Abstract: An object is to provide a flow rate control device that can suppress a manufacturing cost and greatly reduce burdens of setting and maintenance. A flow rate control device 11 of the invention is comprised with a flow rate adjusting valve 21 that is installed in a flow path 13, a flow rate measurement part 41 that measures a flow rate of a fluid flowing through the flow path 13, a controller 61 that controls opening degrees of the flow rate adjusting valve 21 based on a measurement result of the flow rate measurement part 41, and a pressure deficiency detecting function that detects pressure deficiency when a limit sensor 246 (an opening detecting sensor) that detects the opening of the flow rate adjusting valve 21 detects the opening degrees are full.

Abstract: A flowmeter that achieves both high reliability and a low cost is provided. The flowmeter includes an impeller that is rotatably supported in a flow path, a magnetic sensor that detects a magnetic change associated with a rotation of the impeller, and a magnet that applies a magnetic field to the magnetic sensor, wherein the impeller is formed of a magnetic material that is not magnetized, and the magnetic sensor and the magnet are arranged outside the flow path.

Abstract: An object is to provide a flow rate control device that can suppress a manufacturing cost and greatly reduce burdens of setting and maintenance. A flow rate control device 11 of the invention is comprised with a flow rate adjusting valve 21 that is installed in a flow path 13, a flow rate measurement part 41 that measures a flow rate of a fluid flowing through the flow path 13, a controller 61 that controls opening degrees of the flow rate adjusting valve 21 based on a measurement result of the flow rate measurement part 41, and a pressure deficiency detecting function that detects pressure deficiency when a limit sensor 246 (an opening detecting sensor) that detects the opening of the flow rate adjusting valve 21 detects the opening degrees are full.

Abstract: A flowmeter includes a metallic body that has a flow path therein, an impeller that is rotatably supported in the flow path inside the body, a pickup coil that is configured to detect a number of rotations of the impeller, the pickup coil being disposed outside the body, a coil case that is made of metal, and accommodates the pickup coil, an amplifier circuit board that is configured to amplify a detection signal of the pickup coil, and an amplifier case that is made of resin, and accommodates the amplifier circuit board. The coil case and the amplifier case are connected via a resin case that is made of resin and includes an insulation material therein.

Abstract: A flowmeter includes a metallic body that has a flow path therein, an impeller that is rotatably supported in the flow path inside the body, a pickup coil that is configured to detect a number of rotations of the impeller, the pickup coil being disposed outside the body, a coil case that is made of metal, and accommodates the pickup coil, an amplifier circuit board that is configured to amplify a detection signal of the pickup coil, and an amplifier case that is made of resin, and accommodates the amplifier circuit board. The coil case and the amplifier case are connected via a resin case that is made of resin and includes an insulation material therein.