OL 462 Automated High- Intensity Integrating Sphere Calibration Standard0 pages

Bulletin 119 / Rev. 5-07
OL Series 462
Automated Integrating Sphere Calibration Standard
GENERAL
The OL Series 462 Automated Integrating Sphere
Calibration Standard is designed for accurately calibrating
instruments such as microphotometers, telephotometers,
image intensifiers, and imaging spectroradiometers for
photometric, radiometric, or spectroradiometric response. It
serves as a highly accurate, large area, uniform, diffusely
radiating source with a near normal luminance that can be
varied over 6 decades with essentially constant color
temperature.
The OL Series 462 consists of an Optics Head and a
separate microprocessor controlled luminance display/
lamp power supply/motor controller console (OL 462-C
Controller). This enables remote location of either unit,
which facilitates alignment or positioning of the source with
respect to the device to be calibrated. The source module/
optics head is designed such that it can be configured with
integrating spheres having diameters of 4, 6, 8, 12, and 18
inches with exit (radiating) ports of 1, 1½, 2, 3, and 6 inches,
respectively.
OPTICS HEAD
The Optics Head has a 150-W tungsten-halogen,
reflectorized lamp with a motorized, computer-controlled
variable aperture between the lamp and the entrance port of
the integrating sphere. This combination provides for
continuous adjustment of the sphere luminance over a
range of more than 106. A precision silicon detector/ filter
combination with an accurate photopic response is mounted
in the sphere wall and monitors the sphere luminance. The
in-line sphere port concept with an intermediate spider baffle
provides exceptional high luminance levels while
maintaining high uniformity in the near normal luminance
across the radiating aperture.
A motorized, computer-controlled shutter is located
between the lamp and the entrance port of the integrating
sphere. The uminance/ radiance output can be switched
between zero and any desired level without adjustment or
lamp changes.
An optional filter holder, mounted at the exit port,
accommodates alignment targets, filters, de-coupling
diffusers etc. for specific user requirements. Spectral
shaping filters can be utilized to simulate various sources
such as illuminates A, B, C, D65, etc. In addition to
luminance and color temperature, the OL Series 462 can
be obtained with calibrations for spectral radiance over all
or part of the 350 to 2500 nm wavelength range.
CONTROLLER
The microprocessor-based OL 462 Controller performs all
the system interface and monitoring functions. An
automatic ramp up/ down function eliminates potentially
dangerous current surges to the lamp. Luminance, color
temperature, lamp current, and operational prompts are
displayed on a 2 line by 20 character alphanumeric vacuumfluorescent
display. A 20 key keypad, rotary encoder knob,
and main system power switch are also located on the front
panel for easy access to all system functions. Luminance is
displayed with 5 digit resolution in units specified by the
user. As an option, the display can be factory programmed
to read in virtually any pertinent units the user desires. DC
current supplied to the lamp has a 0.001 ampere resolution
with a6 0.05% uncertainty. The Controller computes the color
temperature of the source and displays lamp current or color
temperature over the range of 2000 to 3000K. The
luminance, color temperature, and lamp current can also be
set by an external computer via the standard RS-232C
interface. RS-422 and GPIB (IEEE-488) interfaces are also
available. An internal microprocessor controlled elapsed
time meter enables the user to keep track of the number of
hours the lamp has been in operation.