Abstract: A Boehm system clarinet having improved A key features. An auxiliary shaft having an auxiliary actuating spatula in rough proximity to the spatula of the B flat key affords operation of the A key with the right index finger without impairing the operation of that key in the normal manner by the left index finger. A temperature compensation mechanism on the auxiliary shaft assures that the auxiliary shaft cannot freeze up in response to temperature changes and impair operation of the A key in the normal Boehm system mode. An adjustable link mechanism disposed between the A and A flat keys makes the operation of those keys smoother and quieter.

Abstract: A method and apparatus for seating tubeless tires, particularly large tubeless truck tires, on a rim. A tank having a volume related to the internal volume of the largest tire to be seated is charged with compressed air at a pressure which is within the range of pressures considered safe for general purpose vehicular applications. A discharge barrel having an internal passage with an area of from 8 to 20 square centimeters is disposed between the tank and the bead of the tire and positioned so that air discharged therefrom strikes the bead from a direction roughly perpendicular to the plane of the bead. An approximately full-flow valve, positioned in flow control relationship to the barrel, is opened abruptly to direct a pneumatic pulse having a fast-rising leading edge against the bead. The bead then seats on the rim as a result of the combined effect of the motion imparted thereto by the impact of the pulse and the air injected into the tire in connection with that impact.

Abstract: A seating tool for facilitating the seating of a tubeless tire on a rim. The seating tool includes a plurality N of relatively inflexible arcuate segments each having a head end, a tail end, and a curved inner surface, N being equal to three or more. The arcuate segments are positioned in a head-to-tail configuration to form a closed approximately circular hoop in which the head end of each segment is in overlapping sliding relationship to the tail end of the adjacent segment. The seating tool also includes a plurality N of threaded tightening mechanisms which are connected to the hoop in the vicinity of respective regions of overlap to vary the arcuate lengths of such regions and thereby apply a symmetrically distributed compression force to a tire positioned within the hoop.

Abstract: An improved electrode assembly for use in amperometric gas sensors. A portion of the interior of the electrode assembly that is adjacent to the electrode is filled with an electrochemically inert water-repellant fluid. Once the fluid is in place, a fluid barrier is inserted to cover the fluid and to serve as a foundation for the introduction of a sealing compound. A pressure relief structure, such as a gas bubble, may be provided within the fluid to relieve the pressures incident to the thermal expansion and contraction of the electrode assembly. Because of the water repellancy of the fluid, the electrolyte solution which surrounds the electrode assembly is prevented from migrating into the interior thereof and thereby initiating output current errors.

Abstract: An improved assembly for holding a filter element so as to define a filter assembly for removing particulate matter from a sample gas stream. First and second housing sections mount and enclose a replaceable filter element. An annular wall extending between the housing sections divides the interior of the housing into a first region open to an inlet, and a second region open to an outlet, the filter element being mounted in the second region, downstream of the wall. A plurality of openings through the wall assure that particulate matter collects evenly over the surface of the filter element. In this manner, the useful life of the filter element is greatly extended.

Abstract: An apparatus for compensating for changes in the mass flow rate of a sample gas stream in gas analysis instruments having outputs that are calibrated in terms of the concentration of a component of the sample stream. In instruments in which a pressure regulated sample gas stream is applied to a detector assembly through a flow restrictor such as a sample capillary, a gas flow sensor is connected in series with the flow restrictor to develop a correction signal that varies in accordance with the mass flow rate of the sample stream. A correcting circuit combines the correction signal from the flow sensor with the output signal from the detector assembly to produce a corrected output signal that correctly indicates the concentration of the component of interest.

Abstract: A sensor mechanism for measuring a property of a fluid which must not be allowed to escape into the environment. A sensor housing provides a chamber from which a sensing element may be extended into contact with the fluid to be measured, and into which the sensing element may be retracted prior to being sealed off from the fluid. When the sensing element is in its retracted position, the closure of a valve seals the chamber off from contact with the fluid. A purging inlet and a purging outlet allow the interior of the sensor housing to be purged of traces of fluid trapped therein by the closure of the valve, prior to the time that the sensor housing is disassembled for the servicing or replacement of the sensing element. An improved sealing arrangement allows the interior of the sensor housing to remain sealed off from the environment without the use of sliding seals. An improved cleaning arrangement allows the sensing element to be cleaned without removing it from the sensor housing.

Abstract: A fluorescent sulfur dioxide analyzer that includes a generator for producing a standard gas of known sulfur dioxide content. A source of ultraviolet radiation illuminates the interior of a reaction chamber in which an oxygen containing gas is passed over a deposit of sulfur. During passage, a part of the oxygen reacts with the sulfur to produce sulfur dioxide. Because the quantity of sulfur dioxide is predictable and reproducible, the resulting sulfur dioxide containing gas is suitable for use as a standard or span gas in the analyzer with which it is used, thereby eliminating the need for the storage tanks or permeation tubes.

