Apparatus for determining a vertical level or density of a material column

1. An apparatus for determining a vertical level or density of a material column including a granular solid or a solid-liquid mixture, the apparatus comprising:

a support member; and

at least one measurement module;

wherein the measurement module comprises:

a support arm mounted to the support member and extending outwardly from the support member;

a displacer mounted to the support arm; and

a force measurement device configured to measure a force attributable to a mass of the displacer mediated by a buoyancy of the displacer in the material column,

wherein the measurement module has a data connection to a data processing unit for transmitting measurement data from the measurement module to the data processing unit to generate level or density information about the material column,

wherein the apparatus further comprises a vibration actuator configured to vibrate material surrounding the displacer in the material column to fluidize the material surrounding the displacer in the material column,

wherein the vibration actuator is mounted to, or disposed within, the support member, the support arm, or the displacer.

2. The apparatus according to claim 1 , wherein the vibration actuator is configured to vibrate the displacer to vibrate material surrounding the displacer in the material column to fluidize the material surrounding the displacer in the material column.

3. The apparatus according to claim 1 , wherein the vibration actuator is configured to generate a vibration frequency in a range 1 Hz to 800 kHz.

4. The apparatus according to claim 1 , wherein the apparatus comprises a controller for controlling the vibration actuator, the controller being configured to cause the vibration actuator to generate a vibration immediately before the force measurement device takes a measurement.

5. The apparatus according to claim 4 , wherein the controller is configured to cause the vibration actuator to continue vibrating during the measurement.

6. The apparatus according to claim 4 , wherein the controller is configured to cause the vibration actuator to stop vibrating during the measurement.

7. The apparatus according to claim 4 , wherein the controller is configured to vary one or both of amplitude and frequency of vibration.

8. The apparatus according to claim 7 , wherein the controller is configured to tune one or both of amplitude and frequency of vibration based on the measurement data from the force measurement device.

9. The apparatus according to claim 4 , wherein the controller is configured to implement a cleaning cycle wherein the vibration actuator imparts a different mode of vibration to that used for taking measurement.

10. The apparatus according to claim 1 , wherein the data processing unit is configured to process the measurement data to remove vibrational noise from the vibration actuator.

11. The apparatus according to claim 1 , wherein the displacer is mounted to the support arm via the force measurement device and the force measurement device is contained within the displacer.

12. A method of determining a vertical level or density of a material column including a granular solid or a solid-liquid mixture, the method comprising:

introducing the apparatus according to claim 1 into the material column;

vibrating material surrounding the displacer in the material column to fluidize the material surrounding the displacer in the material column;

measuring a force attributable to the mass of the displacer mediated by the buoyancy of the displacer in the material column;

transmitting measurement data from the measurement module to the data processing unit, and

processing the measurement data from the measurement module to generate level or density information about the material column.

13. The method according to claim 12 , wherein the material column comprises cement or grout.

14. An apparatus for determining a vertical level or density of a material column including a granular solid or a solid-liquid mixture, the apparatus comprising:

a support member; and

at least one measurement module;

wherein the measurement module comprises:

a support arm mounted to the support member and extending outwardly from the support member;

a displacer mounted to the support arm; and

a force measurement device configured to measure a force attributable to a mass of the displacer mediated by a buoyancy of the displacer in the material column,

wherein the measurement module has a data connection to a data processing unit for transmitting measurement data from the measurement module to the data processing unit to generate level or density information about the material column,

wherein the apparatus further comprises a vibration actuator configured to vibrate material surrounding the displacer in the material column to fluidize the material surrounding the displacer in the material column,

wherein the data processing unit is configured to process the measurement data to remove vibrational noise from the vibration actuator.

15. An apparatus for determining a vertical level or density of a material column including a granular solid or a solid-liquid mixture, the apparatus comprising:

a support member; and

at least one measurement module;

wherein the measurement module comprises:

a support arm mounted to the support member and extending outwardly from the support member;

a displacer mounted to the support arm; and

a force measurement device configured to measure a force attributable to a mass of the displacer mediated by a buoyancy of the displacer in the material column,

wherein the measurement module has a data connection to a data processing unit for transmitting measurement data from the measurement module to the data processing unit to generate level or density information about the material column,

wherein the apparatus further comprises a vibration actuator configured to vibrate material surrounding the displacer in the material column to fluidize the material surrounding the displacer in the material column,

wherein the displacer is mounted to the support arm via the force measurement device and the force measurement device is contained within the displacer.