54
Version 4.2 rev 06 Oct 2020
8.2 x 8.2 mm / 512 x 512 sensor
Lowest Noise Imaging EMCCD
Mechelle
4.11.1 e
FFect
oF
a
Mbient
t
eMpeRatuRe
on
tHe
R
elative
e
FFiciency
c
oRRection
When the ambient temperature changes, the refractive index of the prisms will change which result in a shift of the
orders in the vertical direction, i.e. the light of a certain wavelength will fall on a different pixel on the sensor. Since there
is a small variation between the response of pixels, therefore the relative efficiency correction will not be valid and the
corrected signal should look like that shown below:
Figure 26: Effect of the temperature change on relative efficiency corrected signal
NOTE: If the ambient temperature is changed by ±3ºC, the Relative Efficiency Correction will not be valid and the
corrected signal will look similar to the above, but the wavelength calibration will remain accurate.
4.11.2 R
elative
e
FFiciency
c
oRRection
WitH
s
ub
-s
pectRuM
To carry out the relative efficiency correction with sub-spectrum, the following procedure must be carried out:
1. Firstly, take a full spectrum as described previously.
2. Click the
button to select the wavelength range required and click update.
3. Close the wavelength selector window.
4. Click
and carry out the
Relative Efficiency Correction Procedure
.
NOTES:
1. Do not take a scan between selecting the wavelength range and relative efficiency procedure. If you do, the
button will not be active, i.e.
2. If the wavelength range is changed, the following message will be displayed:
The
REC
procedure must then be repeated. The software will also change the acquisition settings to
Full Image
for the
next acquisition only to prepare for Relative Efficiency procedure. Just click the
button and carry out the procedure
again.
3. If the sub-spectrum set is between 400 - 975 nm, only a QTH Standard lamp is needed, so the deuterium
lamp is not necessary
