Abstract: A differential pressure transmitter, a pneumatically operated square root extracting device therefor and methods of making the same are provided, the transmitter comprising a unit for producing an output pneumatic signal from a pneumatic source in relation to the air velocity pressure of air flowing in a passage, a unit that senses the difference between the total pressure and the static pressure of the air flowing in the passage, and a unit for extracting the square root of the air velocity pressure of the air from the pneumatic output signal as the pneumatic output signal is being produced so that the pneumatic output signal is substantially linear with respect to the air velocity of the air flow in the passage whereby the transmitter comprises a linear air velocity transmitter, the unit for extracting the square root comprising a cam having a cam face that defines at least part of the involute of a circle.

Abstract: A differential pressure transmitter, a pneumatically operated square root extracting device therefor and methods of making the same are provided, the transmitter comprising a unit for producing an output pneumatic signal from a pneumatic source in relation to the air velocity pressure of air flowing in a passage, a unit that senses the difference between the total pressure and the static pressure of the air flowing in the passage, and a unit for extracting the square root of the air velocity pressure of the air from the pneumatic output signal as the peneumatic output signal is being produced so that the pneumatic output signal is substantially linear with respect to the air velocity of the air flow in the passage whereby the transmitter comprises a linear air velocity transmitter, the unit for extracting the square root comprising a cam having a cam face that defines at least part of the involute of a circle.

Abstract: A differential pressure transmitter, a pneumatically operated square root extracting device therefor and methods of making the same are provided, the transmitter comprising a unit for producing an output pneumatic signal from a pneumatic source in relation to the air velocity pressure of air flowing in a passage, a unit that senses the difference between the total pressure and the static pressure of the air flowing in the passage, and a unit for extracting the square root of the air velocity pressure of the air from the pneumatic output signal as the pneumatic output signal is being produced so that the pneumatic output signal is substantially linear with respect to the air velocity of the air flow in the passage whereby the transmitter comprises a linear air velocity transmitter, the unit for extracting the square root comprising a cam having a cam face that defines at least part of the involute of a circle.

Abstract: A pneumatic control system, control unit and method of making the same are provided, the system comprising a pneumatic source, a pneumatically operated device that produces an output, and a control unit for interconnecting the source to the device. The control unit has an input interconnected to the source and an output interconnected to the device, the control unit having a set point for selecting a desired output of the device. The control unit has a valve unit for controlling the interconnection between the input and the output thereof so as to regulate the pressure value in the output of the control unit. The control unit has a regulating unit for operating the valve unit to tend to produce an output of the device that corresponds to the selected output of the set point.

Abstract: A pneumatic control system, control unit and method of making the same are provided, the system comprising a pneumatic source, a pneumatically operated device that produces an output, and a control unit for interconnecting the source to the device. The control unit has an input interconnected to the source and an output interconnected to the device, the control unit having a set point for selecting a desired output of the device. The control unit has a valve unit for controlling the interconnection between the input and the output thereof so as to regulate the pressure value in the output of the control unit. The control unit has a regulating unit for operating the valve unit to tend to produce an output of the device that corresponds to the selected output of the set point.

Abstract: A control panel layout sheet having on one side thereof first indications indicating control devices that are to be mounted on the control panel to be made from the sheet, second indications indicating the external pneumatic lines that are to be interconnected to the devices, and third indications indicating the external electrical lines that are to be interconnected to the devices whereby the layout sheet is adapted to be utilized as a guide for constructing a control panel having all of the control devices and external pneumatic and electrical lines thereon. The first, second and third indications are disposed on the sheet in substantially the exact location that the control devices and external pneumatic and electrical lines will take in a respective control panel to be made therefrom so that the layout sheet substantially simulates a completed control panel when facing the same.

Abstract: A manifold adapted to detachably carry on one side thereof a plurality of pneumatically and electrically operated control units each of which is adapted to be fluidly and electrically interconnected to pneumatic structure and electrical structure of the manifold. That one side of the manifold has external interconnecting structure for the pneumatic structure and the electrical structure whereby external pneumatic and electrical lines can be interconnected to the same side of the manifold that the units are adapted to be interconnected thereto.

Abstract: A manifold adapted to detachably carry on one side thereof a plurality of pneumatically and electrically operated control units each of which is adapted to be fluidly and electrically interconnected to pneumatic structure and electrical structure of the manifold. That one side of the manifold has external interconnecting structure for the pneumatic structure and the electrical structure whereby external pneumatic and electrical lines can be interconnected to the same side of the manifold that the units are adapted to be interconnected thereto.

Abstract: An adjustable bimetal construction adapted to provide an adjustable throttling range and having a first bimetal member and a second bimetal member, one opposed end of the first bimetal member being operatively interconnected to the frame while the other end thereof is movable relative to the frame and one opposed end of the second bimetal member also being operatively interconnected to the frame while the other end thereof is movable relative to the frame. A device operatively interconnects the other ends of the bimetal members together to provide a combined bimetal action at the other ends thereof which can be adjusted through different positions of the device.