Fluke 8062A, Instruction Manual

Page: 88 / 124

8062A
Instruction Manual
4-26
Table 4-7. Troubleshooting the Resistance Function: Voltage Sources
for Ranges
Range
Voltage Source
(
±
10%)
Comment
200
Ω
2 k
Ω
20 k
Ω
200 k
Ω
M
Ω
4.5V
1.2V
1.2V
1.2V
2.1V These values should be obtained when
no external resistors are connected to
the resistance inputs. Measure voltage
between common (J2) and TP10. Note
that the M
Ω
and 200 k
Ω
ranges will be
loaded by a 10 M
Ω
input impedance.
Use a high impedance voltmeter for the
measurement or decrease the voltage
source magnitude appropriately. A DMM
with a 10 M
Ω
input impedance will read
approximately 1.9V in the M
Ω
range.
Table 4-8. U3 (MAC) Pin Descriptions
Pin No. Mnemonic Description
1 Tone 2.66 kHz square wave to tone generator.
2
3
4 CFO
CM+
CM- Output, + input, - input, respectively, of the
continuity function comparator.
5
6
7
VSS
HI
LO
-5.1V supply (externally generated).
Input to the a/d converter.
Sense ground for the a/d converter.
8
9 FC+
FC- Connections to the “flying capacitor” which
stores the reference voltage applied to the a/d
converter during the read period. Plus and
minus signs indicate polarity of stored voltage.
10
11
COM
VREF+
Analog common.
Input for 1V reference voltage for a/d converter
and power supply.