Level Sensor for a specific application

I’m looking for a level sensor for a specific application: I need to measure the oil level inside the oil separators while transferring POE oil from the tank to the oil separators. The separator will be pre-charged with 17 FL.OZ. of POE oil, and the connection of the separator is ½ inch and the transfer pipes will be around ½ inch as well, which is really small, so I believe it requires sensors that are more microscopic. Is there any specific cost-effective sensors you would recommend for this application?

Hello Viktoriaa.sholudko,

Welcome to the DigiKey TechForum!

This is a very interesting application - there are some pieces of information that we’ll need to consider prior to suggesting any sensors. Although size is very important in this matter, there are some other factors to consider as well.

Are you hoping to use a distance sensing device or will you need a sensor that can detect the composition of the mixture (Float Level, Capacitive Level, Ultrasonic Level, Pressure Transducer, or Optical Level sensors)?

How will the sensor be mounted to the oil separator, and the information be relayed to the reading device?

Finally, what is the resolution that you’re looking for on the sensor to ensure you get an accurate reading?

The answers to these questions will help narrow down the best options for your application.


Thank you for the response!

So, going a little deeper to the application, the project is to construct a more automated way of charging the oil separators with the POE oil from the storage tank, and it is simply for a human worker who is pouring the oil into the separators to save time on the process; for today he uses scales to measure the level of this oil in the separators, and I’m trying to find an alternative for him to have it more automated. From here, I don’t have any specifications on which exactly type of the sensor we would need for this, but as the connection to the separator is that small, ½ inches, we don’t have much to consider (most of companies don’t produce that small ones); I look for the option I would be able to use.

I’m thinking about two ways: first way is a level sensor attached to the connection (any type of level that would be microscopic enough for 1/2inch), or a flow rate sensor to attach inside the transfer pipe, and while pouring to time the properly to know when the oil reached the right amount.

Moving from this application:

The level sensor will have to be mounted to the ½-inch connection of the oil separator.

The resolution: the clarity of measurement should be in between 16.5ish to 18ish, so the amount of oil the human worker is trying to measure inside is around 17FL.OZ, it just needs to be between the top and bottom levels of the separator.

Please let me know if there are any other specification that could be helpful.

Thank you so much,


Is the human worker using the scales to measure the existing oil in the oil separators to maintain 17oz, or is it for a repeated processes of inserting 17oz of oil every time? If the former, then there will need to be a sensor that is constantly monitoring the oil ratio in the separator. If the latter, then would something like part 1649-1052-ND be what you’re looking for? The size is actually 1/4", but it could be possible to use an adapter to connect the sizes.

It is for repeated process of inserting 17oz of oil every time. Yes, this part looks something that would work. Would it be compatible with the POE oil (viscosity is 32cSt) and what is the max flowrate it can handle?

Thank you,


Also, are there any flow rate sensors suitable for this application that you would recommend? As an option, we can go with the flow rate sensor, would be possible with some calculations, and timing the process.

Thank you in advance,



Part 1649-1052-ND should work with the POE oil; I was not able to find any data on it for measuring the POE oil itself, however it does have some data for water and isopropyl alcohol. Performing the measurement of the 17oz using weight to calibrate the sensor should suffice though.

There are actually a few choices that you could use for this application which you can find HERE, however you may find part 2330-SM6000-ND really fits your needs. It is 1/2" so should fit your connector on the separator. It too would need calibration as well, however it has multiple programming options, of which there is a quantity meter and preset counter. This means once it is calibrated you’ll be able to send a command and it will send the 17oz without any human intervention.

Hello Viktoriia,

You have a fascinating application.

I am very curious how you solved the problem. A picture or even a short description of your solution would be greatly appreciated.

Please let us know if we an assist. It would be a welcome challenge for this community to explore application ideas with you.



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