Method for calibration in level measurement

Claim 1

A method for calibrating a device for measuring a level and a volume of a material in a container wherein the device includes a sensor located above the highest fill level of the material which measures a distance to the surface of the material in the container and an evaluation circuit in which a relationship between the level of the material and the volume of the material in the container is stored, said evaluation circuit computing the level of the material in the container using the distance measured by the sensor and an empty distance corresponding to a distance measured by the sensor when the container is empty, and said evaluation circuit determining the volume of the material in the container using the computed level of the material in the container and the stored relationship between the level of the material and the volume of the material, said calibration method comprising the steps of: a) interrupting an on-going filling or emptying of the container; b) recording an actual volume of the material in the container during the interruption; c) measuring the distance to the surface of the material in the container with the sensor of the measuring device to be calibrated; d) entering the actual volume of the material into the evaluation circuit; e) determining, in the evaluation circuit, the level of the material corresponding to the entered actual volume of the material as a function of the stored relationship between the level of the material and the volume of the material; f) computing the empty distance by summing the level of the material determined in the evaluation circuit and the distance to the surface of the material measured with the sensor; and g) storing the computed empty distance in the evaluation circuit for use in computing the level of the material and in determining the volume of the material in the container.

Claim 2

A method for calibrating a device for measuring a level and a volume of a material in a container wherein the device includes a sensor located above the highest fill level of the material which measures a distance to the surface of the material in the container and an evaluation circuit in which a relationship between the level of the material and the volume of the material in the container is stored, said evaluation circuit computing the level of the material in the container using the distance measured by the sensor and an empty distance corresponding to a distance measured by the sensor when the container is empty, and said evaluation circuit determining the volume of the material in the container using the computed level of the material in the container and the stored relationship between the level of the material and the volume of the material, said calibration method comprising the steps of: a) interrupting an on-going filling or emptying of the container; b) recording an actual volume of the material in the container during the interruption; c) measuring the distance to the surface of the material in the container with the sensor of the measuring device to be calibrated; d) entering the actual volume of the material into the evaluation circuit; e) determining, in the evaluation circuit, the level of the material corresponding to the entered actual volume of the material as a function of the stored relationship between the level of the material and the volume of the material; f) computing the empty distance by summing the level of the material determined in the evaluation circuit and the distance to the surface of the material measured with the sensor; and g) storing the computed empty distance in the evaluation circuit for use in computing the level of the material and in determining the volume of the material in the container.

Claim 3

A method for calibrating a device for measuring a level and a volume of a material in a container wherein the device includes a sensor located above the highest fill level of the material which measures a distance to the surface of the material in the container and an evaluation circuit in which a relationship between the level of the material and volume of the material in the container is stored, said evaluation circuit computing the level of the material using the distance measured by the sensor and an empty distance corresponding to a distance measured by the sensor when the container is empty, and said evaluation circuit determining the volume of the material in the container using the computed level of the material and the stored relationship between level of the material and volume of the material; wherein the relationship between the level of the material and volume of the material in the container is a linear relationship of unknown slope; said calibration method comprising the steps of: a) interrupting an on-going filling or emptying of the container; b) recording an actual volume of the material and an actual level of the material in the container during the interruption; c) measuring the distance to the surface of the material in the container with the sensor of the measuring device to be calibrated; d) entering the actual volume of the material and the actual level of the material into the evaluation circuit; e) computing, in the evaluation circuit, the slope of the linear relationship between the level of the material and the volume of the material using the actual volume of the material and the actual level of the material; f) computing the empty distance by summing the actual level of the material and the distance to the surface of the material measured with the sensor; and g) storing the computed slope of the linear relationship between the level of the material and the volume of the material and the computed empty distance in the evaluation circuit for use in computing the level of the material and in determining the volume of the material in the container.

Claim 4

A method for calibrating a device for measuring a level and a volume of a material in a container wherein the device includes a sensor located above the highest fill level of the material which measures a distance to the surface of the material in the container and an evaluation circuit in which a relationship between the level of the material and volume of the material in the container is stored, said evaluation circuit computing the level of the material using the distance measured by the sensor and an empty distance corresponding to a distance measured by the sensor when the container is empty, and said evaluation circuit determining the volume of the material in the container using the computed level of the material and the stored relationship between level of the material and volume of the material; wherein the relationship between the level of the material and volume of the material in the container is a linear relationship of unknown slope; said calibration method comprising the steps of: a) interrupting an on-going filling or emptying of the container; b) recording an actual volume of the material and an actual level of the material in the container during the interruption; c) measuring the distance to the surface of the material in the container with the sensor of the measuring device to be calibrated; d) entering the actual volume of the material and the actual level of the material into the evaluation circuit; e) computing, in the evaluation circuit, the slope of the linear relationship between the level of the material and the volume of the material using the actual volume of the material and the actual level of the material; f) computing the empty distance by summing the actual level of the material and the distance to the surface of the material measured with the sensor; and g) storing the computed slope of the linear relationship between the level of the material and the volume of the material and the computed empty distance in the evaluation circuit for use in computing the level of the material and in determining the volume of the material in the container.