Liquid Level Transmitter, Waterproof 5m Cable 12‑32VDC 4‑20mA Water Level Transducer, Liquid Level Sensor Detector(0-1m)

I've got about 3 weeks testing in water and about 3 weeks in a fuel oil tank and here are some things I have learned:1. The documentation sucks, but if you follow what another reviewer put here for a schematic, you will not have any problems.2. Isolate your two power supplies. If you don't you will smoke your 4-20mA to 0-5v converter. Also mentioned by another reviewer. I used two wall warts, ungrounded. I tied the shielding on the twisted pair and the sensor together and let that float.3. It is very noisy (regardless of the shielding configuration) so plan to use either a running average or kalman filter for data smoothing.3. VERY important-and not mentioned anywhere I noticed. DO NOT use a compression gland to seal or strain relieve the cable. There is a plastic capillary tube inside that provides an atmospheirc pressure balancing (unless you are making a barometer). First image included with this review is historical barometric pressure juxtaposed against my data. Second image shows how long it takes for the capillary to collapse and start being a barometer.Good luck. I would have given 5-stars if not for #1 above. There is no good reason for the marginal documentation.Edit: if you're trying to make a 0-1m level sensor look at the ST VL53L0X laser tof. Ultimately simpler (hardware wise) cheaper and more accurate. I'm running both for now to see which is more reliable. I found ultrasonic completely unreliable.

This product did exactly what it promised. I have had it installed for a few weeks now with no problems. The reason for the four stars is the documentation is terrible. I was an instrument/automation engineer for almost 45 years (certified by ISA in fact) so I understand 4-20 mA loop powered devices, how they are used, and what to watch out for. Someone without that experience would struggle to figure out how do I get a voltage out of this thing, and then because they specify the power supply needed with zero resistive load, might pick an in appropriate power supply and wonder why is this not working with a dropping resistor? A few diagrams and some text would really help the average home automation devotee. But they are none existent.

Seems to work as a expected. At a depth of 0 meters, the current is 3.6mA (with a 400 Ohm bias resistor). At a depth of 2 meters, the current is 8 mA. This suggests that I have a 5 meter version.I plotted current vs. depth for 5 data points. The transfer function is fairly linear, but not exactly. Good enough for my application.

This review is for a 1 meter level sensor.The first sensor failed after about 1 month, I purchased another one and it failed also in about a monthThe sensor is installed in a blackwater tank on a boat (toilets are flushed with salt water). The tank is 0.5 meters high and is well vented so there should not be any air pressure building up.When the tank is drained, the sensor does not return to zero, in fact it stays very close to the last reading. Removing the sensor from the tank does not change the reading. Removing the "anti-blocking connector" and inspecting the diaphragm does not indicate a problem.The sensor is supplied with 12 to 15 volts DC. There is a 250-ohm resister in series to allow the voltage to be measured.When I check regarding warranty information on Amazon, I am told to contact the manufacturer which is "generic". So there doesn't seem to be a manufacturer to contact about warranty replacement.I have worked with data collection systems interfacing sensors for over 40 years. I cannot find anything I am doing wrong so I can only chalk it up to sensor failure.

I've run this through the usual kind of current to voltage converter you can find on Amazon and AliExpress, and also through the smaller, lower power one from DFRobot (the Gravity Current to Analog). I've used two different voltage sources, one at 12V and the other at 17V. No matter how I configure the device, it doesn't seem to work. At first it seems to be measuring pressure correctly, but sustained power seems to slowly increase the amount of current being transmitted. The diaphragm is clear of debris. I've tried using a relay to disconnect the pressure sensor for 30 minutes at a time. It still increases the amount of current. I've tried in open air and under water. Still increases all the same.

I needed to remotely monitor the depth of water in a rain water catchment tank. This device allows me to do just that cheaply and simply. My setup used this device (0-3 meter version), a current to voltage converter (about $4 here on Amazon), an analog to digital voltage reader (ADS1115 type, about $5), and a raspberry pi. I was surprised how accurate of a reading I got with this device. I calibrated it using 12 inches of water, and it accurately read from 2 inches to 9 feet of water within 2% accuracy.

Buena calidad. Recomiendo hacer pruebas antes de usarlo, para verificar valores.

It work perfectly. I can get milimeter precision with ads1115 and the 0-3m model. Time will say how durable is it.

Ha trabajado bien para el propósito de medición de tinaco de agua.