Beckhoff EPP3504-0023 Short Manual page 51

Measurement mode
Input 3-wire
impedance
Differential tbd.
±Input 2
CommonM
ode
Noise (with/ without filtering)/ preliminary data:
Measurement mode
Noise E
Noise, PtP
(without
filtering, at
23°C)
E
Noise, RMS
Max.
SNR
Noiseden
sity@1kH
z
Noise (with E
Noise, PtP
50 Hz FIR
filter, at
23°C)
E
Noise, RMS
Max.
SNR
2
) In real bridge measurement, an offset adjustment is usually carried out after installation. The given offset
specification of the box module is therefore practically irrelevant. Therefore, specification values with and
without offset are given here. In practice, the offset component can be eliminated by the functions Tare and
also Features [} 000] of the box module or in the controller by a higher-level tare function. The offset
deviation of a bridge measurement over time can change, therefore Beckhoff recommends a regular offset
adjustment or careful observation of the change.
3
) Values related to a common mode interference between SGND and internal ground.
4
) The offset specification does not apply to 2-wire operation, since the offset is increased on the device side.
Therefore, a system-side offset adjustment is recommended, see Tare- or ZeroOffset function [} 000]. The
final targeting basic acuuracy within the 2-wire operation is mainingly dependent by the quality of this
system-side offset adjustment.
5
) The channel measures electrically to 8 mV/V, but displays its measured value scaled to 2 or 4 mV/V. The
Compensated function facilitates measurement of low levels even with high offset.
Transition resistances of the connection contacts
The transition resistance values of the connection contacts affect the measurement. The measuring
accuracy can be further increased by a user-side adjustment with the signal connection plugged in.
The temperature sensitivity of the box module and thus of the measurement setup can be reduced if an
external, more temperature-stable supplementary resistor is used for operation of the box module in half-
bridge or even full-bridge mode instead of the internal supplementary resistor for quarter-bridge mode.
EPP3504-0023
StrainGauge/SG 1/4-bridge 1 kΩ 2/3-wire
32 mV/V 8 mV/V
No usage of this input in this mode
tbd.
tbd. tbd.
StrainGauge/SG 1/4-bridge 1 kΩ 2/3-wire
32 mV/V 8 mV/V
< 350.0 ppm < 820.0 ppm
FSV
< 2734 digits < 6406 digits
< 11.2 µV/V < 6.56 µV/V
< 70.0 ppm < 140.0 ppm
FSV
< 547 digits < 1094 digits
< 2.24 µV/V < 1.12 µV/V
> 83.1 dB > 77.1 dB
< 0.03 < 0.02
< 85.0 ppm < 48.0 ppm
FSV
< 664 digits < 375 digits
< 2.72 µV/V < 0.38 µV/V
< 14.0 ppm < 8.0 ppm
FSV
< 109 digits < 63 digits
< 0.45 µV/V < 0.06 µV/V
> 97.1 dB > 101.9 dB
4 mV/V (comp.)
tbd.
tbd.
4 mV/V (comp.)
< 1640.0 ppm
FSV
< 12813 digits
< 6.56 µV/V
< 280.0 ppm
FSV
< 2188 digits
< 1.12 µV/V
> 71.1 dB
< 0.02
< 96.0 ppm
FSV
< 750 digits
< 0.38 µV/V
< 16.0 ppm
FSV
< 125 digits
< 0.06 µV/V
> 95.9 dB
NOTE
Version: 1.2
Product overview
5)
2 mV/V (comp.)
tbd.
tbd.
5)
2 mV/V (comp.)
< 3280.0 ppm
FSV FSV
< 25625 digits
< 6.56 µV/V
< 560.0 ppm
FSV FSV
< 4375 digits
< 1.12 µV/V
> 65.0 dB
< 0.02
< 192.0 ppm
FSV FSV
< 1500 digits
< 0.38 µV/V
< 32.0 ppm
FSV FSV
< 250 digits
< 0.06 µV/V
> 89.9 dB
5)
5)
51