US 2009/0260414 A1 · METHOD OF CALIBRATING MEASUREMENT SYSTEMS

Abstract

There is provided a method of calibrating a measurement system for measuring a position (h) of a meniscus of a liquid fuel included within a marine fuel tank and therefrom generating a corresponding content signal indicative of a proportion of the tank filled with fuel. The method includes steps of: (a) from a first time instance when the tank is substantially empty, filling during a calibration phase the tank with the fuel at a substantially constant rate whilst simultaneously recording corresponding values (h(t)) of a meniscus position indicative signal generated by the measurement system; (b) at a second time instance after said first time instance, terminating filling of the tank with fuel when the position indicative signal corresponds to the tank being substantially filled with fuel; and (c) subsequently, after the calibration phase, applying signal processing to the position indicative signal to generate the content signal indicative of the proportion of the tank filled with fuel, the signal processing accounting for the tank during the calibration phase being filled at the substantially constant rate.

Claims14

Dependent claims

A method of calibrating a measurement system operable to measure a spatial position of a meniscus of a liquid included within a container and therefrom generating a corresponding liquid content signal indicative of a proportion of the container filled with the liquid, the method including steps of:

(a) from a first time instance when the container is in a first state including a first quantity of the liquid, progressively filling during a calibration phase the container with the liquid at a substantially constant volumetric rate, which rate is unknown, of liquid delivery whilst periodically simultaneously recording corresponding generated values of a meniscus position indicative signal generated by the measurement system;
(b) at a second time instance after the first time instance during the calibration phase, terminating progressive filling of the container with the liquid when the position indicative signal corresponds to the container being in a second state including a second quantity of the liquid;
and
(c) determining the position of the meniscus at a lower and upper position over which calibration is desired and/or a given volumetric capacity K of the container corresponding to the meniscus being at an upper position, for example at the second state;
and
(d) subsequently, in normal use after the calibration phase, applying signal processing to the position indicative signal provided from the measurement system to generate the corresponding liquid content signal indicative of the proportion of the container filled with the liquid, the signal processing accounting for the container during the calibration phase having been filled at the substantially constant volumetric rate of liquid delivery to the container.

3 more elements

A measurement system operable to measure a spatial position of a meniscus of a liquid included within a container and therefrom generating a corresponding liquid content signal indicative of a proportion of the container filled with the liquid, the measurement system being operable to being calibrated:

(a) from a first time instance when said container is in a first state including a first quantity of liquid by progressively filling during a calibration phase said container with the liquid at a substantially constant rate, which rate is unknown, of liquid delivery whilst simultaneously recording corresponding generated values of a meniscus position indicative signal generated by said measurement system;
(b) at a second time instance after said first time instance during said calibration phase, by terminating progressive filling of said container with said liquid when said position indicative signal corresponds to the container being in a second state including a second quantity of liquid,
(c) determine the position of the meniscus at a lower and upper position over which calibration desired and/or a given volumetric capacity K of the container corresponding to the meniscus being at an upper position, for example at the second state;
and
(d) subsequently, in normal use after said calibration phase, by applying signal processing to said position indicative signal provided from the measurement system to generate said corresponding liquid content signal indicative of said proportion of the container filled with the liquid, said signal processing accounting for said container during said calibration phase having been filled at the substantially constant rate of liquid delivery to the container.

2 more elements

Dependencies are inferred from the claim text.

Method of calibrating measurement systems

Life of this patent

Method of calibrating measurement systems

Life of this patent

Abstract

Claims14