JPH0363515A - Level measuring device - Google Patents

Abstract

PURPOSE:To reduce a measuring time without lowering an accuracy of level measurement by rapidly feeding a water till attaining a prescribed liquid level for measurement and changing-over to the low speed feeding thereafter. CONSTITUTION:First of all, only a solenoid valve 7 is opened to rapidly feed the water from an orifice 6 with large diameter. This rapid feeding is performed until either one of each level gage 2a-2e is made to be ON, and even when either one is made to be ON, the solenoid valve 7 is closed for the present to stop the feeding. The liquid level is settled due to the stop of feeding and a whole level is averaged; therefore, after that, the rapid feeding and the stop of feeding are repeated until even either one is made to be ON during a certain time while observing outputs of the level gages 2a-2e again. With such a manner, the liquid level is made to be almost an uniform level at almost the same state as the liquid level for measurement, at the time when the certain time is elapsed.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an improvement in an apparatus for measuring the level of a structure or the like by utilizing changes in the liquid level.

(Prior art) Structures constructed on relatively soft ground experience uneven settling of various parts over time. Recently, a construction method that equalizes the overall amount of settlement of a structure by expanding and contracting support jacks while measuring the amount of settlement has been attracting attention, until the ground stabilizes and the amount of settlement subsides.

In this case, in order to constantly monitor the base level displacement at a large number of locations, a measurement method has been proposed in Japanese Patent Application No. 63-269235 etc. by the present applicant that uses changes in the liquid level to measure the level. .

This is done by attaching a level meter to each foundation that detects a predetermined liquid level on and off, connecting them to a communicating pipe, and increasing the liquid level by gradually supplying water. By comparing and calculating the liquid level when each level meter is turned on based on the output of a reference level meter, a relative level displacement can be detected.

(Problem to be solved by the invention) By the way, water is supplied to the communication pipe during level measurement, and water is drained after the measurement is completed in preparation for the next measurement.
If the number of measurement sites is tens or more, it takes a long time to raise the liquid level to a predetermined level by supplying water through the communication pipe.

On the other hand, if you try to supply a large amount of water rapidly in a short period of time, the liquid level will not rise uniformly at all measurement points due to pipe resistance, etc., and the liquid level will increase in areas far from the water supply point. Even when the level was low, water sometimes overflowed from the level gauges nearby.

If you supply water at a low flow rate to avoid overflow,
It takes a considerable amount of time to fill all the communication pipes with water, and the measurement time becomes very long.

The present invention aims to solve such problems.

(Means for Solving the Problems) Therefore, as shown in FIG. Means 50 for rapidly supplying water to a communicating pipe in a device adapted to measure the level at a measuring point
In addition, a means 51 for supplying water at a low speed, a means 52 for draining water from a communicating pipe at a low speed, and a means 52 for rapidly supplying water until any one of the level meters is turned on, and then at least one is turned on within a certain time range. Measurement preparation water supply means 53 that repeatedly supplies and stops water so that the level is maintained, and then performs low-speed drainage until all level meters are turned off; and measurement control means that performs level measurement while supplying water at a low speed after this water supply. 54.

(Function) When measuring the level, water is first supplied rapidly (in large quantities), so the liquid level at each measuring point rises rapidly. When the water level reaches this level, stop the rapid water supply and wait until the average water level becomes even.

Thereafter, rapid water supply and stop are repeated for a predetermined period of time until the liquid level of at least one level meter always exceeds a specified value. After that, the water supply is stopped and the water drains at low speed.

Low-speed drainage is continued until all level meters are turned off, and when they are turned off, drainage is stopped and measurement preparation is completed.

Next, water supply is started at a low speed, and the level is measured while the liquid level rises slowly and uniformly.

The level meter is turned on in order from the lowest level at the measurement site where the level meter is attached, and the reference liquid level at the time it is turned on is read with another reference level meter, each level is measured and determined by fif&. Measurement ends when the level meter at the highest position turns on.

(Example) The embodiment shown in FIG. 2 will be described.

Reference level meters 2a, 2b, 2a, etc. l are installed at predetermined reference positions and continuously detect and output changes in the liquid level.
- is a level meter that is attached to each measurement site and detects and outputs a predetermined liquid level on and off; each of these outputs is input to the controller 4.

Reference level meter 1 and each level meter 2 a, 2 b, 2
are connected to each other by a communication pipe 3, and water is supplied to the communication pipe 3 from a water supply source 5 such as a pump through a filter 12 as necessary.

Therefore, in the water supply circuit 13, a large-diameter orifice 6 and a solenoid valve 7, which constitute a high-speed water supply means, and a small-diameter orifice 8 and a solenoid valve 9, which constitute a low-speed water supply means, are connected in parallel to each other.

