JP5707625B2 - Light spot discrimination water level meter - Google Patents

Description

The present invention includes (1) water level measurement when the measurement water depth is large and the measurement span is long, and (2) zero level adjustment and full scale without generating a water level error with respect to the water level serving as a reference for reading the scale plate scale. No adjustment is required. (3) To provide a water level meter having features such as being capable of measuring the water level of a pond, a dam, etc. because of a cross section with an inclination. This water level gauge can also be applied to the measurement of liquid level in tanks of chemical plants.

A plurality of LED lamps can be freely lit by a lighting control circuit by arranging LEDs as SMD parts as light emitters and arranging a plurality of LEDs linearly at intervals of 10 mm or less on a flexible insulating tape. Further, infrared LED light is more easily absorbed than visible light because infrared light has an absorption band due to molecular vibration of water. High sensitivity elements for infrared rays have been put into practical use as light receivers.
The light receiver can also be mounted on a flexible insulating tape as an SMD component like the LED.
From the water level measurement water limit to the measurement water limit, LED as a light emitting device, a photodiode as a light receiving device, the light receiving and emitting body according to a flexible tape arranged phototransistor in place intervals (mounting body) installed in the water level measurement range The flashing of the light emitter is received by the light receiver.
Even if the light emitter under the water surface is turned on, the light is absorbed by water and hardly emitted into the air. Therefore, the light receiving device (mounting body) on the water surface cannot recognize the lighting state.
Further, the light from the light emitter below the water surface cannot be recognized because the light is absorbed by the light receiver below the water surface.
The lighting state of the light emitter above the water surface can be recognized by the light receiver of the light emitting / receiving body (mounting body) above the water surface.
The light emitters of the light receiving / emitting body (mounting body) are sequentially turned on, and the light receiver recognizes the light spot position of the light receiving / emitting body (mounting body) in accordance with the lighting timing. The lighting position of the light emitter on the water surface can be recognized, and the light receiving position of the light emitter below the water surface cannot be recognized by the light receiver. That is, the measured water level is determined between the recognized lowermost light emitter and the unrecognizable uppermost light emitter.
The present invention measures the water level by detecting the position of the boundary between the light spot recognition and the light spot non-recognition by recognizing the light spot of the light emitter disposed below the water surface with the light receiver.

Conventionally, a float method is used as a mechanical method for water level gauges such as rivers, dams, and reservoirs. This method converts the water level from the rotation angle of the reel that winds the wire attached to the float that moves up and down as the water level rises and descends. It can obtain a water level measurement accuracy of about ± 1 cm, but requires a large water measuring tube as a civil engineering structure. And For this reason, dams, large rivers, etc. have not been used much recently.
A water pressure type water level gauge is often used as a contact type water level gauge for measuring in contact with the measurement water surface.
This method measures the water pressure proportional to the water depth with a pressure-sensitive element, and requires an air release tube to measure it compared to the atmospheric pressure. If it is buried in sediments such as rivers, it will cause measurement errors. For this reason, stability over time has become an issue.
As the non-contact water level gauge, an ultrasonic water level gauge and a radio wave level gauge are used.
Since the sensor part does not contact the water surface, these can be measured stably over time.
However, the water level that can be measured practically for both ultrasonic and radio wave types due to the fact that the radiation angle increases depending on the distance from the sensor, and there is an obstacle that shields the ultrasonic wave or radio wave within the radiation angle. Is limited.
The radio wave type has better measurement accuracy than the ultrasonic type, and an accuracy of ± 1 cm can be obtained regardless of the measurement span.
The light spot discrimination water level meter of the present invention does not require a large water measuring tube unlike the float type, and there is no problem of deterioration of measurement accuracy over time like the water pressure type water level meter. This is a water level gauge with no limit on the water depth to be measured.
In addition, the measurement accuracy can be adjusted to the scale of the metered water plate, so that an accuracy equivalent to the arrangement interval of the light emitters can be obtained without requiring zero point and full scale calibration.

