The invention concerns a piezoelectric resonator (10), intended to be packaged in a case, including a base (12) formed of a first fixing zone (121), a second central mechanical uncoupling zone (122) and a third zone (123) opposite to the first fixing zone. At least two vibrating arms (13a, 13b) extend from said third zone, on each of which at least one groove (141a-144a, 141b-144b) is formed on at least one of the top or bottom faces of the arms. The resonator is characterised in that the base i...

Methods and apparatus for detecting photoacoustic signals in fluid media are described. The present invention differs from conventional photoacoustic spectroscopy in that rather than accumulating the absorbed energy in the fluid of a sample cell, the absorbed energy is accumulated in an acoustic detector or sensitive element. In a preferred embodiment, the acoustic detector comprises piezoelectric crystal quartz. The quartz is preferably in the shape of a tuning fork.

A method for manufacturing a quartz oscillator having a stable temperature drift characteristic attributed to the quartz oscillating piece and a quartz oscillator are disclosed.The method comprises a quartz crystal etching step S1 of processing a quartz oscillating piece into a predetermined shape by etching, an electrode membrane forming step S2 of forming an electrode on the quartz oscillating piece, a quartz crystal mounting step S3 of mounting the quartz oscillating piece in an oscillator pa...

A quartz crystal unit has a quartz crystal tuning fork resonator capable of vibrating in a flexural mode of an inverse phase. The quartz crystal tuning fork resonator has a fundamental mode of vibration, a second overtone mode of vibration, a quartz crystal tuning fork base, and a plurality of quartz crystal tuning fork tines connected to the quartz crystal tuning fork base. A merit value M.sub.2 for the second overtone mode of vibration of the quartz crystal tuning fork resonator is less than 3...

A crucible for melting a silica for fusion of said silica into a desired shape. The crucible having a main body with inner and outer surfaces comprised of a refractory material. In addition, the inner surface adjacent at least a melting zone of the furnace includes a substantially gas-tight barrier layer comprised of a material selected from rhenium, osmium, iridium, and mixtures thereof.

A microwave microstrip oscillator includes a thin dielectric substrate, a Gunn diode mounted within the thickness of the substrate, an annular conductive resonator lying on the surface of the substrate and at least partially surrounding the Gunn diode, and a varactor diode associated with the Gunn diode for controlling the frequency of oscillation of the Gunn diode. A microstrip circuit coupled to the Gunn diode extracts an output power signal at a desired microwave frequency.

A fixture for portable quartz floodlights in which a plurality of clips are secured to the periphery of the housing. A portion of each clip overlies the safety guard and lens to press the guard and lens into assembled relationship with a peripheral flange which extends around the housing, A handle is attached to the housing at the top center to facilitate transportation of the fixture,

A quartz optical fiber comprising a core having a higher refractive index and made of pure quartz containing fluorine and phosphorus pentoxide and a cladding having a lower refractive index, a weight ratio of fluorine and phosphorus pentoxide in the core being larger than 1 (one), which is substantially free from unstability of the glass structure.

A quartz quadrupole comprises a quartz substrate, conductive strips and low-conductivity strips. The substrate includes hyperbolic inner surfaces which provide the geometry for the conformed conductive strips to produce an appropriate electric field for mass filter operation. The use of quartz as a substrate material provides the thermal and electrical characteristics required by high performance mass filtering operations, including scanning mode operation to 800 amu and above. During such opera...

An assembly is formed of an outer tubular silica member having therein an inner tubular silica member which has an open end fused to the inner wall of the outer member and a closed end in the form of a reentrant dimple having a thinned-out annular area of weakness in its sidewalls, a thin-walled molybdenum cup is inserted over the inner member into the annular space between said outer and inner members, the walls of said outer and inner members are fused to embed and hermetically seal the walls ...