Bridging the Gap: From Level Detection to Intelligent Control—Webinar

In this session, Shaw from APG and Kelvin from ControlByWeb sit down for a candid, conversational discussion on integrating APG ultrasonic level sensors with I/O modules to unlock smarter, more efficient automation systems.

This is a practical, real-world conversation that blends product expertise with field insights. If you’re looking to better understand how to bring sensors and control modules together for reliable, scalable solutions, this session is for you.

Transcript:

This is Kelvin with ControlByWeb and I’m here with Shaw Merrill with Automation Products Group, and today we’re going to talk about level measurement and control. We’re going to talk everything from the instrumentation side—the sensor side—all the way to the controller and what you do with that signal. And we’re going to cover specifically ultrasonic level sensors today.

So Shaw is our expert. He comes with APG, Automation Products Group. They’ve been manufacturing ultrasonic level sensors and other sensor technologies since the ’80s. Since the ’80s. It’s been a long time. Yeah, a little over 30 years. Shaw’s been there the entire time. He’s the guy. Close to, close to. But they’ve been manufacturing ultrasonic level sensors and other technologies for over 30 years here in the USA. Built to order. Yep, custom products. We have some off the shelf, but most of them are custom ordered to what they want. Yeah, so that they’re going to match the sensor technology to your needs.

Today, we’re just going to talk about one of the technologies they manufacture, which is ultrasonic, and then we’ll also talk about how ControlByWeb controllers take that signal and turn it into conditional logic, turn it into remote alarms, notifications—all the things you want out of a controller, especially in the modern IoT age. So yeah, Shaw, take it away. Tell us about ultrasonic sensors.

Yeah, I think on the ultrasonics, you want to start with the basics—kind of how they operate and what they are. So an ultrasonic sensor uses sound waves to measure distance—to measure levels. You can do presence detection as well with those. Basically what’s happening is it’s sending a sound wave from the face of the sensor out to the surface of whatever you’re measuring. So if you’re in a water tank, for example, it’ll send that sound wave out to the surface of the water, bounce off of that surface of the water back to the sensor to get its reading, and then it calculates that in time to give you your level reading or your distance reading. So that’s the basic principle of how the ultrasonic works.

We then take that, calculate the distance reading, and then give it an output. It either goes in an output like a 4 to 20 milliamp signal or a Modbus RS-485 output that you guys can take and use in your control devices. So one of the advantages of an ultrasonic sensor in a lot of different applications—whether it be in a water tank, whether it be chemical, in water wastewater applications—is it’s a non-contact sensor, or what we would refer to as a non-contact type of technology, because the sensor doesn’t actually come in contact with the medium that you’re measuring. We’re using the sound waves to contact that and measure the distance or measure that level reading.

And so you’re not actually coming in contact, which is an advantage because there’s a lot of people who don’t want that in contact—especially if they’re using potable water or drinking water. You’ve got to worry about contamination; you don’t want it touching that. Yeah, there are other liquids that are very sticky, right, that will actually build up on your sensor and mess that up. So that’s a big deal. You’ve got to be careful with those, so that non-contact is a big advantage.

Another big advantage of ultrasonic sensors is they’re an inexpensive sensor compared to some of the other ones that you’ll find out there for measuring level and distance. For, you know, $400 or $500, you can get a sensor for measuring your tank or whatever you’re wanting to measure. Combine that with your controller and, you know, you’re under $1,000 for an application, which is a phenomenal price—great value for the technology that you’re getting.

Another advantage is the accuracy you get with an ultrasonic sensor. It may not be as fine accuracy as some other technologies that are out there, but for an ultrasonic you’re looking at 0.25% of the detected range. We won’t get into the detail of that, but it’s very fine accuracy—which is really good. Most applications, that’s plenty, right? More than what you need. A lot of people are only looking for maybe a percent or two of accuracy. And so if you get below that 1%, now you’re talking very accurate, very good readings for whatever your application may be.

As far as installation of your ultrasonic sensors, they’re very straightforward, very simple. All of our ultrasonics either come with a 2-inch what’s called an NPT thread or a 3-inch NPT thread. You can get a little bit smaller if you need as well, but it just installs right on top of your tank or whatever your application is. You wire it up to your controller and the simple part of it is it’s basically plug-and-play. You can wire up that sensor, you’ve got it installed in your tank, and you’re ready to go.

