UltaSonic Sensors

[p3t3rv]

im looking for a simple way to measure water level in a large pond filter system

the water inlet has a filter bag like a hoover but when it clogs up with weed ect the pump keeps pumping and the water level drops what i need to do it switch the pump off when the water drops to one level and re start it when the level rises to normal and do a flash buzzz combo to notify the filter bag is blocked

maximum differnce between hi lvl and low lvl is about 12" i was wondering if ultra sonics could be the answer i want to avoid the normal 3 wires in the water or float valve kind of sensors

 

[jbeng]

Over in the "Project Design/Ideas/Reviews" forum krishtriram had a similar question. Link: https://www.electro-tech-online.com/threads/protel-2004-needs.9458/
Industry uses ultrasonic sensors frequently to measure tank levels, etc. One thing of note: there is usually a "dead zone" in front of the sensor where the target won't be seen. This is due to the reflection of the sonic pulse arriving too soon after being sent and not being reliably detected. Just mount your sensor a suitable minimum distance away from your target (probably listed on the sensor's data sheet) and you should be fine. Other than that, you shouldn't have any problem using ultrasonic in this application. JB

 

[In Lupus Corpore]

:idea: There are other approaches to consider. The filter should be on the pump suction to protect the pump as well as the pond. In this configuration the discharge pressure will start to drop as the flow decreases. Install a pressure gauge at the discharge and check the pressure with a clean filter. They buy a pressure switch (possibly an oil sender for a car. Try to get one that's adjustable and set it for the value halfway between the clean filter discharge pressure and 0. Wire it to shut off the pump.

 

[In Lupus Corpore]

I left something out. While the pond level is dropping the pump is running starved for suction. This leads to a condition know as cavitation which will cause heat and erosion of all the wet parts of the pump. A better approach, still, is to use a differential pressure switch.