JPS6086445A - Dipping type gravimeter - Google Patents

Abstract

PURPOSE:To measure and record specific gravity in each depth of liquid to be measured highly accurately and automatically by using a signal from a differential pressure oscillator for measuring the specific gravity and a signal from a pressure oscillator for measuring pressure and executing prescribed arithmetic. CONSTITUTION:The differential pressure oscillator 22 detecting the differential pressure of an upper side seal diaphragm 10 and measuring its specific gravity and a differential pressure oscillator 28 detecting the differential pressure of a lower side seal diaphragm 16 and measuring the pressure are arranged in a weight case 2. A specific gravity signal P1 from the oscillator 22 and a pressure signal P from the oscillator 28 are inputted to an operation display device 31. The operation of P/P1=(h+H1) is executed to calculate (h+H1) and the distance of a dipping gravimeter under the liquid surface is measured. Thus, the specific gravity in each depth of the liquid to be measured is measured and recorded highly accurately and automatically.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an immersion type hydrometer suitable for use in shaft construction, etc.

[Prior art]

In recent years, the current state of construction has required not only high-rise buildings but also more efficient use of underground structures due to the soaring land prices, and the demands for larger and more durable foundation works are also accompanied by demands for construction safety and pollution prevention. Together, they have proposed a new construction method commonly known as the MDWI method. This MDWI
The method is a construction method for constructing continuous walls or columns deep underground, such as underground external walls of buildings, foundation piles, water-stop walls of tanks and dams, side walls of subways and public ditches, etc. The entire procedure is explained below. , ■Use an excavator to dig a trench or vertical hole with a shape and depth appropriate for the structure.

At this time, excavation is carried out while filling the trench or Omukai with stabilizing liquid (slurry) to prevent the earth wall from collapsing. Also, when the groove length is long, it is done in increments of a certain length.

■Reinforcement cages assembled according to the shape of the groove or hole are inserted into the liquid in the groove or hole as core material.

■Before and after inserting the reinforcing steel cage, the accumulated soil (slime) in the stabilizing solution is discharged to the outside using a vacuum.

■ Gently pour comfrey from the bottom of the groove or hole using a tremie pipe. At the same time, all of the stabilizing liquid recovery operations are carried out in parallel.

What is important here is that in addition to the above-mentioned work, it is necessary to consistently and carefully control the quality of the stabilizing liquid. Failure to do so will lead to serious problems in construction, such as reduced excavation accuracy and collapse of trench walls. become. Therefore, in order to maintain the stability of the structure by injecting a stabilizing liquid that matches the ground and construction conditions, it is necessary to measure the specific gravity, viscosity, sand fraction, pH value, etc. of the stabilizing liquid at each depth. For this reason, an immersion type hydrometer suitable for use in sword/karu construction has recently been proposed by the same applicant (Japanese Patent Application No. 123957/1983).

In this method, a heavy housing with seal diaphragms attached to two points at different heights is suspended in the liquid to be measured, and the specific gravity is measured based on the differential pressure between the diaphragms. Due to the specific gravity of the liquid between the slams, it was not possible to fit the hydrometer to a distance below the liquid level.

Therefore, the distance below the liquid level is measured visually using an appropriate measure, but such visual measurement not only requires personnel, but also automatically records the distance below the liquid level in accordance with the specific gravity. It had the disadvantage that it could not be done.

[Summary of the invention]

The present invention has been made in view of the above-mentioned points, and the seal diaphragm is installed at two positions at different heights.
A pressure transmitter that detects the differential pressure between both diaphragms is installed inside, and a pressure transmitter that measures the pressure applied to the seal diaphragm on the high pressure side is installed inside the heavy housing suspended in the liquid to be measured. This immersion type hydrometer is capable of accurately measuring the specific gravity at each depth by arranging the entire device and calculating the signals from both transmitters, and is effective even in liquids whose specific gravity changes greatly due to temperature changes. It is something to do.

〔Example〕

Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.

FIG. 1 is a front view showing an embodiment of the immersion type hydrometer according to the present invention with the inner container pulled out, and FIG. 2 is a plan view of the device.
FIG. 3 is a longitudinal sectional view of the device.

