PCIe/PXIe-6301 Series |
| 9
Internally, the ADC operates at the single conversion rate per each bank. For multiple
channels in the same bank, the sample rates are further reduced. For example, if you
chose 800S/s sample rate, the driver software will automatically select level 5 for you.
Your measurement accuracy will be determined by Level 5. For accuracies at different
levels, please refer to Table 6.
Resistance Measurement Accuracy
PCIe/PXIe-6301 measures RTD resistance. It has built-in filters to improve the
measurement accuracy.
The accuracy is defined by:
Accuracy = Gain Error (% of reading)
+ Offset Error (mΩ).
The single point resistance measurement accuracy is shown in Table 4. The offset error
has included 6 times of noise error for that level. The ADC level is chosen by the driver
software, it corresponds to internal ADC conversion rate. This information is important
for you if you want to further improve the accuracy by averaging the acquired
resistance values. At level 0, ADC already works at 2.3Hz, most system noise is being
removed already. Please refer to 2.4.
Table 4 Resistance Measurement Accuracy
JY6301 Accuracy = ±(Gain Error % + Offset Error mΩ)
Temperature
ADC Level
Internal
ADC Rate
(Hz)
Full Scale
Accuracy
@ 100Ω
(2,3-wires)
Full Scale
Accuracy @
100Ω(4-
wires)
Tcal±5
℃
Level 0
2.3
0.0462
+
25.9
0.0462 +
25.3
30.5 mΩ
30.0 mΩ
Tcal±5
℃
Level 1
5.1
0.0462
+
26.2
0.0462 +
25.5
30.8 mΩ
30.1 mΩ
Tcal±5
℃
Level 2
26.5
0.0462
+
26.8
0.0462 +
26.3
31.4 mΩ
30.9 mΩ
Tcal±5
℃
Level 3
41.0
0.0462
+
26.8
0.0462 +
26.6
31.5 mΩ
31.2 mΩ
Tcal±5
℃
Level 4
410.0
0.0462
+
31.1
0.0462 +
30.2
35.7 mΩ
34.8 mΩ
Tcal±5
℃
Level 5
830.0
0.0462
+
56.3
0.0462 +
44.6
60.9 mΩ
49.2 mΩ
Tcal=25
℃
typical.
Add 0.0160% to the gain, 20mΩ to the offset for temperatures outside Tcal±5
℃
Offset error contains 3σ,σ is the noise error.
2, 3-wires
4-wires
