2640a 4-wire resistance measurement specifications, A-12 – Fluke NetDAQ 2645A User Manual
Page 222

2640A/2645A NetDAQ
Users Manual
A-12
2640A 4-Wire Resistance Measurement Specifications
A-15.
Tables A-15 to A-17 provide 2640A specifications for the 4-wire resistance
measurement function. The 4-wire measurements use 2 input channels a decade
apart, e.g., channels 4 and 14.
Table A-15. 2640A 4-Wire Resistance Temperature Coefficient
Specification
Characteristic
Temperature Coefficient
Add 1/10th the 90 day specification per
º
C
above 28
º
C or below 18
º
C.
Accuracy at -20
°
C
Multiply the -10
°
C to + 60
°
C accuracy
specification by 2. After 1 hour warmup. For
accuracy between -10
°
C and -20
°
C, interpolate
linearly
.
Table A-16. 2640A 4-Wire Resistance Range and Resolution Specifications
Resolution
Current
Full Scale
Maximum voltage
Range
Slow
Fast
Applied
Voltage
applied by instrument
300
Ω
1 m
Ω
3 m
Ω
1 mA
300 mV
3.5V
3 k
Ω
10 m
Ω
30 m
Ω
100 µA
300 mV
3.5V
30 k
Ω
100 m
Ω
300 m
Ω
10 µA
300 mV
3.5V
300 k
Ω
1
Ω
3
Ω
10 µA
3.0V
3.5V
3 M
Ω
10
Ω
30
Ω
1 µA
3.0V
3.5V
Table A-17. 2640A 4-Wire Resistance Accuracy Specifications
Accuracy, 3
σ
+ (% input + V)
18
º
C to 28
º
C
-10
º
C to 60
º
C
Range
90 Day
1 Year
1 Year
Slow
Fast
Slow
Fast
Slow
Fast
300
Ω
.015%+20 m
Ω
.02%+80 m
Ω
.02%+50 m
Ω
.02%+120 m
Ω
.084%+126 m
Ω
.084%+336 m
Ω
3k
Ω
.02%+.3
Ω
.02%+.8
Ω
.02%+.5
Ω
.02%+1.2
Ω
.084%+1.26
Ω
.084%+3.36
Ω
30 k
Ω
.03%+3
Ω
.04%+10
Ω
.03%+5
Ω
.04%+15
Ω
.126%+12.6
Ω
.168%+42
Ω
300 k
Ω
.1%+40
Ω
. 2%+100
Ω
.1%+60
Ω
.2%+150
Ω
.42%+168
Ω
.84%+420
Ω
3 M
Ω
*
.25%+800
Ω
*
.5%+10k
Ω
*
.25%+1 k
Ω
*
.5%+1.5k
Ω
*
1.05%+3.36
Ω
2.1%+4.2 k
Ω
*
* The 3 M
Ω
range is susceptible to the absorption of humidity under extreme conditions. If the instrument is
operated normally within its specified temperature-humidity range, the 3 M
Ω
range meets its accuracy
specifications. However, if the instrument is “soaked” at 50
°
C, 90% RH the 3M
Ω
range may require 1 hour
of “dry-out” time at 25
°
C, <40% RH for each hour of “soak” time in order to achieve its specified accuracy.