Method for producing a sensor

Abstract

The present disclosure relates to a method for producing a sensor comprising the steps of: adapting a sensor adapter of the sensor element to a first section of the process connection, introducing the sensor element with the sensor adapter first into the first section of the process connection, so that the sensor element projects beyond the process connection with a second section and the first section of the process connection and the first section of the sensor element form a gap, connecting the sensor element to the process connection by creating a weld connection between the first section of the process connection and the sensor adapter of the sensor element in the region of the gap.

Claims

1. A method for producing a sensor, comprising: adapting a sensor adapter of a sensor element to a first section of a process connection, wherein the process connection includes a custom-fit opening for a sonotrode; placing the sensor element with the sensor adaptor on an anvil; introducing the sensor element with the sensor adapter into the first section of the process connection such that a sensor tip of the sensor element projects beyond the process connection and the first section of the process connection and the sensor adapter form a gap; placing a sonotrode in the custom-fit opening of the process connection such that the gap is between the sonotrode and the anvil; and creating an ultrasonic weld connection between the first section of the process connection and the sensor adapter in the region of the gap, thereby connecting the sensor element to the process connection.

2. The method according to claim 1, wherein the sensor is a conductivity sensor.

3. The method according to claim 1, further comprising: finishing the weld connection between the process connection and sensor element by a machining process including vibratory finishing, carving, deburring, turning, milling, or grinding.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The present disclosure is explained in more detail based upon the following drawings. Illustrated are:

(2) FIG. 1 shows a longitudinal section of a sensor with a sensor element and a process connection, in which the sensor element is arranged on the anvil, and the sonotrode is arranged on the process connection,

(3) FIG. 2 shows a longitudinal section of a sensor with a sensor element and a process connection, in which the process connection is arranged in the anvil, and the sensor element is arranged within the sonotrode,

(4) FIG. 3 shows a longitudinal section of a sensor corresponding to FIG. 2, in which the sensor is welded by means of an intermediate ring to the process connection,

(5) FIG. 4 shows a longitudinal section of a sensor with a sensor element 3 and a process connection 2, in which the process connection is arranged on the sonotrode and the sensor element is arranged on the anvil, and

(6) FIG. 5 a sensor that is produced in a manner corresponding to one of the methods described in the description of FIG. 1.

DETAILED DESCRIPTION

(7) The present disclosure will be explained with reference to a conductivity sensor in particular, with reference to a conductive conductivity sensor. The basic concept is, however, applicable to other types of sensors that use metal electrodes. A wide range of sensors are conceivable from the field of process automation, such as pH sensors, amperometric sensors, etc.

(8) FIG. 1 shows a sensor 1 comprising a sensor element 3 and a process connection 2. The sensor element 3 is made of a technical ceramic such as zirconium dioxide in general, of an electrically nonconductive material. In one embodiment, the zirconium dioxide is magnesium-stabilized, aluminum-stabilized, or iridium-stabilized. The process connection 2 is made of a metal in particular, of stainless steel. By means of the process connection 2, the sensor 1 can be attached to a container (not shown).

(9) The sensor element 3 comprises a sensor adapter 4 for introducing the sensor element 3 into the process connection 2, and a sensor tip 6 by means of which the sensor element 3 projects beyond the process connection 2.

(10) An interior of the process connection 2 is divided into two cylindrical sections that each have an inner radius, wherein the second inner radius is greater than the first inner radius. The first section with the smaller outer radius serves to accommodate the sensor adapter 4.

(11) If the sensor element 3 is fastened to the process connection 2, the first inner radius and an outer radius of the sensor adapter 4 form a press fit. In so doing, the second section of the process connection 2 and the sensor adapter 4 of the sensor element 3 form a gap.

(12) The sensor element 3 and the process connection 2 are connected by welding. For this purpose, the gap 8 between the first section 5 of the process connection 2 and the sensor adapter 4 is welded by ultrasonic welding. The ultrasonic welding is accomplished by introducing the sensor element 3 with the sensor tip 6 first into a custom-fit anvil 10. Analogously, a sonotrode 9 is introduced into a custom-fit opening in the process connection such that the gap 8 is arranged between the anvil 10 and the sonotrode. The weld connection is produced by vibrations of the sonotrode.

(13) FIG. 2 shows a longitudinal section of a sensor 1 with a sensor element 3 and a process connection 2, in which the process connection 2 is arranged in the anvil 10, and the sensor element 3 is arranged within the sonotrode 9. This embodiment shows an alternative sensor production method.

(14) FIG. 3 shows a longitudinal section of a sensor 1 corresponding to FIG. 2, in which the sensor 1 is welded by means of an intermediate ring 12 to the process connection 2. If an intermediate ring 12 is used, numerous finishing steps of a contact region between the sensor element 3 and the process connection 2 become superfluous.

(15) FIG. 4 shows a longitudinal section of a sensor 1 with a sensor element 3 and a process connection 2, in which the process connection 2 is arranged on the sonotrode 9, and the sensor element 3 is arranged on the anvil 10. This embodiment shows an alternative sensor production method.

(16) FIG. 5 shows a sensor 1 that is produced in a manner corresponding to one of the methods described in the description of FIG. 1.