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Delayline Detector DLD4040 Manual
DLD4040 R2.55 & R3.54 Manual | Surface Concept GmbH
4.1.2 Dark Count Rate Measurement
• Check the detector output by means of your end-user software (e.g. GUI software) after ramping to the
operation voltage (the use of the rate meter where available is recommended).
• The dark count rate without any source should be as given in the specification sheet.
• Accumulate the dark counts for several minutes (e.g. 15 minutes). The DLD image should appear
homogeneous and sharply bounded. See
for an example (your specific DLD image can differ
in size, shape and segmentation).
Example:
Assume the following operation voltage for “MCP-B”: +1800V and “U_DLD”: +400V. “MCP-F” is
terminated to GROUND. First ramp “U_DLD”: to +400V, then a ramp time of approx. 5 min. should be used
to increase “”MCP-B” and U_DLD” parallel to +1800V and +2200V (“MCP-B” + 400V) respectively..
The analogue readout electronics have been adjusted to optimized detector voltages.
The starting operation voltages are given in the specification sheet of the detector.
Please note that one cannot compensate a voltage lower than the specified operation
voltages by increasing the intensity to the detector. This will only lead to complete false
measurement results.
Figure 4: Example for DLD image of accumulated dark
counts.
