Abstract: The disclosure includes an inductive conductivity sensor for measuring the specific electrical conductivity of a medium with a transmitter coil energized by an input signal, a receiver coil coupled with the transmitter coil via the medium, which receiver coil supplies an output signal that is a measure for the conductivity of the medium, and a housing enclosing the transmitter coil and the receiver coil, which housing comprises at least one housing section designed to be immersed in the medium, the housing wall of said housing section surrounding the transmitter coil and the receiver coil. The housing is made of a magnetic plastic or resin for inductively decoupling the transmitter coil from the receiver coil. In certain embodiments, the housing may be made of a ferromagnetic material. Another aspect of the disclosure includes a method for manufacturing the conductivity sensor.

Abstract: A retractable assembly, comprising: a housing; an immersion tube, which is axially movable between a service position and a process position. A first inlet facing away from the medium and a second inlet facing the medium. The immersion tube is moved from the service position to the process position by supplying the first inlet with energy, and the immersion tube is moved from the process position to the service position by supplying the second inlet with energy. A first mechanical blocking member shifts against a spring bias, and the blocking member engages in a first groove on the immersion tube. The first groove is located in the movement direction. The spring bias is so embodied that supplying the second inlet with energy releases the blocking member from the groove, whereby movement of the immersion tube from process position to service position becomes possible.

Abstract: A method for manufacturing an inductive conductivity sensor, wherein on both sides of a circuit board coils are placed surrounding an opening of the circuit board, and the circuit board with the coils is inserted into a housing. A sleeve is inserted through a first opening of the housing through the opening of the circuit board into the housing. The sleeve includes a first end section and a second end section and the sleeve is inserted with the first end section first into the housing, and wherein the sleeve is welded with the housing by means of a sonotrode by ultrasonic welding. Both the first end section as well as also the second end section of the sleeve are welded with the housing, wherein the sonotrode is applied exclusively on the sleeve on the side of the second end section. The invention relates further to an inductive conductivity sensor.

Abstract: A method for manufacturing an inductive conductivity sensor, with coils on both sides of a circuit board are placed surrounding an opening of the circuit board. The circuit board with the coils is inserted into a housing, wherein a sleeve is inserted in the housing through a second opening of the housing through the opening of the circuit board out to a first opening. The first opening, the second opening and the opening of the circuit board are aligned with one another, wherein the sleeve includes a first end section and a second end section and the sleeve is inserted with the first end section first in the housing, and wherein the sleeve is welded with the housing by means of a sonotrode by ultrasonic welding. The first end section of the sleeve is welded with the housing and with a counterpart inserted into the first opening. The invention relates further to an inductive conductivity sensor.

Abstract: A method for manufacture of an inductive sensor, wherein coils are placed on both sides of a support plate surrounding an opening of the support plate, and the support plate with the coils is inserted into a housing. A sleeve is inserted through a first cavity of the housing through the opening of the support plate into the housing. In order to achieve a secure and temperature independent joint between the sleeve and the housing, the sleeve (5) is welded with the housing (2).

Abstract: A method for manufacture of an inductive sensor, wherein coils are placed on both sides of a support plate surrounding an opening of the support plate, and the support plate with the coils is inserted into a housing. A sleeve is inserted through a first cavity of the housing through the opening of the support plate into the housing. In order to achieve a secure and temperature independent joint between the sleeve and the housing, the sleeve (5) is welded with the housing (2).