Azbil Corporation

Tetsuya Shimakata

Takashi Nomiyama

Koichi Kondo

Miho Egawa

One A/D converter and the other A/D converter have a common power supply voltage and sample an A/D conversion value at short time intervals and at a long time intervals, respectively. Both the A/D converter and the A/D converter are set in a constant active state (continuous conversion mode). This allows the total consumption current combining the consumption current of the A/D converter and the consumption current of the A/D converter to be constant, so that the power supply voltage is stabilized and a stable A/D conversion value can be obtained from each of the A/D converters.

Measurement instrument

When the damping time constant D&#x3c4; is changed to D&#x3c4;=0, the sampling period Ts is automatically changed from 100 ms to 50 ms. The sampling time is automatically changed from 60 ms to 30 ms. Thus, when the damping time constant D&#x3c4; is changed to D&#x3c4;=0, a processing unit samples an electrical signal corresponding to the pressure difference of a fluid detected by a differential pressure sensor for the sampling time ts=30 ms in every sampling period Ts=50 ms, and finds the measurement value &#x394;P of the differential pressure by performing a variety of operation processing including a linearization operation and a square root operation on the sampled electrical signal. In the operation processing, the processing unit does not perform a damping operation.

Differential pressure transmitter

When a major failure is detected, display of a measurement value on a display section is stopped, and instead of the measurement value, an abnormal code, which indicates the contents of the major failure, is displayed on the display section. When a minor failure is detected, an abnormal code, which indicates the contents of the minor failure, and a measurement value are alternately displayed on the display section by being switched one from the other.

Growing community of inventors

Tokyo, Japan

Tetsuya Shimakata