PR electronics 4225 - Page 13

4225V100-UK 13
Accuracy, the greater of basic and absolute values:
Input
Type Basic accuracy Absolute accuracy Temperature coecient
Frequency input ≤ 0.0002 Hz ≤ ±0.01% of input frequency ≤ ±0.0005% / °C
Output
Type Basic accuracy Absolute accuracy Temperature coecient
Current output 8 µA ≤ ±0.05% of span ≤ ±0.005% / 0.8 µA / °C
Voltage output 2 mV ≤ ±0.05% of span ≤ ±0.005% / 200 µV / °C
Frequency output n.a. ≤ ±0.002% of output frequency
+0.0004% of f
max.
≤ ±0.0005% / °C
EMC - immunity influence. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . < ±0.5% of span
Extended EMC immunity:
NAMUR NE 21, A criterion, burst . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . < ±1% of span
of span = of selected standard range
In case of digital readout of measurement value, e.g. via Modbus communication enabler interface, the input accuracy can be
calculated as in example 1.
Basic accuracy
Input
= 0.0002 Hz
Absolute accuracy
Input
= 0.001%
Calibration temperature
= 20...28°C
Example 1: Digital readout via Modbus, input low 200 Hz, input high 800 Hz:
Accuracy
Input_low
= 0.01% x 200 Hz = 0.02 Hz
Accuracy
Input_high
= 0.01% x 800 Hz = 0.08 Hz
Choose the greater of Basic accuracy
Input
= 0.0002 Hz and Accuracy
Input_low / high
= 0.02 Hz / 0.08 Hz
Accuracy
Input_low / high
= 0.02 Hz / 0.08 Hz
Example 2: Analog current output, input low 1 kHz, input high 8 kHz, output span 4...20 mA = 16 mA:
Accuracy
Input_low
= 0.01% x 1000 Hz = 0.1 Hz
Accuracy
Input_high
= 0.01% x 8000 Hz = 0.8 Hz
Accuracy
Output
= 0.05% x 7000 Hz = 3.5 Hz
Total accuracy
Low
= Accuracy
Input_low
+ Accuracy
Output
Total accuracy
Low
= 0.1 Hz + 3.5 Hz = 3.6 Hz
Total accuracy
High
= Accuracy
Input_high
+ Accuracy
Output
Total accuracy
High
= 0.8 Hz + 3.5 Hz = 4.3 Hz
Example accuracy calculations are based on factory calibration ambient temperature, and do not take into account other
potential sources of inaccuracy, e.g. power supply eect, ambient temperature fluctuation etc. which must also be considered.