A circuit for determining the slope of a signal of a predetermined minimum duration and below an upper limit by carrying out an integration first in a positive and then in a negative direction in which means are provided to insure that the integration is carried out and an output provided only when measuring a portion of the signal which is free from disturbances.

Apparatus for determining the amount and location of imbalance in an article which is to be balanced about its axis includes a table for receiving the article and for positioning its axis. The table is supported upon a base for substantially free tilting movement generally about a point on a vertically extending axis defined by the base. A number of proximity transducers for sensing the orientation of the table relative to the base are provided. A pair of force coils positioned in quadrature abo...

The position of an object which moves along a fixed path is determined by measuring the phase displacement of two signals received from demodulators connected to an aerial located along the path. A transmitter carried by the objects feeds signals to the demodulators and one of these sends a demodulated signal direct to a comparator while the other sends its signal to the comparator along the aerial.

A composition is tested for its flame retarding ability by determining the decrease in the amount of hydrogen molecules produced in a reaction zone from hydrogen radicals when said composition is present in the reaction zone over the amount produced in the same reaction zone without said composition.

An apparatus for determining the value or change in physical properties of a fluid, particularly viscosity, comprising a conduit that is vibrated longitudinally and wherein the relative movement of fluid in the conduit provides a measure of the physical property. According to the invention the conduit is in the form of an endless loop so that the fluid oscillations are confined to the loop, thereby providing an apparatus that is insensitive to conditions in the interconnecting conduits which con...

A method for determining amount of treadwear of a tire is disclosed. The tire tread surface is impregnated with a radioactive material (iodine dissolved in toluene) and initial radioactivity measured at the tread surface. Subsequent measurements of radioactivity after wearing away tread indicate the amount of tread loss, when such measurements are compared with a calibration curve of radioactivity prepared for rubber of same composition and radioactive material of same concentration. Calibration...

Method of determining total ionic content of an aqueous sample solution by an ion exchange procedure in which all of the cationic species present are converted to an easily eluted alkali metal cation in a first ion exchange resin bed means after which the anions in the aqueous sample are all exchanged in an anion exchange resin bed means for an easily eluted anion, such as hydroxide or acetate, thereby exchanging all ion species in the sample solution for a single predetermined ion pair and ther...

An acuity meter for presenting visual acuity targets to the eye of a human subject being tested in order to determine accurately and conveniently the acuity capability of his visual system. The apparatus includes an optical display which presents a plurality of targets, one at a time, to the person being tested, a set of switches by which the person being tested indicates his response, and an electronic control system which controls the presentation of the targets in accordance with the subject'...

An improved gas-sensing electrochemical cell for measuring dissolved hydrogen sulfide in a sample solution. The cell comprises a potentiometric sulfide ion-sensitive electrode and a fluoride ion-sensitive electrode, both in contact with an acid internal standard solution comprising an aqueous solution of a fluoride salt. A hydrophobic hydrogen sulfide gas-permeable membrane separates the sample solution from the internal solution.

A sensing head for determining wheel alignment angles is mounted on a wheel clamp assembly and includes gravity sensing variable impedance electrolytic transducers which are selectively positionable relative to the assembly and are connectable in a bridge circuit for indicating the angle of the respective transducer to the horizontal, and a spirit level also prepositioned on the assembly, with one transducer and the spirit level being in parallel opposed relation to one another.