Caveat Emptor, Let the Buyer Beware
Seismic Accelerographs are very expensive. A single unit will easily cost you an average of well over and about a million pesos (Philippine Currency), more or less, certainly much more than the price of some quality brand-new cars. Prices range from a little less than a million pesos to around 2 million pesos for a single unit depending on the brand and supplier that you will be dealing with. But why so expensive? Is it worth the usefulness of the device? Only the suppliers can answer these most commonly asked questions and the best that buyers can do is to thoroughly require them to provide you with clear and satisfactory answers.
With so much cost involved in purchasing seismic accelerographs, one must be fully equipped with utmost care and purchasing knowledge as this equipment will be installed in the very structures that you will be spending a lot of your working time in, supposedly, with your safety and the structural health in mind. Diligence in the entire procurement process is a must. Mistakes can be very costly in the long run. Hands-on supervision in the entire procurement process is irreplaceable to ensure everything falls rightly into place. In my honest opinion, this is not something to be passed on to subordinates as the nature and purpose of the purchase truly requires top-level decision making and close monitoring.
This blog was specifically written primarily to properly guide, inform and protect the buying entities into making wise and logical decisions and have their money’s full worth in whatever brand of seismic accelerograph that they will prefer to buy. The decision will and always rests solely on the buyer.
The truth is, very few people are aware of what seismic accelerographs are. It is not some common commodity that we can regularly see in malls, hardware and even online shopping sites, thus can easily be inspected and inquired upon. It is as strange an equipment as anything can be that even some of the most experienced engineers have not had the first-hand experience of physically seeing one or are at least close to being familiar with the technical aspects, specifications and functions of the equipment.
What Are Seismic Accelerographs?
The Department of Public Works and Highways and Seismic Accelerograph suppliers often refer to their products as earthquake recording instruments (ERI). Their specific and main function supposedly revolves around Structural Health Monitoring according to most product suppliers. It is along this line that their marketing campaign has been directed to and is the usual description that they are passing on to their clients.
However, one can have a good insight to the nature of seismic accelerographs looking at the manner it is aptly described and defined according to the DEFINITION OF TERMS AND ACRONYMS of the GUIDELINES AND IMPLEMENTING RULES ON EARTHQUAKE RECORDING INSTRUMENTATION FOR BUILDINGSissued by the Department of Public Works and Highways (DPWH):
“SEISMIC ACCELEROGRAPH. Accelerograph that records the acceleration of particles on the surface of the earth as a function of time, which is called an accelerogram. The accelerograph generally records three (3) mutually perpendicular components of motion in the vertical and two (2) orthogonal horizontal directions.”
“ACCELERATION. The rate at which the velocity of a particle with time as recorded by seismic accelerograph (expressed in Gal or cm/sec squared).”
“TRI-AXIAL. The characteristics of an accelerometer to provide ground shaking sensing in three (3) dimensions commonly known as x, y, z (i.e., transverse, longitudinal, and vertical).”
Readers are presumed to be aware of the DPWH requirement on the installation of Earthquake Recording Instruments (ERI) as it will not be separately discussed on this blog.
All upcoming and future posts will strictly be based on the “contents” of the GUIDELINES AND IMPLEMENTING RULES ON EARTHQUAKE RECORDING INSTRUMENTATION FOR BUILDINGS issued by the Department of Public Works and Highways (DPWH).
You may drop an email at seismicphils@gmail.com if you wish to request for a free full copy of the DPWH IRR and will gladly send it to you in PDF format. Please include your name, company and designation so can be properly addressed back.
