Ultrasonic Level Sensor Installation Checklist

ultrasonic level sensor installationOver the years we have provided several articles on how to install an ultrasonic sensor, proper mounting, using a stilling well, as well as the top 10 mistakes with ultrasonic sensors. Well today is your lucky day. We are making life a bit easier for you and combining these articles into one fun to read complete installation guide!

Proper mounting is critical for the successful operation of an ultrasonic level sensor. I know it sounds a bit heavy, but trust us, if you nail the installation you are on your way to worry free readings. In a few minutes you will be able to sit back and relax while you enjoy success.

Physically installing an ultrasonic sensor is actually quite simple, however preparation is the key. There are some essential steps you can take to ensure it is just right. We want to make sure your good sensor performs its best and is happy – so let’s start with the pre-installation.

Yep that’s right. Before you pick up the sensor and screw it into place there are some things you can do to insure your installation will provide the best environment for your sensor.

Choose The Proper Sensing Range

The first thing you want to do is make sure you have selected the right sensor for your application. Typically you want to select a sensing range that is greater than the actual distance to the target. There are a number of other factors to consider when selecting an ultrasonic sensor, which we cover in “Three Tips to Getting the Right Range for your Ultrasonic Sensor”. It basically boils down to 3 main things:

  1. Sensing distance
  2. Blanking distance – this is the distance directly in front of the sensor face where targets are unable to be measured, and
  3. Target Type – whether you are detecting a soft or hard target.

Once you have determined these factors, selecting the right sensor is a cinch.

Use A Clean Power Source

Quality matters when it comes to power. Because you are dealing with high gain instrumentation, a clean source of power is critical to reduce electrical noise and ensure proper sensor operation. Always try to avoid low quality power supplies.

OK, so you have selected the right ultrasonic sensor and verified your power source, now you are ready to jump in and install this sound machine. As you select the mounting location here are some tips to ensure optimum sensor performance.

Make Sure You Have A Clear Path

Mount the sensor in a location that provides an unobstructed column of air from the sensor to the target. Generally speaking you need a 3-4 foot diameter unobstructed column even at longer ranges. If this is not possible a stilling well provides a good solution. We will discuss how to install the sensor with a stilling well later in this article.

When looking for a clear path for your sensor you also want to note where any fill spouts are located. Mounting too close to the spout could result in false readings. White noise from the filling can also be a problem as it can interrupt the sound wave.

If your tank has a domed top avoid mounting the sensor in the direct center of the dome. This does seem a bit counterintuitive so let us explain. The shape of the domed top could amplify small, undesired signals inside the tank and lead to false readings. Your sensor does not need a hearing aid.

You also want to keep the sensor away from the tank wall, especially if the walls are corrugated or if there will be product buildup on the tank walls. The sensor could “see” the bumps on the walls as a level and return a false level reading.

Keep Your Target Level Below Your Blanking Distance

Always mount the sensor above the highest anticipated target level by at least the minimum blanking distance. The blanking distance is usually 4 – 12 inches depending on the model sensor you have selected.

Keep A 90° Mounting Angle

Make sure the face of the sensor is perpendicular to the target surface. If the sensor is just a few degrees off perpendicular the target may not be detected.

One more thing, just like you and I, ultrasonic sensors need protection if they are mounted in direct sunlight. Try to shade the sensor in this situation as the sun can harm the sensor housing and cause overcompensation for temperature as the sensor heats up.

Now that your preparation is done you can install the sensor. But remember that as you twist the sensor into place do not over tighten. Last but certainly not least, always screw your sensor in by hand to avoid cross threading. Thread failure can be a problem if you damage the threads by over-tightening them or crossing threads. Now is not the time to prove your strength.

Use A Stilling Well If You Need It

As we indicated earlier sometimes you can’t provide the optimum unobstructed clear path to the target with sufficient space for your sensor. In this case it may be a good idea to consider installing your sensor in a stilling well. Here are 5 easy steps to a quick and easy installation:

  • Choose a seamless PVC or steel pipe with the appropriate threaded NPT fitting to mount the ultrasonic sensor. You may need to use a reducer.
  • Drill a ¼” vent hole in the pipe within the blanking distance of the sensor. This allows the liquid to travel up the pipe.
  • If the pipe needs to touch the bottom of the tank, drill several ¼” holes in the last few inches so the liquid can enter the stilling well. You’ll typically need 4 to 6 holes.
  • Place the pipe as vertical as possible. Make sure the transducer face is at least the minimum blanking distance away from the maximum height of the liquid.
  • Mount the pipe using brackets, metal straps, or the best means possible for your application, to ensure the stilling well will stay place and not move from the vertical position.

Don’t hesitate to contact us if you have any questions about installing your ultrasonic sensor.

If you really like to read and would like more detailed information about installing and selecting an ultrasonic level sensor check out these articles:

Explore APG Ultrasonic Sensors


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