Earthquake and T&M Equipment - Page 1
Forum section: electronics / testgear

author: nadona
author_rank: Regular Contributor
timestamp: March 30, 2014, 06:52:26 am
content: Earthquakeshttp://earthquaketrack.com/r/greater-los-angeles-area-california/recentare keep hitting my home, originated from 3~10 miles away.Last night I was working with some ratio equipments. Here's what happened right after 5.1 magnitude.First picture shows all 3 meters not affected in zero check mode at 10uV range. Second picture shows all 3 affected in operation mode. Left side Keithley 155 is battery operated meter.Most of the null-meters whether turned on or not were affected and some rack-mount DMMs, also.Hard to believe.

author: SeanB
author_rank: Super Contributor
timestamp: March 30, 2014, 07:14:28 am
content: Time to get some really good shock mounts then, or move to an area with less likelihood of dropping off into the ocean.

author: GreyWoolfe
author_rank: Unknown
timestamp: March 30, 2014, 12:42:31 pm
content: +1, salt water is really corrosive and will mess up the calibration of the equipment.

author: nctnico
author_rank: Super Contributor
timestamp: March 30, 2014, 01:01:08 pm
content: 5.1? That should shake things up.Many years ago I was involved in a project to use computers and instruments in a car. We used the coiled steel wire shock mounts as shown in this picture:http://electronicdesign.com/site-files/electronicdesign.com/files/archive/electronicdesign.com/files/31/33078/figure_02.jpg

author: HighVoltage
author_rank: Super Contributor
timestamp: March 30, 2014, 02:36:05 pm
content: Quote from: GreyWoolfe on March 30, 2014, 12:42:31 pmI lived in California for a while and had the same problem. My first office was close to the ocean and we had to recalibrate our instruments more often than I was used to.I was working in a lab in Los Angeles, during the Northridge quake in 1994.Everything was mounted "earthquake safe" on the walls.Well, we learned that whatever was done to protect the instruments was not enough.Several heavier scopes and other equipment got damaged during the quake.

author: nadona
author_rank: Regular Contributor
timestamp: March 30, 2014, 09:06:29 pm
content: After reading SeanB's response, I found thishttp://www.amazon.com/dp/B002FHNCLK/ref=wl_it_dp_o_pC_nS_ttl?_encoding=UTF8&colid=3LIORJO5PVNM4&coliid=I289AEM2PKROK3But it seems likeQuote from: HighVoltage on March 30, 2014, 02:36:05 pm

author: Lightages
author_rank: Unknown
timestamp: March 30, 2014, 11:52:57 pm
content: After living through many "earthquakes"here in Chile (they call anything under 7 a "tremblor" instead of a "terremoto") I really am beginning the question the Richter scale being applied equally around the world. The strongest I have felt here was a 6.5 and it was entertaining but caused zero damage here and absolutely no concern. Just last week we had a 5.5 fairly close and it was a few shakes and a being on the ocean feeling for a minute. There is no way what I experienced here so far could damage anything other than things that might fall from a shelf.There is no way any rack mounted equipment could have been damaged with a 5.1 here. I really wonder.....

author: romantronixlab
author_rank: Regular Contributor
timestamp: March 31, 2014, 12:01:34 am
content: Quote from: Lightages on March 30, 2014, 11:52:57 pmtemblor = tremorterremoto = earthquakeJust for those who wonder what do that mean.

author: nadona
author_rank: Regular Contributor
timestamp: March 31, 2014, 01:22:39 am
content: Quote from: nadona on March 30, 2014, 06:52:26 amQuote from: Lightages on March 30, 2014, 11:52:57 pm

author: IanB
author_rank: Super Contributor
timestamp: March 31, 2014, 01:56:45 am
content: Quote from: Lightages on March 30, 2014, 11:52:57 pmFunnily enough, they called the thing that happened here in California a tremblor too. Perhaps the word has been adopted into the English language?But in fact a single number on the Richter scale does not tell the whole story. It measures power on a logarithmic scale, but it says nothing about what form that power takes. For instance it conveys no information about the frequency content of the vibrations, whether the vibrations are compression waves or lateral waves, nor whether they are horizontal or vertical, nor information about the peak acceleration felt, nor information about local ground conditions (whether soft and sandy or hard and rocky), etc.Earthquakes or tremors are typically felt much less if the ground underfoot is rock rather than sand or sediment (which can locally magnify the vibrations).Perhaps you live on rocky terrain? (In which case you are fortunate.)

author: edavid
author_rank: Super Contributor
timestamp: March 31, 2014, 02:14:33 am
content: Quote from: IanB on March 31, 2014, 01:56:45 amThe word is temblor, in both (Latin American) Spanish and (American) English. Yes, it comes from Spanish.

author: chickenHeadKnob
author_rank: Super Contributor
timestamp: March 31, 2014, 02:24:52 am
content: Hello Nadona,When I heard about that quake and its location I thought about you. I also live on the pacific rim and we are due a magnitude 9. Like many I have been too lazy to really secure my shelves of stuff in the proper way, and I have stacks of gear ontop of one another.@Lightages: To confirm what IanB says consider the Christchurch NZ, quake of 2011. It had very strong vertical movement but lower total energy (relative richter) of 6.3 or something.links:http://www.gns.cri.nz/Home/News-and-Events/Media-Releases/Multiple-factorshttp://en.wikipedia.org/wiki/2011_Christchurch_earthquakeI know my stuff and house are going straight to hell when the big one hits.

author: IanB
author_rank: Super Contributor
timestamp: March 31, 2014, 02:46:38 am
content: Quote from: edavid on March 31, 2014, 02:14:33 amI have to say we would use the word tremor in Britain. I never heard the word tremblor before coming to the USA.

author: Lightages
author_rank: Unknown
timestamp: March 31, 2014, 03:54:49 am
content: Yes I meant to write "temblor" but I made a typo and didn't notice.

author: jpb
author_rank: Super Contributor
timestamp: March 31, 2014, 03:23:19 pm
content: Fujitsu built a chip fabrication plant in Newton Aycliffe in the north of England (it was subsequently sold to Filtronic and then RFMD).The relevance of this is that the plant was built to be earthquake proof - despite the fact that we never get serious earthquakes in the UK (we get all excited and it makes the news head lines if we have a level 1 that is noticed by someone somewhere).But Fujitsu had the policy of making all their plants earthquake proof regardless of where they were built (probably why it cost so much and they had to sell it - that and the bottom falling out of the DRAM market).