li-190sa quantum sensor li-190sa quantum sensor

quantitative lamp measurements for photoresist processes, general
lamp evaluation, quality control, surface color measurements,
photochemistry and photobiology.
INNOVATIVE OPTICS
The measurement optics of the LI-1800 has three major components
— a filter wheel, holographic grating monochromator, and
a silicon detector. The filter wheel contains seven order-sorting
filters which eliminate second order harmonics and enhance
stray light rejection by filtering out radiation that is not in the
same spectral region as that being measured. The filter wheel
also has a black target that serves as a dark reference for each
scan.
The dispersing element is a holographic grating monochromator
which is available in two wavelength ranges; 300-850 nm with a
4 nm bandwidth and 300-1100 nm with a 6 nm bandwidth.
Optional monochromator slits are also available for changing the
bandwidth and sensitivity to meet your application.
The monochromator is driven by a precision stepping motor
under control of the internal microcomputer. Wavelength drive
intervals are user selectable at 1, 2, 5 or 10 nm. The LI-1800’s
high efficiency silicon detector and autoranging electronics
allow scanning rates of over 30 nm per second.
INTERNAL MICROCOMPUTER
The heart of the LI-1800 system is the internal microcomputer
which controls scanning and the collection, reduction and storage
of data. Communication with the LI-1800 is accomplished
using the 1800-01A Portable Terminal or any other RS-232
terminal or computer. The LI-1800 is easy to use, yet powerful.
A menu of simple commands covers all facets of operation from
scanning to data output.
SIMPLIFIED SCANNING
Scanning is accomplished by one command; however, the
LI-1800 lets you specify several parameters to get the scan you
want, including wavelength limits, wavelength drive interval,
and the number of scans to average. Averaging scans provides
accurate data under conditions of fluctuating radiation. Multiple
scan averaging also improves sensitivity (signal to noise ratio) in
low radiation conditions, since it reduces the noise level by a
factor approaching the square root of the number of scans.
After each scan the LI-1800 stores your data in its internal RAM
memory. Standard memory in the LI-1800 is 256K bytes and is
expandable to 512K bytes. The standard 256K memory typically
holds 200 scans from 300-1100 nm (2 nm steps) or 530 scans
from 400-700 nm.
DATA REDUCTION
The LI-1800’s built-in data reduction routines calculate irradiance,
radiance, CIE chromaticity coordinates, illuminance,
luminance, photon flux density, the ratio of spectral irradiance in
two regions of a scan, and more. A data file can also be plotted
on the 6000-03B Plotter/Printer using the LI-1800’s plotting
routine.
SPECIFICATIONS
Holographic Grating Monochromator Options
LI-1800/12 LI-1800/22
Wavelength Range: 300-850 nm 300-1100 nm
Standard Bandwidth
(1/2 mm slits): 4 nm 6 nm
Wavelength Accuracy: ± 1.5 nm ± 2 nm
Wavelength
Repeatability: ± 0.5 nm ± 0.5 nm
Linear Dispersion: 8 nm/mm 12 nm/mm
Grating:
1200 grooves/mm 800 grooves/mm
Automatic
Filter Wheel: 6 filters 7 filters
Noise Equivalent Irradiance
(Standard cosine receptor, W cm -2 nm -1 )
300-850 nm 300-1100 nm
300 nm 6 × 10 -8 7 × 10 -8
350 nm 4 × 10 -8 4 × 10 -8
400 nm 2.5 × 10 -8 1.5 × 10 -8
500-800 nm 8 × 10 -9 8 × 10 -9
800-850 nm 2.5 × 10 -8 —
800-1040 nm — 6 × 10 -9
1100 nm — 1.5 × 10 -8
Noise Equivalent Irradiance
(1800-11 Remote Cosine Receptor, W cm -2 nm -1 )
300-850 nm 300-1100 nm
350 nm 2 × 10 -7 2 × 10 -7
400 nm 1 × 10 -7 7 × 10 -8
500-800 nm 3 × 10 -8 3.5 × 10 -8
800-850 nm 1 × 10 -8 —
800-1040 nm — 3 × 10 -8
1100 nm — 6 × 10 -8
NOTE: NEI is the noise of the instrument detector and amplifier expressed in
terms of the irradiance necessary to generate a detector output of an equivalent
size. NEI values given are for standard 1/2 mm slits. Changing to 1 mm slits
typically increases the sensitivity and reduces the NEI 3 to 4 times. The 1/4 mm
slits decrease the sensitivity and increase the NEI 3 to 4 times.
Maximum Irradiance Levels (W cm -2 nm -1 )
300-400 nm 5 × 10 -3
400-1000 nm > 1 × 10 -3
Maximum irradiance levels are for 1/2 mm slits with standard
teflon cosine receptor and filters.
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