check water in plastic pipe

Hi I have an air conditioning system which have the water pipe that go over a window and if it is moved a little bit rarely it happens that the water does not go away and the more water comes the more the pipe gets stuck and more water is collected and the pipe gets full. The consequences are that my air conditioning split does lose water and the water goes on my wall and my floor. I was wondering if there is a way to monitor the plastic pipe from external and check if the water flows or not. I cannot unmount the pipes because I am not expert and I do not want to touch it. Just check if the pipe gets full of water. Thank you Camillo

use a proximity sensor :) These sensors will often use in industrial PLC (SPS) controls. You can adjust the sensitivity level by a small crew. We did use this sensors in a galvanic tool for detection of water and acids in plastic pumplines to prevent pums to run dry. It's easy, to place the sensor outside of pipe. A other solution is a calorimetric sensor. Use a PTC or NTC heat it up per current, measure the voltage over the resistor. If the sensor will cool down by liquid, the voltage will be different ;)

Hi great ideas thanks! As a proximity sensor you mean an ultrasonic sensor or a pir sensor? Will it work also from outside the pipe? I think it would need also some kind of calibration first with the pipe empty and the pipe full, or i just can bet what value it will be with the pipe full? Thank you Camillo

As a proximity sensor you mean an ultrasonic sensor or a pir sensor?

No an inductance or capacitave sensor.

Grumpy_Mike:
No an inductance or capacitave sensor.

Exactly :slight_smile:
And the best is, you don’t need open the plastic-pipe.
But note, that different liquids with different resistant needs different adjustments for sensor.
We had a serious problem with DI-water (purge) and acids (etch), what alternate to detect (yes or no only). If you have only water all will be fine :slight_smile:

Thank you! I am not an expert in hardware, do You have a link to a sample sensor like those You mention that I can connect to an Arduino? Camillo

http://www.aliexpress.com/item/high-quality-capacitive-proximity-sensor-LJC18A3-B-Z-AY-18mm-diameter-10mm-detective-distance-DC-6/485043402.html that should it do. For a brand name you pay 10x more and chinese dealer distribute worldwide. But you need time - some weeks. These sensor will work with 6V - most brands needs more, standard is 24V. But with a small 12V switching supply you can drive sensor and a 5V regulator for Arduino. For adaption from sensor output to Arduino input i would recommand a optocoupler or a reed-relay

A capacitive sensor is the way to go. All you need is two pieces of a conductive material (tin foil works) and a large resistor.

Hi Is there a way to have this capacitive sensor to clamp wrap the pipe so that it can stay fixed to the pipe over time? Like the clamps used for current meters? Thank you Camillo

taxus: A capacitive sensor is the way to go. All you need is two pieces of a conductive material (tin foil works) and a large resistor.

I found something about this here:http://playground.arduino.cc/Main/CapacitiveSensor?from=Main.CapSense Just do not know how to connect all the stuff around the plastic pipe... Any idea? Thank you Camillo

The sensitive Area from capacitive and inductive sensors is the round face. This plate must face to face onto the plasticpipe. You may need a nonmetallic block (plastic, wood... whatever) with a hole for sensor. This Block you can fix with a cable-tie around the pipe. This construction we used.