8062A
Instruction Manual
3-10
DC
AC
Common
A
Inputs
to A/D
Converter
True RMS
AC
Converter
Current
Shunt
LO
HI
dy29f.eps
Figure 3-5. Current Measurement
3-8. Resistance
Measurement
Resistance measurements are made using a ratio technique as shown in
Figure 3-6. When the resistance function is selected, a series circuit is
formed by the ohms source, a reference resistor from the voltage divider
(selected by the range switches), and the external unknown resistor. The ratio
of the two resistors is equal to the ratio of the voltage drop across each of
them. Since the voltage drop across the reference resistor and the value of the
reference resistor are known, the value of the second resistor can be
determined. Input protection during resistance measurements consists of a
thermistor and a double-transistor clamp.
The operation of the a/d converter during a resistance measurement is
basically as described earlier in this chapter, with a few exceptions. During
the integrate period the voltage drop across the unknown resistor charges the
INTEG capacitor. During the read period, the voltage across the known
resistor (stored on the flying capacitor) discharges the INTEG capacitor. The
length of the read period is a direct indication of the value of the unknown
resistor.
Summary of Contents for 8062A
Page 4: ......
Page 8: ...8062A Instruction Manual iv...
Page 10: ...8062A Instruction Manual vi...
Page 14: ...8062A Instruction Manual 1 2...
Page 24: ...8062A Instruction Manual 2 2...
Page 50: ...8062A Instruction Manual 2 28...
Page 52: ...8062A Instruction Manual 3 2...
Page 62: ...8062A Instruction Manual 3 12...
Page 64: ...8062A Instruction Manual 4 2...
Page 90: ...8062A Instruction Manual 4 28...
Page 92: ...8062A Instruction Manual 5 2...
Page 102: ...8062A Instruction Manual 5 12 8062A 4031 iv39c eps Figure 5 2 A1 Main PCB Assembly...
Page 106: ...8062A Instruction Manual 6 2...
Page 108: ...8062A Instruction Manual 6 4 dy55c eps Figure 6 1 Accessories...
Page 118: ...8062A Instruction Manual 7 2...
Page 122: ...8062A Instruction Manual 7 6...
Page 123: ...8062A Instruction Manual 7 7 8062A 1201 iu46c eps Figure 7 5 A1 Main PCB Schmatic Diagram...
Page 124: ...8062A Instruction Manual 7 8 8060A 1003 iu61f eps Figure 7 6 A3 RMS PCB Schmatic Diagram...