CN2190781Y

CN2190781Y - Water level transmitter

Info

Publication number: CN2190781Y
Application number: CN 94226957
Authority: CN
Inventors: 李载达
Original assignee: Individual
Current assignee: Individual
Priority date: 1994-03-18
Filing date: 1994-03-18
Publication date: 1995-03-01
Anticipated expiration: 2004-03-18

Abstract

The utility model relates to a probe device of a water level measuring instrument. A porous stone having homogeneous interstices is encapsulated in a liquid inlet of the lower part of a casing; the back end of the porous stone is communicated with an air chamber through a narrow pressure leading passage; the air chamber is positioned on a compression surface under a silicon cup; the ratio of the length to the diameter of the narrow pressure leading passage is larger than 20; the diameter of the narrow pressure leading passage is smaller than 20 mm. Silicone oil is arranged in the air chamber and the narrow pressure leading passage.

Description

Water level transmitter

The utility model relates to the probe apparatus of a kind of probe apparatus of level gauging instrument, particularly Water Level Measuring Meters.

At present in the water cycle of the wastewater treatment of some waterworks, environmental protection and large enterprise is handled, all will be with the variation of level gauging instrument sensed water level.The probe apparatus of existing instrument is that transmitter adopts the diffuse si pressure-sensitive device usually.Because the silicon face of diffuse si pressure-sensitive device can not directly contact with water, otherwise can chronic corrosion silicon materials.All adopt at present at silicon compression face the place ahead stainless steel diaphragm, the centre is full of the pressure that silicone oil and measured medium isolate to come measuring media, have the secondary diaphragm pressure-active element can with the corrosive liquid of stainless steel compatibility in carry out pressure survey, but it costs an arm and a leg, and is not add 5 to 6 times of isolation diaphragm.Owing to increased the barrier film lamella, diaphragm and oil have all been participated in the pressure transmission in addition, make temperature effect and linear all variation of pressure-active element, and its synthesis precision will reduce by 1 to 2 times.

The purpose of this utility model is exactly in order to address the above problem, and a kind of with low cost, water level transmitter that precision is high is provided.

Technical solution of the present utility model:

A kind of water level transmitter, it includes seal casinghousing (7), the silicon cup (4) of housing (7) interior bottom idiozona resistor stripe (5), it is characterized in that in the bottom inlet of housing (7), being packaged with the uniform permeable stone in its gap (1), the rear end of permeable stone (1) is communicated with air chamber (3) by the thin passage of impulse (2) of housing (7), air chamber (3) is positioned on the following compression face of silicon cup (4), the length L of the thin passage of impulse (2) and the ratio of its diameter phi are greater than 20, and the diameter phi of the thin passage of impulse (2) is equipped with silicone oil less than 2mm in air chamber (3) and the thin passage of impulse (2).

The utility model is simple in structure, with low cost, utilize surface tension of liquid and pressure balance principle to design rational water inlet and impulse channel architecture, make water directly not contact the silicon cup compression face of pressure-sensitive device, reach the silicon compression face with level pressure being had no simultaneously loss, finish the course of work that pressure is transformed into electric weight output, have higher precision.

Fig. 1 is a structural representation of the present utility model.

As Fig. 1, when housing of the present utility model (7) water inlet effect water column static pressure, hydraulic pressure affacts on the interior silicone oil of the thin passage of impulse (2) because the gap good uniformity of permeable stone (1) itself by permeable stone (1), pore size is similar to the sand grains size, make permeable stone (1) under hydraulic action, air in its gap evenly rises, automatically be pressed into the thin passage of impulse (2), form the compression face that air bubble affacts silicon cup (4), promptly the compression face at silicon cup (4) forms air film, be silicon layer under the air film, water layer is in the bottom, thereby water is isolated automatically, but air film, oil reservoir, after the pressure self-poise between water layer pressure is reached the compression face of silicon cup (4), make the resistor stripe (5) on it produce variation accordingly, micro-signal is amplified through circuit board (6), compensation and voltage current transformation are handled, transfer out current signal to measurement instrument from cable (8) at last, finish the water level detecting process.Housing (7) in inside, has the excellent waterproof structure with all device sealings.

Claims

1, a kind of water level transmitter, it includes seal casinghousing (7), the silicon cup (4) of housing (7) interior bottom idiozona resistor stripe (5), it is characterized in that in the bottom inlet of housing (7), being packaged with the uniform permeable stone in its gap (1), the rear end of permeable stone (1) is communicated with air chamber (3) by the thin passage of impulse (2) of housing (7), air chamber (3) is positioned on the following compression face of silicon cup (4), the length L of the thin passage of impulse (2) and the ratio of its diameter phi are greater than 20, and the diameter phi of the thin passage of impulse (2) is equipped with silicone oil less than 2mm in air chamber (3) and the thin passage of impulse (2).