2645A Four-Wire Resistance Measurement Specifications; 2645A Two-Wire Resistance Measurement Specifications - Fluke 2640A Service Manual

2645A Four-Wire Resistance Measurement Specifications

Tables 1-34 to 1-36 provide 2645A specifications for the four-wire resistance
measurement function. The four-wire measurements use 2 input channels a decade apart,
e.g., channels 4 and 14.
Table 1-34. 2645A Four-Wire Resistance Temperature Coefficient
Specification
Temperature
Coefficient
Table 1-35. 2645A Four-Wire Resistance Range and Resolution Specifications
Resolution
Range
Slow
300Ω 10 mΩ 30 mΩ
3 kΩ 100 mΩ 300 mΩ
30 kΩ 1Ω 3Ω
300 kΩ 10Ω 30Ω
3 MΩ 100Ω 300Ω
Table 1-36. 2645A Four-Wire Resistance Accuracy Specifications
Range
90 Day
Slow
300Ω .02%+60 mΩ .02%+.1Ω
3 kΩ .02%+.6Ω .02%+2Ω
30 kΩ .02%+6Ω .2%+200Ω
300 kΩ .5%+80Ω 1%+2 kΩ
3 MΩ 1.3%+1 kΩ 2%+120 kΩ

2645A Two-Wire Resistance Measurement Specifications

The 2645A specifications for the two-wire resistance measurement function is based on
the four-wire resistance measurement specification (above) except you add a 700 to 1000
ohm positive offset. This value varies for each channel and temperature gradient
(nominal +1%/ºC).
Add 1/10th the 90 day specification per °C above 28°C or below 18°C.
Current
Applied
Fast
1 mA 300 mV
100 µA
300 mV
10 µA
300 mV
10 µA
3.0V
1 µA
3.0V
Accuracy, 3σ + (% input + Ω)
18°C to 28°C
1 Year
Fast Slow
.02%+.1Ω
.02%+1Ω
.02%+10Ω
.5%+150Ω
1.3%+2 kΩ
Introduction and Specification
Characteristic
Full Scale Maximum Voltage
Voltage Applied by Instrument
3.5V
3.5V
3.5V
3.5V
3.5V
-10°C to 60°C
1 Year
Fast Slow
.02%+.2Ω .084%+.25Ω
.02%+3Ω .084%+2.5Ω
.2%+300Ω .084%+25Ω
1%+3 kΩ 2.1%+336Ω
2%+200 kΩ 5.46%+4.2 kΩ
Specifications
1-32.
Fast
.084%+.42Ω
.084%+8.4Ω
.84%+840Ω
4.2%+8.4 kΩ
8.4%+200 kΩ
1-33.
1
1-23