CN2216676Y

CN2216676Y - Capacitance level gauge

Info

Publication number: CN2216676Y
Application number: CN 94249065
Authority: CN
Inventors: 王文义
Original assignee: Individual
Current assignee: Individual
Priority date: 1994-12-31
Filing date: 1994-12-31
Publication date: 1996-01-03
Anticipated expiration: 2004-12-31

Abstract

The utility model relates to a capacitance level gauge, using a capacitance type sensor as an electrode, displays the liquid level on a displayer after the capacitance signal which is proportionally changed with the liquid level is processed by a transmitter which is composed of an oscillating circuit, a transmission circuit and a detecting amplifying circuit. The utility model mainly adopts a four-operational amplifier integrated package LM324 and a resistance-capacity element which is externally connected. The level gouge has the advantages of simple structure and low cost.

Description

A kind of capacitance level gauge

The utility model belongs to a kind of level gauging instrument, particularly relates to a kind of capacitive liquid level gauge.

Present liquid level instrument, the complex structure that has involves great expense, maintenance difficult, is difficult for penetration and promotion, and as ultrasonic level gage, what have is simple in structure, but the test section is a movable member, thereby very easily damage, poor reliability, maintenance capacity is big, as float level meter.Chinese patent CN2042952U discloses a kind of capacitance digital and has shown the liquid level meter, it is capacitance type sensor to be manufactured itself have independently negative electrode, measure the restriction that not whether conducted electricity by measured medium and container body, expanded application, but the complex structure of its capacitance type sensor and transmitter, cost is higher.

The purpose of this utility model provides a kind of simple in structure, lower-cost capacitance level gauge.

Its concrete scheme is: for the normal temperature in the open-top receptacle, non-corrosive medium detects, as gas holder, water tower liquid level etc., it adopts the insulated metal lead to make sensor, as with the utmost point of the Cx of the proportional variation of liquid level change, another very inserts the metal bare conductor or the canister wall of conducting medium, transmitter is by oscillatory circuit, transmission circuit, detector amplifier is formed, oscillatory circuit is by four high guaily unit integrated package 1/4IC1 and outer meeting resistance R1, R2, R3, external capacitor C1 forms, capacitor C 1 one termination 1/4IC1 negative input ends, transmission circuit is by four high guaily unit integrated package 2/4IC1 and outer meeting resistance R4, external capacitor C2, C0 forms, be connected to 1/4IC1 output terminal and 2/4IC1 negative input end respectively with the Cx two ends of the proportional variation of liquid level change, amplifying circuit is by four high guaily unit integrated package 3/4IC1 and outer meeting resistance R5, R6, variable resistor W2, capacitor C 3 is formed, the output terminal of 2/4IC1 connects the positive input terminal of 3/4IC1 by diode D2,3/4IC1 output termination display.

Detection for corrosivity conducting medium and non-conductive medium, it adopts capacitance type sensor to place and detects the mode of holding bucket and sealing with packoff, transmitter is by oscillatory circuit, transmission circuit, detector amplifier is formed, oscillatory circuit is by four high guaily unit integrated package 1/4IC1 and outer meeting resistance R1, R2, R3, external capacitor C1 forms, capacitor C 1 one termination 1/4IC1 negative input ends, transmission circuit is by four high guaily unit integrated package 2/4IC1 and outer meeting resistance R4, external capacitor C2, C0 forms, be connected to 1/4IC1 output terminal and 2/4IC1 negative input end respectively with the Cx two ends of the proportional variation of liquid level change, amplifying circuit is by four high guaily unit integrated package 3/4IC1 and outer meeting resistance R5, R6, variable resistor W2, capacitor C 3 is formed, the output terminal of 2/4IC1 connects the positive input terminal of 3/4I C1 by diode D2,3/4IC1 output termination display.

Capacitance type sensor can apply the metal bar of insulating material for the outside according to the survey media type, also can be the capacitance type sensor of forming by electrode tube, electrode stem, nut and insulation spacer, electrode stem is set in the electrode tube by nut and insulation spacer, has on the electrode tube to make to detect the aperture that medium flows into.

