70
Apr-09
Avantes
www.avantes.com
the optimal smoothing without losing resolution. If resolution is not an important issue, a higher
smoothing parameter can be set to decrease noise against the price of less resolution.
Slit or
Fiber
AvaSpec-102
Pixel 77 µm
AvaSpec-128
Pixel 63.5
µm
AvaSpec-256
AvaSpec-1024
Pixel 25 µm
AvaSpec-2048
AvaSpec-2048x14
Pixel 14 µm
AvaSpec-3648
Pixel 8 µm
AvaSpec-
NIR256
Pixel 50 µm
10µm
n.a.
n.a.
n.a.
0
0
n.a.
25µm
n.a.
n.a.
0
0-1
1
n.a.
50µm
0
0
0-1
1-2
2-3
0
100µm
0-1
0-1
1-2
3
5-6
0-1
200µm
1
1
3-4
6-7
12
1-2
400µm
2
2-3
7-8
13-14
24-25
3-4
500µm
3
3-4
9-10
17
31
4-5
600µm
3-4
4
11-12
21
37
5-6
Setup Menu: Use 16bit ADC in 14bit mode (only USB2 platform, HW rev 1D and later)
The 14bit AD Converter used with the as5216 boards revision 1B and 1C inside the AvaSpec-USB2 has
been replaced by a 16bit ADC since the release of the as5216 board revision 1D. Therefore, the
default range in Scope Mode for an AvaSpec-USB2 has changed from a 14bit range (0..16383) to 16bit
(0..65535).
If the menu option “Use 16bit ADC in 14bit mode” is enabled (preceded by a checkmark), the 16bit
range AD Counts will be converted to a 14bit range by the as5216.dll (divide by 4.0). This option has
been added for customers who have been already working with earlier versions of the AvaSpec-USB2
with 14bit ADC, and want to be able to compare the data in scope mode between both
spectrometers. Note that by setting the 16bit ADC into 14bit mode, you will not loose resolution
because the numbers are not truncated or rounded to integer numbers, e.g. 5 counts in 16bit mode
will become 1.25 counts in 14-bit mode.
If multiple AvaSpec-USB2 spectrometers are connected simultaneously and one or more devices
don‟t support the 16bit ADC (rev 1B or rev 1C as5216 board), all spectrometers will be set
automatically into 14bit mode (range 0..16383 AD counts).
Setup Menu: Correct for Dynamic Dark (AvaSpec-2048/3648 only)
The pixels of the CCD detector (AvaSpec-2048/3648/2048x14) are thermally sensitive, which causes
a small dark current, even without light exposure. To get an approximation of this dark current, the
signal of the first 14 optical black pixels of the CCD-detector can be taken and subtracted from the
raw scope data. This will happen if the correct for dynamic dark option is enabled. As these 14
pixels have the same thermal behavior as the active pixels, the correction is dynamic.
Note that this option is different from the dark current that needs to be saved before any
transmittance or absorbance measurements can be taken (File-Save Dark). If the correct for dynamic
