Hitachi, Ltd.

Akira Nagasu

Yoshimi Yamamoto

Tomoyuki Tobita

Yukio Takahashi

Takeo Nagata

Ken'ichi Aoki

Satoshi Shimada

Hiroyasu Uchida

Masao Fukunaga

Yoshitaka Matsuoka

Yutaka Sakurai

Syozo Kasai

Tomomasa Yoshida

Yosimi Yamamoto

Teruo Kobayahsi

Toshihiro Onose

In a multiple function type differential pressure sensor including a semiconductor chip having a differential pressure detector for detecting a differential pressure, temperature detector for detecting a temperature, and static pressure detector for detecting a static pressure provided on a semiconductor substrate of a single chip, two or more pairs of differential pressure detectors means are incorporated, and a difference between outputs of the two or more pairs of differential pressure detectors is fetched out.

Process state detector, semiconductor sensor and display device for

Composite condition detection apparatus for detecting static pressure,

A multi-function differential pressure sensor includes a semiconductor chip, a stationary base having a joining portion joined to a thick wall portion of the semiconductor chip, and a housing joined to the stationary base. The semiconductor chip is provided with a differential pressure detection unit, a static pressure detection unit, and a temperature detection unit. The joining portion of the stationary base is not thicker than the semiconductor chip. The stationary base has one or more thin wall portions located, in a plan view, within a circular pressure sensitive diaphragm of the semiconductor chip.

Multi-function differential pressure sensor with thin supporting base

A differential pressure transmitter for detecting a difference between a pressure of a first detection fluid in a first pressure-receiving chamber and a pressure of a second detection fluid in a second pressure-receiving chamber, including a first diaphragm for sealing the first detection fluid, a second diaphragm for sealing the second detection fluid which is installed almost in parallel to the first diaphragm, a first isolation chamber communicated to the first pressure-receiving chamber, a second isolation chamber communicated to the second pressure-receiving chamber, a third diaphragm installed between the first and the second chambers and in a direction different from those of the first and second diaphragms, and a differential pressure detection sensor installed on and connected to at least one of the first and the second isolation chambers. The differential pressure transmitter having a symmetrical construction has a high sensitivity because difference between transmitting coefficients in pressure transmitting paths in high and low pressures is minimized.

Differential pressure transmitter having symmetrical construction

A compact pressure differential/pressure detector is a process detection apparatus for measuring a pressure, a level, a pressure differential of a process fluid. The detector is constructed of a pressure sensing block having sensors for sensing a pressure and a pressure differential, a signal processing block for processing signals from the pressure sensing block, and a terminal board block for receiving power supply from outside and transmitting signals to outside. These blocks are arranged along the same axis. Furthermore, an indicator indicating a process state is also arranged along the same axis and received in a covering case. The case is firmly attached to the pressure sensing block. The process detection apparatus permits a compact design and offers an excellent maintainability.

Process detection apparatus

A differential pressure transmitter detects a differential pressure condition of a fluid by means of a semiconductor sensor. First and second seal diaphragms are provided in a member which constitutes the differential pressure transmitter, to form first and second pressure receiving chambers. An overload protection diaphragm and first and second damper chambers are provided at positions close to the first and second pressure receiving chambers. Also, there are provided a passage for connecting the first pressure receiving chamber and the first damper chamber, a passage for connecting the second pressure receiving chamber and the second damper chamber, and passages for connecting the first and second damper chambers respectively with the semiconductor sensor. Even when a change is caused in the temperature of a processed fluid to be detected, the differential pressure transmitter quickly detects the temperature change, so that a differential pressure of the processed fluid can be measured with high accuracy.

Compact differential pressure transmitter having first and second damper

Multi-function differential pressure sensor with thin stationary base

A semiconductor differential pressure transducer comprises a pair of pressure receiving chambers at both sides of a pressure receiving part, and a pair of compensating chambers and a pair of pressure measuring chambers which are placed in the pressure receiving part, and the pressure receiving chambers communicate with the pressure measuring chambers through the compensating chambers.

Semiconductor differential pressure transducer

A differential pressure transmitter has a pressure receiving portion and a sensor portion which are constituted from separate parts separably jointed with each other. The sensor portion includes a semiconductor sensor having one side formed with a resistance pattern and the other side which has a thick-walled peripheral portion and a thick-walled central portion. The semiconductor sensor is incorporated in the sensor portion as being supported at the thick-walled peripheral portion thereof. The pressure receiving portion includes seal diaphragms disposed on both sides of the pressure receiving portion and a central diaphragm disposed therein. The semiconductor sensor is arranged such that the side thereof carrying the resistance pattern faces the pressure receiving portion.

Differential pressure transmitter

A pressure transducer is arranged to mount a semiconductor pressure sensor in a housing such that the pressure of a high-pressure fluid is applied to one side of the semiconductor pressure sensor through a high pressure seal diaphragm and a sealed liquid in the high pressure side, while the pressure of a low-pressure fluid is applied to the other side of the sensor through a low-pressure seal diaphragm and a sealed liquid in the low pressure side, and a protecting member is provided closer to the low-pressure seal diaphragm.

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Ibaraki-ken, Japan

Akira Nagasu