Packoff is according to pressure condition, and packoff is made up of nut, insulcrete, flange, insulation sleeve during low pressure;

During middle and high pressure, packoff is made up of nut, insulation spacer, gland bonnet, gland, packing, seal, high pressure flange, lens and sealing block;

Capacitance type sensor of the present utility model and sealing device structure are simple, transmitter only is made up of a four high guaily unit integrated package and external resistor-capacitor unit, thereby cost is lower, because test section of the present utility model does not have movable member, thereby reliability height, easy to maintenance, and can adapt to various conductions and non-conductive medium under high temperature, high pressure, the severe corrosive occasion.

Further specify the utility model below in conjunction with accompanying drawing and by embodiment:

Fig. 1 is the structural representation of insulated metal lead capacitance formula sensor;

Fig. 2 is a structural representation of measuring the capacitance type sensor of the conducting medium that is corrosive;

Fig. 3 measures the structural representation of the capacitance type sensor of non-conductive medium;

Fig. 4 is the schematic diagram of sealing device under the low pressure;

Fig. 5 is the structural representation of mesohigh lower sealing device;

Fig. 6 is for measuring the synoptic diagram of non-corrosiveness conducting medium liquid level in the open-top receptacle;

Fig. 7 is for measuring the synoptic diagram of open-top receptacle internal corrosion conducting medium liquid level;

Fig. 8 is for measuring the synoptic diagram of non-conductive medium liquid level in the open-top receptacle;

Fig. 9 is for measuring the synoptic diagram of closed container internal corrosion conducting medium liquid level;

Figure 10 is for measuring the synoptic diagram of non-conductive medium in the closed container;

Figure 11 is the circuit theory synoptic diagram of transmitter.

Embodiment 1: measure non-corrosiveness conducting medium such as water in the open-top receptacle.As capacitance type sensor and as the utmost point of Cx, another is the metal bare conductor 3 (chamber wall is non-conductive) of chamber wall 2 (chamber wall is an electric conductor) or a following hanging heavy hammer very with metal-insulator lead 1.The two poles of the earth are connected between the 1/4IC1 output terminal and 1/4IC1 negative input end of transmitter.Transmitter is by oscillatory circuit, transmission circuit, detector amplifier is formed, oscillatory circuit is by four high guaily unit integrated package 1/4IC1 and outer meeting resistance R1, R2, R3, external capacitor C1 forms, capacitor C 1 one termination 1/4IC1 negative input ends, transmission circuit is by four high guaily unit integrated package 2/4IC1 and outer meeting resistance R4, external capacitor C2, C0 forms, be connected to 1/4IC1 output terminal and 2/4IC1 negative input end respectively with the Cx two ends of the proportional variation of liquid level change, amplifying circuit is by four high guaily unit integrated package 3/4IC1 and outer meeting resistance R5, R6, variable resistor W2, capacitor C 3 is formed, the output terminal of 2/4IC1 connects the positive input terminal of 3/4IC1 by diode D2,3/4IC1 output termination display Rf, display can be analog also can be digital, because Cx is along with the proportional variation of liquid level, produce oscillator signal by oscillatory circuit, liquid level signal input transmission circuit with the Cx representative, to deliver to detector amplifier with the voltage signal of the proportional variation of liquid level height after treatment and amplify, demonstrate liquid level by display Rf at last.

Embodiment 2: measure open-top receptacle internal corrosion conducting medium, it has the appearance of detection bucket 4, the outside applies the metal bar of insulating material as capacitance type sensor 5 (as shown in Figure 2), packoff 6, packoff (as shown in Figure 4) is by nut 7, and insulcrete 8, flange 9, insulation sleeve 10 are formed, and sensor 5 is placed in insulcrete 8 and the flange 9, sensor 5 passes through insulation sleeve 10 with flange 9, and nut 7 plays insulating effect by the insulation utmost point 8.Flange 9 is fastening with detection appearance bucket 4, nut 7 is fixing with sensor 5, by sensor 5 and hold bucket 4 respectively lead-in wire as with Cx the two poles of the earth of the proportional variation of liquid level change, be connected between transmitter 1/4IC1 output terminal and the 2/4IC1 negative input end, transmitter circuit and change send principle with embodiment 1.

