JPS608754A - Electrostatic potential measuring device - Google Patents

Abstract

PURPOSE:To detect and measure a static electricity safely and accurately by using a voltage sensor provided with a light source which irradiates light interruptedly through an optical fiber cable. CONSTITUTION:Electrooptic crystals 11, 12, 13, and 14 are arranged, and electrodes (a) and (b) are provided before and after the intermediate electrooptic crystal 13 provided with a projecting part 13' and are connected to an electric power source 15 by lead wires a' and b' to form a voltage sensor 16, and light P' of a light emitting diode 17 is led to the electroptic crystal 11 by an optical fiber 18, and light P emitted from the electrooptic crystal 14 is led to a light receiving diode 20 by an optical fiber 19. When irradiation and stop of light 33 to the projecting part 13' from a light source 31 through an optical fiber 32 are repeated, a voltage changing in AC appears, and output light P0 for irradiation of the light and a variation PAC for stop of the light are compared with each other to obtain the magnitude of the input voltage, and the static electricity is detected without the influence of the variation of the output light P0.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a measuring device for measuring the voltage generated by static electricity in a charged fluid.

Static flow of liquids, gases, powders, etc. [flow that can be charged with electricity (L) Taking oils and fats as an example, when oils and fats are transported through pipes and stored in storage tanks, the oils and fats are transported through pipes, pumps, filters, etc. As it flows through, it comes into contact with them and becomes electrically charged, becoming a highly charged object in the storage tank.

By the way, when measuring to know the amount stored in a storage tank or the like, a metal object such as a measuring stick may be lowered and immersed.

At this time, a spark discharge occurs between the electrically charged oil and fat and the metal body, and this may combine with the oil and fat and vaporized gas, causing an explosion and fire.

For this reason, related organizations such as fire departments and transportation are currently studying ways to accurately measure the voltage generated by static electricity as a measure to prevent accidents caused by the generation of static electricity. It is hoped that a device that can measure this will emerge.

By the way, in order to know the charged state of the stored fluid, the conventional method of measuring the charged potential is as shown in FIG. A measuring device connected by line 4 was used.

However, since the measuring device 1t as described above uses metal for the measurement lead wire, a discharge phenomenon occurs during the measurement and the electric field is disturbed, so that accurate measurement cannot be performed.

In order to solve the above-mentioned problems with measurement devices using metal lead wires, a τH1ll determination device using a voltage sensor using the pneumatic effect and an optical fiber cable has been proposed in recent years.

The basic structure of a voltage sensor (bismuth, silicon oxide, commonly known as BSO sensor) that utilizes the electro-optic effect is as shown in Figure 2, which consists of a series of electro-optic crystals 11
, 12.13.14 are lined up, electrodes a and b are provided before and after the intermediate crystal 13, and - electrodes a and b are leads]! a′
, b' are connected to the power supply 15 to form a voltage sensor 16, and the light P' of the light emitting diode 17 is guided to the electro-optic crystal 11 at one end by an optical fiber cable 18, and the electro-optic crystal 14 at the other end is connected to the power supply 15 at The light P emitted from the optical fiber cable 19 is directed to a light receiving diode 20.

By the way, the upper Ff1. The light iP passing through the sensor 16 has the characteristics shown in Figure 3 with respect to the voltage V applied between the electrodes a and 5.

In other words, when the voltage to be measured V is zero, the light intensity p becomes p, but when a positive voltage is applied, the light intensity p becomes p.

If it becomes stronger and has negative polarity, p. It looks weaker.

ti using the above sensor with voltage IH11 constant
There are 11 types of all methods since then, the probe type and the spherical electrode type.

The former probe type, as shown in FIG. Connect the other electrode to oil:'rl 21 with lead P;
It measures the potential difference between the oil and the ground.

In the spherical electrode type, as shown in FIG.
A spherical electrode 25 with electrodes 6 connected by lead wires a' and 6 and optical fiber cables 18 and 19 connected thereto is inserted into oil A in an oil tank 26 to detect the surface electric field of the spherical electrode 25. It is.

By the way, both of the above measurement methods are based on the optical fiber cable 18.
．． When the transmission loss of the light emitting diode 19 changes over a long period of time and the output of the light emitting diode 17 changes, po in the light intensity in FIG. 3 changes.

For this reason, there is a problem in that detection and measurement are performed as if the light intensity p had changed due to a change in the voltage to be measured V, and accurate measurement results could not be obtained.

