Friday, March 16, 2007

Triaxial Accelerometer operates in high temperatures.

Dytran Instruments, Chatsworth, CA, offers the Model 3023AH High Temperature Triaxial Accelerometer.

Mar 15, 2007
Featuring .36 x .36 in. footprint, miniature Model 3023AH features integral electronics (IEPE) and has 2-10,000 Hz frequency range. Unit is engineered to perform over -60 to +325°F range, making it suited for automotive NVH applications on engines and HASS/HAST chambers or critical flight test applications. Fully welded and hermetically sealed, accelerometer weighs 3 g, has sensitivity of 10 mV/g, and features ¼-28 4-pin connector.

Thomas Net News

Tuesday, March 13, 2007

RFID Gets Help from Fluidic Self-Assembly

Microfluidics is a technology in its infancy, and its potential for manufacturing very small products will certainly attract investment and spark advances. But will it change manufacturing industries in a way similar to the transition from electronics to microelectronics? Fluidic self-assembly itself may lead to smaller and less expensive RFID tags

read more | digg story

Vibration spectrum analysers for diagnostics

Datastick Systems, Inc. — News Release
Michael Scandling, V.P. Marketing.
Phone: (408) 871-3300
Fax: (408) 871-3313

Datastick Systems introduces new-generation handheld Vibration Spectrum Analyzers for machine diagnostics and predictive maintenance

Easy-to-use PDA-based Datastick® VSA-1214 and VSA-1215 Vibration Spectrum Analyzers break down the barriers of cost and training to allow more facilities to reap the cost-saving reliability benefits of vibration analysis in predictive maintenance

Datastick Systems has introduced the VSA-1214 and VSA-1215 Vibration Spectrum analysers, its new-generation PDA-based vibration data collectors and analysers that enable facilities of all sizes to use vibration analysis in machine-condition monitoring, predictive maintenance, and routine troubleshooting to reduce costs and downtime. The announcement was made by Michael Scandling, Vice President of Marketing, at the Datastick Systems, headquarters in Silicon Valley. The pocket-sized system includes the all-new Datastick VSA-1214 or VSA-1215 Vibration spectrum analyser module attached to a state-of-the-art Palm T|X handheld computer with Datastick Spectrum version 1.6 software, which collects vibration measurements and displays and stores them as time waveforms and FFT spectra.

The system also includes the new version 1.6 of Datastick Reporting System (DRS) for VSA, which imports the data from the handheld into a special Microsoft Excel-based application on the PC.

The new products are shipping this week.

'Datastick continues to knock down the barriers that prevent facilities from taking advantage of the cost savings, reduced downtime, and increased reliability that result from vibration analysis as part of predictive maintenance,' said Scandling.

'Starting with price, going on to ease of use, and finally to the big hurdle of lack of in-house vibration expertise in many facilities, Datastick eases the way.

Our entry-level VSA-1214 sells for under $4,000, and operational training is quick and easy.

Most important, customers don't need in-house vibration analysts because our completely open PC software is based on Excel -- they can email their data to the consultant of their choice.' Datastick customer Craig Clark, Manager of Engineering and Maintenance for BBA Fiberweb's Industrial Division said, 'In my opinion, the Datastick VSA handhelds offer the highest capability-to-cost ratio.

Think about it: for less than $5,000, I can avert a $200,000 bearing failure.

In terms of ROI, I can't think of a better investment.' The new system features a new Datastick hardware module with a completely redesigned, extremely low-noise analog input for standard ICP-type accelerometers and velocity sensors, optimised digital circuitry, and a built-in rechargeable lithium-ion battery with proprietary power management circuitry to allow the VSA-1215 to operate and power ICP sensors far beyond an eight-hour shift.

The VSA-1215 system displays and records overall vibration and ISO vibration severity alerts, as well as acceleration waveforms with a resolution of up to 6,400 points (3,200 points for the VSA-1214); and acceleration, velocity, or displacement spectra with up to 3,200 lines of FFT resolution (1,600 FFT lines for the VSA-1214).

User-selectable maximum frequencies range from 20 KHz down to 50 Hz (10 KHz to 50 Hz for the VSA-1214).

The tenth-order hardware antialiasing filter provides an extremely clean signal, while new low-noise electronics and specialized algorithms keep the noise floor so low that velocity signals are useable down to 1 Hz (60 CPM - cycles per minute).

'The VSA-1215 shows low-frequency velocity and displacement peaks that get buried in noise with many other handheld units -- even systems that cost two to four times as much,' said Steve Sabram, Datastick Chief Technology Officer and President.