If you want to fine-tune that sensor to your application—let’s say you want to change your max distance reading or you want to, you know, there are several sensors within the ultrasonic that you can go in and fine-tune and really dial it in, kind of like you are on a radio—you’re dialing in, tuning in that station really clear. If you want to really fine-tune the sensor, we can get into that and you can do that. But at its surface level, the ultrasonic—all of our ultrasonics—are really plug-and-play. You just plug them in and they’re ready to go. And they work.

And there are a couple of things to keep in mind, right? You’ve got to protect that sound wave, make sure it’s not going to hit something it doesn’t want to. You’ve got—what is your angle as it comes down from the sensor? Yeah, our sensors have a 9° angle, which means from the face of the sensor, it goes out 9°. So the further you get away from the sensor, the sound waves get wider in that tank. Some of the things you want to take into account when you’re looking at an ultrasonic sensor are the environment that it’s going into. Do you have vapors or foam? Things like that. Some of those are not really great with ultrasonics because they’ll bounce off the foam or bounce off the vapor and you get false readings.

Then you can get into other sensors like a submersible pressure transducer or radar sensor. You want to look at your tank and make sure it has smooth sides so that it’s not bouncing off different levels in the tank. And you want to make sure that the sensor is installed in the right place at the top of the tank—you don’t want it right in the middle, but you don’t want it right on the edge next to the wall either, for fear of getting some of those sound waves bouncing off anything that may be on the side of that tank.

Yeah, because it’s really a sensitive device. It’s going to pick up on a lot of things. But you guys have a lot of installation tips and tricks to bypass that too. We have all those on our website—you can go on and find videos on how to install it, how to fine-tune them with some of the programming software, all the things you want to look at as far as installation and conditions.

So, we’ve gone through what an ultrasonic is, some of the advantages, how easy they are to install and use. There are a lot of different applications they can be used in—in fact, a plethora of applications. We see them a lot in the water and wastewater markets where people are using them in water tanks or sewer applications under sewer lids, monitoring stormwater surge, things like that. They’re used a lot in the car wash industry. That’s an interesting one. You know, if you’ve gone through an automatic car wash, oftentimes they’re using ultrasonics to judge where your car is, to do a profile if you’re dealing with a sedan versus a pickup.

So there are a lot of different applications where ultrasonics are used because of their advantages—they’re inexpensive, easy to install and program, and accurate sensors. Those three things are the biggest selling points of ultrasonics. It makes them a really good general-purpose level measurement or distance measurement sensor. And you can get them in the different outputs. If you just want a simple 4 to 20 device, we can do that. If you want Modbus, we can do that. If you want other outputs, there are options as well.

So, if there were three things that I need to remember about ultrasonic, what would those be? That’s a really good question. Three things to remember about ultrasonic are: your environment—you want to know what it’s going into, so you know if it’s the right technology to use; you want to know the distance you’re measuring—how tall is your tank, 10 ft, 25 ft—because that helps determine which sensor you need, since they’re offered in different ranges. What would be a maximum? Our sensors go up to about 50 ft. Nice. Common is 25 ft. Yeah. As short as 9 in. Okay. Anywhere from 9 in up to 50 ft. And third, you want to think about your budget. How much do you want to spend? If you want to go budget-friendly, ultrasonic is definitely the way to go.

Yeah, ultrasonics are really cool—and they’re all over the place. In the industrial world, we’re often talking about things that are invisible to most people, but ultrasonic sensors are really a backbone of level measurement technology.

So once you have an accurate sensor, now what do you do with that signal? As Shaw mentioned, you have a 4 to 20 milliamp output, one of the most common sensor outputs across many technologies. You also have Modbus RS-485, which is still very common. When you take those signals and want to do something with them—make a logical decision, log data, send it to a cloud, an IoT platform, or a SCADA—that’s where the controller comes in.

Here are two controllers that we make. ControlByWeb manufactures the X404 and the X412. The X404 is a Modbus RS-485 input device, and the X412 is one of our most popular analog input devices for 4 to 20 milliamp or 0 to 10 volt signals. It also has four embedded relays. These two devices are very commonly paired with ultrasonic level sensors from APG.

