Abstract: A Bourdon tube adapted for connection to a source of fluid pressure operates both a mechanically driven gauge pointer and an optical-electronic transmitter for providing operatively parallel output signals corresponding to values of pressure incurred by the fluid source. Simultaneously operative from the displaceable end of the Bourdon tube are both a mechanical movement for effecting amplified displacement of the pointer relative to a dial plate and an opaque vane displaceable within the transmitter between a photoemitter and a pair of photosensors. Circuitry in the transmitter responsive to discrete changes in light interruption between the vane and one of the photosensors emits a signal current corresponding to the pressure value at any given position of the vane.

Abstract: A portable food thermometer affording an audible alarm at a preset cooking completion temperature. A water reservoir defined within a two-part housing is fillable by the user in advance of use. An elongated sensing probe insertable in the food is secured extending through one of the housing parts inward of the reservoir and contains a slideable rod supported on a confined temperature sensing material. Expansion of the sensing material in response to increasing food temperature forces the rod outward of the probe. Opposite the free end of the rod is a spring loaded ball valve sealing the reservoir from a whistle outlet. Temperature graduations on the housing enable adjusting the spacing between the rod and valve at room temperature for presetting the operating temperature of the unit. On reaching set point cooking temperature, the outwardly forced position of the rod acts to open the valve enabling steam in the reservoir to activate the whistle alarm.

Abstract: A differential pressure module is secured in switching relation to the actuating plunger of an electrical switching mechanism. Comprising the differential pressure module are two piston/cylinder assemblies connected together in back-to-back configuration by secured cross members forming a floating yoke. Each of the assemblies includes a diaphragm in communication with a separate oppositely directed fluid inlet and through which a force differential effective from the separate forces acting in opposition to each other is applied via the yoke against the switch actuator. A cast body intervening between the assemblies defines the fluid inlets while maintaining the pressure of each isolated from the other.