Abstract: A calibration apparatus and associated method for the measurement of valuable fluids in storage or at the point of transfer. More particularly, a calibration apparatus and method for use with capacitive liquid level measurement systems.

Abstract: A method and apparatus for calibrating a liquid level measurement system of the type having capacitive sensors, by simulating the electrical effects of sensors in an empty condition and their interconnecting cables, at a time when the sensors are full or partially filled. By a sequential balancing technique, using a conventional bridge circuit, a precision, highly stable variable impedance device is adjusted to individually simulate the effects of each sensor and cable combination with the sensor in an empty condition. The settings of the variable impedance device are recorded, and at a later time when the sensors are no longer empty, these settings are reproduced, so as to recreate the electrical effects of each sensor cable combination one at a time. The individual effects are separately transferred into a network having a plurality of variable impedance channels, until each channel simulates the effects of a corresponding sensor and cable.

Abstract: A heating device, usable in an oven for heating chromatographic equipment, includes an intake for passing an air flow produced by an air supply connected thereto into a cavity formed inside of a tubular member. A heating element, preferably located within that cavity, heats the air flow to an elevated temperature as well as the walls of the tubular member. A heater housing having an enclosed volume contains the tubular member. The heated air flow passes from the cavity into the enclosed volume where it is distributed along both the interior surfaces that define the enclosed volume and the outside of the walls of the tubular member. The interior surfaces are thereby heated while the heated air flow receives further heat from the heated cavity walls. A manifold including an elongated portion having a plurality of apertures formed therethrough with integral nozzles is connected to the heater housing for receiving therefrom the heated air flow.

Abstract: A densimeter utilizes a low mass, neutral buoyancy float in association with a precision transducer which sense the deviation of the float position from a fixed neutral point corresponding to a predetermined fluid density within a range of fluid densities to be measured. The sensor output is accumulated and digitally added to a number corresponding to the predetermined density to thereby form an accurate representation of the fluid density.