Water levels - Precision!
Close
Login to Your Account
Page 1 of 2 12 LastLast
Results 1 to 20 of 27
  1. #1
    Join Date
    Aug 2004
    Country
    UNITED STATES
    State/Province
    California
    Posts
    1,106
    Post Thanks / Like
    Likes (Given)
    8
    Likes (Received)
    6

    Default Water levels - Precision!

    I'm interested in Water levels. Hilgar and Watts made them...

    Here is a new version. Accuracy of .0005 in 200 feet claimed and as many measuring cups as you want to string together on tubes. No line of sight necessary. That's hard to believe but?

    I know temperature is an issue but that's true with anything. Also water tension but there are surfactants to reduce that.

    A friend pointed out that entrapped air might be a problem but that seems easy to get rid of by putting water into a tank and letting it sit for a while before filling the system from the bottom of the tank.

    http://www.precisiontools.biz/wp-con...e-20160706.pdf

  2. #2
    Join Date
    Mar 2013
    Location
    Surbiton, surrey, UK
    Posts
    1,568
    Post Thanks / Like
    Likes (Given)
    1897
    Likes (Received)
    977

    Default

    Quote Originally Posted by chevy43 View Post
    I'm interested in Water levels. Hilgar and Watts made them...

    Here is a new version. Accuracy of .0005 in 200 feed claimed and as many measuring cups as you want to string together on tubes. No line of sight necessary. That's hard to believe but?

    I know temperature is an issue but that's true with anything. Also water tension but there are surfactants to reduce that.

    A fiend pointed out that entrapped air might be a problem but that seems easy to get rid of by putting water into a tank and letting it sit for a while before filling the system from the bottom of the tank.

    http://www.precisiontools.biz/wp-con...e-20160706.pdf
    Ive got a pair of HW fluid levels somewhere tho not used them as yet. Tyrones yer man on using them, iirc you use something like kerosene instead of water, avoids corrosion and is more accurate, I think.

    EDIT:- Ooo just looked at the pdf. Mine are way different but work on the same principle.

    Cheers
    D

  3. #3
    Join Date
    Nov 2013
    Location
    Eastern Massachusetts, USA
    Posts
    4,142
    Post Thanks / Like
    Likes (Given)
    4451
    Likes (Received)
    4330

    Default

    I don't know about the level of precision claimed but yes, water levels can be very accurate and there is no need to have line of sight. You could fish the tubing through a building crawlspace and get good readings on either side of the building.

    As mentioned a surfactant helps and the number one detriment to accuracy would be different air pressure at each end such as a breeze at one location.

  4. #4
    Join Date
    Aug 2004
    Country
    UNITED STATES
    State/Province
    California
    Posts
    1,106
    Post Thanks / Like
    Likes (Given)
    8
    Likes (Received)
    6

    Default

    What stops me from just making my own out of sight tubes and a depth mike and a good magnifying loop?

    I would need two matching height precision pieces of steel tube to put the depth mike on with a slot cut out to see the fluid level. Is there anything else to it?

  5. #5
    Join Date
    Mar 2013
    Location
    Surbiton, surrey, UK
    Posts
    1,568
    Post Thanks / Like
    Likes (Given)
    1897
    Likes (Received)
    977

    Default

    Quote Originally Posted by chevy43 View Post
    What stops me from just making my own out of sight tubes and a depth mike and a good magnifying loop?

    I would need two matching height precision pieces of steel tube to put the depth mike on with a slot cut out to see the fluid level. Is there anything else to it?
    Nothing what so ever, they will be as accurate as you make them tho. IIrc mine have block bottoms with dual v ways cut out, cylinder (maybe 1.5" od) for a body with glass windows, around 8 inches tall. The mic heads sit on top. I remember Tyrone saying you watch for the liquid to fall off the needle as you wind out the mic for the read so perhaps no real need for a loupe.

  6. #6
    Join Date
    Aug 2004
    Country
    UNITED STATES
    State/Province
    California
    Posts
    1,106
    Post Thanks / Like
    Likes (Given)
    8
    Likes (Received)
    6

    Default

    Here's the Hilger and Watts version. It looks like two tubes and a depth mike to me....
    Attached Thumbnails Attached Thumbnails s-l1600.jpg  

  7. #7
    Join Date
    Aug 2004
    Country
    UNITED STATES
    State/Province
    California
    Posts
    1,106
    Post Thanks / Like
    Likes (Given)
    8
    Likes (Received)
    6

    Default

    Quote Originally Posted by Demon73 View Post
    Nothing what so ever, they will be as accurate as you make them tho. IIrc mine have block bottoms with dual v ways cut out, cylinder (maybe 1.5" od) for a body with glass windows, around 8 inches tall. The mic heads sit on top. I remember Tyrone saying you watch for the liquid to fall off the needle as you wind out the mic for the read so perhaps no real need for a loupe.
    I was thinking you would turn the depth mike down till the liquid moves when the surface tension jerked onto the mike...??

