System and method for determining a density of a fluid

A system for determining a density of a sample fluid in a tank, comprising:

• a sensor housing situated within the tank;
• a first sensor situated within the tank coupled to the housing via a first extension situated within the tank;
• a second sensor situated within the tank coupled to the housing via a second extension situated within the tank, the first sensor positioned at a first fluid level of the sample fluid and sensing a first fluid pressure at the first fluid level by providing a first substantially static sensor fluid via the first extension, the second sensor positioned at a second fluid level of the sample fluid and sensing a second fluid pressure at the second fluid by providing a second substantially static sensor fluid via the second extension, the second fluid level being different from the first fluid level;
• and
• a transmitter provided in the housing, the transmitter being in fluid communication with the first sensor via the first substantially static sensor fluid in the first extension, and being in fluid communication with the second sensor via the second substantially static sensor fluid in the second extension, the transmitter generating at least one signal which relates to the first and second fluid pressures;
• wherein the first and second substantially static sensor fluids are maintained separately from the sample fluid by the housing.

A method for determining a density of a sample fluid in a tank, comprising the steps of:

• providing a first sensor situated within the tank at a first fluid level in the sample fluid;
• providing a second sensor situated within the tank at a second fluid level in the sample fluid, the second fluid level being different from the first fluid level;
• sensing a first fluid pressure of the sample fluid at the first fluid level using the first sensor to act on a first substantially static sensor fluid, the first substantially static sensor fluid being maintained separately from the sample fluid, and the first sensor communicating with a transmitter using the first substantially static sensor fluid;
• sensing a second fluid pressure of the sample fluid at the second fluid level using a second sensor to act on a second substantially static sensor fluid, the second substantially static sensor fluid being maintained separately from the sample fluid, and the second sensor communicating with the transmitter through the second substantially static sensor fluid;
• and
• generating at least one signal relating to the first fluid pressure and the second fluid pressure to determine the density of the particular fluid.

A method for measuring a fluid pressure of a sample fluid, comprising the steps of:

• providing a sensor situated within the sample fluid at a fluid level, the sensor including a sensor housing, at least two diaphragms and a substantially static sensor fluid, the at least two diaphragms being coupled to the sensor housing, the at least two diaphragms being affected by the fluid pressure of the fluid level, the at least two diaphragms acting on the substantially static sensor fluid;
• and
• determining the fluid pressure of the fluid at the fluid level by measuring the fluid pressure of the substantially static sensor fluid;
• wherein the substantially static sensor fluid and the sample fluid are maintained separately from one another.

A sensor for determining a pressure of a sample fluid, comprising:

• a sensor housing containing a substantially static sensor fluid;
• and
• at least one diaphragm disposed in the sensor housing and acting on the substantially static sensor fluid in response to the pressure provided by the sample fluid,
• wherein the substantially static sensor fluid and the sample fluid are maintained separately from one another and the at least one diaphragm includes a concentric flexible portion having a non-circular shape.