GB2223581A - Measuring device - Google Patents

Abstract

A measuring device for determining the difference between two levels comprising a freely displaceable, elongate flexible tube 3 for containing a liquid and a pressure-sensing device 5, 6 or 7 for sensing liquid pressures and for indicating the difference in levels, if any, between opposite ends of the tube when located at different locations. In use, the tube 3 is connected at its upper end to a vessel (9) containing water 1 metre above a datum. The lower end of the tube is then connected to a manometer with an indicator tube 5 or a digital readout (16) or connected to a pressure gauge 6 or a pressure transducer 7 with LED. The manometer is then placed at different locations and the highs and lows read off. A communication system 8 is also provided. <IMAGE>

Description

MEASURING DEVICE The present invention relates to a measuring device for determining the difference between two levels and is particularly to be used, for example, in civil engineering or other engineering situations where spaced apart locations are involved and normal devices are obstructed or not usable.

It is known to use a simple plastics tube filled with water to determine when two spaced apart points are on the same level but such device cannot be used as a measuring device.

According to the present invention a measuring device for determining the difference between two levels comprises a free, elongate flexible tube containing a liquid or for containing a liquid and having valve means at each end which are capable of being opened and closed when it is desired to zero the device, and indicator means, preferably calibrated, at one end of the flexible tube to indicate the difference, if any, between two levels.

The ends of the free tube are freely displaceable relative to each other although may have means for securing at different locations.

The pressure indicator may be of any suitable means such as a pressure gauge, a pressure transducer with LED or other readout or a transparent tube such as a Bourdon tube calibrated to indicate, in use the measurement distance between the levels of liquid at the two ends of the tube.

It is envisaged that the liquid within the tube will be water which may be coloured to facilitate viewing or other liquid may be utilised such as mercury or other.

The tube may be a plastics material tube connected to the indicator means which will be ventable to "zero" the device.

Preferably, a temperature sensor or indicator will also be provided so as to determine the temperature, preferably of the liquid within the tube, so that appropriate adjustments can be made for vapour pressure and/or density. Preferably the temperature sensor will be in communication with the liquid via a suitable connector in the plastics material tube and where a long length of tube is involved, a plurality of such temperature sensors such as thermometers may be located in communication with the liquid within the tube along the length of the tube at appropriate intervals.

Preferably also a communication system will be provided, such as an intercom unit, so that an operator at one end of the tube may communicate with an operator at the other end of the tube when large distances are involved. It is envisaged that the device according to the present invention may be utilised for measuring substantial differences in levels such as in the region of three metres or the so in civil engineering constructions.

When a pressure transducer such as an electronic pressure transducer with digital readout (also known as a digital manometer) is used, the valve means at the ends of the flexible tube may be dispensed with and the freely displaceable flexible tube simply connected to communicate between a liquid-containing reservoir and the digital manometer.

Thus, also according to the present invention a measuring device for determining the difference between two levels comprises a reservoir means for containing a liquid or containing a liquid; a free elongate flexible tube connectable or connected at one end to said reservoir means and for containing the liquid or containing said liquid with said flexible tube being operatively connectable or connected to a pressure gauge , digital manometer or like transducer.

In its broadest aspect the present invention provides a measuring device for determining the difference between two levels comprising a freely displaceable, elongate flexible tube for containing a liquid and a pressure-sensing device for sensing liquid pressures and for indicating the difference in levels, if any, between opposite ends of the tube when located at different locations.

The invention will be described further, by way of example, with reference to the accompanying drawings in which: Fig. 1 is a schematic illustration- of a first embodiment of the invention; and Fig. 2 is a schematic illustration of a second embodiment of the invention.

Fig. 1 is a schematic illustration of an embodiment of the device which comprises a flexible plastics material tube 3 filled with water and having vent valves 1 and 2 at opposite ends which are openable and closeable so as to enable the levels of water in opposite legs of the tube to be balanced to the "zero" position prior to use. A thermometer 4 is in communication with the water in the tube via a Tconnector so that the temperature of the water can be determined and the appropriate adjustments made to the device to allow for differences in vapour pressure and/or density so as to make such adjustments to the reading of the device as necessary-dependent upon temperature conditions.

In this embodiment a simple glass or other material clear indicator tube or Bourdon tube part 5 is illustrated connected at one end to the tube 3 and at its other end to the vent valve 2. The indicator tube 5 is calibrated in metres in the example. It is to be appreciated that other indicators may by used such as a pressure gauge 6 or a pressure transducer with LED (7) or other readout in known manner.

A communication system will also be provided with wires running along the length of the tube so to enable an operator at one end of the tube to communicate with an operator at the other end of the tube.

In use, the two limbs of the tube 3 are brought together with the ends substantially level and the valves 1 and 2 open and the tube parts moved until the water levels in the tube 5 is at the "zero" position and level. The valve 2 is then closed and one end of the tube located at one location and the other end of the tube having valve means 2 and indicator tube 5 thereon are moved to the requisite location and the new level is from the tube 5 and such preferably indicates the difference in level from the first location as a length measurement.

Various compensations or corrections may be required dependent on temperature.

Whilst the embodiment of the example has, the zero position at the bottom of the indicator tube such may be mid-way so that the device may measure a level different with the indicator at a level above the other end. Alternatively, the disposition of the tube may be reversed.

With an LED device substantial level distances e.g. l,OOOm may be measured.

