Breaking Down Barriers: How to Increase Smart Meter Implementation with Reliability
Posted on October 29th, 2021 by Mallory McGuinness
As the world population quickly increases, smart meters have become valued as a way to reduce water consumption and utility wastage to encourage a sustainable future.
As critical as implementing a smart meter infrastructure may be, the potential for excessive costs associated with the units themselves and the price of service repairs are barriers to progress. As such, smart meter design teams have prioritized reliability over the entire product lifecycle to reduce the need for repairs and lower total cost of ownership.
The smart meter operating environment is hostile for technologically advanced metering functions. Outside condensation, high humidity levels, and the possibility of full submersion call for electronic resilience, and smart meters are often expected to work for seven years or more in these extremely corrosive environments.
Watch our webinar on proven methods of corrosion resistance
Compounding the problem is the fact that as more electronics are added to smart meters to enhance functionality, the more vulnerable these components are, and more protection is required.
Table 1: Meter Concerns
| Types | Advantages | Drawbacks |
|---|---|---|
| Fully Mechanical | Simple design, low-cost, reliable operation | Narrow measurement range, reduced accuracy at low flow rates, cumulative measurement only, lack of real-time information |
| Electromechanical | Real-time information | Requires extra protection for the electronic component, reduced stability |
| Fully Electronic | High accuracy (far greater and more detailed feedback), real-time information | Requires extra waterproof protection and power supply |
In the past, design teams might have turned to legacy methods (such as conventional conformal coatings, potting, or customized enclosures with many seals) to ensure this level of protection, but they may be less relevant with the current generation of meters. Seals, potting, and enclosures add to the weight and bulk of the device which can lead to e-waste concerns down the line when the oversized, heavy meters must be disposed of.
Meanwhile, smart meters use cellular signals or low-power radio frequency (RF) to transmit and collect information about services. Conventional conformal coatings must be applied in thick layers to adequately provide corrosion protection and can interfere with transmittance. This is particularly true if the coating or potting materials make their way into the cell reception area of antennae.
While legacy methods do still have their place in many instances, such as when coupled with thinner coatings for redundant smart meter protection, Parylene conformal coatings, may be the ideal solution for reliability challenges, both as a backup, or standalone protection.
HZO Smart Meter Coatings
HZO Parylene has exemplary barrier properties and demonstrates superiority in uniform coverage and performance at 50% thinness of conventional conformal coatings. These attributes combined ensure that seemingly conflicting goals of bolstering resilience in harsh smart meter environments and ensuring the devices remain lightweight and more compact can be reconciled and met.
Read more about the repeatable Parylene application process
Smart Meter Corrosion Resistance
As smart meters face exposure to highly corrosive environments, the proven corrosion-resistance properties of Parylene are valuable to smart meter product design teams. Among protective polymer coatings, Parylene exhibits some of the best moisture impermeability, and provides one of the lowest water vapor transmission rates (WVTR).
Table 2: Barrier Properties of Conformal Coatings
| Polymer | Gas Permeability at 25 °C, (cc·mm)/(m2·day·atm) | WVTR,(g·mm)/(m2·day) | ||||||
|---|---|---|---|---|---|---|---|---|
| N2 | O2 | CO2 | H2 | H2S | SO2 | CI2 | ||
| Parylene C | 0.4 | 2.8 | 3.0 | 43.3 | 5.1 | 4.3 | 0.1 | 0.08 |
| Parylene N | 3.0 | 15.4 | 84.3 | 212.6 | 313 | 745 | 29.2 | 0.59 |
| Parylene F (VT-4) | – | 16.7 | – | – | – | – | – | 0.28 |
| Epoxy (ER) | 1.6 | 4 | 3.1 | 43.3 | – | – | – | 0.94 |
| Polyurethane (UR) | 31.5 | 78.7 | 1,181 | – | – | – | – | 0.93 |
| Silicone (SR) | – | 19,685 | 118,110 | 17,710 | – | – | – | – |
Ref.: Licari, James J. Coating Materials for Electronic Applications – Polymers, Processes, Reliability, Testing. William Andrew Publishing, 2003 and various companies’ literature.
Parylene is a trustworthy corrosion barrier due to its ability to minimize these factors that affect coating performance:
- Ionic permeability − Salts have a difficult time passing through the coating.
- Liquid water uptake − Parylene absorbs very little water.
- Coating porosity − At a thickness of just 5 to 50 microns, Parylene forms a pinhole/pore-free coating.
Download the HZO Parylene datasheet
Miniaturization Solutions
No other conformal coating can provide the corrosion resistance that Parylene can at its level of thinness, so there is no need to decide whether reliability or dependable signal transmittance are a priority. With the assurance that electronics will remain resilient, even when fully submerged, and signals will be reliably transmitted, product design teams can reduce service calls and lower TCO.
Table 3: Parylene thickness levels and best applications
| Thickness (μm) | 0.1 to 5 | 5 to 12.5 | 12.5 to 25 | 12.5 to 50.8 |
|---|---|---|---|---|
| Relevant Standards | UT Type in IPC-CC-830C | UT Type in IPC-CC-830C | IPC-CC-830B | NASA-STD-8739.1B |
| Protection Level*** | IPX3 / IPX4 | IPX4 / IPX7 | IPX7 / IPX8 | IPX7 / IPX8 |
| Appropriate Products | Consumer Electronic & MEMS Devices | Consumer & Industrial Electronics | Aerospace, Automotive, Industrial, Medical Device, Telecom, & Other High-Reliability Markets | Aerospace, Defense, & Very Harsh Industrial |
HZO Smart Meter Solutions
The engineers at HZO focus on providing solutions that are prescriptive, reliable, easy to incorporate, and budget-friendly. Our team recognized the superiority of Parylene but also acknowledged its shortcomings: Parylene may be more costly than most other conformal coatings and requires a batch-style coating process.
With industry and domain experience, they have been in the shoes of product design teams, and aim to be the knowledgeable, helpful experts they wished they had known before they created a solution to these issues. Understanding the importance of time-to-market and budget, our team has built proprietary coating equipment with optimized meter cubed coating chambers, the largest, most efficient chambers in the industry.
Because our coating equipment can house more substrates and components, our customers are able to save money on coating runs, decrease turnaround time and improve throughput. Whether you are from a large company or small, we respect the criticality of smart meter technology and take measures to exceed quality assurance expectations. To date, our customers have not experienced a single product return attributed to coating issues, despite coating millions of components.
Whether you know exactly what you need, or are unsure to start, our application engineers are happy to discuss a highly configurable process that will easily integrate into your production. Please contact us today to speak with them if your goal is to lower TCO, reduce smart meter service calls, and help your business succeed.
Mallory McGuinness
Mallory McGuinnessDiscover how HZO can protect your product