Apparatus and associated methods relate to measuring density of aircraft fuel. The aircraft fuel is circumferentially pumped about an impeller axis by a centrifugal pump. Differential pressure of the aircraft fuel is measured between two different points within the centrifugal pump, each a different radial distance from an impeller axis. Rotational frequency of the impeller of the centrifugal pump is measured. Density of the aircraft fuel is calculated based on the rotational frequency and the differential pressure.

Apparatus and associated methods relate to measuring density of aircraft fuel. The aircraft fuel is circumferentially pumped about an impeller axis by a centrifugal pump. Differential pressure of the aircraft fuel is measured between two different points within the centrifugal pump, each a different radial distance from an impeller axis. Rotational frequency of the impeller of the centrifugal pump is measured. Density of the aircraft fuel is calculated based on the rotational frequency and the differential pressure.

Apparatus and associated methods relate to simultaneously pumping and measuring density of an aircraft fuel. The aircraft fuel is pumped by a centrifugal pump having an impeller. A rotational frequency of the impeller is determined while the centrifugal pump is pumping the aircraft fuel. Flow rate of the aircraft fuel through the centrifugal pump is sensed. Pressure of the aircraft fuel is measured at two different points within or across the centrifugal pump or a differential pressure is measured between the two different points while the centrifugal pump is pumping the aircraft fuel. Density of the aircraft fuel is determined based on an empirically-determined head-curve relation corresponding to the centrifugal pump. The head-curve relation is empirically determined during a characterization phase. The empirically-determined head-curve relation relates the density of the aircraft fuel to the rotational frequency, the flow rate, and the pressures at the two different points.

Apparatus and associated methods relate to simultaneously pumping and measuring density of an aircraft fuel. The aircraft fuel is pumped by a centrifugal pump having an impeller. A rotational frequency of the impeller is determined while the centrifugal pump is pumping the aircraft fuel. Flow rate of the aircraft fuel through the centrifugal pump is sensed. Pressure of the aircraft fuel is measured at two different points within or across the centrifugal pump or a differential pressure is measured between the two different points while the centrifugal pump is pumping the aircraft fuel. Density of the aircraft fuel is determined based on an empirically-determined head-curve relation corresponding to the centrifugal pump. The head-curve relation is empirically determined during a characterization phase. The empirically-determined head-curve relation relates the density of the aircraft fuel to the rotational frequency, the flow rate, and the pressures at the two different points.

Apparatus and associated methods relate to simultaneously pumping and measuring density of an aircraft fuel. The aircraft fuel is pumped by a centrifugal pump having an impeller. A rotational frequency of the impeller is determined while the centrifugal pump is pumping the aircraft fuel. Flow rate of the aircraft fuel through the centrifugal pump is sensed. Pressure of the aircraft fuel is measured at two different points within or across the centrifugal pump or a differential pressure is measured between the two different points while the centrifugal pump is pumping the aircraft fuel. Density of the aircraft fuel is determined based on a head-curve relation characterizing the centrifugal pump. The head-curve relation relates the fuel density to the rotational frequency, the flow rate, and pressures at the two different points or the differential pressure between the two different points.

A method for dynamically evaluating sag of a fluid by providing a test volume of the fluid into an angled sample chamber, wherein the angled sample chamber has a central axis, and wherein the central axis of the angled sample chamber is angled relative to horizontal, rotating the sample chamber about the central axis for a test period, and determining a sag density, wherein the sag density is a density of a fluid sample taken at a sample location within a stratum of the test volume of the fluid present in the angled sample chamber.

A method for dynamically evaluating sag of a fluid by providing a test volume of the fluid into an angled sample chamber, wherein the angled sample chamber has a central axis, and wherein the central axis of the angled sample chamber is angled relative to horizontal, rotating the sample chamber about the central axis for a test period, and determining a sag density, wherein the sag density is a density of a fluid sample taken at a sample location within a stratum of the test volume of the fluid present in the angled sample chamber.

Provided is a sample transport system capable of avoiding insertion of a sample into an automatic analysis device even when the inability of the automatic analysis device to carry out processing is detected after the sample is transported from a sample preprocessing system. A carrier transfer machine determines whether a sample transferred from a sample transport system unit can be analyzed by an automatic analysis device based on sample information about the sample and information about whether a reagent is loaded in the automatic analysis device, and, if a determination is made that the sample cannot be analyzed, moves a sample container holder to the sample transport system unit without transferring a sample container to a carrier. As a result, it is possible to avoid inserting a sample into an automatic analysis device that is not capable of carrying out analysis on the sample and eliminate unnecessary operations and time.

Provided is a density sensor, a downhole tool, and a well system. The density sensor, in one aspect, includes one or more float chambers, and two or more floats located within the one or more float chambers. In one aspect, the two or more floats have a density ranging from 0.08 sg to 2.1 sg, and further a first of the two or more floats has a first known density (.sub.1) and a second of the two or more floats has a second known density (.sub.2) greater than the first known density (.sub.1). The density sensor, according to this aspect, may further include one or more sensors located proximate the one or more float chambers, the one or more sensors configured to sense whether ones of the two or more floats sink or float within production fluid having an unknown density (.sub.f).

Provided is a density sensor, a downhole tool, and a well system. The density sensor, in one aspect, includes one or more float chambers, and two or more floats located within the one or more float chambers. In one aspect, the two or more floats have a density ranging from 0.08 sg to 2.1 sg, and further a first of the two or more floats has a first known density (.sub.1) and a second of the two or more floats has a second known density (.sub.2) greater than the first known density (.sub.1). The density sensor, according to this aspect, may further include one or more sensors located proximate the one or more float chambers, the one or more sensors configured to sense whether ones of the two or more floats sink or float within production fluid having an unknown density (.sub.f).