Random control is a fundamental vibration testing for various industries and manufacturers of products. The FFT based control algorithm transforms time signals to the frequency domain where analysis, calculation, comparison…average, (etc.) are done. The performance of Random control is determined by how well the FFT describes the system characteristics. Proper spectrum resolution must be chosen in order to avoid missing any desirable observations and to meet the requirement of the control performance.
Read moreModal Shaker Testing Using Periodic Random Excitation
Modal shaker testing is widely used for experimental modal analysis and to acquire frequency response functions. Either single or multiple modal shakers can be used. The type of excitation used may influence the quality of the testing result and frequency response functions.
Although sinusoidal types of excitation signals are occasionally used for modal shaker testing, these tests are typically performed using broadband random type excitation signals. Among these common excitation types, Pure Random is widely used. The Hanning window is generally applied to alleviate leakage caused by the non-periodic signal.
Another popular excitation type is the Burst Random excitation signal. It gained so much popularity because no window function is required. The requirement is to have the burst length selected so that the response decays enough at the end of each time block data. With this constraint, there will not be any leakage in the measurement and a windowing function is not required.
Two somewhat arbitrary types of excitation signals are Pseudo Random and Periodic Random. The characteristics of these two signal types will be discussed in detail here. The results of using these excitation types will be compared to the more popular Pure Random and Burst Random types. It will be shown that the cost of additional testing time is well worth the superior estimation of MIMO FRF signals.
Read moreVibration Institute’s Annual Training Conference 2017 - Rochester, NY
The Vibration Institute’s Annual Training Conference is often referred to as offering ‘second to none’ education in vibration analytics and is considered the place to be for vibration and condition monitoring experts. As such, it has also become an excellent networking opportunity for industry elites, manufacturers, and incoming young professionals. With today’s ever accelerating changes in technology, beyond networking, it is also crucial to stay up to date on vibration analysis techniques with the most capable and usable equipment.
Read moreCenter of Operation and Monitoring of 12 or More Shaker Systems with API
Manufacturing plants often require controlled vibrations on various parts of the plant to run for several hours, days, or even weeks at a time. In some cases, continuous operation is required.
At these facilities, the affordable down time is limited to a few hours in a week. The continuous controlling and monitoring of independently running systems is another significant challenge.
Read moreMounting Strain Gage on UUT
Applying strain gages for measurement may sound daring, but it’s a lot simpler than it sounds. In this article, we will focus on key points of strain gage placement technique. It is important that the strain gage performs well and gives an accurate reading. This means the attachment point must be performed correctly to receive good results. As a result, the strain gage setup process requires a precise and correct following of directions. Crystal Instruments’ Spider-80SG is capable of calibrating and resetting measurement values prior to taking measurement. This is a standard step for all strain measurements to eliminate any offset before measurement starts.
Read morePost Process Data Acquired and GPS-stamped by the CoCo-80X
There are often instances where it may be beneficial to add location information to your acquired data. With the CoCo-80X, these GPS signals can be acquired simultaneously with other measurements -- there is no need to carry a separate GPS device. The CoCo-80X’s large LCD and touch-screen interface makes it easy to use the analyzer and acquire data. All measurements are combined into a single test file, so there’s no need to manage files.
Read moreYou have ten fingers, but that doesn’t mean the input range has to be 10 volts!
I’ve always wondered why some instruments in the market set their hardware input range to 10 V. Perhaps the hardware designer for these instruments possessed ten fingers and chose 10 V out of convenience. I can imagine their bosses eagerly approving the use of 10 V as well, because they too have ten fingers!
Read moreEDM Modal Operates on Spider System with Hundreds of Channels
EDM Modal is a complete Modal Testing and Modal Analysis suite for Experimental Modal Analysis (EMA). It works on the verified Spider hardware systems, ranging from several channels up to hundreds of channels. EDM Modal is developed based upon the sophisticated technologies of modern modal analysis theory and technique. With its intuitive controls and powerful features, EDM Modal is the ultimate tool for modal analysis applications.
Read moreSynchronous Data Acquisition Across A Large Structure or Space
Synchronizing Spider-20Es to a High Channel Count System
Dynamic data acquisition and machine monitoring in factories and plants often require data to be acquired synchronously at various parts of the plant or a factory. Some big machines, especially in the aerospace industry also require data to be acquired at different areas synchronously.
Breakout Box Terminal Guide for Strain Gage Measurement on Spider-80SG
A. Introduction
Strain gages setup on our Spider-80SG is one of the most common questions we received. The Spider-80SG is designed to be used with strain gages; wonderfully, software interface is still within the same easy-to-use and intuitive platform of our EDM software. The connection to Spider-80SG breakout box is the final piece of the puzzle and it is a lot simpler than it looks.
