Alternative To Measuring Wheel

[Dick]

I do home inspections (here on Cape Cod) & with the snow I can lo longer use my measuring wheel to measure the size of the homes I'm inspecting. Is there such a thing as an optical, sonic or laser device that would enable me to measure exterior walls without having to trudge through the snow to do this? Even better (since I have to photograph the homes anyway) does anyone know of a camera based tool that would take digital pictures plus display (or make possible for me to figure out) wall dimensions?

[Charles Spitzer]

laser tape measures work on the inside of rooms.

you'd need to have a known reference length in the shot to measure sizes, then just do it by ratios. you won't get too accurate a length that way though, so it depends upon how accurate you have to be.

[Jeff Wisnia]

What sort of accuracy are you reqired to maintain?

Jeff

[bill a]

I do home inspections (here on Cape Cod) & with the snow I can lo longer use my measuring wheel to measure the size of the homes I'm inspecting. Is there such a thing as an optical, sonic or laser device that would enable me to measure exterior walls without having to trudge through the snow to do this? Even better (since I have to photograph the homes anyway) does anyone know of a camera based tool that would take digital pictures plus display (or make possible for me to figure out) wall dimensions?

[JerryMouse]

Get yourself one of those sticks you see in all archeological pictures, or make your own: Three foot long, alternating black and white bands each foot. Take pictures with the stick in view - perhaps multiple shots down each side, from as far away as is convenient (to minimize distortion).

Print pictures. Measure.

You can test this process on a house of known size - see how close you get and whether the difference is tolerable.

[Greg]

If you got one of those driveway reflectors on a stick and virtually any laser range finder you could measure the gnat's ass

[Michael Daly]

Golf shops stock optical rangefinders that might suit. Some tool shops stock a similar version.

Mike

[Nick Hull]

Those laser range finders are +/- a yard and usually don't work at less than about 60'

[willshak]

On 2/2/2005 5:09 PM US(ET), Dick took fingers to keys, and typed the following:

100' roll up tape measure, and some sticky tape to tape the 'stupid' end to the corners, or initial measuring points, so it doesn't fall off. You can't use a laser measurer unless the target is a flat surface that the laser beam can hit, so it might work on inside corners, but not outside corners, because the beam will not have a target to stop it and will go right past the corner. You could set up a target board or panel to make the outside corner an inside corner, and use the board as the target. Prop the board flat up against the side of the building with enough sticking out past the corner that the laser can hit. Never heard of a camera that could determine dimensions from a photo, but wait a few years.

[Bill]

This is possible, but it might be a bit expensive. They use digital cameras and special targets in some high end industrial measuring systems. I looked into them about 7 years ago for a project I was working on at the time. When I looked into the system they used special cameras at about $35,000 apiece, plus the accessories were expensive, and the special software cost an arm and a leg. As I recall the system I would have needed would have been in the neighborhood of $100,000.

The price may be starting to come down, because I recently saw an episode of "Home Time" in which their tame counter top maker used a similar system to get the dimensions for the counter top they installed. It seemed to have worked pretty good, but I don't know what kind of price they were talking about.

Bill Gill

[Lawrence Wasserman]

I don't understand why you can't continue to use the measuring wheel, regardless of the weather. What am I missing here, other than you'd rather not walk in the snow?

[Greg]

HUH?

Look at this one. 650 feet +/- 1/16"

[Jeff Wisnia]

I stopped myself from suggesting that because he wrote, "without having to trudge through the snow to do this?".

Did I miss something?

Jeff

[Jeff Wisnia]

We had 26" of snow in one day here in Massachusetts (where the OP is too) two weeks ago, with drifts at least four feet high against some parts of my own house.

How the hell is anyone going to get any kind of decent measurements pushing a measuring wheel through that unless someone does a heck of a lot of shoveling or snow blowing first?

Jeff

[Matt]

Yeah, you missed the clue train about 45 years ago.

[Michael Daly]

Run it along the wall?

Mike

[Stormin Mormon]

Ah, I love a simple answer written by a man who understands the real world.

[Stormin Mormon]

A college professor asked the class how to measure the height of a skyscraper using a barometer.....

I am reminded of the story about a student who protested when his answer was marked wrong on a physics test.

In answer to the question, "How could you measure the height of a tall building, using a barometer?" he was expected to explain that the barometric pressures at the top and the bottom of the building are different, and by calculating, he could determine the building's height. Instead, he answered, "I would tie the barometer to a string, lower it to the ground and measure the length of the string."

His instructor admitted that the answer was technically correct but did not demonstrate a knowledge of physics.

The student then rattled off a whole series of answers involving physics - but not one using the principle in question: He would drop the barometer and time its fall. He would make a pendulum and time its frequency at the top and the bottom of the building. He would walk down the stairs marking "barometer units" on the wall.

"You tie a long piece of string to the neck of the barometer, then lower the barometer from the roof of the skyscraper to the ground. The length of the string plus the length of the barometer will equal the height of the building."

"Firstly, you could take the barometer up to the roof of the skyscraper, drop it over the edge, and measure the time it takes to reach the ground. The height of the building can then be worked out from the formula H = 0.5g x t squared. But bad luck on the barometer."

"Or if the sun is shining you could measure the height of the barometer, then set it on end and measure the length of its shadow. Then you measure the length of the skyscraper's shadow, and thereafter it is a simple matter of proportional arithmetic to work out the height of the skyscraper."

"But if you wanted to be highly scientific about it, you could tie a short piece of string to the barometer and swing it like a pendulum, first at ground level and then on the roof of the skyscraper. The height is worked out by the difference in the gravitational restoring force T =2 pi sqr root (l /g)."

"If you merely wanted to be boring and orthodox about it, of course, you could use the barometer to measure the air pressure on the roof of the skyscraper and on the ground, and convert the difference in millibars into feet to give the height of the building."

"But since we are constantly being exhorted to exercise independence of mind and apply scientific methods, undoubtedly the best way would be to knock on the janitor's door and say to him 'If you would like a nice new barometer, I will give you this one if you tell me the height of this skyscraper'."

[Dick]

[willshak]

On 2/3/2005 3:10 PM US(ET), Jeff Wisnia took fingers to keys, and typed the following:

I was thinking more of him trying to push a measuring wheel through 2' of snow up in Mass., which would not be too accurate. Even without snow, the measuring wheel is really not that precise rolling over grass, dirt, stones, etc., and absent a perfectly straight path for the wheel. He still has to trudge through snow to get photos of all sides of the house.