Changes in Optical
I have been involved in the light or optical
radiation measurement industry for more
than four decades. In the early years, a
major strength was that we continually
provided new, often unique, reliable instruments along with the assurance of
proper stable calibration, based on internal
hardware. We also supplied calibrated
incandescent sources, with and without
special filters, allowing the user to maintain calibration accuracy using an external
The calibration of a photometer, radiometer or colorimeter is fundamentally
the comparison of the output of the instrument system to the characteristics of a
known standard, be it a source or similar
instrument that exhibits a certified characteristic, and then adjusting the instrument
to read the known parameter(s) correctly.
For example, if a calibrated source
with an output of 1000 lx is measured by
an illuminance meter, the meter should
accurately read 1000 lx. If the instrument
doesn’t read the correct value, it must be
adjusted or calibrated. A variety of meth-
ods can accomplish this.
Letters to the Editor
Photonics Spectra welcomes letters from readers who would like to comment on
the publication's content or offer opinions on issues of importance to the photonics
community. Please send comments to firstname.lastname@example.org.
Topics must fall within the publication's scope. Libelous or inflammatory letters
will not be published. Letters will run as space is available and will be edited for
length, grammar and style. Anonymous letters will not be published.