CN2294478Y

CN2294478Y - Capactive sensor for measuring liquid dielectric coefficient

Info

Publication number: CN2294478Y
Application number: CN 97201686
Authority: CN
Inventors: 宋茂; 张柏松; 金孝华; 吕彬; 张玉华
Original assignee: KAIYUE ELECTRICAL EQUIPMENT CO Ltd NINGBO; Beijing University of Technology
Current assignee: KAIYUE ELECTRICAL EQUIPMENT CO Ltd NINGBO; Beijing University of Technology
Priority date: 1997-03-11
Filing date: 1997-03-11
Publication date: 1998-10-14
Anticipated expiration: 2007-03-11

Abstract

The utility model relates to a capacitive sensor for measuring liquid dielectric coefficient, belonging to the technical field of sensor manufacture. The utility model is characterized in that the utility model is composed of a capacitive sensor element whose exterior is applied with a teflon film, a white teflon disk whose radial direction is provided with a groove, a top cover which is covered on the white teflon disk, an outer sleeve whose internal wall is connected with the internal thread of the top cover and can fix the disk, and a hollow nut which is connected with a hollow handle of the top cover and is used for leading out wires of electrodes. The capacitive sensor element is composed of two half cylinders, and electrode plates of the positive electrode and the negative electrode of the capacitive sensor element form a cross plug-in type. The white teflon disk is connected with the capacitive sensor element by two screws which are provided with the leading out wires of the electrodes in a winding way and four connecting screws. The utility model has the advantages of good conformance of primary capacitance values, no oil suspension on the electrode plates of the electrodes, high measuring precision, convenient manufacture, low cost, etc.

Description

Measure the capacitance type sensor that liquid dielectric coefficient is used

A kind ofly measure the capacitance type sensor that the liquid dielectric coefficient uses and belong to capacitive sensor element manufacturing technology field.

The capacitance type sensor that is used to measure liquid dielectric coefficient generally has parallel plate type and two kinds of structures of drum type brake, its shortcoming is: because its positive and negative electrode is the staggered form structure, welding technology complexity between its pole plate, be easy to generate thermal deformation, add the error of assembly technology, so just be difficult to guarantee the requirement of pole spacing precision, thereby the consistance of its initial capacitance value is very poor, therefore, the qualification rate of finished product is low, and manufacturing cost is also expensive; And fluid remaining on the metal polar plate can directly influence the accuracy of next time measuring, and must often clean and could continue use.

The purpose of this utility model is to provide a kind of capacitance type sensor that can be used for measuring liquid dielectric coefficient.

Of the present utility model being characterised in that: it is the pole plate intersection dock capacitive transducer of a kind of garden cylindricality, and it just is made up of the usefulness two and half garden tubes of an outer coating tetrafluoroethylene film, negative plates intersection plug-in type electric capacity sensing element 1, the electrical isolation garden dish 2 of using the screw 6 that goes between around top electrode to link to each other and radially slotting with its upper surface with attachment screw 7, be buckled on the garden dish 2 and the top cover 3 of band wiring hole, be connected with the peripheral internal thread of top cover 3 and can hold the outer sleeve 4 of electrical isolation garden dish 2 and form with the hollow nut that is used for the extraction electrode lead-in wire 5 that is threaded with the hollow handle on the top cover 3.Above-mentioned parts and interconnected relationship thereof are asked for an interview accompanying drawing 1～accompanying drawing 3.

Evidence: it has reached the designing requirement of expection.

In order in conjunction with the embodiments present specification to be done detailed description below, now as follows present specification used accompanying drawing title and numbering brief introduction thereof:

Fig. 1: the front elevation of capacitance sensing element 1;

Fig. 2: the longitudinal section of this capacitance type sensor;

Fig. 3: with the white polytetrafluoroethylpipe is that 2 front elevation is coiled in the garden that material is made.

Embodiment:

Just forming with two and half garden tubes, negative plates is intersected plug-type capacitance sensing element 1 usefulness wire electrode cutting machine bed and is made, the polytetrafluoroethylene film that is used to eliminate the extension oil phenomenon of metal polar plate on it applies with electrostatic painting process, electrical isolation garden dish 2 usefulness white polytetrafluoroethylpipe materials are made, it links to each other with 4 attachment screws with 2 screws 6 around top electrode lead-in wire respectively with capacitance sensing element 1 and by the boss rank of outer sleeve 4 inwalls that are connected with internal thread with top cover 3 peripheries holding and fix, its surface radially have the lead-in wire groove with leading electrode lead-in wire thus the handle by top cover 3 outwards draw from the endoporus of the hollow nut 5 that is threaded with it, in addition, also have 4 vent ports 8 on its surface and the top cover 3.

Test result: product qualified rate is not less than 98%, and cost of manufacture descends significantly; The consistance of initial capacitance value is in 0 ℃～40 ℃, the environment of relative humidity below 80%, and through repeatedly measuring, its absolute error is not more than 0.3PF, and relative error is less than 2/1000ths; Without cleaning, continuously the gasoline of different labels to be measured, its index value that records compares with the index value of using the Unite States Standard (USS) checkout equipment to record, and its relative error is no more than 1%.Thereby, reached the requirement of the technical indicator of product fully.

It not only can be directly used in the dielectric coefficient of measuring different labels gasoline, after connecting support circuit, can directly measure the label of gasoline.Simultaneously, it also can be by measuring the water cut that dielectric coefficient that difference contains the alcohol of water cut removes to measure alcohol to be measured, and correspondingly, it also can be used for measuring the dielectric coefficient of other liquid, can measure analog quantity to be measured after mixing corresponding circuit.

Claims

1. measure the capacitance type sensor that liquid dielectric coefficient is used for one kind, contain capacitive sensor element and auxiliary thereof, it is characterized in that: it is the pole plate intersection dock capacitive transducer of a kind of garden cylindricality, and it just is made up of the usefulness two and half garden tubes of an outer coating tetrafluoroethylene film, negative plates intersection plug-in type electric capacity sensing element (1), (2) are coiled in the electrical isolation garden of using screw (6) around top electrode lead-in wire to link to each other with attachment screw (7) with its upper surface and radially slotting, be buckled in garden dish (2) and go up and be with the top cover (3) of wiring hole, be connected with the peripheral internal thread of top cover (3) and can hold the outer sleeve (4) of electrical isolation garden dish (2) and form with the hollow nut (5) that is used for the extraction electrode lead-in wire that is threaded with the hollow handle on the top cover (3).

2. the capacitance type sensor that mensuration liquid dielectric coefficient according to claim 1 is used is characterized in that: described electrical isolation garden dish (2) is made with white polytetrafluoroethylpipe.