Measurement SG 1/1 bridge (full bridge) 4/6-wire connection

To determine the measuring error:

The nominal/technical measuring range is specified in "mV/V"; the maximum permitted supply voltage is 5 V.

The maximum nominal measuring range that can be used for the bridge voltage is therefore
±32 mV/V ⋅ 5V = ±160 mV; the internal circuits are configured accordingly.

The internal measurement is ratiometric, i.e. the feed voltage and the bridge voltage are not measured absolutely, but as a ratio.

The integrated supply can be used as power supply. An external supply is permitted, as long as 5 V is not exceeded.

The transition resistance values of the terminal contacts affect the measurement. The measuring error can be reduced further through compensation by the user, with active signal connection.

Full bridge calculation:

Measurement SG 1/1 bridge (full bridge) 4/6-wire connection 1:

The strain relationship (µStrain, µε) is as follows:

Measurement SG 1/1 bridge (full bridge) 4/6-wire connection 2:

Note: specifications apply for 2.5 V SG excitation.

Measurement mode		SG 1/1 bridge
Measuring range, nominal		-32…+32 mV/V
Measuring range, end value (full scale value)		32 mV/V
Measuring range, technically usable		-34.359…+34.359 mV/V
PDO resolution		24 bit (including sign)
PDO LSB (Extended Range)		4.096 nV/V
PDO LSB (Legacy Range)		3.814.. nV/V
Basic accuracy: Measuring deviation at 23°C, with averaging (²		4-wire connection: ±0.09%_FSV = ±900 ppm_FSV typ. 6-wire connection: ±0.05%_FSV = ±500 ppm_FSV typ.
Integrated power supply		0.5…5 V adjustable, max. supply/excitation 21 mA (internal electronic overload protection) therefore 120R strain gauge: up to 2.5 V 350R strain gauge: up to 5.0 V
Temperature coefficient	Tc_Terminal	< 20 ppm/K typ.

²) Dominant part of the basic accuracy is its offset specification (see following tables). The process described in the Offset correction section eliminates this proportion and increases the measurement accuracy considerably.

Measurement mode		SG 1/1 bridge (4 wire)
Offset/Zero Point deviation (at 23°C)	E_Offset	< 850 [ppm_FSV]
Gain/scale/amplification deviation (at 23°C)	E_Gain	< 200 [ppm]
Non-linearity over the whole measuring range	E_Lin	< 120 [ppm_FSV]
Repeatability	E_Rep	< 15 [ppm_FSV]
Noise (without filtering)	E_{Noise, PtP}	< 320 [ppm_FSV]		< 2500 [digits]
	E_{Noise, RMS}	< 56 [ppm_FSV]		< 438 [digits]
	Max. SNR	> 85 [dB]
	Noisedensity@1kHz	< 25.34
Noise (with 50 Hz FIR filtering)	E_{Noise, PtP}	< 18 [ppm_FSV]		< 141 [digits]
	E_{Noise, RMS}	< 3.5 [ppm_FSV]		< 27 [digits]
	Max. SNR	> 109.1 [dB]
Common-mode rejection ratio (without filtering)³		DC: < 0.15 typ.	50 Hz: < 0.5 typ.		1 kHz: < 10 typ.
Common-mode rejection ratio (with 50 Hz FIR filtering)³		DC: < 100 typ.	50 Hz: < 10 typ.		1 kHz: < 1 typ.
Largest short-term deviation during a specified electrical interference test		±0.1%_FSV = ±1000 ppm_FSV typ.
Input impedance ±Input 1 (Internal resistance)		Differential 4.1 MΩ \|\| 11 nF typ.
Input impedance ±Input 1 (Internal resistance)		CommonMode 1 MΩ \|\| 40 nF typ. Methodology: Resistor against -U_V, capacitance against SGND
Input impedance ±Input 2		No usage of this input in this mode

³) Values related to a common mode interference between SGND and internal ground.

Measurement mode		SG 1/1 bridge (6 wire)
Offset/Zero Point deviation (at 23°C)	E_Offset	< 470 [ppm_FSV]
Gain/scale/amplification deviation (at 23°C)	E_Gain	< 120 [ppm]
Non-linearity over the whole measuring range	E_Lin	< 120 [ppm_FSV]
Repeatability	E_Rep	< 15 [ppm_FSV]
Noise (without filtering)⁴	E_{Noise, PtP}	< 230 [ppm_FSV]		< 1797 [digits]
	E_{Noise, RMS}	< 38 [ppm_FSV]		< 297 [digits]
	Max. SNR	> 88.4 [dB]
	Noisedensity@1kHz	< 17.2
Noise (with 50 Hz FIR filtering)⁴	E_{Noise, PtP}	< 18 [ppm_FSV]		< 141 [digits]
	E_{Noise, RMS}	< 3.5 [ppm_FSV]		< 27 [digits]
	Max. SNR	> 109.1 [dB]
Common-mode rejection ratio (without filtering)³		DC: < 0.15 typ.	50 Hz: < 0.5 typ.		1 kHz: < 10 typ.
Common-mode rejection ratio (with 50 Hz FIR filtering)³		DC: < 100 typ.	50 Hz: < 10 typ.		1 kHz: < 1 typ.
Largest short-term deviation during a specified electrical interference test		±0.1%_FSV = ±1000 ppm_FSV typ.
Input impedance ±Input 1 (Internal resistance)		Differential 4.1 MΩ \|\| 11 nF typ.
Input impedance ±Input 1 (Internal resistance)		CommonMode 1 MΩ \|\| 40 nF typ. Methodology: Resistor against -U_V, capacitance against SGND
Input impedance ±Input 2 (Internal resistance)		Differential 5 MΩ \|\| 10 nF typ.
Input impedance ±Input 2 (Internal resistance)		CommonMode 1.25 MΩ \|\| 40 nF typ. Methodology: Resistor against -U_V (+2.5V), capacitance against SGND

³) Values related to a common mode interference between SGND and internal ground.

⁴) Specifications valid for HW Version ≥ 10, only! Valid specifications until HW Version 10 are as follows:

Measurement mode		SG 1/1 bridge (6 wire), < HW10
Noise (without filtering)	E_{Noise, PtP}	< 960 [ppm_FSV]	< 7500 [digits]
	E_{Noise, RMS}	< 170 [ppm_FSV]	< 1328 [digits]
	Max. SNR	> 75.4 [dB]
	Noisedensity@1kHz	< 76.93
Noise (with 50 Hz FIR filtering)	E_{Noise, PtP}	< 77 [ppm_FSV]	< 602 [digits]
	E_{Noise, RMS}	< 15 [ppm_FSV]	< 117 [digits]
	Max. SNR	> 96.5 [dB]

The channel value (PDO) is interpreted directly [mV/V]:

Measurement SG 1/1 bridge (full bridge) 4/6-wire connection 18: — Representation measuring range SG 1/1 bridge