8500C/8500C+ System Maintenance Manual D-1
Appendix D. 8520CS Signal Selector
D.1 Introduction
The 8520CS Signal Selector is similar to the 8520C Signal Selector referenced in Section 4, but it has
inputs for 8 Velocimeter channels, rather than 12 channels. The 8520CS also has the following input
channels: 4 balanced differential output Accelerometers, 2 Magnetic Pickups and 2 Photocells
compatible with the Chadwick-Helmuth 10200 Photoprobe. The following sections highlight the
differences between the 8520CS and 8520C in the areas of physical description, theory of operation,
and testing. Disassembly/reassembly instructions and a parts list are also included.
D.2 Leading Particulars
Table D-1. 8520CS Signal Selector (Only)
Input Power
Velocimeter signal input levels
Input Impedance
Accelerometer (balanced differential output)
- Frequency Response:
Magnetic pickup signal inputs
Photocell input:
Dimensions:
Weight
28VDC
8 Channels, 0 to 7.125Vpk
100K (unselected channel), 2.5K (selected)
4 Channels, 10-150 pC/g (programmable)
+/-2% 14Hz to 20kHz
-5% at 8Hz (nominal)
-12% at 5Hz (nominal)
2 channels, 0.5Vpk to 12Vpk
2 channels, compatible with Chadwick-
Helmuth’s high speed Photocell Probe 10200
(ref Manual 10473-1)
7.1 x 10.81 w x 4.01 h in.
4.5 lbs