Abstract: A composition ratio estimation device estimates a composition ratio of a content having mixed substances with different boiling points in a tank. The content is retained as a liquid in the tank lower part. The substances are partially floatable as a gas or liquid in a space in the tank upper part. The device includes a reference object disposed in the space, a transmitting-receiving unit that transmits radar waves toward the reference object and the surface of the liquid and receives reflected radar waves, a temperature measuring unit that acquires a level at which a boiling point of a floating substance is reached, a dielectric constant calculating unit that stores in advance a physical distance between the unit and the object and calculates a dielectric constant of a space between the unit and the object, and a composition ratio derivation unit that derives a composition ratio of the liquid.

Abstract: A composition ratio estimation device estimates a composition ratio of a content having mixed substances with different boiling points in a tank. The content is retained as a liquid in the tank lower part. The substances are partially floatable as a gas or liquid in a space in the tank upper part. The device includes a reference object disposed in the space, a transmitting-receiving unit that transmits radar waves toward the reference object and the surface of the liquid and receives reflected radar waves, a temperature measuring unit that acquires a level at which a boiling point of a floating substance is reached, a dielectric constant calculating unit that stores in advance a physical distance between the unit and the object and calculates a dielectric constant of a space between the unit and the object, and a composition ratio derivation unit that derives a composition ratio of the liquid.

Abstract: A high liquid-level alarm device is configured such that one casing includes a plurality of liquid-level alarm units, the liquid-level alarm units are directed for monitoring one liquid level, issue an alarm for a different height of the liquid level, have radio wave detection units for detecting a radio wave, respectively, each of the liquid-level alarm units has a radio wave detection unit for detecting a radio wave, transmits a radio wave when not detecting a radio wave, and performs a determination operation as to whether a predetermined liquid level is reached, and when one of the liquid-level alarm units is performing the determination operation, the rest of the liquid-level alarm units do not perform the determination operation.

Abstract: A high liquid-level alarm device is configured such that one casing includes a plurality of liquid-level alarm units, the liquid-level alarm units are directed for monitoring one liquid level, issue an alarm for a different height of the liquid level, have radio wave detection units for detecting a radio wave, respectively, each of the liquid-level alarm units has a radio wave detection unit for detecting a radio wave, transmits a radio wave when not detecting a radio wave, and performs a determination operation as to whether a predetermined liquid level is reached, and when one of the liquid-level alarm units is performing the determination operation, the rest of the liquid-level alarm units do not perform the determination operation.

Abstract: An ASK modulator which modulates an input signal in accordance with a logic level of the input signal, changes the amplitude of the input signal, and generates an amplitude shift keying (ASK) modulated signal is provided. This ASK modulator has an oscillating means for generating a carrier signal, a frequency filter means which passes a prescribed frequency component of the input signal and outputs a frequency limited signal having the prescribed frequency component, and a modulator which modulates the input signal based on the level of the carrier signal and on the level of the frequency limited signal and outputs the ASK modulated signal having a limited frequency component.

Abstract: A first base station (2k) is connected to a communication line (L1), and performs wireless communication on control information with a terminal station (1) via a control channel. Moreover, a second base station (3k) corresponding to the first base station (2k) is connected to a communication line (L2) and performs wireless communication on data with the terminal station (1) via a communication channel based on the control information from the first base station (2k).

Abstract: An amplitude-modulated carrier signal is demodulated by passage through a limiting amplifier that converts the amplitude-modulated carrier signal to a signal of constant amplitude, and also produces a received signal strength indicator signal. The received signal strength indicator signal is used as the demodulated signal.