A chemical sensor apparatus and method of making same is disclosed in which an ion sensitive silicon die is sandwiched between an elastomeric media seal and a conductive elastomeric pad contained within a housing. The conductive elastomeric pad contacts a printed circuit board (PCB) which leads from the housing. The die, elastomers and PCB are secured by a press-fit electrically conductive plug, which contacts and makes an electrical connection with the PCB. The plug functions as a counter electrode for the apparatus as well as a mechanical lock that seals the principal components of the apparatus within the housing in a substantially flush hermetic seal.
An electrochemical sensor has a sensor housing and an ion-sensitive field effect transistor (ISFET) with a source connection (S) and a drain connection (D). An ion-sensitive surface area (IS) on the front surface of the ISFET is immersible in a measuring medium. A clamping element serves to clamp the ISFET with its rear surface against an end surface of the sensor housing. The clamping element has a central opening leaving the ion-sensitive surface area (IS) exposed. A leak-tight circular connection between the clamping element and the sensor housing is formed by vibratory, preferably ultrasonic, welding. The ISFET is sandwiched between two rubber-elastic elements, at least one of which forms a leak-tight seal against penetration of the measuring medium from the ion-sensitive surface area (IS) to the source- and drain connections (S) and (D).
The invention provides pressure sensors for use in wet environments. A pressure sensor package according to the invention has a housing having a pair of cavities separated by a wall member. Sequentially contained within one cavity is a conductive elastomeric seal pad, a pressure sensor and an elastomeric media seal. A pressure cap is attached to the housing such that the pressure cap and the housing together form a hermetic seal. The pressure cap has a port for admitting a gas under pressure into the first cavity. A signal amplifier is positioned within the second cavity and a cover encloses the signal amplifier within the second cavity. An electrical connector through the wall member forms an electrical connection between the pressure sensor and the signal amplifier. A lead frame extends through the housing and forms electrical connections with the pressure sensor and the signal amplifier.
A sensor (10,110) is provided for determination of various concentrations of one or more components within a fluid sample. The sensor (10,110) includes an injection molded body (12,112), at least two electrodes (30,31,32,130,131,132), an enzyme (57,157), and, if desired, an electron transfer mediator. The body includes a reaction zone (24,124) for receiving a fluid sample. The electrodes (30,31,32,130,131,132) are at least partially embedded with in the plastic body (12,112) and extend into the reaction zone (24,124). Also contained within the reaction zone is an enzyme (57,157) capable of catalyzing a reaction involving a compound within the fluid sample.
A sensor is provided for the determination of various concentrations of one or more components within a fluid sample. The sensor includes an injection molded body, at least two electrodes, an enzyme, and if desired, an electron transfer mediator. The body includes a reaction zone for receiving a fluid sample. The electrodes are at least partially embedded within the plastic body and extend into the reaction zone. Also contained within the reaction zone is an enzyme capable of catalyzing a reaction involving a compound within the fluid sample. Additionally, the sensor incorporates fill detection which activates a meter, attached to the sensor, for measuring the electrochemical changes occurring in the reaction zone.
A sensor is provided for the determination of various concentrations of one or more components within a fluid sample. The sensor includes an injection molded body, at least two electrodes, an enzyme, and if desired, an electron transfer mediator. The body includes a reaction zone for receiving a fluid sample. The electrodes are at least partially embedded within the plastic body and extend into the reaction zone. Also contained within the reaction zone is an enzyme capable of catalyzing a reaction involving a compound within the fluid sample. Additionally, the sensor incorporates fill detection which activates a meter, attached to the sensor, for measuring the electrochemical changes occurring in the reaction zone.
