Yokogawa Electric Corporation

Ikuhiko Ishikawa

Toru Shimura

Takashi Arai

Shuichi Sato

Yusaku Yoshida

Yasumi Koike

Masakazu Saito

Masafumi Nakamura

Shinnosuke Yoshida

Youichi Iwano

Yuichi Kaneko

Daisuke Harigane

Kazuyuki Endo

Wandong Li

Ryou Hagiwara

Hironobu Oota

A field device according to one aspect of the present invention includes a plurality of types of sensors, at least one converter configured to acquire measured results of the plurality of types of sensors and to convert the measured results into measured information, the measured information being a physical quantity, and an information providing device configured to acquire and store the measured information from the at least one converter and to provide the stored measured information to an outside of the field device in a case that a predetermined condition is satisfied.

Field device and information providing method

An electromagnetic flowmeter measures a flow rate of a liquid of a measurement target that flows in a magnetic field formed within a measurement pipe. The electromagnetic flowmeter includes at least one pair of detection electrodes configured to detect an electromotive force generated due to a flow of the liquid, and configured to output a flow rate signal of a magnitude of the detected electromotive force, a measurement circuit configured to supply an alternating current between the detection electrodes and an earth electrode, and a control calculator configured to control a frequency of the alternating current to be 1 kHz or more, and configured to calculate a conductivity of the liquid whose conductivity is 1 mS/cm or more based on the flow rate signal output when the alternating current flows between the detection electrodes and the earth electrode.

Electromagnetic flowmeter and control method for diagnosing presence or absence of an attached conductive substance to the electrode surface

A field device, which measures a physical quantity in a plant or processes the physical quantity, includes: an instruction unit configured to output a verification execution instruction signal for instructing execution of verification of the field device; an operation verifying unit configured to verify an operation of at least one element of the field device in response to the verification execution instruction signal and to verify an operation of the field device based on the verification result; and an output unit configured to output the verification result which is a result of verification of the operation by the operation verifying unit.

Field device

An electromagnetic flowmeter applies a magnetic field, which is generated by excitation current, to a fluid to be measured flowing in a measurement tube, and measures a flow rate of the fluid to be measured on the basis of a detection signal to be generated from an electrode provided in the measurement tube. The electromagnetic flowmeter includes an excitation circuit configured to generate the excitation current having a positive excitation period, a negative excitation period and a non-excitation period, and a diagnosis unit configured to detect an abnormality based on characteristics of the fluid to be measured, on the basis of a level of the detection signal in a non-excitation stable period, which is a period in which a differential noise of detection signal to be generated in the non-excitation period converges.

Electromagnetic flowmeter

A portable device maintenance support apparatus includes one set of terminals configured to connect to a hybrid communication network performed based on any one of a plurality of protocols, by a compound signal in which an analog signal is superimposed with a digital signal including at least device information, the hybrid communication network being performed between the portable device maintenance support apparatus and a field device, the one set of terminals being common to the plurality of protocols.

Portable device maintenance support apparatus, system, and method

There is provided a two-wire transmitter which is connected to an external circuit by two transmission lines and which outputs a certain current signal to the external circuit using the external circuit as a power source. The two-wire transmitter includes: a sensor configured to convert a physical quantity into a first electrical signal and output the first electrical signal; a signal processing circuit configured to perform certain processing on the first electrical signal and output a second electrical signal; a constant current circuit configured to determine the certain current signal to be output to the external circuit, based on the second electrical signal; a reference voltage output unit configured to output a reference voltage based on the second electrical signal; and a shunt regulator circuit configured to determine a circuit voltage of the two-wire transmitter based on the reference voltage.

Two-wire transmitter

An electromagnetic flowmeter for giving a magnetic field to a measurement fluid, detecting an electric signal occurring in the measurement fluid according to the magnetic field, and computing a flow quantity value based on the electric signal includes a zero point measurement section for measuring a zero point of the measurement fluid; a storage section for storing the measured zero point measurement value; a determination section for determining whether or not the difference between the preceding zero point measurement value stored in the storage section and the present zero point measurement value is beyond a predetermined value range; and at least either a transmission section for transmitting the determination result or a display section for displaying the determination result when the determination section determines that the difference is beyond the predetermined value range.

Electromagnetic flowmeter and zero point measurement method thereof

A field equipment includes: a signal processing section; a first calculation control section for generating a first control signal which controls a start of a signal processing of the signal processing section; first and second insulating sections coupled to the first calculation control section; and a second calculation control section coupled to the first and second insulating sections and the signal processing section, the second calculation control section receiving the first control signal and then transmitting a second control signal corresponding to the first control signal to the signal processing section. The signal processing section generates a processed signal based on the second control signal. The second calculation control section receives the processed signal, then transmits data related to the first signal to the first calculation control section via the second insulating section, and then shifts to a low power consumption mode.

Field equipment of two-wire

An electromagnetic flowmeter includes: a detector for detecting a flow rate voltage; a shielded cable having an inner conductor provided around a cable core to which the flow rate voltage is applied from the detector; and a converter for receiving the flow rate voltage via the shielded cable, and performing a signal processing on the received flow rate voltage so as to output the processed flowrate voltage, wherein a preamplifier of the converter includes: an input circuit which is connected between the cable core and a common voltage point and has an input voltage dividing point for dividing the flow rate voltage; a main amplifier circuit which amplifies the flow rate voltage; and a feedback voltage distribution section which receives an output voltage from the main amplifier circuit, and distributes the output voltage as positive feedback voltages to the inner conductor and the input circuit respectively with different ratios.

Electromagnetic flowmeter including a feedback voltage distributed to the inner conductor of the shielded cable and the input circuit

An electromagnetic flow meter of a switching control system in which a DC voltage is applied to an exciting coil via switching elements, a direction of an exciting current flowing through the exciting coil is switched over at a predetermined excitation timing, and the switching elements are turned ON or OFF so as to hold the exciting current to be a predetermined value. The electromagnetic flow meter has first and second detection resistors which are connected in series to ends of the exciting coil via the switching elements, respectively, wherein a midpoint of the first and second detection resistors is grounded to set a voltage of the midpoint as a circuit reference voltage.

Electromagnetic flow meter with reduced power consumption and reduced exciting current

In order to attain a desired magnetic flux density, a parallel configuration of N divided magnetic circuits is formed, and accommodated on one pair of plate cores as N groups of exciting coils. According to the configuration, the burden of the magnetic coercive force which is driven by one of the magnetic circuits is reduced to 1/N. As a result, the consumption of the excitation power in each of the magnetic circuits can be reduced to (1/N). The total of magnetic fluxes which are obtained as a result of parallel driving of the N magnetic circuits are collected onto the single plate core.

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Tokyo, Japan

Ikuhiko Ishikawa