Apparatus for measuring a hydraulic fluid flow rate and/or leakage rate through an object to be tested

US5347848A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Eberhard Schoeffel · Bamberg, DE
• Josef Ernst · Eppstein, DE

Key dates

• Filing date: Jan 15, 1993
• Grant date: Sep 20, 1994
• Expiry date: Jan 15, 2013

Classification

• Technology area (CPC G): Physics
• CPC primary: G01M3/3245
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

The apparatus for measuring a hydraulic fluid flow rate and/or leak rate through an object, particularly a valve, includes an approximately vertical measurement tube, a capacitive sensor mounted on the measurement tube, an equalization vessel extending vertically next to the measurement tube, and a source of hydraulic fluid connected to the equalization vessel and the measurement tube below the capacitive sensor and a source of a pneumatic medium connected to both the equalization vessel and the measurement tube above the capacitive sensor. Hydraulic and pneumatic valves are also provided so that hydraulic fluid can be accommodated in a lower part of the equalization vessel and pneumatic medium in an upper part. A connector tube with a connector valve is connected to the equalization vessel at about the level of the capacitive sensor so that the level of hydraulic fluid can be set at the capacitive sensor in the measurement tube at the beginning of the measurement. The capacitance rate of change is a measure of the hydraulic fluid flow or leak rate.