FI83464C - ANALYZING FOR THE ELECTRIC EQUIPMENT. - Google Patents

Description

1 83464

DEVICE TO PROTECT THE ELECTRICAL SENSOR

The invention relates to a device as defined in the preamble of claim 1 for protecting an electrical sensor 5, e.g. under pressurized, temperature-varying and / or humid conditions.

Various methods or devices for protecting electronic components are already known. These are generally intended to protect the component against external conditions or variations thereof, such as weather variations. Such electronic components include e.g. various electronic either active or passive components such as, for example, transistors, capacitors, resistors, combinations thereof, sensors, etc., or groups of components.

The components can be protected and isolated from their environment, e.g. by molding them, e.g. in resin, sealing them tightly in metal cylinders and enclosing them with a plastic film. U.S. Pat. No. 3,909,504 discloses a package of electronic components comprising a sealed polyethylene bag surrounding the components, interposed between circuit boards serving as a component base, which are also attached to the bag. The circuit boards and the bag are in turn placed in a PVC-25 tube and the extra space is filled with suitable foam.

However, the protection devices presented above are relatively complex and are not suitable for use, for example, in field conditions when protecting sensors.

The object of the invention is e.g. eliminating the above-mentioned shortcoming and implementing an easy-to-use device with a safe protective effect to protect electronic sensors. The characteristic features of the invention appear from the appended claim.

35 The advantages of the invention include implementation of effective moisture protection; the protective agent surrounding the sensor in the protective hood is liquid and moisture cannot penetrate it 2 83464. If the sensor is surrounded by a pressurized liquid medium, a corresponding pressure also exists in the protective medium and the medium thus does not come into contact with the sensor itself. The device 5 according to the invention also avoids possible galvanic pair error voltages caused by the electrical conductivity of the surrounding medium.

In the following, the invention and its other advantages will be described in detail with reference to the accompanying figure, which shows an electrical sensor mounted on a substrate, in this case a strain gauge, and a device according to the invention for protecting this component against environmental conditions.

The device 1 according to the invention comprises a protective hood 15 2 made of an elastic material, such as rubber or the like, which protective hood 2 is placed around the strain gauge strip 7 against the base 8 and fastened tightly, preferably glued, to it. The protective cap 2 is filled with a liquid protective substance 3 such as Teflon, silicon-20 cone or the like. It is advantageous to provide the protective hood 2 with a wider electric foot, 4 from which it is easy to attach it to the base 8.

The protective hood 2 is provided with a sheath 5 or a similar tubular channel for introducing the conductors of the sensor 7 or the sensor-25 group into the protective hood from outside the base.

The device according to the invention is installed in place, e.g. in the embodiment according to the figure, so that the protective dome 2 is already glued to the target surface, i.e. 30, around a strain gauge strip 7 attached to the base 8. Prior to this, the conductor 6 is threaded through the sheath 5 and properly connected to the sensor 7. The protective agent 3 is injected from the space between the sheath 5 and the conductor 6 into the sheath 2. The conductor 6 is glued or attached to the sheath 6 by other known methods 35. out after filling from the protective cover 2.

When the space 3 83464 outside the protective cover 2 of the base 8 is pressurized, the elastic liquid protective substance 3 inside the protective cover 2 is at the same time pressurized to the ambient pressure, whereby the moisture protection is independent of the external pressure.

The invention has been described above with reference to only one preferred embodiment thereof, but it is clear that the device according to the invention can be implemented in many ways within the scope of the inventive idea set out in the appended claim.

Claims (2)

4,8464 CLAIMS Device for protecting an electrical sensor, e.g. under pressurized, temperature-varying and / or humid conditions, comprising a protective cover (2) made of an elastic material and filled with a liquid protective substance, characterized in that the protective cover (2) is provided with a sensor (4) and a sheath (5) or the like and the device is placed around the sensor (7) 10 and against the measuring point (8) and fixed, most preferably glued, to this sensor (4), and the conductor (6) or conductors are brought into the protective cover (2). ) through the sheath (5) or the like. 15 PATENTKRAV Anordning fürddden av en elektrisk givare t.ex. in the case of a tracer, with a temperature variation and / or a function of the spindle, the anchorage of the omfat-20 is provided by a shield (2), which is made of an elastic material and a flap with a shield, with melting (4) and with sleeve (5) or with overheads and anchorage with placebo (7) with up to 25 mating sites and fuses, with the exception of fused, with the presence of molten (4), with and without (6) or with leds -gar har införts in skyddskäpan (2) genom bushan (5) eller motsvarande.