White Papers

Determining an Effective Analog Sampling Rate

Q: How often should my equipment make measurements? A: This question often arises when people draft plans to automatically measure a physical quantity such as temperature, pressure, acidity, liquid level, and so on. You can approach this problem in several ways, from an educated guess to a mathematical analysis of your system. The examples that follow use temperature measurements because people measure temperature more than any other physical characteristic.

Posted in: Electronics & Computers, White Papers

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Analog Signal Conditioning for Accurate Measurements

By Jon Titus Q: Should I put some sort of circuit between my sensor and an analog-to-digital converter? A:Yes. You probably need some signal conditioning. The explanation below goes on for a bit, but stay with it and you'll understand what you need and why you need it. Before you make any connections, get the electrical specifications for the analog-to-digital converter (ADC) and for the sensor or sensors in your system. Let's assume the data-acquisition module uses a Maxim Integrated Products MAX197 12-bit ADC. This device can accept eight differential (2-wire) inputs or 16 single-ended (1-wire) inputs. Maxim's specifications show an input impedance of 21 kohms for single-ended inputs and 16 kohms for differential inputs.

Posted in: Test & Measurement, White Papers

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Differential Nonlinearity in Analog Measurements

By: Jon Titus, Sealevel Systems, Inc. Q: In a previous answer you noted, "... most applications require linearity but not absolute precision..." What does that mean?

Posted in: Test & Measurement, White Papers, Briefs

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Piezo Motors Power MRI Robot

Surgeons treating brain cancer face a conundrum: They can capture ultra-high-resolution images of the tumor using magnetic resonance imaging (MRI) or they can use ultra-precise surgical tools to remove the tumor, but they can’t do both at the same time. At least they couldn’t prior to the creation of the innovative MRI robot from the Worchester Polytechnic Institute team.

Posted in: Medical, White Papers, MDB

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Wire Springs versus Machined Springs A Comparison

The first question generally asked about Machined Springs is how they compare with Wire Wound Springs. Commencing with this question, this review of Machined Springs will proceed. Wire Springs appeared early in the Industrial Revolution. They established their value immediately, and have not wavered from that most useful course. Certainly, enhancements in materials and manufacturing have been forthcoming, but the basic concept has not changed much. Spring wire coiled hot or cold with ends configured within the limits of coil wire has proven to be a very cost effective, industrial tool that exhibits elasticity within the bounds of known, engineering understanding. Uses range from deep ocean applications to man's reach into the universe. Finding a modern day device large or small, that does not benefit from elasticity, and particularly that provided by Wire Wound Springs, is a rare find.

Posted in: Mechanical Components, White Papers

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Engaging stakeholders in the home medical device market

The Growing Home Medical Device Market – How Could It Impact Med Tech Stakeholders? 90% of patients prefer digital technology tools (such as mobile apps) over medication, per an October 2013 survey by Digitas Health. And, Semico Research's Aging in Place: The Internet of Things for the Golden Years forecasts that the home medical device market will reach $30 billion in revenues by 2017. Gain expert insight into engaging stakeholders of the growing home medical device market - including implications for manufacturers, intended device uses, end users, safety and essential performance, transformation requirements, mobile apps + more.

Posted in: Medical, White Papers

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Piezo Engineering Tutorial

1.0 The Direct and Inverse Piezoelectric Effect In 1880, while performing experiments with tourmaline, quartz, topaz, cane sugar and Rochelle salt crystals, Pierre and Jacques Curie discovered that when mechanical stress was applied to a crystal, faint electric charges developed on the surface of that crystal. The prefix “piezo” comes from the Greek piezein, which means to squeeze or press. As a result, piezoelectricity is electrical charge that is produced on certain materials when that material is subjected to an applied mechanical stress or pressure. This is known as the direct piezoelectric effect.

Posted in: Mechanical Components, White Papers

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