Abstract: Method and apparatus is disclosed for calibrating a timing light used in conjunction with an engine scope tester. The timing light is fired by an offset circuit in an engine scope tester having a meter indicating the offset amount. The engine scope tester is synchronized to the firing of a simulated No. 1 cylinder spark plug. The light from the timing light is detected by a phototransistor connected to a voltage reference source which amplifies the signal from the phototransistor to a usable level. The output of the voltage reference source is connected back to a vertical deflection circuit of the oscilloscope on the engine scope tester. The calibration marks on the oscilloscope of the engine scope tester are used to calibrate the meter on the engine scope tester indicating the offset to the timing light.

Abstract: A film badge sensitive to non-ionizing radiation and a method of making same. The film badge consists of dissolved bilirubin bound in a polymeric film base and sealed within an optically transparent substrate. The film badge is useful during phototherapy for the treatment of hyperbilirubinemia in the newborn and is capable of measuring the total irradiance effective in decomposing bilirubin.

Abstract: A method and apparatus for the calibration of a gamma radiation measurement instrument to be used over any of a number of different absolute energy ranges. The method includes the steps of adjusting the overall signal gain associated with pulses which are derived from detected gamma rays, until the instrument is calibrated for a particular absolute energy range; then storing parameter settings corresponding to the adjusted overall signal gain, and repeating the process for other desired absolute energy ranges. The stored settings can be subsequently retrieved and reapplied so that test measurements can be made using a selected one of the absolute energy ranges. Means are provided for adjusting the overall signal gain by varying the voltage supplied to a multiplier phototube included in the instrument, or by varying the gain of attenuators coupled to the output of the phototube.

Abstract: A method of measuring the disintegration rate of a beta-emitting radionuclide in a liquid sample by counting at least two differently quenched versions of the sample. In each counting operation the sample is counted in the presence of and in the absence of a standard radioactive source. A pulse height (PH) corresponding to a unique point on the pulse height spectrum generated in the presence of the standard is determined. A zero threshold sample count rate (CPM) is derived by counting the sample once in a counting window having a zero threshold lower limit. Normalized values of the measured pulse heights (PH) are developed and correlated with the corresponding pulse counts (CPM) to determine the pulse count for a normalized pulse height value of zero and hence the sample disintegration rate.

Abstract: A standard for calibrating a densitometer or the like is disclosed consisting of an optically transparent substrate supporting a plurality of spaced bands of different predetermined optical densities. Each band comprises alternate dark and clear strips and is sized to eclipse a beam of light generated in the densitometer and defining an illuminated zone. The width of the clear strips is large compared to the wavelength of the light beam and small compared to the width of the illuminated zone so that the quantities of light passing through the bands as the standard moves through the densitometer, and hence the optical densities of the bands, are directly proportional to the ratio of the areas of the clear strips to the areas of the dark strips in the bands. The bands are placed at an angle to the scan axis of the illuminated zone to present a gradient change in optical density to a scanning densitometer which is within the response time thereof.

Abstract: Apparatus is disclosed for accomplishing electrophoresis in an automated manner. A supported electrophoretic medium, having been implanted with sample to be analyzed, is moved through a chamber wherein the electrophoresis takes place. The apparatus comprises an electrophoresis separation chamber containing a pair of elongated electrolyte wells, electrolyte contained within the wells, electrodes disposed within the electrolyte and connectable to an appropriate source of power, and a wicking arrangement communicating with each of the electrolyte wells to provide a continuous electrical contact zone.

Abstract: A radioactivity measuring instrument, and a method related to its use, for determining the radioactivity of a sample measured in the presence of significant background radiation, and for determining an error value relating to a specific probability of accuracy of the result. Error values relating to the measurement of background radiation alone, and to the measurement of sample radiation and background radiation together, are combined to produce a true error value relating to the sample radiation alone.

Abstract: In a table top centrifuge of the type including a rotor and a housing defining a chamber for the rotor, the housing having a removable cover therefor, there is disclosed an improvement wherein the cover has first and second passageways extending entirely therethrough, from the center and periphery, respectively, thereof to spaced locations on one of the outer surfaces thereof to define inlet and outlet ports, respectively. A refrigeration unit is provided having a cold air outlet port and a warm air inlet port at spaced locations on one of the outer surfaces thereof, the spacing between and orientation of the centrifuge and refrigeration unit inlet and outlet ports being such that positioning of the one outer surfaces of the centrifuge and refrigeration units in contact with each other aligns the outlet and inlet ports of the refrigeration unit with the inlet and outlet ports, respectively, of the centrifuge.

Abstract: An electrochemical detection cell particularly suited for portable applications because of its small size and low cost. An enclosure is provided having two membrane surfaces. Electrodes are suspended internally between the two membranes supported by an electrochemically inert hydrophilic material containing an electrolyte solution. An improved electrode structure for use within the cell is disclosed.

Abstract: A method and apparatus for inhibiting measurement of nuclear radiation in a scintillation counter during periods of excessive background radioactivity produced, for example, by cosmic energy surges impinging on the scintillation counter. The count rate of a radioactive source or sample being measured is monitored and detector means are provided for detecting the occurrence of an energy surge exceeding a predetermined energy level. When a surge is detected, inhibit means inhibits counting for a time period which varies inversely with the count rate.

Abstract: A pressure transducer and method of manufacture is disclosed wherein a tantalum diaphragm is held in position in a pressure transducer by sandwiching the tantalum diaphragm between a stainless steel weld ring and the stainless steel body of the pressure transducer. The stainless steel weld ring is welded to the stainless steel body at a temperature above the melting point of the stainless steel but below the melting point of the tantalum whereby simultaneous to the welding of the weld ring to the body, a braze is created between the tantalum diaphragm and both the stainless steel weld ring and stainless steel body. This braze creates the required hermetic seal between the tantalum diaphragm and the stainless steel body. Additionally, an inert seal is provided between the pressure body of the transducer and the tantalum diaphragm disposed interior of the inner circumference of the stainless steel weld ring whereby process fluids which would otherwise erode the weld ring are isolated therefrom.

