sensorValue = analogRead( TANK_SENSOR_PIN ); constrainedValue = constrain( sensorValue, TANK_EMPTY_SETTING, TANK_FULL_SETTING ); tankLevel = map( constrainedValue, TANK_EMPTY_SETTING, TANK_FULL_SETTING, 0, 100 );
That's an interesting device, however the following excerpt from the datasheet would concern me: "The MPX2010 series pressure sensor operating characteristics and internal reliability and qualification tests are based on use of dry air as the pressure media. Media other than dry air may have adverse effects on sensor performance and long term reliability".Allowing water into the device doesn't sound like a good idea to me. It would be possible to have the pressure sensor connected to an air-filled tube, with the other end of the tube at the bottom of the tank; but in this arrangement, the air is always going to be at 100% relative humidity, so it's hardly dry. Or maybe you have an ingenious arrangement that keeps the sensor in dry air all the time?
That's a neat idea, using oil to separate the wet air from the dry air! I guess expansion of the two air pockets may make the reading temperature-sensitive, but probably not enough to matter.
The water level reading with ping article sounds good. I am not sure what was meant by the floating platform idea though. Surely you would just keep the ping in a fixed location above the water which would rise and fall.
There was mention of using a pressure lock keeping air and water separate with oil. That is quite neat but oil and fish might not mix so contamination might be an issue.
There is another thread about measuring the level in a petrol tank (sorry there is a bit of a cross post). Looking at that I came across the fact that there are piezoresistive sensors available. One of these could simply be bolted into the bottom of the tank. It sounds as if they may be sensitive to temperature but I guess in a fishy environment that will be controlled or at least measured and so could be compensated for if need be.I get the idea with the oil and air now, neat, and you could always use codliver oil.
Errm the MPX2010 is a piezoresistive pressure sensor, it still can't be submerged.
QuoteErrm the MPX2010 is a piezoresistive pressure sensor, it still can't be submerged.But, but, but... I skimmed the datasheet and it said it was suitable for use with nasty chemicals.Surely that means the pressure surface can come in direct contact with them and H2O (though it dissolves a lot of stuff) is not in the nasty class?
Alright, let me give a bit more detail....The purpose of this project is to be able to monitor the level of my top off tank for my salt water aquarium while I'm traveling. ...