Let them drink beer, or try ultrasonic meters

December 05, 2014

Let them drink beer, or try ultrasonic meters

What are we going to do when all of the fresh water supplies in the world are exhausted? We'll drink beer, of course! Or maybe not. Besides the fact t...

What are we going to do when all of the fresh water supplies in the world are exhausted? We’ll drink beer, of course! Or maybe not. Besides the fact that beer will ultimately dehydrate us, beer production consumes five liters of water for each liter of beer brewed. And this estimate doesn’t include all the water needed to grow the ingredients used to brew the beer. So, no water, no beer.

Thinking about this makes me realize that water is used to produce everything. Beyond daily use for bathing, food preparation, and cleaning of clothes, virtually all manufacturing requires water. Did you know that your computer took almost 7,000 liters of water to make? And, that the water used in semiconductor manufacturing processes is mostly ultra-pure water?

The fact of the matter is that, as living beings, we are dependent on water. Now, don’t get depressed and stop reading. I admit that even though I am an environmentalist, I often hate hearing environmental stories because they make me feel helpless and never seem to have a happy ending. I promise that there can be a happy ending here. Our water issues are so massive that solving them will take a lot of new approaches and innovative solutions.

One area to attack is the water distribution infrastructure. A third of U.S. utilities report a loss of more than 40 percent of fresh water annually due to leaks in the water distribution systems. This includes leaks in the big pipes transporting water, all the way down to leaks around your house. Imagine a 40 percent loss in any other commodity, such as gasoline! We simply wouldn’t put up with the excessive bills, waste, and pollution. But in the case of water, our most precious resource, we have closed our eyes and failed to act.

One way to correct the leaking water distribution system is with better metering. Our typical mechanical meters are actually very poor at detecting flows below about 30 liters per hour. Worse yet, mechanical meter accuracy degrades over time as the mechanical parts wear out. Today, there’s a better way to measure water flow – ultrasonic waves. Ultrasonic meters can measure with 10X greater accuracy than mechanical meters. Given that the average U.S. household leaks 45,000 liters of water per year, the average estimated leak flow rate is 5 liters per hour. This isn’t enough for your mechanical meter to detect, but well within the range of an ultrasonic meter. In addition, ultrasonic measurement doesn’t require any moving parts, so there’s nothing to wear out.

Ultrasonic sounds great, but what’s the catch? It needn’t be more expensive, as ultrasonic metering will more than pay for itself over time. With ultrasonic meters in an automated water meter infrastructure, utilities could identify leaks and bill for what they now overlook. They could recoup revenue and tighten their distribution infrastructure. With an estimated cost of $1.50 per 4,500 liters of water, utilities stand to recover $15 per customer per year. Depending on the cost of meters in volume, utilities should achieve a relatively quick return on investment. This is good for the utility companies, and we would all have a metering infrastructure that continues to perform accurately and reliably for decades.

I think that makes a lot of sense. I suggest you check out Maxim’s ultrasonic water meter, MAXREFDES70#. It’s a reference design, built to help meter manufacturers accelerate their designs and reduce the cost of different types of meters.

David Andeen is the director of reference designs at Maxim Integrated. He joined Maxim in 2005 and has had roles in both sales and segment marketing, prior to his current responsibility. Andeen holds a Ph.D. in Material Science from the University of California, Santa Barbara.

David Andeen, Maxim Integrated