And I'm not a fluid-dynamics expert, but I feel quite strongly that only = the=20 pressure and density of the fluid is needed to calculate the height -- no= t=20 the area. Look to some fluid-dynamics books for the correct answer. Once you have that, do yourself a favor and calculate the possible error = range=20 based on realistic ambient pressure values. If acceptable, you can elimi= nate=20 the ambient sensor, OR as I do with a boost gauge in my car, have a mode=20 where you can re-calibrate by sampling ambient. In your case, when the t= ank=20 is empty. This will save you the cost of 1 sensor. On an unrelated note, I'm sure Olin has been called many things to date, = but=20 never "Frat Boy" :-) Cheers, -Neil. On Tuesday 29 July 2003 15:04, rrc124+@PITT.EDU scribbled: > I'm a Computer Science major. Not an EE major. I'm doing my best to lea= rn > about these things, but sometimes I figure it would be more worth it to= ask > people who have been there, done that, before I go out and drop $50 on > hardware I may not even need. This is strictly a hobby for me. Hobbies > should be fun and educational. Sitting in a room reading 20 EE textbook= s > does not fit this idea. Doing research, building prototypes, and asking > friendly opinions does. > > To add some substance to this post, I discovered that Jameco has a bunc= h of > pretty cheap, highly accurate pressure sensors. I will be buying two an= d > setting up a system that Neil described. To answer the problems he post= ed, > a) the beer will not be sloshing, it will remain in a fixed motionless > unit. b) the weight of 5 gallons of water is approx 41.65 pounds. Figur= ing > an approx tank diameter of 12 inches, we get a base area of 113 in^2 so= i > think that would mean 0.37 psi or so. This is just to give us an idea o= f > the ranges that must be covered. I will let you guys know how this all > works out. Thanks for the comments! > > > --- Begin Orginal Message --- > From: Olin Lathrop > To: PICLIST@MITVMA.MIT.EDU > CC: > Date: 7/29/2003 3:50:55 PM > > Frat Boy wrote: > > I have a 5 gallon water tank...the kind that spring water comes in fo= r > > your office water coolers. I will be filling it with various types of > > beer ... > > > > So does anybody have any experience or advice they can offer ... > > Yeah. Less beer, more study. > > > ***************************************************************** > Embed Inc, embedded system specialists in Littleton Massachusetts > (978) 742-9014, http://www.embedinc.com -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email listserv@mitvma.mit.edu with SET PICList DIGEST in the body