Abstract: A portable, automated chemical analyzer having a polarographic oxygen electrode submerged in a batch of stirred solution. The signal from the electrode is directly differentiated and amplified to produce a signal proportional to the time rate of change of oxygen concentration. The membrane of the polarographic sensor is stretched very tightly over the cathode surface to provide a high signal-to-noise ratio. Methods for analyzing cholesterol-cholesterol oxidase and various other enzyme systems by the polarographic electrode oxygen sensing apparatus include the steps of converting the sensed signal into time rate of change of oxygen concentration and recording the maximum rate of change of oxygen concentration.

Abstract: This invention provides a snap-in terminal for electrical connection between an external conductor and a conductive film deposited on a nonconductive substrate. The terminal is stamped from a flat sheet of resilient conductive material and comprises a center position having a forward extension to which the external conductor may be attached and a rearward extension curved downward for establishing electrical contact with the film on the substrate, and a plurality of legs extending outward from the center portion and bent about 90.degree. downward from the center portion, each leg having at its terminus a tab. The terminal is installed by inserting the legs into a slot in the substrate contiguous with the film. The tabs deflect to fit within the restricted space of the slot and then recover their original position as they emerge from the slot at the bottom of the substrate, thereby securing the terminal to the substrate.

Abstract: A kinetic assay is provided for measuring alpha-amylase content in aqueous solutions. The assay is based on the following reactions:alpha-1,4 linked glucan .sup.alpha-amylase alpha-maltosealpha-maltose + PO.sub.4 .sup.-.sup.-.sup.- .sup.MP Glucose + beta-D-G-1-Pbeta-D-G-1-P .sup.beta-PGM G-6-PG-6-P + NAD .sup.G6PDH 6-P-G + NADHthe concentration of alpha-amylase is determined by measuring the rate of increase in absorbance associated with the production of NADH which is a measure of the activity of alpha-amylase.A novel reagent system is used with the assay and comprises:A polysaccharide having glucose molecules primarily connected through alpha 1,4 linkageMaltose phosphorylase (MP)Phosphate ions (PO.sub.4 .sup.-.sup.-.sup.

Abstract: An improved apparatus and method for braking the rotation of a centrifuge rotor is disclosed comprising magnet means operable in a first position wherein substantially no eddy currents are induced in a rotating rotor made of electrically conductive material by the magnetic flux of the magnet means and a second position wherein eddy currents are induced into the rotating rotor sufficiently to slow the rotor. In the preferred embodiment, the magnet means is movable by fluid pressure from the second position to the first position and movable by a bias force from the first position to the second position.

Abstract: An improvement to a misfire monitor sensing lean-roll in an internal combustion engine by comparing the rate of change in O.sub.2 in the exhaust gases with respect to time against a limit is disclosed. In the preferred embodiment, the sensed O.sub.2 level in the exhaust is used as an input to rescaling means which automatically normalizes the values used in the comparison to a standard range. Normalization is accomplished alternately by rescaling the rate of change value, rescaling the limit value used, or diluting the exhaust gases sampled to the level of a "standard" air blown engine to which the comparison limit is scaled.

Abstract: An adjustable supporting arrangement used within the sample receiving cavity of a centrifuge rotor to hold and align a plurality of test tubes. The arragement is comprised of a series of similarly configured interface layers which can be variably arranged to accommodate different sized test tubes. A bracket member is utilized to retain the alignment of the various interface layers and hold them as a single unit for convenient movement into and out of the rotor cavity. Incorporated within the supporting arrangement is a separate cushion pad to receive the bottom ends of the test tubes. A uniquely designed divider plate can be placed within the supporting arrangement to partition the rotor cavity into two areas for receipt of two sets of test tubes in stacked relation.

Abstract: Exhaust gas diagnostic apparatus capable of use on both catalytic converter equipped and non-catalytic converter equipped motor vehicles is disclosed. A fast response oxygen analyzer is coupled with means for differentiating the signal output of the oxygen analyzer. In this manner, both the quantity and rate of change of oxygen in the exhaust gas is made available to apparatus included therein for indicating and/or alarming quantity and rate of change values outside preset limits. The apparatus is particularly directed to the detection of an engine misfire condition. The apparatus disclosed permits diagnosing problems without disconnecting the air injector system (if present) or having a port prior to the catalytic converter. As it alarms on transients, it is independent of the steady state oxygen level.

Abstract: A fluorometer for analyzing a sample by detecting light induced radiation emitted from the sample including apparatus for generating a narrow slit of light in the plane of the sample and transfer apparatus including a light shield having an acutely angled port immediately adjacent the sample for collecting radiation emitted by the sample and transmitting same via a light pipe to a remote detector.

Abstract: An adaptor for use in a centrifuge bucket for evenly distributing a number of cylindrical test tubes thereacross and for maximizing the number of test tubes positionable in the bucket. The adaptor comprises a thin, flat, disc-shaped plate having a diameter approximately equal to the inside diameter of the bucket and a plurality of separate, unconnected partitions made integral with and extending normal to one side of the plate, the partitions defining a plurality of cavities for receipt of the bases of the test tubes. The partitions support substantially less than the entire circumference of each tube and have lengths which are substantially less than the lengths of the tubes. A lifting tray and handle provide means for lifting the adaptor and test tubes from the rotor bucket.