CPT Gauge Calibration
CPT Gauge Calibration
(OP)
What time intervals do most calibrate the guages for CPT (or Piezo-cone)? 6 months? 12 months?
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RE: CPT Gauge Calibration
Interesting question . I looked into the technical brichure of Gouda and Van den Berg, they don't say anything about frequency of calibration. CPT test is covered by an ASTM standard ( I don't work with it ). I have an old 1979 version of ASTM D3441 where they don't even talk about calibration ( they call for +/- 5% accuracy ).
I would say it's important to carry out one calibration before using the machine ( some parts can be exchanged in 100 and 200 KN heads from Gouda for example and can lead to results 4 times greater than reality ! ). If your tests are carried out in soft soils, i don't believe you need another calibration except if you change parts in the head ( mechanical ) or change the electric cone. If you are working in ranges close to the maximum capacity of the rig, or in case the head or the cones have been hit, it would be necessary to check again.
RE: CPT Gauge Calibration
If you're referring to calibration of the instruments, and not "zero readings" (or baseline readings) which should be performed before and after every sounding, actual calibration frequency should probably depend primarily on frequency of use, and care/maintenance by the operator. I believe there is some guidance in the ASTM Standard (D 5778) as well as the International Reference Test Procedures (I believe established by ISSMGE TC16). The SGI also authored a report specifically on CPTu calibration - I think it came out around 1990, but cannot recall the report number.
FYI, all, a great free reference on the CPT (SCPT, SCPTu, etc etc) is the NCHRP Synthesis 368, which can be found at:
http://onl
Also, I just returned from the Second International Conference on the CPT (CPT '10 - http://www.cpt10.com/) and I understand that the organizers intend to fully publish the conference proceedings free on-line (eventually). Watch for that...
And if you haven't checked out Paul Mayne's website, you're missing out on a wealth of free informations:
http:
RE: CPT Gauge Calibration
RE: CPT Gauge Calibration
However for the contractor,it is commonly 1.5 years.
RE: CPT Gauge Calibration
RE: CPT Gauge Calibration