Liquid level ,code help
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Posts: 46,084
I am using a basic stamp 2 to measure depth of liquid in a tank
using an a/d converter and pressure sensor i need to know how to
convert the voltages to gallons example .5 volts is empty 3 volts
is full . I need to convert and read out gallons to a lcd display 0
gallon at .5 volt to 30 gallons at 3 volts thanks mike
using an a/d converter and pressure sensor i need to know how to
convert the voltages to gallons example .5 volts is empty 3 volts
is full . I need to convert and read out gallons to a lcd display 0
gallon at .5 volt to 30 gallons at 3 volts thanks mike
Comments
equation is y = mx+b where y = gallons, m is a constant, x is the voltage and
b is also a constant.
For .5 volts = 0 gallons and 3 volts = 30 gallons, the equation is
gallons = 12*volts - 6
example: 0 = 12*0.5 - 6 and
30 = 12*3 - 6
Except in your case, the basic stamp does not directly read analog voltage
from a transducer, hence you are using an A/D converter.
What D value gives you 0.5 volts and what D value gives you 3 volts? This
information is needed to modify the equation gallons = 12*volts - 6
ken
================
I AM USING A BASIC STAMP 2 TO MEASURE DEPTH OF LIQUID IN A TANK
USING AN A/D CONVERTER AND PRESSURE SENSOR I NEED TO KNOW HOW TO
CONVERT THE VOLTAGES TO GALLONS EXAMPLE .5 VOLTS IS EMPTY 3 VOLTS
IS FULL . I NEED TO CONVERT AND READ OUT GALLONS TO A LCD DISPLAY 0
GALLON AT .5 VOLT TO 30 GALLONS AT 3 VOLTS THANKS MIKE
[noparse][[/noparse]Non-text portions of this message have been removed]
Wouldn't the pressure reading of the tank change with the atmoshpheric
change in pressure (I'm thinking when it's full....it obviously will when
empty)....
If you need exact readings then you'd have to set up an external pressure
sensor to monitor atmoshpheric changes (IF, it's the amount you're
measuring)...
If you just want to know when it's empty/half-full/full (ballpark levels)
then you won't need it.
Original Message
From: <smartdim@a...>
To: <basicstamps@yahoogroups.com>
Sent: Saturday, April 24, 2004 6:16 PM
Subject: Re: [noparse][[/noparse]basicstamps] LIQUID LEVEL ,CODE HELP
> The basic starting point is an equation that converts voltage to gallons.
The
> equation is y = mx+b where y = gallons, m is a constant, x is the voltage
and
> b is also a constant.
>
> For .5 volts = 0 gallons and 3 volts = 30 gallons, the equation is
>
> gallons = 12*volts - 6
>
> example: 0 = 12*0.5 - 6 and
>
> 30 = 12*3 - 6
>
> Except in your case, the basic stamp does not directly read analog voltage
> from a transducer, hence you are using an A/D converter.
>
> What D value gives you 0.5 volts and what D value gives you 3 volts? This
> information is needed to modify the equation gallons = 12*volts - 6
>
> ken
> ================
> I AM USING A BASIC STAMP 2 TO MEASURE DEPTH OF LIQUID IN A TANK
> USING AN A/D CONVERTER AND PRESSURE SENSOR I NEED TO KNOW HOW TO
> CONVERT THE VOLTAGES TO GALLONS EXAMPLE .5 VOLTS IS EMPTY 3 VOLTS
> IS FULL . I NEED TO CONVERT AND READ OUT GALLONS TO A LCD DISPLAY 0
> GALLON AT .5 VOLT TO 30 GALLONS AT 3 VOLTS THANKS MIKE
>
>
> [noparse][[/noparse]Non-text portions of this message have been removed]
>
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the Subject and
Body of the message will be ignored.
>
> Yahoo! Groups Links
>
>
>
>
>
> equation is y = mx+b where y = gallons, m is a constant, x is the voltage and
> b is also a constant.
>
> For .5 volts = 0 gallons and 3 volts = 30 gallons, the equation is
>
> gallons = 12*volts - 6
>
> example: 0 = 12*0.5 - 6 and
>
> 30 = 12*3 - 6
>
> Except in your case, the basic stamp does not directly read analog voltage
> from a transducer, hence you are using an A/D converter.
>
> What D value gives you 0.5 volts and what D value gives you 3 volts? This
> information is needed to modify the equation gallons = 12*volts - 6
Actually, it's not quite that simple ether. You're assuming linear behavior
between pressure and volume which is only true if the tank is rectangular.
if the tank is round then the top & bottom parts of the tank hold less
volume than the middle. The pressure is only related to depth, not volume.
The problem isn't unsolvable thou. With a few more data points you can
"curve fit" the results into an equation that will approximate a "close
enough" answer.
--
Enjoy,
George Warner,
Schizophrenic Optimization Scientists
Apple Developer Technical Support (DTS)
wind affects (wind buffetting!).
At work we use strain gauges on a scale like container.
the problem here is that the gauge changes with temperature....but we're
only looking for .5mm accuracy (I think!).
Another method we use is a 'vibrating wire'. A wire is vibrated at a
certain frequency.
The container is connected to the string and as it fills up with fluids the
frequency increases. There's a frequency correlation wrt the volume. This
too is affected by temperature, but we monitor that and make adjustments.
Is this water level calm? I was thinking....there are easier ways to do
this no doubt....but...
If you were to put a little laser diode in the bottom corner of the
tank....could you aim it up on a angle and try to detect the reflected light
pulse off the undersurface of the water level.
Of course you'd have to have either the transmitter or receiver on a little
lever with angle detection (servo?).
Ya ok....I've got the flu today and have taken too much cough medicine and
am babbling!!
Original Message
From: "George Warner" <geowar@a...>
To: <basicstamps@yahoogroups.com>
Sent: Monday, April 26, 2004 12:52 PM
Subject: [noparse][[/noparse]basicstamps] Re: LIQUID LEVEL ,CODE HELP
> > The basic starting point is an equation that converts voltage to
gallons. The
> > equation is y = mx+b where y = gallons, m is a constant, x is the
voltage and
> > b is also a constant.
> >
> > For .5 volts = 0 gallons and 3 volts = 30 gallons, the equation is
> >
> > gallons = 12*volts - 6
> >
> > example: 0 = 12*0.5 - 6 and
> >
> > 30 = 12*3 - 6
> >
> > Except in your case, the basic stamp does not directly read analog
voltage
> > from a transducer, hence you are using an A/D converter.
> >
> > What D value gives you 0.5 volts and what D value gives you 3 volts?
This
> > information is needed to modify the equation gallons = 12*volts - 6
>
> Actually, it's not quite that simple ether. You're assuming linear
behavior
> between pressure and volume which is only true if the tank is rectangular.
> if the tank is round then the top & bottom parts of the tank hold less
> volume than the middle. The pressure is only related to depth, not volume.
>
> The problem isn't unsolvable thou. With a few more data points you can
> "curve fit" the results into an equation that will approximate a "close
> enough" answer.
>
> --
> Enjoy,
> George Warner,
> Schizophrenic Optimization Scientists
> Apple Developer Technical Support (DTS)
>
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the Subject and
Body of the message will be ignored.
>
> Yahoo! Groups Links
>
>
>
>
>
seen, you don't want to use. That was a radioactive Beta source aimed in a
column through the liquid or whatever you wanted to measure. As the level changes
so does the density of material between the Beta source and the radiation
detector across from it. We used this method in several applications for the
Military when I worked at the Lockheed Nuclear Research Lab.
Of course, no one here would want to play with radioactive materials, just
thought I would mention it. :-)
However, on a more practical note, the strain gauges do seem to work pretty
well. I have used them on a number of projects for dispensing things from lime
to liquids and measuring the amount dispensed based on how much was left in
the containment vessel. Another way is to use a simple float system with a
variable resistor/potentionmeter attached to it. Of course that is not quite as
accurate.
Randy Abernathy
4626 Old Stilesboro Road NW
Acworth, GA 30101-4066
Phone / Fax: 770-974-5295
Cell: 678-772-4113
E-mail: Cnc002@a...
I furnish technical support, repair, and other related services for your
industrial woodworking machinery. My background as Senior Service Engineer for the
SCMI Group for nearly fifteen years with factory training, combines with my
extensive background in electronics, mechanics, pneumatics, electrical and CNC
machinery to offer you needed support for your machinery.
[noparse][[/noparse]Non-text portions of this message have been removed]
SB <steve.brady@r...> wrote:So for more precises measurements...would you weigh the tank? You still get
wind affects (wind buffetting!).
At work we use strain gauges on a scale like container.
the problem here is that the gauge changes with temperature....but we're
only looking for .5mm accuracy (I think!).
Another method we use is a 'vibrating wire'. A wire is vibrated at a
certain frequency.
The container is connected to the string and as it fills up with fluids the
frequency increases. There's a frequency correlation wrt the volume. This
too is affected by temperature, but we monitor that and make adjustments.
Is this water level calm? I was thinking....there are easier ways to do
this no doubt....but...
If you were to put a little laser diode in the bottom corner of the
tank....could you aim it up on a angle and try to detect the reflected light
pulse off the undersurface of the water level.
Of course you'd have to have either the transmitter or receiver on a little
lever with angle detection (servo?).
Ya ok....I've got the flu today and have taken too much cough medicine and
am babbling!!
Original Message
From: "George Warner"
To:
Sent: Monday, April 26, 2004 12:52 PM
Subject: [noparse][[/noparse]basicstamps] Re: LIQUID LEVEL ,CODE HELP
> > The basic starting point is an equation that converts voltage to
gallons. The
> > equation is y = mx+b where y = gallons, m is a constant, x is the
voltage and
> > b is also a constant.
> >
> > For .5 volts = 0 gallons and 3 volts = 30 gallons, the equation is
> >
> > gallons = 12*volts - 6
> >
> > example: 0 = 12*0.5 - 6 and
> >
> > 30 = 12*3 - 6
> >
> > Except in your case, the basic stamp does not directly read analog
voltage
> > from a transducer, hence you are using an A/D converter.
> >
> > What D value gives you 0.5 volts and what D value gives you 3 volts?
This
> > information is needed to modify the equation gallons = 12*volts - 6
>
> Actually, it's not quite that simple ether. You're assuming linear
behavior
> between pressure and volume which is only true if the tank is rectangular.
> if the tank is round then the top & bottom parts of the tank hold less
> volume than the middle. The pressure is only related to depth, not volume.
>
> The problem isn't unsolvable thou. With a few more data points you can
> "curve fit" the results into an equation that will approximate a "close
> enough" answer.
>
> --
> Enjoy,
> George Warner,
> Schizophrenic Optimization Scientists
> Apple Developer Technical Support (DTS)
>
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the Subject and
Body of the message will be ignored.
>
> Yahoo! Groups Links
>
>
>
>
>
To UNSUBSCRIBE, just send mail to:
basicstamps-unsubscribe@yahoogroups.com
from the same email address that you subscribed. Text in the Subject and Body of the message will be ignored.
Yahoo! Groups Links
Do you Yahoo!?
SBC Yahoo! - Internet access at a great low price.
[noparse][[/noparse]Non-text portions of this message have been removed]
balanced system (uses miniture leaf springs -- flextures).
We measure up to 500mm of precip but usually have transformer oil in it in
the summer and antifreeze in the winter (oil stops evaporation).
Anyhow, we measure for 0.2mm of rain.
It's called a Fisher Porter weighing gauge...honestly don't know if the
company is still around...most meterological equipment/companies are being
bought up by Vaisala of Finland!
Original Message
From: "Philip Gmblin" <pipeguy3153@y...>
To: <basicstamps@yahoogroups.com>
Sent: Tuesday, May 18, 2004 8:55 PM
Subject: Re: [noparse][[/noparse]basicstamps] Re: LIQUID LEVEL ,CODE HELP
> I don't necessarily reccomend this, but a friend of mine works in a shop
that makes level gauges. One of the low tech methods they is a magnetic
float to operate reed switches that close/ open sequentially, each onr
switching in/out a resistor stack. On the other hand, .5mm accuracy seems a
stretch by any standard.
>
> SB <steve.brady@r...> wrote:So for more precises
measurements...would you weigh the tank? You still get
> wind affects (wind buffetting!).
>
> At work we use strain gauges on a scale like container.
> the problem here is that the gauge changes with temperature....but we're
> only looking for .5mm accuracy (I think!).
> Another method we use is a 'vibrating wire'. A wire is vibrated at a
> certain frequency.
> The container is connected to the string and as it fills up with fluids
the
> frequency increases. There's a frequency correlation wrt the volume. This
> too is affected by temperature, but we monitor that and make adjustments.
>
> Is this water level calm? I was thinking....there are easier ways to do
> this no doubt....but...
> If you were to put a little laser diode in the bottom corner of the
> tank....could you aim it up on a angle and try to detect the reflected
light
> pulse off the undersurface of the water level.
> Of course you'd have to have either the transmitter or receiver on a
little
> lever with angle detection (servo?).
>
> Ya ok....I've got the flu today and have taken too much cough medicine and
> am babbling!!
>
>
>
Original Message
> From: "George Warner"
> To:
> Sent: Monday, April 26, 2004 12:52 PM
> Subject: [noparse][[/noparse]basicstamps] Re: LIQUID LEVEL ,CODE HELP
>
>
> > > The basic starting point is an equation that converts voltage to
> gallons. The
> > > equation is y = mx+b where y = gallons, m is a constant, x is the
> voltage and
> > > b is also a constant.
> > >
> > > For .5 volts = 0 gallons and 3 volts = 30 gallons, the equation is
> > >
> > > gallons = 12*volts - 6
> > >
> > > example: 0 = 12*0.5 - 6 and
> > >
> > > 30 = 12*3 - 6
> > >
> > > Except in your case, the basic stamp does not directly read analog
> voltage
> > > from a transducer, hence you are using an A/D converter.
> > >
> > > What D value gives you 0.5 volts and what D value gives you 3 volts?
> This
> > > information is needed to modify the equation gallons = 12*volts - 6
> >
> > Actually, it's not quite that simple ether. You're assuming linear
> behavior
> > between pressure and volume which is only true if the tank is
rectangular.
> > if the tank is round then the top & bottom parts of the tank hold less
> > volume than the middle. The pressure is only related to depth, not
volume.
> >
> > The problem isn't unsolvable thou. With a few more data points you can
> > "curve fit" the results into an equation that will approximate a "close
> > enough" answer.
> >
> > --
> > Enjoy,
> > George Warner,
> > Schizophrenic Optimization Scientists
> > Apple Developer Technical Support (DTS)
> >
> >
> >
> > To UNSUBSCRIBE, just send mail to:
> > basicstamps-unsubscribe@yahoogroups.com
> > from the same email address that you subscribed. Text in the Subject and
> Body of the message will be ignored.
> >
> > Yahoo! Groups Links
> >
> >
> >
> >
> >
>
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the Subject and
Body of the message will be ignored.
>
> Yahoo! Groups Links
>
>
>
>
>
>
>
>
> Do you Yahoo!?
> SBC Yahoo! - Internet access at a great low price.
>
> [noparse][[/noparse]Non-text portions of this message have been removed]
>
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the Subject and
Body of the message will be ignored.
>
> Yahoo! Groups Links
>
>
>
>
>