Measurement IEPE 0…20 V

Measurement mode

0…20 V

Measuring range, nominal

0…20 V

Measuring range, end value (FSV)

20 V

Measuring range, technically usable

0…+21.474 V

PDO resolution (unsigned)

23 bit

15 bit 2)

PDO LSB (Extended Range)

2.56 µV

655.36 µV

Input impedance ±Input 1

(internal resistance)

Differential typ. 550 kΩ || 11 nF

2) The analog measurement is always done with 24 bits, in 16-bit mode the eight least significant bits are cut off. For further information see chapter “Commissioning”/ “Process data overview”

Specific data (not valid for ELM3704-10x1/ -10x2, preliminary data in cursive format)

Measurement mode

0…20 V

Basic accuracy: Measuring deviation at 23°C, with averaging 1)

< ±0.035 %FSV
< ±350 ppmFSV
< ±7 mV

Extended basic accuracy: Measuring deviation at 55°C, with averaging 1) 6)

< ±0.062 %FSV
< ±620 ppmFSV
< ±12.4 mV

Offset/Zero point deviation (at 23°C) 1)

EOffset

< 150 ppmFSV

Gain/scale/amplification deviation (at 23°C) 1)

EGain

< 100 ppm

Non-linearity over the whole measuring range 1)

ELin

< 300 ppmFSV

Repeatability, over 24 h, with averaging 1)

ERep

< 10 ppmFSV

Noise (without filtering)

ENoise, PtP

< 75 ppmFSV

< 586 digits

< 1.5 mV

ENoise, RMS

< 13 ppmFSV

< 98 digits

< 0.25 mV

Max. SNR

> 98.1 dB

Noisedensity@1kHz

< 3.54 Measurement IEPE 0…20 V 1:

Noise (with 50 Hz FIR filter)

ENoise, PtP

< 18 ppmFSV

< 141 digits

< 0.36 mV

ENoise, RMS

< 3 ppmFSV

< 23 digits

< 60 µV

Max. SNR

> 110.5 dB

Temperature coefficient 1)

TcGain

< 15 ppm/K typ.

TcOffset

< 5 ppmFSV/K typ.
< 100 µV/K

Crosstalk (without filter)

DC: >115 dB typ.

50 Hz: >105 dB typ.

1 kHz: >80 dB typ.

Crosstalk (with 50 Hz FIR filter)

DC: >115 dB typ.

50 Hz: >115 dB typ.

1 kHz: >115 dB typ.

Largest short-term deviation during a specified electrical interference test

±0.03 % = 300 ppmFSV typ.

1) Valid for ELM3704-00x1 from HW00, ELM370x-00x0 from HW01; specifications of predecessor-HW on request

6) Calculated value according to equation in chapter "General information on measuring accuracy/measurement uncertainty" for quick estimation of usability over the specified ambient temperature range in operation (Tambient). In real use, for example at a relatively constant ambient temperature Tambient, a lower (better) achievable uncertainty is attained. A specific calculation according to chapter "General information on measuring accuracy/measurement uncertainty" is recommended, especially if the instrument allows a wider ambient temperature range in operation than 0...55 °C.

Measurement IEPE 0…20 V 2:Fig.115: Representation 0…20 V measurement range

Note: The channel also works in electrically bipolar mode and records negative values in the unipolar measuring ranges (measurement from 0 V, 0 mA, 4 mA, 0 Ω). This enables the channel to provide a precise diagnosis even with signals < 0. In these measuring ranges the limit value for the "Underrange Error" in Extended Mode is -1% of the full scale value (FSV). The limit value can be set in CoE object 0x80n0:32. This avoids irritating error messages if the channel is not wired (e.g. without sensor) or the electrical signal fluctuates slightly around zero. The process data value of 0x00000000 is not undershot.

If the "UnderrangeError" detection is to be set even less sensitive, the magnitude of the negative limit value in the CoE object referred to above can be set even higher.