Abstract: A gas dryer cartridge for removing the moisture from a sample gas stream prior to the application thereof to a metabolic measuring instrument. A dryer housing having an inlet and an outlet is partitioned into a first, gas drying chamber containing a desiccant and a second, liquid collecting chamber containing an absorbent liquid retaining element. The volume of the liquid collecting chamber is made sufficiently large that it can contain the liquid produced in the event that the desiccant is liquefied as a result of prolonged use. The liquid retaining element prevents the collected liquid from being swept up in the gas stream during the removal or replacement of the cartridge.

Abstract: A filter assembly for collecting particulate matter from a stream of sample gas. A filter housing having at least an inlet section and an outlet section supports one or more removable filter elements between adjacent housing sections. At least one end of each housing section is provided with a tapered flange whereby it may be joined to the end of an adjacent housing section. Quick-release clamping means engages the flanges to provide a convenient means for fastening and unfastening the sections of the filter housing without dislodging appreciable quantities of the particulate matter collected on the filter elements. The filter assembly may be expanded as required to accommodate any desired number of filter stages.

Abstract: An improved apparatus for facilitating the practice of a method for determining the conversion efficiency of the NOx converter of an oxides of nitrogen analyzer. An improved ozone control assembly facilitates the control of the ozone content of the gas mixture that is applied to the input of the analyzer. An improved gas flow regulating arrangement allows the composition of the gas mixture to be changed without affecting the flow rate thereof. Together, these structures improve the stability and ease of use of the conversion efficiency detector.

Abstract: A solid state ion-sensitive measuring electrode is disclosed in which a filler solution comprising sodium silicate is provided between an outer glass membrane of the electrode and an internal metallic wire which serves as a conductor from the electrode to a meter. The filler solution is inserted into the electrode as a liquid, and is subsequently dehydrated to provide a permanent solid-state matrix which is electrically conducting between the outer glass membrane and the internal wire.

Abstract: A master slave controller communication system is disclosed wherein intercommunication occurs between a master controller and a slave controller over the same communication control line. The communication control line contains three busses. At least one bus is a forward/reverse bus and a second bus is a power bus.

Abstract: A carbon monoxide detection apparatus and process are disclosed in which the amount of carbon monoxide is measured by oxidizing it and measuring the heat of oxidation. To accomplish this platinum oxide is used as the catalyst and an operating temperature is maintained at which oxidation of carbon monoxide occurs in the presence of platinum oxide. Various types of heat-change-responsive techniques are disclosed, including measurement of the voltage drop across forward-biased solid-state diodes, and measurement of the voltage generated by thermo-couples.

Abstract: A gas analyzer is disclosed which provides a dual channel capability for the simultaneous determination of the presence and concentration of two gases in a stream of sample gas and which has a single infrared source, a single sample cell, two infrared bandpass filters, and two infrared detectors.A separator between the filters and detectors prevents interchange of radiation between the filters. The separator is positioned by fitting it in a slot.

Abstract: An automatic transfer method and apparatus for a multi-variable control unit having at least two process control units is disclosed which initiates transfer from the selected controller to the non-selected controller through failure of the selected controller to produce transfer preventing signals.

Abstract: In a sulfur dioxide fluorescence analyzer, a method and apparatus for eliminating the fluorescence effects of nitric oxide is disclosed wherein a sample gas is mixed with a diluent which substantially quenches nitric oxide fluorescence.

Abstract: In a sulfur dioxide analyzer which measures the content of sulfur dioxide by fluorescence of sulfur dioxide molecules when illuminated by an ultraviolet light source, there is disclosed a converter containing vanadium pentoxide for removal of polynuclear aromatic hydrocarbons which produce interference when sulfur dioxide is measured by fluorescent methodology.

Abstract: A keyboard type switch is disclosed wherein a domed snap disc performs triatic functions of acting as a tactile feedback source for switch operation, of supplying a conductive path for electrical energy when depressed, and of providing a contact surface for manual operation. The disclosed switch is covered by a multilayered nonconductive membrane and spacer to provide maximum safety from electrical shock to the operator.

Abstract: A phase-control type of closed-loop control system for motors. A reference signal generator generates a digital reference signal having a binary value which varies between first and second values n times during each a-c input voltage cycle. An error signal generator generates a digital error signal having a binary value which varies in accordance with the difference between the desired and actual values of a motor variable such as armature current. The most significant bits of the digital error signal are utilized to select the angular range within which firing signals will be applied to a phase-controlled rectifier network that is arranged to drive the motor. The least significant bits of the digital error signal are compared with the digital reference signal to determine the time, within the selected angular range, when firing signals will be applied to the controlled rectifier network.