Embodiment 3: measure non-conductive medium in the open-top receptacle, its sensor 11 structures as shown in Figure 3, by electrode tube 12, electrode stem 13, nut 14, insulation spacer 15 is formed, and electrode stem 13 relies on nut 14 and insulation spacer 15 to be set in the electrode tube 12, has the aperture (not shown) that several flow into medium on the electrode tube 12.Its packoff 6 is with embodiment 2; With the Cx one of the proportional variation of liquid level change electrode stem 13, an electrode tube 12 very very, be connected between the 1/4IC1 output terminal and 2/4IC1 negative input end of transmitter, transmitter circuit and change send principle with embodiment 1.

Embodiment 4: measure the corrosivity conducting medium in the closed container, and identical during low pressure with embodiment 2.Packoff 6 structures are made up of nut 16, insulating mat spare 17, gland bonnet 18, gland 19, packing 20, seal 21, high pressure flange 22, German-style metal lensring 23 and sealing block 24 as shown in Figure 5 during mesohigh, and remainder is identical with embodiment 2.

Embodiment 5, measure the non-conductive medium in the closed container, and is identical with embodiment 3 during low pressure.Sealing device structure is identical with the packoff among the embodiment 4 during mesohigh, and remainder is identical with enforcement 3.

Claims

1, a kind of capacitance level gauge, has capacitance type sensor, transmitter and display, it is characterized in that: capacitance type sensor is an insulated conductor, transmitter is by oscillatory circuit, transmission circuit, detector amplifier is formed, oscillatory circuit is by four high guaily unit integrated package 1/4IC1 and outer meeting resistance R1, R2, R3, external capacitor C1 forms, capacitor C 1 one termination 1/4IC1 negative input ends, transmission circuit is by four high guaily unit integrated package 2/4IC1 and outer meeting resistance R4, external capacitor C2, C0 forms, be connected to 1/4IC1 output terminal and 2/4IC1 negative input end respectively with the Cx two ends of the proportional variation of liquid level change, amplifying circuit is by four high guaily unit integrated package 3/4IC1 and outer meeting resistance R5, R6, variable resistor W2, capacitor C 3 is formed, the output terminal of 2/4IC1 connects the positive input terminal of 3/4IC1 by diode D2,3/4IC1 output termination display.

2, a kind of capacitance level gauge, has capacitance type sensor, detect and hold bucket, packoff, transmitter, display, it is characterized in that: transmitter is by oscillatory circuit, transmission circuit, detector amplifier is formed, oscillatory circuit is by four high guaily unit integrated package 1/4IC1 and outer meeting resistance R1, R2, R3, external capacitor C1 forms, capacitor C 2 one termination 1/4IC1 negative input ends, transmission circuit is by four high guaily unit integrated package 2/4IC1 and outer meeting resistance R4, external capacitor C2, C0 forms, be connected to 1/4IC1 output terminal and 2/4IC1 negative input end respectively with the Cx two ends of the proportional variation of liquid level change, amplifying circuit is by four high guaily unit integrated package 3/4IC1 and outer meeting resistance R5, R6, variable resistor W2, capacitor C 3 is formed, the output terminal of 2/4IC1 connects the positive input terminal of 3/4IC1 by diode D2,3/4IC1 output termination display.

3, capacitance level gauge as claimed in claim 2 is characterized in that: capacitance type sensor is the metal bar that the outside applies insulating material, and there is screw thread the end.

4, capacitance level gauge as claimed in claim 2, it is characterized in that: capacitance type sensor is made up of electrode tube, electrode stem, nut, insulation spacer, electrode stem is set in the electrode tube by nut and insulation spacer, has on the electrode tube to make to detect the aperture that medium flows into.

5, as claim 3 or 4 described capacitance level gauges, it is characterized in that: packoff is made up of nut, insulcrete, flange and insulation sleeve.

6, as claim 3 or 4 described capacitance level gauges, it is characterized in that: packoff is made up of nut, insulation spacer, gland bonnet, gland, packing, seal, high pressure flange, German-style metal lensring and sealing block.