Product category:
Testing, analysing and monitoring equipment
News Release from: Lambda Photometrics | Subject: Portable digital vibrometer
Edited by the Engineeringtalk Editorial
Team on 03 December 2001
World Trade Center monitored by digital
vibrometer
Polytec's new portable digital vibrometer was used to monitor the stability of World Trade Center Building 4 during the recovery effort at "ground zero".
Polytec's new portable digital vibrometer was used to monitor the stability of World Trade Center Building 4 during the recovery effort at "ground zero" Workers were concerned that heavy-duty equipment being used to remove debris would cause the building to collapse
This article was originally published on Engineeringtalk on 25 Feb 2000 at 8.00am (UK)
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Professor Jim Sabatier working for the Army on sabbatical leave from the National Center for Physical Acoustics at the University of Mississippi, was flown to the disaster site in a helicopter when it was determined that traditional surveying instruments were generating false alarms and unnecessary interruptions in the recovery effort.
The vibrometer continuously monitored vibrational modes of the building between 1.4 and 11 Hz from a distance of about 50 meters, measuring from columns and trusses between 3 m and 20 m above the ground.
After observing these modes for several hours the first night, Dr Sabatier indicated to the (Federal Emergency Management Agency) FEMA engineers that he thought Building 4 was stable.
Monitoring continued for several days in an attempt to provide an early warning to the rescue workers of any impending danger.
Dr Sabatier took turns working 12-hour shifts with two engineers from the US Army CECOM Night Vision and Electronics Sensors Directorate (NVL) located at Fort Belvoir Virginia.
• Polytec recently introduced the PDV-100, the world's first portable laser Doppler vibrometer with digital signal processing.
It is robust, compact and affordable.
The entire vibrometer including 5-hour battery pack, charger and carrying case weighs less than 5 kg.
Digital processing in the PDV-100 ensures high resolution and a direct digital connection with a PC sound blaster board enables ultra-low cost FFT processing.
Analog output via a 24 bit DAC is also provided.
A single enclosure houses the entire vibrometer - laser, interferometer optics and electronics. Request a free brochure from Lambda Photometrics ...
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