Lead-lag compensated temperature sensor

Claim 2

A compensated temperature responsive transmitter for sensing air temperature of an airstream comprising: a housing having a first and a second chamber; a pressure responsive element disposed in said first chamber; a first gas-filled temperature responsive bulb disposed in said airstream; first bellows between said first bulb and a first area on one side of said element for putting said first bulb in closed fluid communication with said first area to urge it in one direction; a second gas-filled temperature responsive bulb disposed adjacent said first bulb in said airstream; second bellows between said second bulb and a second area on the opposite side of said element for putting said second bulb in closed fluid communication with said second area to urge said element in an opposite direction; said first and second areas being of different magnitude; said first and second bulbs responding to a temperature change in said airstream at different rates; inlet means in said second chamber for communicating said second chamber with a supply of fluid under pressure; valve means disposed in said second chamber for varying the pressure of said supply fluid; and means responsive to said movement of said pressure responsive element connected to said valve means for controlling the pressure of said supply fluid.

Claim 3

A compensated temperature responsive transmitter for sensing air temperature of an airstream comprising: a housing having a first and a second chamber; pressure responsive means, including a plate, disposed in said first chamber; a first temperature responsive bulb means disposed in said airstream and in closed fluid communication with a first surface on said plate to urge it in one direction, said first bulb means including a first bellows in said first chamber connected at one end to said housing and at the other end to said first surface on said plate; a second temperature responsive bulb means disposed in said airstream and in closed fluid communication with a second surface on said plate to urge it in an opposite direction, said second bulb means including a second bellows in said first chamber connected at one end to said housing and at the other end to said second surface on said plate; said first bulb being filled with a gas which expands in response to a temperature change in said airstream at a first rate; said second bulb being filled with a gas which expands in response to said temperature change in said airstream at a second rate different from said first rate; said pressure responsive means including a third bellows connected at one end to said housing and at the other end to said second surface, said third bellows having an effective cross-sectional area equal to the effective cross-sectional area of said second bellows; inlet means in said second chamber communicating said second chamber with a supply of hydraulic fluid under pressure; valve means disposed in said second chamber for varying the pressure of said supply fluid; and means responsive to movement of said pressure responsive means extending between said first and second chambers for controlling the pressure of said supply fluid.

Claim 4

A compensated temperature responsive transmitter for sensing air temperature of an airstream comprising: a housing having a first and a second chamber; pressure responsive means, including a plate, disposed in said first chamber; a first temperature responsive bulb means disposed in said airstream and in closed fluid communication with a first surface on said plate to urge it in one direction, said first bulb means including a first bellows in said first chamber connected at one end to said housing and at the other end to said first surface on said plate; a second temperature responsive bulb means disposed in said airstream and in closed fluid communication with a second surface on said plate to urge it in an opposite direction, said second bulb means including a second bellows in said first chamber connected at one end to said housing and at the other end to said second surface on said plate; said first bulb being filled with a gas which expands in response to a temperature change in said airstream at a first rate; said second bulb being filled with a gas which expands in response to said temperature change in said airstream at a second rate different from said first rate; said pressure responsive means including a third bellows connected at one end to said housing and at the other end to said second surface, said third bellows having an effective cross-sectional area equal to the effective cross-sectional area of said second bellows; inlet means in said second chamber communicating said second chamber with a supply of hydraulic fluid under pressure; valve means disposed in said second chamber for varying the pressure of said supply fluid; and means responsive to movement of said pressure responsive means extending between said first and second chambers for controlling the pressure of said supply fluid.