SAE Noise-Con 2017, Sponsored & Attended by Crystal Instruments
What does an automotive engineer, electric engineer, and an airline acoustics engineer have in common? They all had the amazing idea to attend the Crystal-Instruments-sponsored 2017 SAE Noise and Vibration Conference and Exhibition in Grand Rapids, Michigan in June 2017.
Read moreCoCo-80 No. 26. and the 2017 Crystal Instruments Catalog
I recently received a returned CoCo-80 unit from a customer located in India. This customer decided to upgrade their unit to the newer CoCo-80X model. The returned CoCo-80 unit was manufactured and shipped in 2007. This particular unit that was returned to us was the 26th CoCo-80 unit that Crystal Instruments produced.
Read moreVirgin Orbit uses Crystal Instruments' Spider-80X for Shock Response Analysis
Shock Response Spectrum (SRS) Analysis is one of the most often-used methods in Shock and pyro-shock analysis. Recently, Virgin Orbit, a newly formed company under Virgin Groups that target at advanced small satellite business, started to use Crystal Instruments’ Spider-80X to acquire the shock vibration and SRS analysis.
Read moreSentek Dynamics ‐ Crystal Instruments and Small Satellites
The phrase “Good things come in small packages” is true! Small satellites, also known as CubeSats, are being launched at a record pace with the successful February 15, 2017 launch of 104 satellites of which 88 were Planet Labs’ Dove satellites collectively known as Flock‐3p, aboard an Indian Space Research Organization (ISRO) Polar Satellite Launch Vehicle (PSLV) rocket from the Satish Dhawan Space Center in Sriharikota, India. This amazing launch followed the successful June 22, 2016 launch of 12 Planet Labs’ Flock‐2p satellites from the Satish Dhawan Space Center. These spacecraft are shoebox‐sized satellites placed into lower Earth orbit to provide imaging data.
Read moreFemaris SRL - New Crystal Instruments Distributor in Romania
December 2016 - Crystal Instruments extends a warm welcome to the Femaris SRL team, the newest member of Crystal Instruments' growing network of international distributors. Femaris will be offering dynamic signal analysis solutions, vibration control systems, and vibration data collectors in Romania, Eastern Europe.
Read moreSpaceX Orders Multiple Vibration Controller Systems from Crystal Instruments
Crystal Instruments Corporation recently received a large order from SpaceX for multiple high channel count vibration control systems. Each vibration control system will be bundled with advanced application software. This is thus far the biggest contract awarded to Crystal Instruments by SpaceX. During the procurement process, SpaceX engineers conducted detailed reviews of products from Crystal Instruments and compared those with options from several different providers. The final decision made was based on the availability of functions, actual testing performance, and the capability of onsite support.
Read moreNASA’s Johnson Space Center selects Crystal Instruments’ High Channel Spider-80X Data Acquisition System for Environmental Testing of the James Webb Space Telescope
Crystal Instruments has received the impressive honor of supplying a 64 channel data acquisition system, the Spider-80X, for testing of NASA’s James Webb Space Telescope project.
Read moreNew Video: Time Waveform Replication
In addition to the three major test types of Sine, Random and Shock, Crystal Instruments also offers Time Waveform replication, or TWR. This is a method to exactly recreate, or replicate, a vibration in its time waveform format on a shaker system. The data is typically taken from a field environment. The data is typically taken from a field environment. TWR allows engineers to accurately reproduce the data collected in the field.
For more details about Time Waveform Replication Testing: https://www.crystalinstruments.com/time-waveform-replication
Shock Control by Crystal Instruments
Like other types of vibration tests, shock tests, are used to measure the reliability and durability of the object under test. Classical Shock Control provides precise, real-time, multi-channel control and analysis of a transient motion in the time domain. Classical pulse shapes include half-sine, haversine, terminal-peak sawtooth, initial-peak saw tooth, triangle, rectangle, and trapezoid. The recording option records time stream data at the full sample rate for all input channels. Shock response spectrum (SRS) analysis can be applied to any input signal; optionally control of the DUT’s SRS may be executed. Applicable Test Standards include MIL-STD-810F, MIL-STD-202F, ISO 9568 and IEC 60068 (plus user-defined specifications).
For more details about Classic Shock Control: https://www.crystalinstruments.com/classic-shock-control
To learn more about Crystal Instruments' vibration controllers: https://www.crystalinstruments.com/vibration-test-controller
To learn more about Crystal Instruments' vibration control software: https://www.crystalinstruments.com/environmental-testing
New Video: Random Testing with Vibration Controllers
New video from Crystal Instruments featuring Random Testing with Vibration Controllers. Random excitation is widely used to simulate real-world vibration because it reflects motion that cannot be precisely predicted and may be subjected to a number of environmental variables.
For more details about Random Control: https://www.crystalinstruments.com/random-control
To learn more about Crystal Instruments' vibration controllers: https://www.crystalinstruments.com/vibration-test-controller
To learn more about Crystal Instruments' vibration control software: https://www.crystalinstruments.com/environmental-testing