"Lloyd E. Sponenburgh" wrote in message
...

"yourname" wrote in message
news:TLCse.9130$aR1.5312@trndny02...
christ, whats wrong with a water level? 10 bucks worth of fittings and
clear tubing, a length of garden hose and you are good to go.

The real problem is that most people don't know how to use a water level.
That's why those silly things with the buzzer on one end were made.
(BTW... they suck. ONE use and two months of storage destroy them, due to
corrosion and mildew on the pickup contacts. Even with the "cleaning
brush" they _sometimes_ supply with them, you cannot keep one working for
long in a very damp climate.)

A right-good water level is made with a long length of transparent tubing
(about 1/4" to 3/8" i.d.) and a large vessel at the "home" end. The
vessel should be twenty or more times the total volume of the hose to make
the system both easy to use and accurate. A gallon milk jug works fine
for most lengths.

Adapt the lid of the jug so it snugly holds the tubing all the way down to
the bottom of the jug. Fill the hose completely, and fill the jug to at
least the 1/2-full mark. Purge all bubbles from the hose. Provide a
clamp or plug for shutting off the free end of the hose so the water
doesn't pour out when you move it around or set it down.

Place the jug at your "home" reference, and note the distance from its
water level to the "level mark" you want to establish. Then just move the
other end of the hose to the various locations where you want to strike
marks. Measure up or down from the hose's water level the same distance
you measured up or down from the jug level.

If you let the water "settle" between moves of the hose (for say five to
ten seconds after it seems to stop moving), you'll be within a 1/16" or so
everywhere -- even up to a hundred feet from the jug. Bubbles in the hose
will drastically impair its accuracy.

LLoyd

And there will almost always be bubbles in the hose somewhere.