The embodiment illustrated in Fig. 2 is of a measuring device which has a semi-conductor pressure transducer in the form of a digital manometer to indicate differences in levels.

The device of Fig. 2 comprises a reservoir vessel 9 with a top open to atmospheric pressure. The vessel 1 is of transparent material such as transparent glass to enable the level of water 10 therein to be seen. The open top of vessel 9 is partially closed by a cap 11 which has a vent hole 12 therein to enable the contents of the bottle to be subject to atmospheric pressure. The hole 12, however is covered with a material which permits the flow of air but which will not permit the passage of water 10 from the vessel 9. Thus the water 10 is safely contained within vessel 9 during transportation. A suitable material for covering the vent hole 12 is sold under the name "Gortex".

Other means to prevent escape of water may be provided or the cap simply removed or slackened in use or the cap may be dispensed with.

An outlet socket 13 is provided at the base of reservoir vessel 9 for detachable connection of a freely displaceable flexible tube 14 which is connectable at its other end to the input duct 15 of a digital manometer device 16 which comprises a semiconductor transducer with an LCD display. Preferably the manometer has a low range of + 2m to - 2m and a high range of + 20m to - 20m. The manometer device 16 is preferably powered by a battery preferably also shows engineering units on the display.

The outlet socket 13 is preferably of a known snap-in self-closing type such that an end plug member at one end of the tube 14 may be readily inserted to communicate with the water 10 and readily removed whereupon the socket closes to prevent escape of water. The other end of tube 14 has suitable means for connection to duct of the manometer unit 16.

Two ducts 15, 15' are illustrated + and - indicating connection to opposite sides of the pressure diaphragm means. The manometer 16 has a digital read-out display 17 and may be calibrated to read in metres and calibrated to operate on (fresh water) specific gravity 1.

The tube 14 is preferably of flexible plastics material such as PVC anti kink transparent tube of, for example 20 metres long and .4 mm material diameter. An additional tube of, for example, 100 metres may be added.

In use, the device may be operated, for example, by placing the vessel 9 containing water 10 on a support 1 metre above datum and connecting tube 14 to socket 13 and allowing water to flow through and out of tube 14 to displace air therefrom. The other end of tube 14 is then connected to the duct 15 of manometer device 16 and the level of water 10 adjusted to give a base reading of the device 16 adjustable to zero when located at the datum position below the reservoir vessel 9. The manometer device 16 is then placed at different locations and the highs and lows can be readily read by a single person. The drawing illustrates a level difference of .200 metres relative to base of the reservoir.

The digital pressure gauge calibration unit may read a column of fluid to an accuracy of .02%.

The measuring device may be used for levelling rough ground or floors and may also be used for measuring thickness e.g. culvert roofs,floors or chamber to chamber.

Claims (17)

1. A measuring device for determining the difference between two levels comprising a freely displaceable, elongate flexible tube for containing a liquid and a pressure-sensing device for sensing liquid pressures and for indicating the difference in levels, if any, between opposite ends of the tube when located at different locations.

2. A device as claimed in claim 1 in which one end of the tube is connected to a liquid reservoir vessel and the other end connected to the pressure sensing device which is displaceable to different locations.

3. A device as claimed in claim 1, in which the pressure sensing device is a calibrated transparent tube such as a Bourdon tube.

4. A device as claimed in claim 2, in which the pressure sensing device is a pressure gauge of a pressure transducer with LED or LCD or other display or other digital manometer device.

5. A device as claimed in claim 4, in which the pressure sensing device is a manometer device with semi-conductor transducer and digital display.

6. A device as claimed in claim 5, in which the device is calibrated to operate on a fresh water specific gravity of one and to display length measurements representative of pressure differences.

7. A device as claimed in claim 2, in which the flexible tube is detachably connectable to a self-closing outlet socket in a bottom region of the vessel.

8. A device as claimed in claim 2 or 7, in which the top of the vessel is closed by means which prevent the outflow of water but which permits the passage of air.

9. A measuring device for determining the difference between two levels comprises a reservoir means for containing a liquid or containing a liquid; a freely displaceable flexible tube connectable or connected at one end to said reservoir means and for containing the liquid or containing said liquid with the other end of said tube; being connectable or connected to pressure sensing device with indicator means.

10. A device as claimed in claim 9, in which the pressure sensing means is a digital manometer with semi-conductor transducer.

11. A measuring device for determining the difference between two levels comprising a freely displaceable elongate flexible tube containing a liquid or for containing a liquid and having valve means at each end which are capable of being opened and closed when it is desired to zero the device and indicator means, preferably calibrated, at one end of the flexible tube to indicate the difference, if any, between two levels.

12. A device as claimed in claim 11, in which the pressure indicator is a transparent tube such as a Bourdon tube, suitably calibrated to indicate level differences.

13. A device is claimed in claim 12, in which the indicator is ventable to "zero" the device.

14. A device as claimed in any of claims 11 to 13, in which at least one temperature sensor or indicator such as a thermometer, is provided to determine the temperature liquid within the tube.

15. A device as claimed in claim 14, in which an intercommunication unit is provided to enable operators at opposite ends of the tube to speak to each other.

16. A device as claimed in any of claims 11 to 15, in which the liquid is water which may be coloured or is mercury.

17. A measuring device substantially as herein described with reference to Fig 1 or 2 of the accompanying drawings.