Service manual

Typical Results
Channel HI (OHMS) LO (OHMS) GU (OHMS)
0
1
2
3
4
5
6
7
90
8
9
10
11
12
13
14
15
91
92
0.51
0.49
0.48
0.42
0.52
0.52
0.49
0.46
0.49
0.47
0.51
0.43
0.45
0.50
0.48
0.52
0.43
0.44
0.50
0.35
0.31
0.41
0.39
0.41
0.35
0.40
0.36
0.40
0.35
0.36
0.33
0.39
0.41
0.41
0.36
0.41
0.38
0.40
0.61
0.59
0.57
0.61
0.55
0.59
0.60
0.54
0.55
0.60
0.61
0.55
0.58
0.60
0.55
0.54
0.51
0.55
0.61
Test 2-2: DC Isolation Test
This test verifies that sufficient DC isolation exists at various points on the
multiplexer. DC Isolation is checked from HI to Chassis, HI to LO, and HI
to GU (GUARD). This test uses the test fixture (see Figure 2-1).
NOTE
The DMM used should be capable of measuring at least 1 GΩ. If the DMM
indicates an overload, record the reading as >Rmax, where Rmax is the
highest resistance that the DMM can measure. For example, if the DMM is
an 3458A, a typical return for an overload is 1.E+38 and the entry in Table
2-2 should be >1.2 GΩ.
Chapter 2 Verification Tests 33