These devices are edge logic controllers. “Edge” refers to the source of the data—the sensor and machine layer in industrial control systems. At the edge, our controllers connect directly to the sensors, receive the signal, and process it locally.

With a ControlByWeb device, you can use multiple protocols. Modbus TCP/IP is the classic, widely used one. A more modern one is MQTT, which has a lot of advantages—encryption, low bandwidth use, and it’s great for remote sites. Instead of needing to be polled like Modbus, MQTT devices publish data to a broker at whatever interval you set, and anything subscribed can read it.

You can also use REST API get requests. Our devices have open APIs—it’s easy to ping the device with an API call and get data in XML or JSON format, and you have full relay control with HTTP requests. So there are a lot of flexible ways to get your sensor data out of our devices and use it.

And you were talking about price point—one of the amazing things about ControlByWeb devices is that they’re essentially PLCs. They’re streamlined, simplified if-this-then-that logic PLCs, and they’re in the $300 to $600 range. So again, you can take your APG ultrasonic, your X412 or X404, and have a complete level measurement and control system for under $1,000.

As you mentioned, one of the things I like is that if you’ve got more than one tank or the need for more than one sensor, you can do multiple sensors per one device—which is a big advantage. Yeah, it’s huge. Our X404 can monitor up to 32 Modbus devices—sensors in this case—and they just daisy-chain together. Each has its own address, and we’ve made it plug-and-play. When you connect your Modbus APG sensor, with APG specifically, the controller automatically populates all the registers. You don’t have to do any register math or mapping. It’s as plug-and-play as Modbus gets.

That’s a huge advantage—it takes away a lot of the pain points people have when setting up Modbus networks and connecting controllers and sensors together. Absolutely. Modbus can be intimidating for people who haven’t used it before, so having that plug-and-play ability makes it so much easier for anybody to use.

That’s what we’ve seen a lot with ControlByWeb devices—they’re designed to be simple to use, simple to set up, but still extremely powerful. You can run complex logic on them, but the user interface is easy to understand and approachable even if you’re not a controls engineer.

Yeah, that’s kind of our philosophy. We really want it to be powerful enough for engineers and integrators but simple enough for facility maintenance personnel or operators who just want visibility into their systems. For example, with your ultrasonic sensor, I could set this up so that when the level drops below a certain point, the controller automatically turns on a pump. When it reaches a high-level threshold, it turns the pump off. That’s simple level-control logic, but you can go way beyond that—add remote alerts, text messages, email notifications, even data logging to a cloud or local server.

Right, so you can monitor it from anywhere basically.

Exactly. As long as the ControlByWeb device is connected to the internet, or even a local network, you can access it through its built-in web server. Just log into the device with its IP address, and from there you can see live readings, control relays, change logic conditions—all from your browser. No special software needed.

That’s awesome. So really, when you pair the ultrasonic sensors with a ControlByWeb controller, you’ve got everything you need for a complete level measurement and control system.

Exactly. You’ve got your measurement, your control, your monitoring, and your data reporting—all in one package. And because both APG and ControlByWeb design and manufacture their products here in the U.S., you’re getting top-notch support and reliability.

Absolutely. And if you ever need help figuring out which sensor to use for your tank height or what kind of output you need, our team at APG can help with that. And once you have that, ControlByWeb can help you get it integrated into your system.

That’s right. Between both of our companies, we can take you from sensor selection all the way to automation and remote monitoring.

So Shaw, if someone wants to learn more about APG’s ultrasonic sensors, where should they go?

You can go to our website at apgsensors.com. We’ve got all the information there—spec sheets, installation guides, videos on how to set up the sensors—everything you need.

Perfect. And if you want to learn more about ControlByWeb controllers, you can visit controlbyweb.com. We’ve got application examples, setup tutorials, and information on all of our I/O modules and automation devices.

Awesome.

Well, Shaw, thanks so much for joining us today and sharing your expertise.

Thank you for having me.

And thank you all for watching. Be sure to check out both APG and ControlByWeb for your next automation project, and we’ll see you next time.