Stereo Scan 440 - DCU

4. Select SCM Image from the Specimen Current panel or from the
Status! menu, set Brightness to 50% and adjust Contrast until an
image is seen. Then adjust Brightness and Contrast to obtain the
required image.
At low probe currents i.e. on SCM ranges lower than loA full scale, the image
can become degraded by mains field effects and other forms of interference. Also,
on these ranges, the signal bandwidth is very low. The use of long scan times will
overcome the bandwidth restrictions and will also help to reduce interference
effects, but image quality may not be perfect under these conditions.
Measure Mode
Because of the way in which the SCM is configured, selecting Measure mode
increases the Image mode signal level. If you wish to measure the specimen
current in a displayed specimen image, Freeze the image before proceeding.
Select SCM Measure from the Specimen Current panel or from the
Status! menu.
2. The specimen current measured will be displayed beside the Specimen I
legend in the Specimen Current panel or in the Status! menu.
3. To measure the current at one particular point on the specimen, select
Spot from the Scanning menu, click on the cross and drag it to the point
of interest.
Specification
Measurement mode
Measurement Range
Bandwidth
Resolution
Accuracy
Residual Error
lOpA to l00~ in 12 ranges (auto ranging)
5Hz
IpA
:t 2% of Full Scale
< IOpA
Image Mode
Image Range (Full)
Image Range (Useful) *
Bandwidth
3pA to IOJiA in 13 ranges (selected by Contrast)
InA to IOJiA
6kHz to 2MHz (see Table on next page)
Stereoscan 440 Operator Manual