Newport 1936-R series User Manual

Principles of Operation 119 119
Zero Offset
Zero offset is active whenever the Offset annunciator is lit. The zero offset
output is equal to the input value less the zero reference value.
Responsivity Map(s)
This process scales the input value in accordance with current calibration
wavelength and the responsivity map downloaded from the detector
calibration module. The output of this process, i.e. the measurement value, is
the digitized input value divided by the responsivity associated with the
current calibration wavelength or the user defined calibration value. Different
responsivities are used depending upon if the attenuator is on as shown in the
Setup Menu.
Units Correction
Unit’s correction adjusts a measurement value to account for the display units
selected. When the display units are equal to the detector signal units, i.e.
equal to the numerator of the responsivity units, Table 1, the measurement
value is not adjusted. Otherwise the digitized value is adjusted to account for
detector responsivity and/or additional unit conversions such as W-to-W/cm
2
.
NOTE
Per area unit conversions such as W-to-W/cm
2
divide the measurement value by the
active area of the detector. This calculation assumes that the entire active area of
the detector is uniformly illuminated. Per area measurements where the entire
detector active area is not uniformly lit are not accurate. The user must insure that
these conditions are met before utilizing per area units or make measurement
corrections accordingly.
9.4 Typical Detector Signals
The flexibility of the Model 1936/2936 Series analog signal flow is required
in order that it may properly measure the signals that various types of
detectors make.
Basic optical power or energy measurements are related to a measured
detector signal, S, in the following way:


R
S
EorP
Where: R
λ
= Detector responsivity at λ
S = Detector signal
Semiconductor (918D/818 Series Low-Power) detectors provide a current
signal. The 1936/2936 Series is capable of 1pA resolution in order to provide
the highest sensitivity performance with these detectors.

Newport 1936-R series Specifications

General

Brand	Newport
Model	1936-R series
Category	Measuring Instruments
Language	English