'Some handheld systems can't go below 10 Hz for velocity and displacement.

The VSA-1215 allows the user to go down to 1 Hz and even below that, if he needs to, so he can actually see what's happening at low frequencies -- especially subharmonics on machines with operating speeds from 1,800 RPM to below 600 RPM.' The new version 1.6 Datastick Spectrum software for the Palm handheld computer takes full advantage of the Palm T|X's bright, high-resolution 320 x 480 pixel full-colour display--the largest display in any non-tablet handheld vibration analyser.

The display can be oriented to either portrait or landscape views to make it easier to see nuances in FFT spectra.

The spectrum, overall vibration, and ISO-based alert levels are all encompassed in one comprehensive view.

Cursor-position readouts show specific values and harmonic orders when the user touches a data point with a finger or the handheld computer's stylus, and the stylus and touch screen can also be used to zoom and pan directly to areas of interest.

Datastick Spectrum version 1.6 allows users to record vibration data directly onto removable Secure Digital (SD) cards that have been inserted into the Palm handheld.

SD cards with capacities of 2 GB and higher are commonly available, and users can use as many cards as they like, so overall storage capacity is unlimited.

Users transfer vibration data to a PC either by using the Palm handheld's pushbutton HotSync feature or by copying the data directly from the SD card.

Datastick Reporting System (DRS) on a Windows PC automatically organizes the information by machine and creates histories so you can analyse the machine behavior over time.

Reports are created with just a mouse click, and since DRS is based on Excel, Datastick users can share data freely across a network or by email.

'The old saying that you can never have 'too much' storage is true, and with the new VSAs and Datastick Spectrum 1.6, we've removed the storage barriers.

Writing data straight to SD cards allows unlimited data storage and protects against accidental data loss.

Now you can set up an inspection route and collect data directly on the card -- it's easy to keep routes organized,' said Penny Melrose, Datastick CEO.

'Now, even small- to mid-sized facilities benefit from the sophisticated predictive maintenance techniques previously afforded only to the larger companies.'

Thursday, March 01, 2007

Relationships between "ball bank indicator" reading, lateral acceleration rates, and vehicular body-roll rates.

Relationships between "ball bank indicator" reading, lateral acceleration rates, and vehicular body-roll rates.

The objective of the current AASHTO criteria for horizontal curve design is to select the radius and super-elevation so that the lateral acceleration perceived by the occupants of vehicles traversing horizontal curves is kept within comfortable limits. It is considered good design practice to provide roadways on which these comfortable lateral acceleration limits are not violated within an appropriate range of speed values. However, because of geometric constraints, some horizontal curves require significant speed reductions to maintain motorists' comfort levels.

The ball bank indicator has been used since the 1930s to measure the speed at which occupants become uncomfortable. Reported in degrees, the reading of the ball bank indicator is the sum of a vehicle's lateral acceleration and the body-roll minus the roadway superelevation. Ball bank indicator readings and lateral acceleration levels are both indicators of safe speed based on vehicle occupants' comfort levels. Both have been used for highway design since first being introduced, although they are related only theoretically.

The criteria for using ball bank indicators have been modified only slightly in the last 50 years, while vehicle technology and societal changes have experienced significant changes. Ball bank indicator readings were correlated with lateral acceleration rates. Additionally, the influence of vehicular body-roll on ball bank indicator readings was investigated. Ball bank indicator readings and lateral acceleration values were found to be highly correlated. The influence of body-roll on ball bank indicator readings appears to be negligible when using typical passenger cars to determine safe speed on horizontal curves.

Supplemental Notes: This paper appears in Transportation Research Record No. 1658, Highway Geometric Design and Operational Effects Issues.
Accession Number: 00769391

Pagination: p. 34-42
Authors: Carlson, P J; Mason Jr, J M
Features: Figures (2); Photos (1); References (12); Tables (5)
Monograph Info: See related components
Corporate Authors: Transportation Research Board;
500 Fifth Street, NW, Washington, DC 20001 USA
Availability: Transportation Research Board Business Office; 500 Fifth Street, NW, Washington, DC 20001 USA
ISBN: 0309070554
Publication Date: 1999
Serial: Transportation Research Record; Issue Number: 1658
Publisher: Transportation Research Board; ISSN: 0361-1981
Index Terms: Aerodynamic features (Vehicle body components); Comfort; Correlation analysis; Highway curves; Highway design; Lateral acceleration; Radius; Speed; Superelevation; Ball bank indicators; Body-roll; Horizontal curves
Subject Areas: H21: FACILITIES DESIGN, 21: Highway and transport planning