  8. #8
    Join Date
    Sep 2004
    Location
    south SF Bay area, California
    Posts
    2,000
    Post Thanks / Like
    Likes (Given)
    153
    Likes (Received)
    640

    Default

    I would argue with the maker's claim "world's most accurate leveling system", reserving that honor for the instruments used by the Research Physics community . . . one flavor of the type being described in this paper: https://www.slac.stanford.edu/econf/...papers/033.PDF

    That said, kissing cousins of the Hilger & Watts communicating water level are still being made in Japan and Switzerland; the English-language manual for the Swiss-made Wyler 77 can be found here: https://www.wylerag.com/fileadmin/pd...r_Level_77.pdf

    For what it's worth, EDS Precision originally marketed their communicating water level to the folks setting up gas-turbine generators. Then, several years ago, they stuck their corporate toe into the large-machine-tool business, placing sets with (IIRC)Devitt Machinery in Philadelphia and Machine Tool Research in Rochester. I've lost track since then, but do wish them well.

    Homemade water levels are common in carpentry and masonry, less so in the world of machinery setups, but DEFINITELY NOT unknown. My homebrewed version was based on a large-surface-area reservoir with one much-smaller-surface-area vessel machined out of a small block of aluminum. Because the water surface area in the reservoir was so much larger than the surface area in the roving vessel, the change in roving-vessel elevation doesn't influence the change in water-surface elevation nearly as much as it would if same-surface-area vessels were used at both ends of the connecting tube.

    Finally, it's worth noting that the micrometer reading generally increases as the probe extends downward. This means that a measurement point having a numerically-higher micrometer water level is physically lower than a measurement point having a numerically-lower micrometer value.

  9. Likes chevy43 liked this post
  10. #9
    Join Date
    Mar 2013
    Location
    Surbiton, surrey, UK
    Posts
    1,568
    Post Thanks / Like
    Likes (Given)
    1897
    Likes (Received)
    977

    Default

    Quote Originally Posted by chevy43 View Post
    I was thinking you would turn the depth mike down till the liquid moves when the surface tension jerked onto the mike...??
    Im relying on my memory of the conversation so could well be wrong. The levels I have look like the ones youve shown, super simple but very well made. I'll dig them out when I get a mo.

  11. #10
    Join Date
    Aug 2004
    Country
    UNITED STATES
    State/Province
    California
    Posts
    1,106
    Post Thanks / Like
    Likes (Given)
    8
    Likes (Received)
    6

    Default

    Quote Originally Posted by John Garner View Post
    I would argue with the maker's claim "world's most accurate leveling system", reserving that honor for the instruments used by the Research Physics community . . . one flavor of the type being described in this paper: https://www.slac.stanford.edu/econf/...papers/033.PDF

    That said, kissing cousins of the Hilger & Watts communicating water level are still being made in Japan and Switzerland; the English-language manual for the Swiss-made Wyler 77 can be found here: https://www.wylerag.com/fileadmin/pd...r_Level_77.pdf

    For what it's worth, EDS Precision originally marketed their communicating water level to the folks setting up gas-turbine generators. Then, several years ago, they stuck their corporate toe into the large-machine-tool business, placing sets with (IIRC)Devitt Machinery in Philadelphia and Machine Tool Research in Rochester. I've lost track since then, but do wish them well.

    Homemade water levels are common in carpentry and masonry, less so in the world of machinery setups, but DEFINITELY NOT unknown. My homebrewed version was based on a large-surface-area reservoir with one much-smaller-surface-area vessel machined out of a small block of aluminum. Because the water surface area in the reservoir was so much larger than the surface area in the roving vessel, the change in roving-vessel elevation doesn't influence the change in water-surface elevation nearly as much as it would if same-surface-area vessels were used at both ends of the connecting tube.

    Finally, it's worth noting that the micrometer reading generally increases as the probe extends downward. This means that a measurement point having a numerically-higher micrometer water level is physically lower than a measurement point having a numerically-lower micrometer value.
    Did you use water with surfactant (soap)?

  12. #11
    Join Date
    Nov 2007
    Location
    marysville ohio
    Posts
    9,303
    Post Thanks / Like
    Likes (Given)
    2657
    Likes (Received)
    6139

    Default

    I made a set years ago to use making a level spot to check cross weight on race cars. I used self stick floor tile and sheet metal for the wheel pads. I filled the water levels at the race shop in Florida. Some water spilled or evaporated so I topped it up at the track, I don't remember where we were but not in Florida. The water height was totally different, like by 3/8"! No air bubbles. Water in different parts of the country has different specific gravity depending on what is dissolved in it. I poured it into a container and mixed it up. I poured it back in and it was the same height.