Conventionally, when the measured voltage V is alternating current, p is determined by separating the light intensity p into a direct current component PDC and an alternating current component PAC, as shown in FIG. 6, and calculating the degree of variation m. In other words, the DC component PD
It is possible to ignore changes in C.

However, in the case of static electricity, unlike the case of alternating current as shown in Figure 6, it is not possible to separate the direct current component PDC and the alternating current component PAC corresponding to the change in the light intensity p. There is a problem in that changes in p directly appear as measurement errors, making it impossible to perform accurate measurements.

This invention was made to eliminate the above-mentioned problems that occur when measuring voltage of static electricity, and an object of the present invention is to provide a measuring device that can safely and accurately detect and measure static electricity.

The configuration of this invention is to connect a PC via an optical fiber cable.
A voltage sensor equipped with a light source that continuously irradiates the wire is housed in a capsule-shaped sealed auxiliary electrode that is attached to a float, and the auxiliary electrode's outer periphery is covered with a beautiful, insulating protective casing. The space is filled with an electrical resistor [d] to enable high-precision measurement of static electricity voltage.

Hereinafter, the present invention will be described based on the accompanying drawings MS7 to IL1.

FIG. 7 shows the structure of the voltage sensor 16' used in the face of the measuring device 1 of the present invention, and the same parts as the conventional voltage sensor shown in FIG. Omitted.

A protruding portion 13' of a required size is formed on one side of the outer periphery of the intermediate ′ [k crystal 13 with electrodes a and b provided thereon. The optical fiber cable 3 is formed to have a certain thickness, and is connected from another light source 31 to the optical fiber cable 3.
The light 33 is configured to irradiate the protrusion 31' through the light 31'.

Upper Fit: The electro-optic crystals 11, 12, 13, and 14 are formed using a crystal having both a photoconductive effect and an electro-optic effect, such as Bll□Sio, 0.

In the voltage sensor 16' shown in FIG. 7, when light 33 is now directed onto the protrusion 13' of the intermediate electro-optic crystal 13, the insulation resistance is reduced due to the photoconductive effect. When the insulation resistance decreases, the "rI" i% a and 5 of the electrically conductive crystal 13
The '14L load stored in the meantime decreases, r! i:j;l
The power vab between j a and 5 decreases.

Furthermore, when the irradiation of the light 33 to the protrusion 13' is stopped, the insulation resistance is reduced and the heavy pressure vab between the electrodes a and 5 becomes high again.

In this way, by repeating the irradiation and stopping of the light 33 on the protruding ffl eye 3', a voltage that changes in an alternating current manner as shown in FIG. 8 appears, and the voltage as shown in FIG. When P is applied to the electro-optic crystal 13, the amount P of light transmitted through the voltage sensor 16' becomes as shown in FIG.

As shown in Figure 9, compare the output light Po while irradiating the light and the changes PA and C when the irradiation light is stopped 1m=PA
By changing irq li in c/po, input '1
It is possible to set the magnitude of pressure to .

Therefore, by using the voltage sensor 16' shown in FIG. 7 in the same manner as the conventional example shown in FIG. 4 or 5, p.

It becomes possible to detect static electricity without being affected by changes in (drift).

This invention uses the above-mentioned 11-pressure sensor 16' to detect even higher static pressure to improve measurement accuracy. As shown in FIG. 10, A capsule-shaped auxiliary electrode 43 is attached to the upper end of a cylindrical body 42 provided so as to trace the insulator flow) 41 vertically, and a capsule-shaped auxiliary electrode 44 is attached to the lower end thereof in a sealed state by tightening by screwing. Both auxiliary electrodes 43.44
A 'voltage sensor 16' is housed inside, and this sensor 16
't4tNa and b with lead wires a' and b to auxiliary electrode 4
It is connected to 3.44. V. The outer periphery of both auxiliary electrodes 43, 44 is covered with a protective case 45 with good insulation, which is screwed onto the cylindrical body 42, and the internal space of both auxiliary electrodes 43, 44 has a specific resistance of 10'. ~1
A powder or viscous mixture 46 having an electrical resistance of 0''-Q cm is filled.

In addition, the mating parts of the auxiliary electrodes 43, 44 and the protective case 45, 45 with respect to the cylindrical body 42 are glued with waterproof adhesive and waterproofed 245 to prevent water from seeping into the auxiliary electrodes. There is.

A flexible waterproof hose 48 is connected to the upper part of the auxiliary electrode 43 via an insulating joint 47, and the voltage sensor 16''
Fiber optic cables 18, 19 and 3 connected to
2 passes through this waterproof hose 48 and is drawn out to the outside.

