Effective resolution, Effective resolution -6 – Rockwell Automation 1746-NR8 SLC 500 RTD/Resistance Input Module User Manual User Manual
Page 42
Publication 1746-UM003A-EN-P
3-6 Preliminary Operating Considerations
Effective Resolution
The effective resolution for an input channel depends upon the filter frequency
selected for that channel. The following table displays the effective resolution
for the various input types and filter frequencies:
Table 3.2 Effective Resolution for RTD and Resistance Inputs
Input Type
Filter Frequency
28 Hz
50/60 Hz
800 Hz
6400 Hz
100
Ω
Pt RTD (385)
(1)
± 0.1°C
(± 0.1°F)
± 0.1°C
(± 0.1°F)
± 0.2°C
(± 0.4°F)
± 0.8°C
(± 1.4°F)
200
Ω
Pt RTD (385)
± 0.1°C
(± 0.1°F)
± 0.1°C
(± 0.1°F)
± 0.2°C
(± 0.4°F)
± 0.8°C
(± 1.4°F)
500
Ω
Pt RTD (385)
± 0.1°C
(± 0.1°F)
± 0.1°C
(± 0.1°F)
± 0.2°C
(± 0.4°F)
± 0.8°C
(± 1.4°F)
1000
Ω
Pt RTD (385)
± 0.1°C
(± 0.1°F)
± 0.1°C
(± 0.1°F)
± 0.2°C
(± 0.4°F)
± 0.8°C
(± 1.4°F)
100
Ω
Pt RTD (3916)
± 0.1°C
(± 0.1°F)
± 0.1°C
(± 0.1°F)
± 0.2°C
(± 0.4°F)
± 0.8°C
(± 1.4°F)
200
Ω
Pt RTD (3916)
± 0.1°C
(± 0.1°F)
± 0.1°C
(± 0.1°F)
± 0.2°C
(± 0.4°F)
± 0.8°C
(± 1.4°F)
500
Ω
Pt RTD (3916)
± 0.1°C
(± 0.1°F)
± 0.1°C
(± 0.1°F)
± 0.2°C
(± 0.4°F)
± 0.8°C
(± 1.4°F)
1000
Ω
Pt RTD (3916)
± 0.1°C
(± 0.1°F)
± 0.1°C
(± 0.1°F)
± 0.2°C
(± 0.4°F)
± 0.8°C
(± 1.4°F)
10
Ω
Cu RTD (426)
(1) (2)
± 0.1°C
(± 0.1°F)
± 0.1°C
(± 0.2°F)
± 0.4°C
(± 0.7°F)
± 1.0°C
(± 1.8°F)
120
Ω
Ni RTD (618)
(3)
± 0.1°C
(± 0.1°F)
± 0.1°C
(± 0.1°F)
± 0.1°C
(± 0.1°F)
± 0.3°C
(± 0.5°F)
120
Ω
Ni RTD (672)
± 0.1°C
(± 0.1°F)
± 0.1°C
(± 0.1°F)
± 0.1°C
(± 0.1°F)
± 0.3°C
(± 0.5°F)
604
Ω
NiFe RTD (518)
± 0.1°C
(± 0.1°F)
± 0.1°C
(± 0.1°F)
± 0.1°C
(± 0.1°F)
± 0.3°C
(± 0.5°F)
150
Ω
Resistance Input ± 0.01
Ω
± 0.01
Ω
± 0.02
Ω
± 0.08
Ω
500
Ω
Resistance Input ± 0.1
Ω
± 0.1
Ω
± 0.1
Ω
± 0.4
Ω
1000
Ω
Resistance Input ± 0.1
Ω
± 0.1
Ω
± 0.2
Ω
± 0.6
Ω
3000
Ω
Resistance Input ± 0.1
Ω
± 0.1
Ω
± 0.3
Ω
± 1.0
Ω
(1) The digits following the RTD type represent the temperature coefficient of resistance (
α
), which is defined as
the resistance change per ohm per °C. For instance, Platinum 385 refers to a platinum RTD with
α
= 0.00385
ohms/ohm -°C or simply 0.00385 /°C.
(2) Actual value at 0°C is 9.042
Ω
per SAMA standard RC21-4-1966.
(3) Actual value at 0°C is 100
Ω
per DIN standard.