Electric differential pressure converter for the control of probes in the direction of flow

Claim 2

A differential pressure converter comprising: a U-tube manometer having a pair of legs and a base forming said U-tube; a light source disposed between said legs of said manometer; an opaque manometer fluid, the density of which is approximately equal to the density of water, substantially filling said Utube manometer, so as to form a pair of fluid columns, said fluid columns controlling the amount of light from said light source passing through said legs and; a pair of photocells, the shapes of which are elongated in the direction of said fluid columns and are arranged to be normally blocked from the light source by said fluid columns, whereby a differential pressure between said legs results in a drop in the height of one of said fluid columns, thereby producing a proportionality increasing voltage in the thus exposed photocell.

Claim 3

A differential pressure converter according to claim 1, characterized in that the two photocells operate according to the principle of differential connection.

Claim 4

A differential pressure converter according to claim 2, characterized in that a mixture of distilled water, drawing ink, and solvent is used as manometer fluid.

Claim 5

A differential pressure converter comprising: first means for transmitting light in first and second directions; second means displaced with respect to said first means in each of said first and second directions, for generating a differential output signal representative of the difference in the amount of light emitted by said first means and received by said second means in said first and second respective directions; third means, disposed between said first and second means, for receiving first and second pressures and for normally preventing the transmission of light emitted by said first means in said first and second directions to said second means in the absence of a pressure differential between said first and second pressures, and for permitting the transmission of light emitted by said first means to said second means in one of said first and second directions only upon the existence of a pressure differential between said first and second pressures, so as to expose at least a portion of said second means in said one of said first and second directions whereby a differential output signal indicative of the pressure differential and proportional to said at least a portion of said second means will be generated by said second means.

Claim 6

A differential pressure converter comprising: first means for transmitting light in first and second directions; second means displaced with respect to said first means in each of said first and second directions, for generating a differential output signal representative of the difference in the amount of light emitted by said first means and received by said second means in said first and second respective directions; third means, disposed between said first and second means, for receiving first and second pressures and for normally preventing the transmission of light emitted by said first means in said first and second directions to said second means in the absence of a pressure differential between said first and second pressures, and for permitting the transmission of light emitted by said first means to said second means in one of said first and second directions only upon the existence of a pressure differential between said first and second pressures, so as to expose at least a portion of said second means in said one of said first and second directions whereby a differential output signal indicative of the pressure differential and proportional to said at least a portion of said second means will be generated by said second means.

Claim 7

A converter according to claim 4, wherein said third means comprises: a U-tube manometer having a pair of legs, each of which is disposed to intercept light in a respective one of said first and second directions, and a base forming said U-tube; an opaque manometer fluid, the density of which is approximately equal to the density of water, substantially filling said U-tube manometer so as to form a pair of fluid columns, said fluid columns controlling the amount of light from said first means passing through said legs; said first means comprises a light source disposed between said legs of said manometer; and wherein said second means comprises a pair of photocells, the shapes of which are elongated in the direction of said fluid columns and are arranged to be normally blocked by said fluid columns from the light emitted by said light source, whereby a differential pressure between said legs results in a drop in the height of one of said fluid columns, thereby producing a proportionally increasing voltage in the thus exposed photocell.

Claim 8

A converter according to claim 5, characterized in that a mixture of distilled water, drawing ink and solvent is employed as said manometer fluid.