FIG. 1 shows an example of the configuration when the water level is measured in a water channel. 5 shows an arrangement example of one light emitter and two light receivers arranged on a light receiving and emitting body (mounting body) . One light emitter and two light receivers are mounted as SMD parts by performing printed wiring on a flexible insulating tape.
(B) From the upper limit of 3 measurement water surfaces to the lower limit of 4 measurement water surfaces, 5 light receiving and emitting bodies (mounting bodies) in which 1 light emitter and 2 light receivers are arranged at predetermined intervals are installed in the water level measurement range.
(B) Each light emitter is controlled by a 12 light emitter lighting control circuit so that it is lit at a predetermined order and time interval.
(C) When the lighting emitter is slightly below the surface of the water to be measured, since the receiver at the same height is in the vicinity of the position, the lighting emitter is received in order to avoid a lighting check state. It is assumed that the light receiver (referred to as a confirmation discrimination light receiver) receives light by a light receiver that is defined in the upward direction from the lighting light emitter. That is, it is assumed that a light receiver whose upper direction is determined in advance is fixedly assigned to each light emitter as a confirmation determination light receiver.
(D) In accordance with the lighting timing of the lighting light emitter, the confirmation determination light receiver corresponding to this lighting light emitter shall perform the lighting determination of the lighting light emitter.
(E) 6 The lighting state of the light emitter below the measurement water surface absorbs the lighting light in the water, and therefore the lighting state cannot be detected by the confirmation determination light receiver located above this. The lighting state of the lighting light emitter above the surface of the measurement water can be detected by a confirmation determination light receiver located at a predetermined position in the upward direction.
(F) The lighting state is determined by the confirmation determination light receiver corresponding to each light emitter. Based on this judgment, (1) the position of the top light emitter that is underwater and cannot be confirmed for lighting, and (2) the position of the bottom light emitter that is in the air and can be confirmed for lighting. Then, it is determined that the measurement water surface is in the middle of the positions (1) and (2) .

The effects obtained by solving the problems of the conventional water level gauge are as follows.
First, there is no need for a measuring tube with a large diameter required for the installation of a float type water level meter because there is no need for a reel mechanism that winds the wire in balance with buoyancy, unlike the conventional mechanical float type water level meter. It is.
Secondly, when the pressure sensitive part is submerged in water, such as a water pressure level gauge, measurement error will occur if moisture is mixed into the pressure sensitive part from the air release tube or the pressure sensitive part is buried in sediment such as a river. Cause.
There is no deterioration factor based on these in the light spot discrimination water level meter, and zero adjustment and full scale adjustment are not necessary.
Thirdly, long span measurement is possible by unitizing five light-receiving / emitting bodies (mounting bodies) and connecting them in series, compared to ultrasonic water level meters and radio wave type water level meters.
Fourth, the measurement accuracy is such that the water level measurement accuracy of ± 1 cm or less is obtained by setting the arrangement interval of the LEDs on the five light receiving / emitting bodies (mounting body) to 1 cm or less.
Fifth, calibration of the water level scale is not required by setting the horizontal installation position of the 5-light emitting / receiving body (mounting body) together with the horizontal position of the metering water plate.

It is drawing which showed the basic composition of the light spot discrimination | determination water level meter.

In the basic configuration of the light spot discriminating water level meter of FIG. 1, the seven protective tubes protect (a) five light-receiving / emitting bodies (mounting bodies) from driftwood flowing through the river.
(A) It has a wave-dissipating function that averages waves on the water surface.
(C) Blocking interference light caused by external light such as sunlight.
And so on.
The material is a steel pipe or a vinyl chloride pipe, and the inner surface is coated or the like as necessary to adjust the reflection of light.

5 If the length of the light receiving / emitting body (mounting body) is difficult to manufacture, 11 a part of the flexible light-emitting circuit insulator, 1 light emitter, 2 light receivers, and 12 light emitter lighting control circuit if necessary. A light emitting / receiving body (mounting body) is configured as a unit having a standard length including the above, and a long one is configured by electrically connecting these units. By connecting these units and covering them with a 10 transparent waterproofing object made of a long transparent heat-shrinkable tube or the like, a long 5-light emitting / receiving body (mounting body) can be manufactured.

When the 5-light emitting / receiving body (mounting body) is inserted into the protective tube, a 9 weight is provided under the 5 light-receiving / emitting body (mounting body) .

  6 The actual water level fluctuates up and down due to the influence of waves and the like with respect to the measurement water surface. On the other hand, an average water level can be calculated | required by averaging the LED position which recognizes lighting, and the LED position which does not recognize lighting.

The standard of water level of rivers, waterways, dams, etc. is based on the quantity water plate obtained from the reference point elevation.
Therefore, the reference altitude of the water level meter is determined based on the quantity water plate.
When the 5-light emitting / receiving body (mounting body) is installed, the scale plate of the metered water plate is not distorted by being configured in an integrated structure at the same location as the metered water plate.

Since the cross section of the waterway wall has an inclination, for the pond, dam, river, and waterway, 7 protective tubes and 5 light receiving and emitting bodies (mounting bodies) are attached obliquely along the inclination and measured. In this case, there are a method of expanding the LED lamp mounting interval according to the inclination angle and a method of converting the scale by the correction calculation based on the inclination angle with the same interval as the vertical section.

The scope of claims at the beginning of the application is added.
(A) A light receiving / emitting body in which a plurality of light emitters and light receivers are arranged at predetermined intervals from the upper limit of the measurement water level to the lower limit of the measurement water level is arranged in the water level measurement range. That is, each light emitter is installed at a specific height corresponding to the water level. One light receiver is installed corresponding to a plurality of light emitters.
(B) The light emitting / receiving section of the light emitting / receiving body is installed in measurement water in a protective tube as a waterproof structure covered with a transparent object through which light passes.
(C) It is assumed that the light emitters on the light receiving / emitting body are sequentially turned on at intervals determined by the lighting control circuit. It is assumed that a light emitting lighting control circuit for this purpose is provided.
(D) The light emission wavelength of the light emitter is selected to be a light emission wavelength having a larger absorption coefficient with respect to water than visible light.
(E) In synchronization with the lighting timing of the lighting light emitter on the light emitting / receiving body, the light received by the light receiver performs light reception confirmation determination of the lighting light emitter by the light receiving circuit and the lighting state determination circuit. In this case, the light receiver for confirming lighting is assumed to be a light receiver (referred to as a confirmation discrimination light receiver) defined in the upper direction corresponding to the lighting light emitter.
(F) The lighting state by lighting of the light emitter below the surface of the measurement water is absorbed and scattered in the water, so that the lighting state cannot be confirmed by the confirmation determination light receiver. Since the lighting state of the light emitting device above the surface of the measurement water is less absorbed in the air, the confirmation discrimination light receiver can confirm the lighting state.
(G) The measured water level is determined by the lighting confirmation judgment result of the light receiver corresponding to the light emitting equipment that is turned on sequentially.
(1) The position of the uppermost light emitter that is in water and cannot be confirmed for lighting, (2) The position of the lowermost light emitter that is in the air and can be confirmed for lighting, (1), (2) Determined to be in the middle. For this purpose, a lighting state determination circuit for performing water level determination and a water level output circuit are provided.

Claims (1)

A mounting body in which a plurality of light emitters arranged at intervals defined in the vertical direction and a light receiver arranged above the plurality of light emitters are mounted;
A transparent waterproof object having a waterproof structure covering the mounting body;
A protective tube arranged to surround the mounting body;
A light emitter lighting control circuit for sequentially lighting a plurality of the light emitters;
A lighting state determination circuit that determines whether the light receiving device has confirmed the lighting state of the light emitting device that has emitted light, in synchronization with each lighting timing of the plurality of light emitting devices that are sequentially turned on,
The position of the uppermost light emitter determined that the lighting state could not be confirmed by the lighting state determination circuit, and the position of the lowermost light emitter determined that the lighting state could be confirmed by the lighting state determination circuit. A water level output circuit for determining a position between the measured level and a measured water level
Having a water level gauge.

Images