Variable volume piezometer for measurement of volumetric properties of materials under high pressure

Compressibility and density of select liquid and solid foods under pressures up to 700MPa

“…Fig. 1 shows a cross-sectional drawing of the sensor; a detailed sensor description and its operating principle and procedure has been previously reported (Min et al, 2009). The piezometer was cylindrical in shape, and equipped with a movable copper piston at one end.…”

Practical estimation of the in situ physical properties of foods under high pressure

“…Nguyen et al (25), measured up to 600 MPa at 25 o C In situ density: In high pressure processing, measurement of material density changes under pressure is required for estimation of compressibility and compression heating of materials, and for modeling thermal profiles of pressurized food systems (15,28,29). Experiments have been conducted to measure the compressibility of different food materials under pressure (15,(29)(30)(31)(32).…”

“…More recently, a variable volume piezometer and a linear variable differential transformer were used to measure the compressibility and density of both liquid and solid foods under pressure (15,29,30,32). Parameters of empirical models for estimation of density changes of selected foods as a function of pressure are shown in Table 3, and function as follows:…”

“…Experiments have been conducted to measure the compressibility of different food materials under pressure (15,(29)(30)(31)(32). Piezometer, piston-displacement, and hydrometer methods have been used for measurement of the volumetric properties of foods under pressure (33).…”

“…In situ measurement sensor: Development of in situ measurement sensors for food properties under high pressure is challenging. Sensors need to be (1) high pressure tolerant (700 MPa), (2) precise, accurate, and decisive, (4) able to measure solid and liquid biomaterials of any transparency, and (5) without limitations on compression media (15,16). For study of in situ thermal properties under pressure, a reliable measure of temperature is essential.…”