Abstract: A poppet valve assembly is structured divided into a seat portion and a seat retaining portion. A spring is contained within an interior space between the seat portion and the seat retaining portion, where a poppet valve is held between the seat portion and the seat retaining portion in a state biased by the spring. The poppet valve is provided with a through hole for connecting a chamber that contains the spring and a discharge air duct of a spool, and a fine connecting duct for connecting the through hole and an output air pressure chamber. The chamber that contains the spring is separated from a supply air pressure chamber by an O-ring.

Abstract: A spool is provided with a first discharge air duct connecting the first opening to the first discharge air chamber, and a second discharge air duct connecting the second opening to the second discharge air chamber, where the first discharge air duct and the second discharge air duct are divided by a non-duct part. A first output air pressure chamber is adjacent to a first discharge air chamber with a first diaphragm interposed therebetween, the first discharge air chamber is adjacent to a bias chamber with a second diaphragm interposed therebetween, the bias chamber is adjacent to an input air pressure chamber with a third diaphragm interposed therebetween, the input air pressure chamber is adjacent to a second discharge air chamber with a fourth diaphragm interposed therebetween, and the second discharge air chamber is adjacent to a second output air pressure chamber with a fifth diaphragm interposed therebetween.

Abstract: A positioner operating mode identifying function is provided in a calculating unit. A pressure value of an amplified pneumatic pressure signal, from a single-mode pilot relay, is detected by a pressure sensor and sent to the calculating unit. The calculating unit, through the positioner operating mode identifying function, monitors a change in the amplified pneumatic pressure signal corresponding to a change in the control signal, and if the direction of change in the control output and the direction of change of the amplified pneumatic pressure signal are the identical direction, identifies the operating mode of the positioner as the positive operating mode. The operating mode of the positioner is identified as the negative operating mode if the direction of change in the control output and the direction of change of the amplified pneumatic pressure signal are the opposite directions. The identification results displayed on a screen of a display unit.

Abstract: A positioner operating mode identifying function and an use parameter selecting function are provided in a calculating unit. A positive operating parameter and a negative operating parameter are stored in a storing portion. The positioner operating mode identifying function identifies the operating mode of a positioner or from the direction of change of a control output and the direction of change of an amplified pneumatic pressure signal Pout, and the identification result is set automatically as the current operating mode of the positioner. In accordance with the current operating mode identified for the positioner, the use parameter selecting function selects, as the use parameter from the storing portion, the positive operating parameter if the positive operating mode, and the negative operating parameter if the negative operating mode, and sets the selected use parameter automatically.

Abstract: An operating mode of an electro-pneumatic converting unit is stored in advance in an electro-pneumatic converting unit operating mode storing unit. A blockage location identifying function is provided in a calculating unit. The operating unit monitors the magnitude of shift and the direction of shift of the control output, relative to the nozzle back pressure, through the blockage location identifying function, and identifies whether a blockage has occurred in the fixed orifice or the nozzle/flapper mechanism based on the magnitude of shift and direction of shift of the control output, relative to the nozzle back pressure, and based on the operating mode of the electro-pneumatic converting unit, stored in the electro-pneumatic converting unit operating mode storing unit.

Abstract: A spool is provided with a first discharge air duct connecting the first opening to the first discharge air chamber, and a second discharge air duct connecting the second opening to the second discharge air chamber, where the first discharge air duct and the second discharge air duct are divided by a non-duct part. A first output air pressure chamber is adjacent to a first discharge air chamber with a first diaphragm interposed therebetween, the first discharge air chamber is adjacent to a bias chamber with a second diaphragm interposed therebetween, the bias chamber is adjacent to an input air pressure chamber with a third diaphragm interposed therebetween, the input air pressure chamber is adjacent to a second discharge air chamber with a fourth diaphragm interposed therebetween, and the second discharge air chamber is adjacent to a second output air pressure chamber with a fifth diaphragm interposed therebetween.

Abstract: A poppet valve assembly is structured divided into a seat portion and a seat retaining portion. A spring is contained within an interior space between the seat portion and the seat retaining portion, where a poppet valve is held between the seat portion and the seat retaining portion in a state biased by the spring. The poppet valve is provided with a through hole for connecting a chamber that contains the spring and a discharge air duct of a spool, and a fine connecting duct for connecting the through hole and an output air pressure chamber. The chamber that contains the spring is separated from a supply air pressure chamber by an O-ring.

Abstract: A positioner operating mode identifying function and an use parameter selecting function are provided in a calculating unit. A positive operating parameter and a negative operating parameter are stored in a storing portion. The positioner operating mode identifying function identifies the operating mode of a positioner or from the direction of change of a control output and the direction of change of an amplified pneumatic pressure signal Pout, and the identification result is set automatically as the current operating mode of the positioner. In accordance with the current operating mode identified for the positioner, the use parameter selecting function selects, as the use parameter from the storing portion, the positive operating parameter if the positive operating mode, and the negative operating parameter if the negative operating mode, and sets the selected use parameter automatically.

Abstract: A positioner operating mode identifying function is provided in a calculating unit. A pressure value of an amplified pneumatic pressure signal, from a single-mode pilot relay, is detected by a pressure sensor and sent to the calculating unit. The calculating unit, through the positioner operating mode identifying function, monitors a change in the amplified pneumatic pressure signal corresponding to a change in the control signal, and if the direction of change in the control output and the direction of change of the amplified pneumatic pressure signal are the identical direction, identifies the operating mode of the positioner as the positive operating mode. The operating mode of the positioner is identified as the negative operating mode if the direction of change in the control output and the direction of change of the amplified pneumatic pressure signal are the opposite directions. The identification results displayed on a screen of a display unit.

Abstract: An operating mode of an electro-pneumatic converting unit is stored in advance in an electro-pneumatic converting unit operating mode storing unit. A blockage location identifying function is provided in a calculating unit. The operating unit monitors the magnitude of shift and the direction of shift of the control output, relative to the nozzle back pressure, through the blockage location identifying function, and identifies whether a blockage has occurred in the fixed orifice or the nozzle/flapper mechanism based on the magnitude of shift and direction of shift of the control output, relative to the nozzle back pressure, and based on the operating mode of the electro-pneumatic converting unit, stored in the electro-pneumatic converting unit operating mode storing unit.