The common temperature probe contains a thermocouple consisting of two dissimilar metals welded together to form an electrical junction. A voltage that varies with temperature is generated. Slightly less accurate than resistance temperature detectors (RTDs), thermocouples cover a wide temperature range and respond quickly. Combinations of different metals create different voltage responses. All dissimilar […]
Lasers and how to measure their output
Laser is an acronym for light amplification by stimulated emission of radiation. Lasers, of course, started out as comprised of discrete components. The most basic laser consists of a cylinder containing the lasing medium, a material that emits light when exposed to an outside source of energy. The gain medium can be gas, liquid, solid […]
Finding fiber-optic cable anomalies
Optical fiber is a form of waveguide. The lateral dimension of a waveguide depends upon the wavelength of the signal conveyed. A waveguide is not capable of carrying a wavelength much larger than its diameter. Optical fibers are characterized by their core diameters. In single-mode fiber, the standard core diameter is 9 μm. Standard multi-mode […]
Understanding electro-optic modulation
The electro-optic modulator is used to modulate a beam of light. Laser-controlled modulators are capable of operating in the gigahertz range, and modulation may be imposed on the amplitude, phase, or polarization of the beam. The component that makes this possible incorporates an element that exhibits an electro-optic effect, a change in its optical properties […]
Understanding and measuring optoelectronic oscillators
The problem with even a high-end electronic oscillator–such as a quartz crystal oscillator, dielectric resonator, sapphire resonator or air dielectric resonator–is that as the output frequency rises, excessive phase noise also rises. Optoelectronic oscillators are not subject to this and other dysfunctional high-frequency characteristics, and consequently they are suitable in certain exacting 21st century applications […]
Getting familiar with work-at-home instrumentation
The rise in social distancing has fostered a need for professional-grade test instruments that function as well at home as in the lab. David Horn | Digilent The events that have unfolded across the world since the beginning of 2020 have turned the global marketplace upside down. Few industries have felt this seismic shift as […]
Work-at-home tools: PC-based instruments address demanding applications
Advanced technology now lets budget-priced instrumentation handle tasks once requiring specialized and pricey test gear. Trevor Smith | Pico Technology Test & Measurement With a significant segment of engineers and researchers working at home or away from their lab during the pandemic, there is a large incentive to troubleshoot designs and validate performance using systems […]
Monitoring heart rate variability for better athletic ability
Sensors and sophisticated algorithms together deliver check heart-rate variability and other exercise metrics. Alisher Kholmatov, Recep Ozgun Micros, Security & Software Business Unit, Maxim Integrated From weekend warriors to professional athletes, most people who engage in regular sports activity take note of various factors that influence their performance. Some meticulously track certain metrics from game […]
Basics of monitoring vs. testing in current, voltage and power
Industrial measurements often must take place via specialized transducers sized specifically for the current and voltage swings involved. Will Delsman | NK Technologies Older ammeters worked great when the current flowed at a steady 50 or 60 Hz. Consider the antique GE model 8AK1A1AF. I have one that remains accurate after decades of use and […]
Capabilities of modern data recorders
Fast sampling rates and long recording times make data recorders useful for documenting signal qualities that ordinary test equipment can easily miss. Jamie Pederson | B&K Precision Corp. Data recording instruments have a long history that dates back to the 1800s when Charles Babbage incorporated an instrument into a rail car to record over a […]
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