The electrically resistive material 46 filled in the auxiliary electrodes 43 and 44 forms a kind of conductive path, and by lowering the resistance of the internal atmosphere, the voltage generated outside the auxiliary electrode 44 is transferred to the voltage sensor 16'. Detected by optical fiber Kelp19
It is used to detect and measure static electricity by reading the light reading of the optical/voltmeter via the voltmeter.

Figure 1I shows a specific structure for improving measurement accuracy, in which three measuring devices [j 50 are installed in the flow) 41 with a distance maintained between each 4, positions l □, and f at 12.18. , f
By floating and moving the float 50 in the oil tank 51, it is possible to measure the field strength distribution at 1η over the entire interior of the oil tank 51, thereby reducing the generation of static electricity. The situation is 41 degrees <,? ! The f-rank distribution can be effectively reduced.

The measuring device of the present invention has the above-mentioned configuration. For example, as shown in FIG. In order to detect and measure the static electricity generated during oil lubrication by This is to detect the 1p'7i'i; air that is generated on the oil surface without receiving it.

In addition, the outer periphery of the metal auxiliary electrodes 43, 44 is isolated from the oil level with an insulating protective case 45, 45, and the measuring device is attached to a float, so the oil level does not fluctuate due to lubrication, oil feeding, etc. It follows the oil level even when the υIII 'i device is moving, and there is no spark discharge between the υIII 'i device and the oil surface, making it possible to perform measurements safely and efficiently.

It can also be used to measure the electrical charge state in flowing powder.

As described above, according to the present invention, a capsule-shaped auxiliary device is equipped with a voltage sensor attached to a float by irradiating an electro-optic crystal with a photoconductive effect with light to lower its resistance and increase its detection potential. ．． Is it stored in Q and auxiliary? The outer periphery of the F1 pole is covered with an insulating protective case, and the internal space is filled with electrically resistive material to lower the resistance inside the auxiliary electrode.
The static electricity detection level increases significantly, making it possible to accurately and safely detect and measure static electricity voltage.

In addition, since the outer circumference of the auxiliary electrode is loosely covered with an insulating protective case, and an optical fiber cable is used to take out the measurement voltage and irradiate the light, and the auxiliary electrode is attached to a float, there is no possibility of electrical discharge occurring between the auxiliary electrode and the fluid being measured. Safely removes static electricity from fluids that can cause explosions or fires due to discharge.
lll can be determined 0

[Brief explanation of drawings]

Figure 1 is an explanatory diagram showing the conventional 7-meter voltage sensor; Figure 2 is an explanatory diagram showing the basic voltage sensor) 114 structure; Figure 3 is an explanatory diagram showing the voltage sensor Figure 4 is a control system diagram showing the first process using a voltage sensor, and Figure 5 is a diagram showing the second process using a voltage sensor.
1HIj fixed system same system 6 diagram showing u is light irradiation and 1゛j
Figure 7 is a connection system diagram of the voltage sensor used in this invention, and Figure 8 is a diagram showing the relationship between the four input voltages and the degree of modulation due to the stop. 1
] Figure 9 is the original 1 in the same page.
1 (an explanatory diagram showing the relationship between the input terminals for one shot and stop and the modulation layer, FIG. 10 is a vertical UF view of the 6111 foot device according to the present invention, and FIG. 11 is a vertical cross-section 110 showing the usage state of the same as above) Figure 11.12.13.14... Electro-optic crystal, 13'.
...Protrusion, 16...', a pressure sensor 18.19.
32...Optical fiber cable, 31...Light source, 41
...Float, 43.44...i+ii help electrician,
45...'l'l'::r:gui case, 46...
I! LL Qi resistance snout/h Patent issued) Yamadai Sumitomo City Qi Kogyo Co., Ltd.

Claims (2)

[Claims] (1) An optical/electric conversion voltmeter is connected to a voltage sensor using an electro-optic crystal with a photoconductive effect via an optical fiber cable, and a light beam is intermittent to the electro-optic crystal of the voltage sensor via an optical fiber cable. A light source that irradiates the target is provided, and the voltage sensor is built in a pair of auxiliary electrodes that are attached to the float in an insulated state and formed into a capsule shape,
An electrostatic potential measuring device characterized in that the outer periphery of the capsule auxiliary electrode is covered with an insulating preservation case, and the internal space is filled with an electrically resistive material. (2) Does it have a built-in voltage sensor? The electrostatic potential measuring device according to claim 1, wherein seven or more capsule-type auxiliary electrodes are attached to a float.