When you find that conventional temperature sensors based on resistors or capacitors, or simple wire-based sensors such as thermocouples, just won’t operate properly in a challenging environment, look instead to the multiple benefits provided by fibre optic temperature probes.
Fully dielectric construction of the sensor and its attached fibre optic cable gives immunity to the effects of EMI/RFI, allowing use in high voltage environments, magnetic resonance imaging systems and high magnetic fields. The material construction further allows use in radiation, high vacuum and explosive areas, and the physical dimensions typical of fibre optics allows the probe to be treated essentially as an electrical cable, routed along complex pathways and along conduits, but without any of the disadvantages of inaccuracies due to the influence of electromagnetic fields.
One main growth area for fibre optic temperature probes has been in the automotive segment, involving test and development of electric vehicles (EV) including the motors, charging stations and batteries. Faster and accurate temperature measurement is necessary at each stage of EV product development, at both individual component level for identifying performance limits and temperature behavior of individual components, and for fully assembled vehicles to ensure the overall performance and safety.
High voltage connections and operations within the vehicle bring challenges in terms of safety, limited access and electromagnetic noise issues during testing and measurements. Fibre optic based temperature probes are becoming more popular in testing electric and hybrid vehicles due to their immunity to electromagnetic fields, ruggedness, small size, fast response, high accuracy and intrinsic safety of operation.
Our partner Rugged Monitoring has extensive involvement in this application area. [https://www.ruggedmonitoring.com/solutions-details/fiber-optic-temperature-sensors-in-electric-vehicle-temperature-testing/5c9c5fb493c0cc0001d3d7b5 ]. If your temperature instrumentation in EV development and testing is revealing the limitations of conventional sensor technology, ask us how fibre optic temperature probes will solve these issues and provide methods of temperature measurement that can’t be made in any other way.
Energy storage and energy conversion devices are both used to fill the need for portable as well as renewable power. The evolving needs require the improvement in capability to provide pulse-power, long run-time and cycle life. New materials and advancements of engineering play a key role in meeting the market demand.
Li-ion batteries are today’s leading technology in this space. Cyclic voltammetry is used in the development of the material and identification of its potential window (charge cut-off voltage and discharge cut-off voltage), and is also the primary technique in identification of new electrolytes. The BNC connections of both the Solartron Analytical EnergyLab and Princeton Applied Research potentiostats provide an interface common for the glovebox feedthroughs often needed for this type of research.
As the goal of a rechargeable battery is to provide high cycle-life, high efficiency, and high energy density, prospective new materials are combined into a complete cell and tested in a charge – discharge experiment to determine the capacity vs cycle number, cycle-life and Coulombic efficiency. Battery holders for PARSTAT and VersaSTAT potentiostats allow for direct connection of common battery formats to the instrument. Direct connection through a battery holder avoids the added stray capacitance and inductance to impedance measurements, and creates a cleaner signal and a cleaner lab.
The use of auxiliary voltage measurements allows monitoring of both the anode and cathode of a battery. Standard potentiostat design concentrates on the signal and response at the Working Electrode, and the Counter Electrode reactions are not characterized. Other applications use an inert Counter Electrode, but in battery technology this is an active electrode. Being able to characterize this terminal allows users to identify failure mechanisms and properly focus research initiatives. This is available on the PARSTAT 3000A and EnergyLab products for single cell evaluation and PARSTAT MC for multichannel, simultaneous tests for improved throughput.
The typically flat-voltage profile, seen as a key advantage of Li-technology, drives the need for advanced techniques to determine State of Charge. Electrochemical Impedance Spectroscopy (EIS) is the emerging method for making these determinations in-situ. EIS is also used to determine how the battery is functioning with respect to its anticipated lifetime (State of Health). The full range of products from Princeton Applied Research and Solartron Analytical provide these measurement capabilities either as standard or as options. EIS also provides a mechanism via equivalent circuit analysis or simple visual reference to identify the Equivalent Series Resistance (ESR) of a battery. This is a key figure of merit as it represents a loss of the system. The EnergyLab EIS methods, including its innovative FRA-technology and oversampling, allows for characterization of devices of micro-ohm impedance.
For extreme applications that require greater than 5 V or 2 A of current, batteries can be configured in stacks. Since stacks are purposefully designed for operation at high voltages (up to 100 V) or high currents (up to 100 A), external boosters are required. External boosters are available in a wide range of measurement capacities, bandwidth and accuracy to meet a given testing profile. The PMC-2000A and PARSTAT3000A provide the voltage range to test a stack of batteries as well as the standard, additional electrometer to measure the characteristics (including impedance) of a single battery within the stack. The EnergyLab provides multiple electrometers to study even more cells within the stack.
Whatever your requirements in state-of-the-art energy storage and energy conversion applications, AMETEK’s Princeton Applied Research and Solartron Analytical advanced instrumentation provides the tools for market leading impedance analysis, with the widest voltage and current ranges available for anode/cathode and stack testing.