Temperature is a widely measured real-world physical variable, but achieving credible results is harder than it seems, even for a simple device such as a kitchen oven. While many temperature-related measurements require high accuracy, precision, and repeatability – let’s say, to better than 1⁰C – many others do not, yet still bring challenges. Consider the […]
The challenge of temperature measurement and sensor calibration, Part 2
Temperature is a widely measured real-world physical variable, but achieving credible results is harder than it seems, even for a simple device such as a kitchen oven. What is temperature, anyway? While we all “know” intuitively what temperature is, actually defining and calibrating its readings is a complicated discussion. A fundamentalist approach is to go […]
The challenge of temperature measurement and sensor calibration, Part 1
Temperature is a widely measured real-world physical variable, but achieving credible results is harder than it seems, even for a simple device such as a kitchen oven. Calibration of a sensor and its associated electronics channel before making critical measurements or monitoring system performance is a common requirement in many situations. In some cases, it’s […]
Basics of motion-control profiles, Part 3: Implementations
How a motor ramps its angular position or rotational velocity from a starting point to the intended target value is a complicated topic which modern motor controllers address in many ways. Part 2 of this article looked at the basic ramping trajectories of the motion-control system. This final part briefly explores some standard motion-control ICs […]
Basics of motion-control profiles, Part 2: Ramp profiles
How a motor ramps its angular position or rotational velocity from a starting point to the intended target value is a complicated topic which modern motor controllers address in many ways. Part 1 was an introduction to issues related to motor and motion control. This part will focus on the topic of motor ramping and […]
Basics of motion-control profiles, Part 1: Context
How a motor ramps its angular position or rotational velocity from a starting point to the intended target value is a complicated topic which modern motor controllers address in many ways. Controlling the motion of a motor is a major design challenge since how a well a possible motor choice can ramp its speed and […]
Understanding the lock-in amplifier, Part 2: The homodyne solution
The lock-in amplifier allows tiny signals from sensors to be captured with precision despite unavoidable noise limitations and other test and measurement challenges of the signal chain. Part 1 of this article looked at the changes of capturing low-level signals such as from a photodetector despite unavoidable signal-path noise, drift, offsets, and other imperfections. This […]
Understanding the lock-in amplifier, Part 1: The sensing challenge
The lock-in amplifier allows tiny signals from sensors to be captured with precision despite unavoidable noise limitations and other signal-chain test and measurement challenges. There are some basic test and measurement instruments common to scientific labs and engineering benches of all types, whether electronic, biomedical, chemical, optical, or mechanical. Among these are the digital voltmeter, […]
Lissajous figures: From math to measurement to art, Part 3
Parts 1 and 2 looked at the equations, history, and technical role of Lissajous figures. This final part will look at their use in graphics and art. One widely known use was in the opening sequence of award-winning legendary TV series The Outer Limits (1963 to 1965) with its classic voice-over audio “Do not attempt […]
Lissajous figures: From math to measurement to art, Part 2
The Lissajous figures of Part 1 were interesting but of little apparent practical use, but that is not the case. Until the availability of high-accuracy instrumentation for frequency measurement, Lissajous figures served a major role in frequency measurement and assessment. How so? Today, if you want to measure the resonant frequency of a crystal used […]
