Kelton Joyner wrote:

Parallax,
You seem to like figuring out solutions. How about this one.
I have a stainless cylinder 8 inches in diameter, 3 feet high, closed at
the bottom and open on the top.
I want to keep the cylinder filled with liquid nitrogen to within 6
inches of the top and never less than 6 inches from the bottom. I also
want to know when it is half full.
I have a computer with two parallel ports, a solenoid operated cryogenic
valve with an interface to operate from a parallel port, necessary
plumbing to connect to a 1000 gal dewer of liquid nitrogen.
What other parts to I need to fabricate something to measure the liquid
nitrogen in the cylinder.
krj

A styrofoam float, 2 weights, 2 springy arm switches, string, a
battery, wire, a mount, fastenings.

Logic counts as a part? Check status bits on one port. Insulated
cylinder? Vent float? Ambients? How long do you expect 1000 gal
of N to last?

Whom are you freezing?

Terry K

Parallax wrote:

When i bought my boat, it was 10 yrs old and even then the fuel
sending unit didn't work. Over the years, I have replaced it 4 times
and it has NEVER worked right. Those damned sending units are such
crappy technology...electrical/resistive/ mechanical/floating going to
a meter, and they really expect this to work for any length of time on
a boat? So....
Useless idea #3741 (I am really going to try this one)

Take two pieces of flexible tubing maybe 1/2" diameter filled with
hydraulic fluid connedcted to a T. The base of the T has a 1/4" clear
hose going up to where it is visible in the cockpit. The two pieces
of 1/2" hose support the fuel tank whose weight compresses the fluid
causing it to rise. As the tank empties, the level in the clear
tubing falls. So, it is really measuring weight. But, no
electricity, no moving parts (except the fluid) and absolute
simplicity. Now, the problem, most fuel tanks are fastened down
firmly so when this thing is installed, it must be able to move a tiny
amount up and down (maybe should use 1/8" clear tubing).

--
Terry K - My email address is MY PROPERTY, and is protected by
copyright legislation. Permission to reproduce it is
specifically denied for mass mailing and unrequested
solicitations. Reproduction or conveyance for any unauthorised
purpose is THEFT and PLAGIARISM. Abuse is Invasion of privacy
and harassment. Abusers may be prosecuted. -This notice footer
released to public domain. Spamspoof salad by spamchock -
SofDevCo