At least theorically speaking, who measures is supposed to know what
is the nature of the parameter is checking like if he had to built his own
meter.
Nowadays it's extremely rare the case were a laboratory builts an instrument
because nearly everything already exist, and because any instrument has to
be qualified to the existing standards to be professionally utilized.
Practically speaking, qualified precision instruments are made and sold
by known manufacturers who produce and guarantee the precision of
specific or multi specific instruments, able to give direct discrete values
or to show and process for viewing, even complex signals forms.
Then:
To measure Peak, RMS, Average, etc. current it's best to utilize a proper
(AC, DC, RF etc.) and periodically calibrated current meter.
To measure Peak, RMS, Average, etc. voltages it's best to utilize a proper
(AC, DC, RF etc.) and periodically calibrated voltage meter.
To measure Peak, RMS, Average, etc. power it's best to utilize a proper
(AC, DC, RF etc.) and periodically calibrated power meter.
Etc, etc.
To evaluate and measure events and some parameters on a time base,
an instrument like a calibrated oscilloscope is proper.
To evaluate and measure events and some parameters on a frequency
domain, something like a calibrated Spectrum Analyzer is proper.
To evaluate and measure other events and some parameters on a time
domain basis, something like a calibrated time domain Network Analyzer
is proper.
Etc, etc.
All the above, doesn't limit a good technician having theorical basis
and the knowdlege of inherent limitations of instrumentation to make
measurements using some other instrument (indirect measures), but
generally, also that person uses a dedicated instrument whose read
values are straight and accepted as good ones and later "go" to the
work sheets togheter the type of used instruments and the technician
sign, in order to guarantee the measures accuracy.
73,
Mauri I4JMY
E-mail: i4jmy@iol.it
--
FAQ on WWW: http://www.contesting.com/ampfaq.html
Submissions: amps@contesting.com
Administrative requests: amps-REQUEST@contesting.com
Problems: owner-amps@contesting.com
Search: http://www.contesting.com/km9p/search.htm
|