In these figures, the immersion hydrometer, designated as a whole by the reference numeral 1, comprises a hermetically sealed vertically cylindrical weight housing 2. The heavy housing 2 includes a cylindrical case 3 made of stainless steel or the like and open at both ends, and an upper side that securely closes the upper end opening of the cylindrical case 3 via a backing 4 and is fixed to the case 3 with a plurality of bolts 5. It is composed of a disc body 6 and a lower disc body 7 that secretly closes the lower end opening of the cylindrical case 3, and the weight housing 2 is suspended on the surface of the upper disc body 6 so as to be vertically movable in the liquid to be measured. A pair of hanging hooks 8
A and 8b are attached, and a protection plate 9 for protecting an upper seal diaphragm 10 on the low pressure side is attached with bolts 11 at an appropriate distance from the upper disk body 6. On the other hand, the lower disc body 7 is connected to the cylindrical case 3
Ring-shaped mounting plate 1 fitted and fixed to the inner surface of the lower end opening of
3 through a backing 14 with screws.

A weight υ17 that also serves as a protection plate for the lower seal diaphragm 16 on the high pressure side is vertically provided on the ring-shaped mounting plate 13.

Recesses 1B and 19 are formed at the center of the upper surface of the upper disk body 6 and the center of the lower surface of the lower disk body 7, respectively, and these recesses 18 and 19 are covered by the upper seal diaphragm 10 and the lower seal diaphragm 16. As a result, the compartments 20 and 21 are completely formed. Further, a differential pressure transmitter 22 is housed in the heavy housing 2 and is fixed to a connecting member 23 that integrally connects the upper and lower disk bodies 6 and 7. The bolts 5 fixing the upper disc body 6 to the cylindrical case 3 and the lower disc body 7
By removing the bolts 15 that are fixed to the ring-shaped mounting plate 13 and pulling up the hanging hooks 8a and 8b with a rope or the like, they are removed from the upper end opening of the cylindrical case 3 together with the upper disc body 6 and the lower disc body 7. drawn out.

Note that FIG. 1 shows the state at this time. The differential pressure transmitter 22 and each compartment 20.21 are communicated with each other through pressure impulse pipes 24A and 24B, each of which is filled with an internal sealing liquid 25.
Further, the differential pressure transmitter 22 is connected by a cable 26 to an arithmetic display device, a recorder, etc. (not shown) provided outside the device.

Further, inside the weight housing 2, a pressure transmitter 28 is fixedly disposed on the lower disc body 7 and measures the pressure applied to the lower seal diaphragm 16 on the high pressure side.

In such a configuration, the immersion type hydrometer 1 is suspended by chains, wires, etc. hooked to the hanging hooks 8a and 8b, and is immersed in the liquid to be measured, thereby adjusting the height in the liquid to be measured. The total differential pressure at two different locations is detected, and the specific gravity at each depth is continuously measured using the fact that this differential pressure is proportional to the specific gravity of the liquid to be measured.

That is, as shown in FIG. 4, for example, the immersion type hydrometer 1 is placed in muddy water 30 at a depth h+HI (where h is the distance from the liquid level to the upper seal diaphragm 10, and H3 is the distance from the upper seal diaphragm 10 to the upper seal diaphragm 10). 10116), the differential pressure 1p generated in the differential pressure transmitter 22 is calculated by the following equation.

ρl −h−ρa IIHO+ΔP=ρ1@h+ρ@H
1-ρo (Ho+H+) , ΔP-ρ-L-ρo-H! ...(1) However: ρ
l is the specific gravity of the muddy water 30 in the h range, ρ is the specific gravity of the muddy water 30 in the H1 range, ρ0 is the specific gravity of the inner sealing liquid 23, and Ho is the distance between the upper seal diaphragm 10 and the differential pressure transmitter 22.

Here, ρ. =0.97, H+ =5.00mm5 Let the specific gravity ρ of the muddy water 30 be, for example, ρmax=15. ρm1n=0
Then, ΔP −−485 to 265 mrn H20 is set, and the suppression and measurement range (span) of the differential pressure transmitter 22 are set to 485 mm B, 20 and 7, respectively.
Adjust with a value of 50mmH2O.

Then, a current signal (for example, 4 mA to 2 ohmA) proportional to the differential pressure ΔP is sent from the differential pressure transmitter 22 to the calculation display device 31 or the recorder and is recorded.

In addition, if the minimum and maximum specific gravity is on the upper side, ρm1n−〇,
Since ρrrlaX-15, if the differential pressure transmitter 22 is placed in the air, the indication will be 0%, if it is immersed in water (ρ=1), it will be 66.7%, and if it is immersed in muddy water (ρ-15), it will be 100%.
% display.

