
The 9660 gain factor can be verified using the Monitor Output. However, keep in
mind the Monitor Output signal is reconstructed in the analog time domain and is only
a visual aid to assist with setup and verify operation. The Monitor Output is scaled to 8
volts full scale MCA collection as opposed to 10 volts for most traditional analog
spectroscopy amplifiers. This scale factor (10/8) must be taken into consideration
when verifying the 9660 gain factor.
For example when the 9660 Gain is set as follows:
Coarse Gain: 120
Fine Gain: x0.8337
SF Gain: 0.0000e
-2
• The calculated gain is 120 x 0.8337 = 100.04
• The amplitude of the Monitor Output signal measures 4 volts
• The Input signal measures 0.05 volts.
• The 9660 measured gain (corrected for the 8 volt full scale range) is
4/0.05 x 10/8 = 80 x 1.25 = 100
Chapter 5 - Monitor Output
32
Model 9660-9660A ICB Digital Signal Processor