We have an application to measure the level of diesel (DERV) in a bunded storage tank. The height of the tank is 1.83 metres. When the level of the tank reaches 1.83 metres, the tank volume is 79000 litres. Measurement of level will be by a submersible pressure transducer. As these are supplied calibrated in metres H2O, how do I convert the equivalent height of the diesel to give a volume of 79000 litres. TIA
Maybe you should use anti-explosive and antiflammable components. The diesel shouldn't vary much it density with temperature, so the gfretwell reasoning is precise:
p=ro*g*h, being ro= density, g=gravity constant and h=height. Note that just dividing by diesel density is only valid in case you are considering density of water to be 1kg/dm^3. If you were to use other density units such as pounds/ft^^3. Best regards. Ignacio Simón Yarza Mech&electronics and control eng.
"Scott Seidman" escribió en el mensaje news:Xns96C487FFC6950scottseidmanmindspri@188.8.131.52...
Is the volume proportional to height? Many fuel tanks have semicircular bottoms and tops. Submerging the pressure transducer to the bottom may be a problem. A good way is to read the pressure in the outlet pipe, provided that the pressure drop due to flow can be neglected.
"John G" wrote in news:4317948c$0$524$5a62ac22 @per-qv1-newsreader-01.iinet.net.au:
Again, nobody said it was a water sensor. It is a pressure transducer. "Water" only has to do with the calibration of the sensor. Of course the sensor you use needs to be appropriate for the environment, but the fact that the calibration is in units of height of water says absolutely nothing about what the suitable environment is.
The diesel-fuel tanks for my emergency generators are about five feet long horizontally, with substantially flat ends. The tanks are about 2.5 feet thick, with semicircular tops and bottoms being and flat midsections also about 2.5 feet high, for a total height of about five feet. The volume is the sum of a cylinder and a box, each 2.5 x 5. The rounded parts are not a negligible part of the whole.
2000 gallons is the allowable limit for indoor fuel storage, so the tanks are not completely filled. (They hold about 2100 gallons.) The rest of the reserve is buried outdoors, with heaters to allow it to flow in cold weather. The indoor tank allows time for the outdoor fuel to warm, and provides gravity feed to the turbines (similar to jet engines). We measure fuel on hand, both indoors and out, with a dip stick and conversion table.
-- Engineering is the art of making what you want from things you can get. ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
Well, I assume the transducer is designed for this hazardous environment.
To convert from meters H2O to another fluid, simply divide the reading by the specific gravity of the fluid. Since diesel is less dense than water, a full tank will not exert as much pressure on the transducer and the signal will indicate a height less than 1.83 meters. But when you take the transducer reading and divide it by the specific gravity of diesel fuel, you correct for this density difference.
Jerry Avins wrote in news: email@example.com:
ANY pressure sensor, whether sitting on the bottom of the tank as the OP described, or at the outlet pipe, will provide an output proportional to the height of liquid in the tank. The outlet at the tank will give you the same reading, plus an offset for any difference in height, as the bottom of the tank sensor.
It is easier to connect the sensor to a tee in the outlet line than to put it into the tank.
If there is a pressure drop in the line due to flow, the reading will be low. That can be avoided with a large diameter line between the tank and the tee, or a separate line for the gauge in which there is no flow.
I understand the physics of pressure head and frictional losses, but I don't know which problem you alluded to.