In-situ sensor system and method for data acquisition in liquids

A sensor system for data acquisition in a liquid, comprising:

• a) two pressure sensors separated by a fixed distance within a container of said liquid;
• b) material to which said pressure sensors are fixed, said material having a known coefficient of thermal expansion;
• c) a temperature sensor to provide a temperature measurement for correction of the distance between said two pressure sensors based on said coefficient of thermal expansion;
• and
• d) a data acquisition system for acquiring data from said pressure sensors and from said temperature sensor.

A sensor method for measuring density in a liquid, comprising the steps of:

• a) determining the length at a known temperature between two pressure sensors fixed to a material with a known coefficient of thermal expansion;
• b) placing said pressure sensors in a container of said liquid;
• c) measuring the difference in pressure between said two pressure sensors by measuring the pressure at the level of the two pressure sensors in the liquid;
• d) measuring the temperature of the liquid at the location of each pressure sensor with a temperature sensor;
• e) correcting for a change in said length of said material to which said pressure sensors are fixed using the measured temperature of the liquid and the known coefficient of thermal expansion of the material to provide a corrected length between the two pressure sensors;
• and
• f) calculating the density of said liquid using a difference in pressure between said two pressure sensors and said corrected length between said two pressure sensors.