Apparatus for measuring variables

Claim 2

In apparatus for determining the state of a fluid by measuring two variable characteristics thereof, the improvement comprising, in combination: first means for expressing one of said variables in terms of a first change of position; second means for expressing the other of said variables in terms of a second change of position; third means operatively associated with said first and second means for deriving from said first and second changes of position an indication of the relative displacement of said first and second changes of position with respect to each other; and fourth means connected to said first means for combining a third change of position with said first change of position to modify the operation of said measurement deriving means.

Claim 3

An apparatus as claimed in claim 1, wherein: said second means include means for tracking said first change of position with said second change of position; and said fourth means include means for adjusting the position of said first means relative to said tracking means.

Claim 4

An apparatus as claimed in claim 1, wherein: said second means include means for tracking said first change of position with said second change of position; said third means include means for detecting a loss of tracking between said first and second changes of position; and said fourth means include means for adjusting the level of said tracking loss.

Claim 5

An apparatus as claimed in claim 1, wherein: said second means include means for effecting said second change of position essentially relative to a predetermined axis; and said fourth means include means for adjusting the position of said first means relative to said second means and relative to said predetermined axis.

Claim 6

An apparatus as claimed in claim 1, wherein: said second means include means for tracking said first change of position with said second change of position essentially relative to a predetermined axis; and said fourth means include means for adjusting the position of said first means relative to said tracking means and relative to said predetermined axis.

Claim 7

In apparatus for determining when the quantity of a confined gas is diminished below a predetermined mass threshold, the improvement comprising, in combination: first means for measuring the pressure of said gas; second means for at least indirectly measuring the temperature of said gas; third means operatively associated with said first and second means for combining said pressure and temperature measurements to derive an indication of whether the quantity of said confined gas exceeds the predetermined mass threshold; and adjustable fourth means operatively associated with said first and second means for establishing a variable threshold of said pressure and temperature measurements.

Claim 8

In apparatus for determining when the quantity of a confined gas is diminished below a predetermined mass threshold, the improvement comprising, in combination: first means for measuring the pressure of said gas; second means for at least indirectly measuring the temperature of said gas; third means operatively associated with said first and second means for combining said pressure and temperature measurements to derive an indication of whether the quantity of said confined gas exceeds the predetermined mass threshold; and adjustable fourth means operatively associated with said first and second means for establishing a variable threshold of said pressure and temperature measurements.

Claim 9

An apparatus as claimed in claim 6, wherein: said first means include means for expressing variations in the pressure of said gas in terms of a first change of position; said second means include means for expressing variations of said temperature of said gas in terms of a second change of position; said third means include means for deriving said indication from the relative displacement of said first and second changes of position with respect to each other; and said fourth means include means for combining a third change of position with one of said first and second changes of position.

Claim 10

An apparatus as claimed in claim 7, wherein: at least one of said first and second means include means for tracking one of said changes of position with the other of said changes of position; and said third means include means for deriving said indication of whether the quantity of said confined gas exceeds the predetermined mass threshold by detecting the maintenance or loss of tracking between said first and second changes of position; and said fourth means include means for adjusting the threshold below which said first and second changes of position will no longer track.

Claim 11

An apparatus as claimed in claim 7, wherein: one of said first and second means includes means for effecting one of said first and second changes of position essentially relative to a predetermined axis; and said fourth means include means for adjusting the position of the other of said first and second means relative to said one means and relative to said predetermined axis.

Claim 12

An apparatus as claimed in claim 7, wherein: at least one of said first and second means include means for tracking one of said changes of position with the other of said changes of position essentially relative to a predetermined axis; said third means include means for deriving said indication of whether the quantity of said confined gas exceeds the predetermined mass threshold by detecting the maintenance or loss of tracking between said first and second changes of position; and said fourth means include means for adjusting the position of the other of said first and second means relative to said tracking means and relative to said predetermined axis.

Claim 13

In apparatus for determining when the quantity of a confined gas is diminished below a predetermined mass threshold, the improvement comprising, in combination: means for measuring the pressure of saiD gas, including an expansible pressure sensing tube having an end deflectible by pressure variations, and means for connecting said tube to said quantity of confined gas; means for at least indirectly measuring the temperature of said gas, including a device deflectible by temperature variations, said deflectible pressure sensing tube end being arranged in tracking relationship with said temperature deflectible device so long as the predetermined mass threshold is exceeded; means for deriving from said tracking relationship an indication of the relationship of said quantity of confined gas to said predetermined mass threshold; and means for establishing a variable threshold of said pressure and temperature measurements, including adjustable means for varying the relative positions of said pressure sensing tube end and deflectible device.

Claim 14

In apparatus for determining when the quantity of a confined gas is diminished below a predetermined mass threshold, the improvement comprising, in combination: means for measuring the pressure of saiD gas, including an expansible pressure sensing tube having an end deflectible by pressure variations, and means for connecting said tube to said quantity of confined gas; means for at least indirectly measuring the temperature of said gas, including a device deflectible by temperature variations, said deflectible pressure sensing tube end being arranged in tracking relationship with said temperature deflectible device so long as the predetermined mass threshold is exceeded; means for deriving from said tracking relationship an indication of the relationship of said quantity of confined gas to said predetermined mass threshold; and means for establishing a variable threshold of said pressure and temperature measurements, including adjustable means for varying the relative positions of said pressure sensing tube end and deflectible device.

Claim 15

An apparatus as claimed in claim 11, wherein: said means for deriving an indication from said tracking relationship include an electric contact mounted on said deflectible pressure sensing tube end adapted to contact said deflectible device during the maintenance of said tracking relationship and said adjustable means include means for varying the contact pressure of said electric contact relative to said deflectible device.

Claim 16

An apparatus as claimed in claim 11, wherein: said pressure sensing tube is coiled about a predetermined axis; and said adjustable means include means for varying the relative positions of said pressure sensing tube end and deflectible device relative to said predetermined axis.

Claim 17

An apparatus as claimed in claim 11, wherein: said deflectible device includes a bimetallic temperature sensing strip.

Claim 18

An apparatus as claimed in claim 11, wherein: said deflectible device includes a bimetallic temperature sensing strip; and said adjustable means include means for adjusting the position of said temperature sensing strip.

Claim 19

An apparatus as claimed in claim 11, wherein: said pressure sensing tube is coiled about a predetermined axis; said deflectible device includes a bimetallic temperature sensing strip bent about said predetermined axis; and said adjustable means include means for adjusting the position of said bent bimetallic strip relative to said predetermined axis.

Claim 20

An apparatus as claimed in claim 11, wherein: said pressure sensing tube is coiled about a predetermined axis; said deflectible device includes a bimetallic temperature sensing strip bent about said predetermined axis; said means for deriving an indication from said tracking relationship include an electric contact mounted on said deflectible pressure sensing tube end and adapted to contact a free end portion of said bimetallic strip; means for mounting said pressure sensing tube with said electric contact in tracking relationship with said free end portion of said bimetallic strip; and said adjustable means include means for effecting rotary movement of said bent bimetallic strip relative to said predetermined axis, and means for locating said bimetallic strip in any of several angular positions.