Title:
DIFFERENTIAL PRESSURE MEASURING EQUIPMENT
Document Type and Number:
Japanese Patent JP3178564
Kind Code:
B2
Abstract:
PURPOSE: To diagnose the leakage of encapsulated liquid without dismounting a measuring equipment by providing a CPU and a memory, storing an initial zero point output value obtained by equalizing the pressure on the high and low pressure sides, and then comparing it with a zero point output value at the time of self-diagnosis.
CONSTITUTION: When a pressure is applied from the high pressure side, the pressure functioning onto a seal diaphragm 13 is transmitted to a silicon diaphragm 8 through an encapsulated liquid 102. When a pressure is applied from low the pressure side, the pressure functioning onto a seal diaphragm 12 is transmitted through an encapsulated liquid 101 to the silicon diaphragm 8. Consequently, the silicon diaphragm 8 is distorted depending on the pressure difference and the distortion is taken out electrically by means of a strain gauge 91 in order to measure the differential pressure. When self-diagnosis is carried out, the pressure is equalized on the high and low pressure sides 5, 4 and the zero point output value is measured. It is then compared with an initial zero point output value stored in a CPU and a decision is made that the encapsulated liquid has leaked if a threshold value is exceeded. This constitution allows self-diagnosis of leakage without dismounting the equipment.
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Inventors:
Saichiro Morita
Akira Fujita
Akira Fujita
Application Number:
JP14927593A
Publication Date:
June 18, 2001
Filing Date:
June 21, 1993
Export Citation:
Assignee:
Yokogawa Electric Corporation
International Classes:
G01L13/02; G01L9/00; G01L27/00; (IPC1-7): G01L13/02; G01L27/00
Domestic Patent References:
| JP2213736A | ||||
| JP636431A |