  13. Likes chevy43 liked this post
  14. #12
    Join Date
    Oct 2005
    Country
    UNITED STATES
    State/Province
    Pennsylvania
    Posts
    14,854
    Post Thanks / Like

    Default

    Quote Originally Posted by moonlight machine View Post
    I made a set years ago to use making a level spot to check cross weight on race cars. I used self stick floor tile and sheet metal for the wheel pads. I filled the water levels at the race shop in Florida. Some water spilled or evaporated so I topped it up at the track, I don't remember where we were but not in Florida. The water height was totally different, like by 3/8"! No air bubbles. Water in different parts of the country has different specific gravity depending on what is dissolved in it. I poured it into a container and mixed it up. I poured it back in and it was the same height.
    Don't you know anything ?
    For race cars....You must use Mountain Dew......

  15. #13
    Join Date
    Dec 2008
    Country
    UNITED STATES
    State/Province
    New York
    Posts
    10,055
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    2616

    Default

    Quote Originally Posted by chevy43 View Post
    I'm interested in Water levels. Hilgar and Watts made them...

    Here is a new version. Accuracy of .0005 in 200 feet claimed and as many measuring cups as you want to string together on tubes. No line of sight necessary. That's hard to believe but?

    I know temperature is an issue but that's true with anything. Also water tension but there are surfactants to reduce that.

    A friend pointed out that entrapped air might be a problem but that seems easy to get rid of by putting water into a tank and letting it sit for a while before filling the system from the bottom of the tank.

    http://www.precisiontools.biz/wp-con...e-20160706.pdf
    .
    thinkerf makes slant tube water levels for sawmills. my experience with water levels is they do not normally repeat to .001" over distances. also each end of water level where it sits needs to be level and not leaning
    .
    a boss water level are 2 each plastic graduated cylinders maybe liter capacity connected by plastic tubing. usually plastic graduated cylinders are mounted to wide 8"by 8" aluminum plate so it doesnt tip over. you can put top of a cement block wall at the wall corners and see if each end out of level maybe 1 or 2 mm just by reading the water height difference in the 2 graduated cylinders. biggest advantage is you can leave each graduated cylinder sitting on the block wall without wind blowing them over and let the water level stabilize as it can take time for water level to stabilize. a mason or carpenter doesnt worry about <3mm they only looking if its way off like 12 or 25 mm out of level. the larger in diameter plastic tubing used usually stabilizes faster. small dia tubing can take a long time to stabilize and not repeat to as fine a tolerance as larger tubing
    .
    you can use WD40 instead of water but its messy if it gets spilled. my experience is it usually gets spilled sooner or later. water spills easier to deal with most times. any thin oil or kerosene would be a more messy spill
    .
    TKT Engineering

  16. #14
    Join Date
    May 2017
    Country
    FINLAND
    Posts
    1,686
    Post Thanks / Like
    Likes (Given)
    479
    Likes (Received)
    780

    Default

    Quote Originally Posted by moonlight machine View Post
    I made a set years ago to use making a level spot to check cross weight on race cars. I used self stick floor tile and sheet metal for the wheel pads. I filled the water levels at the race shop in Florida. Some water spilled or evaporated so I topped it up at the track, I don't remember where we were but not in Florida. The water height was totally different, like by 3/8"! No air bubbles. Water in different parts of the country has different specific gravity depending on what is dissolved in it. I poured it into a container and mixed it up. I poured it back in and it was the same height.
    Florida has probably saltiest tap water of anywhere so its kind of expected. And the water that you added could have been at different temperature.

    .0005" in 200ft is pretty optimistic thinking IMO, temperature sensitivity sucks big time.

  17. #15
    Join Date
    Dec 2008
    Country
    UNITED STATES
    State/Province
    New York
    Posts
    10,055
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    2616

    Default

    i have seen maybe 1 mm water level repeatability if temperature stable and its not windy and tubing is large enough that air bubbles rise relatively fast
    .
    you use small tubing and air bubbles might not move at all. they get stuck and need the plastic tubing wiggled or shaken to move the air bubbles. works better if tubing more vertical. if tubing is horizontal for long lengths than repeatability is much harder to get. water got large air bubbles but often also has small air bubbles in it too. it takes time for the bubbles to rise up and to move in the tubing. its like soda pop takes time for bubbles to come out
    .
    no way you get .001" repeatability till all the bubbles are out and good luck waiting for that

  18. #16
    Join Date
    Sep 2011
    Country
    GERMANY
    Posts
    2,657
    Post Thanks / Like
    Likes (Given)
    1649
    Likes (Received)
    939

    Default

    Quote Originally Posted by chevy43 View Post
    I'm interested in Water levels. Hilgar and Watts made them.
    I've recently been calibrating a Talyvel4 level (0.1 arcsec resolution, 0.2 arcsec accuracy) so am also interested in the accuracy of precision levels. The Talyvel is a damped mechanical pendulum, supported by 5 fine CuBe wires, whose position is sensed with two inductive coils forming two legs of an inductive/resistive bridge.

