G01L 19/0672 Leakage or rupture protection or detection
• CPC Class Codes: G01M 3/24 using infrasonic, sonic, or ultrasonic vibrations

Abstract

The invention relates to a pressure sensor, the measuring cell of which is provided with at least one membrane for the protection of the pressure-sensitive element and a measuring chamber, filled with pressure medium, in which the pressure-sensitive element is housed. According to the invention, the membrane is monitored for damage, whereby at least one surface wave sensor is arranged in the chamber filled with pressure medium. On damage to the membrane occurring, process medium is mixed with the pressure medium. A substance change in the sensitive region of the surface wave sensor is thus brought about which results in a differing signal run time. Any change in run time is an indictor of damage to the pressure sensor and may be signaled as such.

Claims

1. A pressure sensor having at least one membrane for protection of the pressure-sensitive element, which is accommodated in a measurement chamber that is filled with a pressure medium,

wherein at least one surface acoustic wave sensor, which is wetted by the pressure medium, is arranged in each measurement chamber.

2. The pressure sensor as claimed in claim 1,

wherein the surface acoustic wave sensor has a transmitting element and a receiving element, which are connected to an amplifier to form a resonant circuit.

3. The pressure sensor as claimed in claim 1,

wherein the surface acoustic wave sensor has a threshold-value circuit.

4. The pressure sensor as claimed in

claim 1, wherein an encapsulated surface acoustic wave sensor is arranged in each measurement chamber and is associated with the surface acoustic wave sensor, which is wetted by the pressure medium, of the same measurement chamber.

5. The pressure sensor as claimed in

claim 1, wherein an encapsulated surface acoustic wave sensor is arranged in a measurement chamber and is associated with both surface acoustic wave sensors which are wetted by the pressure medium.

6. The pressure sensor as claimed in claim 2, wherein the surface acoustic wave sensor has a threshold-value circuit.

7. The pressure sensor as claimed in claim 3, wherein an encapsulated surface acoustic wave sensor is arranged in each measurement chamber and is associated with the surface acoustic wave sensor, which is wetted by the pressure medium, of the same measurement chamber.

8. The pressure sensor as claimed in claim 3, wherein an encapsulated surface acoustic wave sensor is arranged in a measurement chamber and is associated with both surface acoustic wave sensors which are wetted by the pressure medium.