MOGlabs MWM, Manual, Page: 37 / 96

4.8 Status bar
29
4.8 Status bar
The status bar shows secondary information including the measured air
device temperature and air pressure, the serial number, and the communi-
cations channel including
IP
address and port number if communicating by
TCP/IP
, or the
USB
port number. There is also the ability to change sensor
row used for acquisiton of spectra.
Status
A colour indicator shows green when the main peak is properly acquired,
red otherwise, indicating the displayed wavelength is not valid.
Focus
The focus button will open a new window showing the sensor area around
the current peak (typically 160 x 160 pixels), to allow convenient optimisa-
tion of the focus (see calibration in the next chapter). It can also be useful
for finding the optimum pixel row (see below). The row number should be
adjusted until the laser spot is at the centre of the focus window.
To centre the diffracted spot in the focus window, put the cursor as close as
possible to the spot and click with the
left
mouse button. The row number
will be changed such that the location of the cursor becomes centred. If
the spot is off the focus window, click as close as possible (e.g. top or
bottom of the focus window) and repeat until the spot becomes visible.
Note that the row number is not recorded on the device: the next time
mogwave
is started it will start at the row number saved in the device
EEPROM
. To set the current row as the device default, click the
right
mouse
button anywhere in the focus window.
Warning: changing the default row on the device will affect the calibration.
Recalibration is recommended.
Ctrl-focus
Hold the Ctrl key down, and click on Focus, to open a very wide but not
very high focus window. This is useful for adjusting the diffractive optical
element for different wavelengths (see calibration chapter).
Row
The imaging sensor has many pixel rows. At the factory, the
MWM
is
aligned and focussed and the optimal sensor row is determined and saved
in the device
EEPROM
.