In the case of such a setting example, the noteworthy point is that when the differential pressure transmitter 22 is placed completely in the air, the zero point can be easily obtained at 0% of the indication, but if this convenience is not taken into consideration, various values may be obtained depending on the value of ρm10. It is also possible to change the range.

Furthermore, since h has been deleted as shown in (1) Equation 7) above, it is necessary to take it up as a calculation item, and therefore the data that is continuously calculated and recorded moment by moment is This means that the specific gravity of the saliva to be measured in a range of 1 (1) at the current position of this device is represented by 5.

For this reason, the distance below the liquid surface of the immersion hydrometer 1 (h + H
+) cannot be measured, but in order to measure this distance, the pressure applied to the seal diaphragm 16 on the high pressure side is emitted by the pressure transmitter 28.The pressure signal P from this pressure transmitter 28 and the differential pressure Since the relationship P = P 1・(h+H+) holds true with the specific gravity signal P+ from the transmitter 22, when requested, (h + H+) = "/P'+...
(2) becomes.

Therefore, the P, Plk calculation and display device 31 can be used to perform calculation processing, and by recording this value, the distance below the liquid surface of the immersion hydrometer 1 can be automatically measured and recorded, and as a result, the depth can be calculated. Makes it possible to measure specific gravity at all times.

In addition, in a liquid to be measured whose specific gravity changes greatly due to temperature changes, it is difficult to completely determine whether the specific gravity changes with depth or temperature.
As mentioned above, the pressure applied to the high-pressure side seal diaphragm 16 is measured and calculated at the same time, and the distance below the liquid surface is measured, so the ratio ffi for each depth remains unchanged due to temperature changes.
'zCan be measured accurately.

Note that the specific gravity measuring device according to the present invention is not used only for measuring specific gravity in a specific construction method such as the above-mentioned MDW method, but may also be used for measuring the specific gravity or density of various stored liquids. Of course it comes out.

Further, in the above embodiment, the weight housing 2 has a built-in differential pressure transmitter 22 and a pressure transmitter 28, and the signals from these transmitters 22 and 28 are sent to the calculation display device 31 for calculation and recording. However, the system is not limited to this, but it is possible to install all the calculators inside the weight surface/body 2 to calculate the signals from both transmitters, and send the specific gravity and liquid surface signals to a recorder installed outside the housing. Of course there are good things to do.

〔Effect of the invention〕

As explained above, in the immersion type hydrometer according to the present invention, tL seal diaphragms are provided at two different height positions of the weight casing suspended in the liquid to be measured, and the differential pressure is applied to the casing. A differential pressure transmitter placed inside the body detects the total specific gravity of the liquid to be measured between the two cylinders, and a pressure transmitter is placed inside the M-view casing, and this pressure optical transmitter measures the high pressure side. Since it is configured to measure the pressure applied to the seal diaphragm and calculate the signals from both transmitters, it is possible to automatically measure and record the specific gravity at each depth of the liquid to be measured with high precision. Furthermore, it is possible to provide a highly versatile hydrometer that can be applied to liquids whose specific gravity largely changes due to temperature changes.

[Brief explanation of the drawing]

FIG. 1 is a front view showing an embodiment of the specific gravity measuring device according to the present invention with contents pulled out, FIG. 2 is a plan view of the same device,
FIG. 3 is a longitudinal sectional view of the device, and FIG. 4 is a diagram for explaining specific gravity measurement. 1... Specific gravity measuring device, 2... Weight casing, 3...
... Cylindrical case, 6... Upper disk body, I... Lower disk body, 8a, 11b... Hanging hook,
10.16... Seal diaphragm, 18.19.
... φ recess, 20.21 ... compartment, 22 ... differential pressure transmitter, 23 ... connection member, 24A, 24B
...Pressure tube, 25..Internal sealing liquid, 28..Pressure optical signal. Patent applicant Yamatake Honeywell Co., Ltd. Agent Sakiri Yamakawa (and one other person)

Claims (1)

[Claims] 2 different heights of the outer wall of the weight casing immersed in the liquid to be measured
A differential pressure transmitter detects the differential pressure between the seal diaphragms provided at each point position, and a pressure transmitter detects the pressure applied to the high-pressure side diaphragm of the seal diaphragms, and the output signals from both transmitters are calculated by a calculator. An immersion-type hydrometer characterized by measuring the total specific gravity at each depth.