Further, a drainage circuit 11 is provided to drain the water filling the communication pipe 3, and this drainage circuit 11 has a small-diameter orifice 15 and a solenoid valve 16 as a low-speed drainage means in parallel with a solenoid valve 17 for normal drainage. The circuit is connected.

The opening and closing of each of these solenoid valves 7, 9, 10.16 is controlled by signals from the controller 4, thereby supplying water to each level meter 2a, 2b, 2c, and so on. Perform level measurement.

In other words, level measurement using each level meter 2g, 2b, 2cm, etc. is carried out while gradually supplying water to the communication pipe 3 so that the liquid level rises uniformly.In this case, as the liquid level rises, Level meters 2a, 2b, 2c located in low positions.
It turns on in order from ..., so each level meter 2a,
By reading the liquid level of the reference level meter 1 when 2b, 2c, . . . are turned on, the relative level at each measurement site can be measured.

In order to measure the level with high precision, this water supply must be carried out gradually as the level gauges 2a, 2b, 2e... approach the measuring liquid level so that the liquid level rises uniformly. It is also necessary to shorten the overall water supply time by rapidly supplying water until it approaches the measurement liquid level, which is unrelated to measurement accuracy.

The control operation by the controller 4 for realizing such water supply control will be explained with reference to the flowchart in FIG. 3.

First, the solenoid valve 7 is opened to rapidly supply water from the large-diameter orifice 6. At this time, the other solenoid valves 9, 10, 16 are closed.
This process continues until one of the following is turned on.

During rapid water supply, the liquid level does not rise uniformly due to the influence of pipe resistance, and generally the liquid level closer to the water supply source is higher.

If any one of them turns on, the solenoid valve 7 is closed for the time being to stop the water supply. When the water supply is stopped, the liquid level settles down and the overall level becomes average, so check the outputs of level meters 2a, 2b, 2c, etc. again.
For a certain period of time, rapid water supply and shutoff are repeated until any one of them is turned on.

In this manner, after a certain period of time has elapsed, the liquid level reaches a substantially uniform level in a state close to the measured liquid level.

When the amount of water supplied is large, the slope of the liquid level in the communication pipe becomes large, and one level meter 2a is detected first.

Even if 2b, 2c, etc. are turned on, the average water level is far from the measured liquid level.Therefore, by repeating rapid water supply and stop within a certain period of time, the average water level can be determined most efficiently in a short period of time. It is possible to reach the vicinity of the measured liquid level.

After stopping the water supply, the solenoid valve 16 is then opened to slowly drain the water through the orifice 15 little by little.
continues until all are turned off.

In this way, in order to prepare for measurement, after the water has been supplied to near the measured liquid level and a certain stabilization time has elapsed, the solenoid valve? Open it and begin the measurement process.

In this measurement process, water is supplied via the small-diameter orifice 8, and the liquid level is gradually raised while maintaining a uniform level.

Level meter 2 in order from the lowest level of the measurement site.
The outputs of a, 2b, 2e, etc. are turned on, and by comparing these with the output of the reference level meter 1 at that time, the level of each part is determined.

In this way, by rapidly supplying water to the vicinity of the measurement liquid level, the water supply time is shortened, and by supplying water to gradually raise the liquid level during measurement, highly accurate level measurement is possible. It is.

The measurement ends when all the level meters 2a, 2b, 2c, .

(Effects of the Invention) As described above, according to the present invention, water is rapidly supplied up to a predetermined measured liquid level, and thereafter the water supply is switched to a low-speed water supply.
This has the effect of shortening measurement time without reducing level measurement accuracy.

[Brief explanation of drawings]

FIG. 1 is a claim correspondence diagram showing the configuration of the present invention, FIG. 2 is a circuit diagram showing an embodiment, and FIG. 3 is a flow chart showing the control operation of the controller. 1... Reference level meter, 2 a, 2 b, 2 c.
... Level meter, 3... Communication piping, 4... Controller, 6.8.15... Orifice, 7, 9, 10.1
6...Solenoid valve.

Claims (1)

[Claims] In a device that supplies water to a level meter installed at each measuring point via a communicating pipe and measures the level of each measuring point based on the output of each level meter, a means for rapidly supplying water to the communicating pipe; A means for supplying water at a low speed, a means for draining water from a communicating pipe at a low speed, and a means for rapidly supplying water until any one of the level meters turns on, and then at least one remains on within a certain period of time. The system is equipped with a measurement preparation water supply means that repeats water supply and stop as shown in FIG. A level measuring device characterized by: