Reg-Sensor

hi,

its a simple calculation.

gross (brutto), net (netto), tare (tara)

Measure the bottle if empty (store this value, press the button to make tare), then fill the bottle with water (its net) - then if you measure that all (its gross) - then calculate to net.

ya thanks much for ur answer but i need a sensor to know how much of water inside the bottle 

and for calculation purpose ur answer is helpful

For such applications, you should probably use a strain gauge based compression load cell. Such sensors aren't very big, some have integrated amplifiers and even digital outputs. This is similar to technology used in weighing scales which usually use larger beam-type strain gauges.

 My thought was to show how to think about which method you should use and how much effort you can put into it.

) One method would be with a defined balloon that has a strain gauge on the outside. When water is poured in, it expands and you can convert and deduce the amount.
Because a bottle made of a solid material is not optimal for weighing.
) -> unless you do it using the method I suggested earlier.

) So if you want to fill the water directly into a bottle, then an optical sensor would be possible, which detects the reflection of the water.
This would require a defined and correspondingly calculated bottle that has a reflective strip on the back.
A beam of light shines through the bottle, which is deflected by the water level depending on the filling height.
If the light is no longer detected by the sensor, then the water's edge has been reached there. You can read the water level on the scale on the bottle and convert it to the amount.

) At the bottom in the bottle there may be a pressure sensor. The weight of the water presses on this sensor.
But there must be a sensor in the bottle here.
Weighing the whole bottle is then a bit more complex, because the weight of this built-in sensor has to be subtracted.

->> Such bottle you can buy in a "house held" shop, which can have 1 litre or more.

) Ultrasonic sensors would be one possibility, sending them into the bottle from above, the corresponding echo that comes back can be converted to the volume.
Here, too, a corresponding effort is required.

If you don't want to modify the bottle, you could put a small load cell under it to measure its weight.

/challenges-projects/design-challenges/sixth-sense-design-challenge/b/blog/posts/sixth-sense-mechanical-design---graffitibot-blog-15

If you are okay to put 2 strips of copper tape on the outside of the bottle, you can measure the level using capacitance.

/products/roadtest/b/blog/posts/keysight-technologies-u1282a-digital-multimeter---applications---water-level-sensing

/products/roadtest/rv/roadtest_reviews/557/texas_instruments_fd

/challenges-projects/design-challenges/bluetoothunleashed/b/blog/posts/stirling-blue---fuel-measurement---blog-4

What accuracy do you need? There are resistive pressure sensors that might be suitable for simple low accuracy measurement.

To get a good answer you need to provide more information.

How accurate must the sensor be.

How many do you need (is just one for a lab or do you want to make a million smart water bottles)

How much can it cost

Must it work automatically and communicate by wire or radio

How much electrical power is allowed

How big is your budget

You have to answer ALL these questions to get a reasonable reply.

MK