Page 19 - PEN Ebook May 2021
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TEST & MEASUREMENTS                                                                     Test & Measurements

                                                                   over the sensing area. The sensor transforms
          When considering materials and construction of a

          battery, evaluating the pressure dynamics is critical    compressive pressure loads to a change in
          to maintain the material spacings, control gassing,      resistance.
          and prevent excess swelling.                            →   Sensors typically have about 2,000 sensing
                                                                     points, but some sensors can be designed
                                                                     with over 16,000 sensing points.
          WHAT IS PRESSURE MAPPING?                               →   Sensing element spacing (pitch) can be as
          Even between relatively flat surfaces, you might           narrow as 0.64 mm (0.025 in.).
          find the interface pressure distribution is often not   →   Sensors can measure pressure ranges up
          uniform within localized areas of peak pressure.           to 25,000 PSI (172 MPa)

          Pressure mapping technology helps design engi-          →   High-temperature sensor options up to
          neers obtain insight into areas that may impact            200°C (400°F)
          design and quality.
                                                                ▶   The scanning electronics collect analog data
          As shown in Figure 1, pressure mapping systems           from the sensor and convert the data into a
          are made of three components – sensors, scanning         digital signal.
          electronics, and software – to deliver real-time,       →   Scanning speeds available up to 20,000 Hz

          actionable data, in ways other methods cannot.
                                                                ▶   The software displays real-time activity of
 A Novel Method for   ▶   The sensor is an array of piezoresistive sens-  the sensor area, allowing users to see force,

                                                                   pressure, contact area, and timing data.
             ing points that measure pressure distribution
 Measuring Pressure


 Exchanges within



 Battery Housing for



 Lifecycle Testing





 By Camilo Aladro, Pressure Mapping Product Manager, Tekscan, Inc.



 Many of those that are familiar with the construc-  Regardless of the industry, consumer electronics,
 tion of a prismatic lithium-ion battery will say that   or energy storage systems to name a few, users are
 it breathes. Charging and discharging causes tem-  requesting batteries that are lighter, more compact,
 perature changes, electrochemistry, and mechanics   have a higher energy density and faster charging.
 of the internal components that, in turn, change   They must also be safe in the event of catastrophic
 the internal pressures. As manufacturers try to   incidents. These features can often be in conflict, it
 create a product that is efficient, lightweight, and   can be a challenge to find a balance and stay cost
 safe, it is of paramount importance that designers   competitive.
          Figure 1: Designers and engineers use pressure mapping systems, such as the one shown above, to measure interface pressure
 intimately understand these characteristics.  between two mating surfaces.


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