    One of the documents that I have come across on this topic is about the surveying carried out for the Stanford Linear Collider (SLAC) https://www.slac.stanford.edu/cgi-wr...-tn-82-001.pdf . This requires a hierarchy of different tools and measurements.

    Page 35-48 discusses the calibration and use of the water level system. The system consists of 110 liquid level wells interconnected by valve-controlled unpressurized air and water lines. The wells are glass containers partially filled with water. The height of the top of the well relative to the surface of the water can be measured (or "read") by a depth micrometer in the top of the well. A tooling ball mounted on top of the micrometer provides the reference fiducial for elevation measurements. To quote directly from page 35/36:

    "The resolution of the liquid level wells, fixed by the micrometer's digital readout, is +/-0.01 mm., but systematic errors limit the accuracy to about +/- 0.1mm. Over the large distances encountered in the ring, the liquid level makes it possible to measure slopes as small as +/- 0.0000002 radians (+/-0.2mm in 1000m.)"

    This is an accuracy of about 0.04 arcsec. It is impressive: the "ancient" technology of the water level is a factor of 5 BETTER than the Talyvel4. It is good enough that the Earth's surfaces of constant gravitational potential must be modelled as ellipsiods of revolution rather than as spheres.

    (John: the paper you linked describes an 2-axis SAST tiltmeter, with a ± 17 milliradians range and "sensitivity" better than 0.05 milliradian. This sensitivity appears to be their accuracy, and is 50 microradians, so about a factor of fifty worse than the Talyvel4 and about a factor of 250 worse than the water level used by SLAC.)

  19. #17
    Join Date
    Feb 2011
    Country
    UNITED STATES
    State/Province
    Texas
    Posts
    2,112
    Post Thanks / Like
    Likes (Given)
    1454
    Likes (Received)
    909

    Default

    This is an interesting thread! One more method to research.

  20. #18
    Join Date
    Oct 2010
    Country
    UNITED STATES
    State/Province
    Oregon
    Posts
    5,064
    Post Thanks / Like
    Likes (Given)
    4283
    Likes (Received)
    1826

    Default

    Quote Originally Posted by moonlight machine View Post
    I filled the water levels at the race shop in Florida. Some water spilled or evaporated so I topped it up at the track, I don't remember where we were but not in Florida. The water height was totally different, like by 3/8"! No air bubbles. Water in different parts of the country has different specific gravity depending on what is dissolved in it.
    That's astonishing. I never would have imagined the effect could be anywhere that large. Really tiny tubes, I presume.

  21. #19
    Join Date
    Nov 2007
    Location
    marysville ohio
    Posts
    9,303
    Post Thanks / Like
    Likes (Given)
    2657
    Likes (Received)
    6139

    Default

    Quote Originally Posted by sfriedberg View Post
    That's astonishing. I never would have imagined the effect could be anywhere that large. Really tiny tubes, I presume.
    3/4" diameter or so for the upright vial and mabe 5/16 diameter for the hose between them. I just added water to one upright vial and had them standing side by side when I saw the difference in water height. All clear tygon hose with lexan upright vials so I know it was not an air lock or bubble.

  22. #20
    Join Date
    Aug 2004
    Country
    UNITED STATES
    State/Province
    California
    Posts
    1,106
    Post Thanks / Like
    Likes (Given)
    8
    Likes (Received)
    6

    Default

    Quote Originally Posted by DMF_TomB View Post
    i have seen maybe 1 mm water level repeatability if temperature stable and its not windy and tubing is large enough that air bubbles rise relatively fast
    .
    you use small tubing and air bubbles might not move at all. they get stuck and need the plastic tubing wiggled or shaken to move the air bubbles. works better if tubing more vertical. if tubing is horizontal for long lengths than repeatability is much harder to get. water got large air bubbles but often also has small air bubbles in it too. it takes time for the bubbles to rise up and to move in the tubing. its like soda pop takes time for bubbles to come out
    .
    no way you get .001" repeatability till all the bubbles are out and good luck waiting for that
    I figure the easiest way to get rid of air is put the water in a tall tank or barrel for a couple of days and fill the level from a tube out of the bottom of the barrel


Tags for this Thread

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •