摘要:
Measurements are obtained by a computing unit based on an output Vh from an indirectly-heated constant-temperature controlling flow rate measuring section (16) and an output Vout from a two-constant-point temperature difference detecting flow rate measuring sections (18a, 18b). In the flow rate measuring section (16), a heating element (163) is feedback-controlled based on a detected temperature by a heat sensing element (162) to obtain an output Vh based on the feedback-controlled condition. An output Vout is obtained from flow rate measuring sections (18a, 18b) based on the detected temperature difference between a heat sensing element (182) disposed on the liquid-flow-direction upstream side of the flow-rate measuring section (16) and a temperature sensing element disposed on the downstream side. A computing unit outputs as a measurement a flow rate obtained based on the output Vh in a flow rate region where a flow rate is larger than a predetermined boundary flow rate, and outputs as a measurement a flow rate obtained based on the output Vout in a flow rate region where it is less than a boundary flow rate. Accordingly, a flow rate is measured with good precision and sensitivity over a wide flow rate range from a trace-amount flow rate region to a comparatively large flow rate region.
摘要:
Measurements are obtained by a computing unit based on an output Vh from an indirectly-heated constant-temperature controlling flow rate measuring section (16) and an output Vout from a two-constant-point temperature difference detecting flow rate measuring sections (18a, 18b). In the flow rate measuring section (16), a heating element (163) is feedback-controlled based on a detected temperature by a heat sensing element (162) to obtain an output Vh based on the feedback-controlled condition. An output Vout is obtained from flow rate measuring sections (18a, 18b) based on the detected temperature difference between a heat sensing element (182) disposed on the liquid-flow-direction upstream side of the flow rate measuring section (16) and a temperature sensing element disposed on the downstream side. A computing unit outputs as a measurement a flow rate obtained based on the output Vh in a flow rate region where a flow rate is larger than a predetermined boundary flow rate, and outputs as a measurement a flow rate obtained based on the output Vout in a flow rate region where it is less than a boundary flow rate. Accordingly, a flow rate is measured with good precision and sensitivity over a wide flow rate range from a trace-amount flow rate region to a comparatively large flow rate region.
摘要:
Measurements are obtained by a computing unit based on an output Vh from an indirectly-heated constant-temperature controlling flow rate measuring section (16) and an output Vout from a two-constant-point temperature difference detecting flow rate measuring sections (18a, 18b). In the flow rate measuring section (16), a heating element (163) is feedback-controlled based on a detected temperature by a heat sensing element (162) to obtain an output Vh based on the feedback-controlled condition. An output Vout is obtained from flow rate measuring sections (18a, 18b) based on the detected temperature difference between a heat sensing element (182) disposed on the liquid-flow-direction upstream side of the flow rate measuring section (16) and a temperature sensing element disposed on the downstream side. A computing unit outputs as a measurement a flow rate obtained based on the output Vh in a flow rate region where a flow rate is larger than a predetermined boundary flow rate, and outputs as a measurement a flow rate obtained based on the output Vout in a flow rate region where it is less than a boundary flow rate. Accordingly, a flow rate is measured with good precision and sensitivity over a wide flow rate range from a trace-amount flow rate region to a comparatively large flow rate region.
摘要:
A device placed in a tank and used for detecting a leakage of liquid in the tank. Vertical measurement tube passages (10, 14) into which the liquid in the tank is introduced have a measurement tube (10) and a measurement thin tube (14). The measurement thin tube (14) communicates with the measurement tube and is located lower than the measurement tube. The measurement thin tube has a cross-sectional area that is equal to or smaller than {fraction (1/50)} of that of the measurement tube. A thermal flow sensor (16) used for measuring a liquid flow rate is attached to the measurement thin tube (14). There is provided leakage detecting means (22) for detecting a leakage of liquid in the tank according to the flow rate value measured by the sensor. The leakage detecting means generates a leakage detection signal when a flow rate value measured by the sensor is within a range greater than 0 and smaller than the flow rate value obtained when liquid is added to the tank or when the liquid in the tank is taken out. Thus, even a leakage of a very small amount is detected easily and accurately without stopping the use of the tank.
摘要:
A device placed in a tank and used for detecting a leakage of liquid in the tank. Vertical measurement tube passages (10, 14) into which the liquid in the tank is introduced have a measurement tube (10) and a measurement thin tube (14). The measurement thin tube (14) communicates with the measurement tube and is located lower than the measurement tube. The measurement thin tube has a cross-sectional area that is equal to or smaller than {fraction (1/50)} of that of the measurement tube. A thermal flow sensor (16) used for measuring a liquid flow rate is attached to the measurement thin tube (14). There is provided leakage detecting means (22) for detecting a leakage of liquid in the tank according to the flow rate value measured by the sensor. The leakage detecting means generates a leakage detection signal when a flow rate value measured by the sensor is within a range greater than 0 and smaller than the flow rate value obtained when liquid is added to the tank or when the liquid in the tank is taken out. Thus, even a leakage of a very small amount is detected easily and accurately without stopping the use of the tank.
摘要:
Measurements are obtained by a computing unit based on an output Vh from an indirectly-heated constant-temperature controlling flow rate measuring section (16) and an output Vout from a two-constant-point temperature difference detecting flow rate measuring sections (18a, 18b). In the flow rate measuring section (16), a heating element (163) is feedback-controlled based on a detected temperature by a heat sensing element (162) to obtain an output Vh based on the feedback-controlled condition. An output Vout is obtained from flow rate measuring sections (18a, 18b) based on the detected temperature difference between a heat sensing element (182) disposed on the liquid-flow-direction upstream side of the flow rate measuring section (16) and a temperature sensing element disposed on the downstream side. A computing unit outputs as a measurement a flow rate obtained based on the output Vh in a flow rate region where a flow rate is larger than a predetermined boundary flow rate, and outputs as a measurement a flow rate obtained based on the output Vout in a flow rate region where it is less than a boundary flow rate. Accordingly, a flow rate is measured with good precision and sensitivity over a wide flow rate range from a trace-amount flow rate region to a comparatively large flow rate region.
摘要:
A flow rate/liquid type detecting method for detecting the flow rate of a fluid and, at the same time, detecting any one of or both the type of the fluid and the concentration of the fluid, characterized in that: by using a flow rate/liquid type detecting apparatus comprising a main passage through which a fluid to be detected flows, an auxiliary passage branched from the main passage, and a flow rate/liquid type detecting sensor device provided in the auxiliary passage, is provided, and in conducting any one of or both the detection of the type of the fluid to be detected and the detection of the concentration of the fluid to be detected, an auxiliary passage opening/closing valve is closed, and the fluid to be detected is allowed to temporarily stay within the flow rate/liquid type detecting sensor device to conduct any one of or both the detection of the liquid type and the detection of the concentration, and in detecting the flow rate of the fluid to be detected, the auxiliary passage opening/closing valve is opened to allow the fluid to be detected to flow into the flow rate/liquid type detecting sensor device to detect the flow rate.
摘要:
A flow rate/liquid type detecting method for detecting the flow rate of a fluid and, at the same time, detecting any one of or both the type of the fluid and the concentration of the fluid, characterized in that: by using a flow rate/liquid type detecting apparatus comprising; a main passage through which a fluid to be detected flows, an auxiliary passage branched from said main passage, and a flow rate/liquid type detecting sensor device provided in said auxiliary passage, is provided, and in conducting any one of or both the detection of the type of said fluid to be detected and the detection of the concentration of said fluid to be detected, said auxiliary passage opening/closing valve is closed, and said fluid to be detected is allowed to temporarily stay within said flow rate/liquid type detecting sensor device to conduct any one of or both the detection of the liquid type and the detection of the concentration, and in detecting the flow rate of the fluid to be detected, said auxiliary passage opening/closing valve is opened to allow the fluid to be detected to flow into said flow rate/liquid type detecting sensor device to detect the flow rate.
摘要:
A flow rate/liquid type detecting method for detecting the flow rate of a fluid and, at the same time, detecting any one of or both the type of the fluid and the concentration of the fluid, characterized in that, by using a flow rate/liquid type detecting apparatus comprising: a main passage through which a fluid to be detected flows, an auxiliary passage branched from the main passage, and a flow rate/liquid type detecting sensor device provided in the auxiliary passage, is provided, and in conducting any one of or both the detection of the type of the fluid and the detection of the concentration of the fluid, the auxiliary passage opening/closing valve is closed, and the fluid is allowed to temporarily stay within the flow rate/liquid type detecting sensor device to conduct any one of or both the detection of the liquid type and the detection of the concentration, and in detecting the flow rate of the fluid detected, the auxiliary passage opening/closing valve is opened to allow the fluid to flow into the flow rate/liquid type detecting sensor device to detect the flow rate.
摘要:
A flow rate/liquid type detecting method for detecting the flow rate of a fluid and, at the same time, detecting any one of or both the type of the fluid and the concentration of the fluid, characterized in that, by using a flow rate/liquid type detecting apparatus comprising: a main passage through which a fluid to be detected flows, an auxiliary passage branched from the main passage, and a flow rate/liquid type detecting sensor device provided in the auxiliary passage, is provided, and in conducting any one of or both the detection of the type of the fluid and the detection of the concentration of the fluid, the auxiliary passage opening/closing valve is closed, and the fluid is allowed to temporarily stay within the flow rate/liquid type detecting sensor device to conduct any one of or both the detection of the liquid type and the detection of the concentration, and in detecting the flow rate of the fluid detected, the auxiliary passage opening/closing valve is opened to allow the fluid to flow into the flow rate/liquid type detecting sensor device to detect the flow rate.