US 12,259,360 B2
Device and method for determining the volume and porosity of objects and bulk materials
Viktor Sydoruk, Juelich (DE); Johannes Kochs, Aachen (DE); Dagmar van Dusschoten, EP Munstergeleen (NL); and Siegfried Jahnke, Velbert (DE)
Assigned to FORSCHUNGSZENTRUM JUELICH GMBH, Juelich (DE)
Appl. No. 17/296,557
Filed by Forschungszentrum Juelich GmbH, Juelich (DE)
PCT Filed Nov. 14, 2019, PCT No. PCT/DE2019/000298
§ 371(c)(1), (2) Date May 25, 2021,
PCT Pub. No. WO2020/125828, PCT Pub. Date Jun. 25, 2020.
Claims priority of application No. 10 2018 009 800.2 (DE), filed on Dec. 18, 2018.
Prior Publication US 2022/0011272 A1, Jan. 13, 2022
Int. Cl. G01N 29/24 (2006.01); G01F 17/00 (2006.01); G01N 29/22 (2006.01)
CPC G01N 29/2418 (2013.01) [G01F 17/00 (2013.01); G01N 29/222 (2013.01)] 23 Claims
OG exemplary drawing
 
1. A method for determining a volume Vs of one or more objects to be measured, the method comprising:
carrying out an empty measuring chamber measurement, carrying out the empty measuring chamber measurement comprising:
providing a closed measuring chamber in an empty state, the closed measuring chamber having a gas space, the empty state being a state in which the one or more objects to be measured are not present in the gas space,
applying an applied signal func (A,f,t) to a transducer having a membrane, the applied signal func (A,f,t) causing a first mechanical movement of the membrane of the transducer, the first mechanical movement of the membrane causing an alternating compression and expansion of a gas in the gas space of the measuring chamber in the empty state,
generating, by a sensor head configured to measure mechanical movement of the membrane, a first measurement, in the form of a first measurement signal ε, of the first mechanical movement of the membrane, the first measurement signal ε having the form:

OG Complex Work Unit Math
wherein A is an amplitude of the applied signal, f is a frequency of the applied signal, t is time, V0 is an internal volume of the measuring chamber, Pa is an ambient pressure, Yq is a quasi-adiabatic index of the gas in the gas space of the measuring chamber, S is a surface area of the membrane, C (A, f, t) is a function having the form

OG Complex Work Unit Math
if the sensor head is configured for inductive or capacitive measurements or having the form C0(func (A, f, t)-Floss) if the sensor head is configured for optical measurements, C0 is a correlation coefficient, and Floss is a force loss brought about by a bending force of the membrane and inertial force;
carrying out an occupied measurement chamber measurement, carrying out the occupied measurement chamber measurement comprising:
applying, while the one or more objects to be measured are present in the gas space of the measuring chamber, the same applied signal func (A,f,t) to the transducer, the applied signal func (A,f,t) causing a second mechanical movement of the membrane of the transducer, the second mechanical movement of the membrane causing an alternating compression and expansion of the gas in the gas space of the measuring chamber in which the one or more objects to be measured are provided, and
generating, by the sensor head, a second measurement, in the form of a second measurement signal εs, of the second mechanical movement of the membrane, the second measurement signal εs having the form:

OG Complex Work Unit Math
and
determining the volume Vs of the one or more objects to be measured based on (i) a relative change εrel of the first measurement signal ε and the second measurement signal εs and (ii) the relationship

OG Complex Work Unit Math