PASCO SE-7183 Spectrometer - Manual (Page 8)

6
A BOUT THE SPECTROMETER PROPERTIES
Integration Time
Integration time is analogous to the shutter speed of a camera. With a higher the
integration time, the spectrometer is more sensitive to lower light levels. For
typical applications, adjust the integration time so that the greatest light
intensity that you anticipate registers as an Intensity measurement of about
85%.
Wavelength
This property determines the wavelength (in nm) that will be measured in time
acquisition mode. For instance, if you wanted to measure the absorbance of
yellow light, you would set the wavelength to about 575 nm.
Bandwidth
Bandwidth specifies the range of wavelength that will be measured in time
acquisition mode. The Bandwidth value is equal to the number of pixels on
either side of the pixel specified by the Wavelength parameter. Therefore, the
total number of pixels that will contribute to a measurement equals
"Bandwidth" × 2 + 1.
Average
This property specifies the number of discrete acquisitions that SPARK collects
and averages before displaying and recording a spectrum or data point. A higher
the value results in a better the signal-to-noise ratio. The signal-to-noise ratio
will improve by the square root of the number of scans averaged.
Boxcar
This parameter sets the boxcar smoothing width. Boxcar smoothing averages
groups of adjacent pixels. For example, if the value is 5, SPARK averages each
pixel with 5 pixels to its left and 5 pixels to its right (a total of 11 pixels). The
greater this value, the smoother the data and the higher the signal-to-noise ratio;
however, high values also cause a loss of spectral resolution. The signal-to-noise
ratio will improve by the square root of the number of pixels averaged.
Save Reference
Selecting this property causes SPARK to save a reference spectrum, which it will
use in the calculation of the Absorbance, Transmission, and Relative Irradiance
measurements.