VEGA VEGABAR 83 4 … 20 mA - Operating Instructions User Manual

Page 61

11 Supplement

VEGABAR 83 • 4 … 20 mA

45033-EN-131010

Determination of characteristics

Limit point adjustment according to IEC 61298-2

Characterstic curve

Linear

Reference installation position

upright, diaphragm points downward

Influence of the installation position

Ʋ Piezoresistive/strain gauge measur-

ing cell

depending on the process fitting and the chemical seal

Ʋ METEC

measuring cell

< 5 mbar/0.5 kPa (0.07 psig)

Deviation (according to IEC 60770)
Applies to the digital signal output (HART, Profibus PA, Foundation Fieldbus) as well as to the

analogue current output 4 … 20 mA and refers to the set span. Turn down (TD) is the ratio nominal

measuring range/set span.
The deviation corresponds to the value F

in chapter "Calculation of the total deviation". The value

results out of the accuracy class and the respective turn down.

Accuracy class

Non-linearity, hysteresis and re-

peatability with TD 1 : 1 up to 5 : 1

Non-linearity, hysteresis and re-

peatability with 5 : 1

0.075 %

< 0.075 %

< 0.015 % x TD

0.1 %

< 0.1 %

< 0.02 % x TD

0.2 %

< 0.2 %

< 0.04 % x TD

Influence of the product or ambient temperature
Thermal change zero signal and output span
Applies to the digital signal output (HART, Profibus PA, Foundation Fieldbus) as well as to the

analogue current output 4 … 20 mA and refers to the set span. Turn down (TD) is the ratio nominal

measuring range/set span.
The thermal change of zero signal and output span corresponds to the value F

in chapter "Calcu-

lation of the total deviation (according to DIN 16086)".
Piezoresistive/strain gauge measuring cell

Turn down

In the compensated tem-

perature range 10 … +70 °C

(+50 … +158 °F)

Outside the compensated tem-

perature range

TD 1 : 1

< 0.05 %/10 K

typ. < 0.05 %/10 K

TD 1 : 1 up to 5 : 1

< 0.1 %/10 K

TD up to 10 : 1

< 0.15 %/10 K

Ceramic/Metal measuring cell - Standard

Medium or ambient tempera-

ture T

Accuracy class 0.1 %

Accuracy class 0.2 %

-40 … 0 °C (-40 … +32 °F)

< {0.15 % + 0.015 %/K x (-T)} x

{0.5+0.5 x TD}

< {0.1 % + 0.03 %/K x (-T)} x

{0.5+0.5 x TD}

0 … 40 °C (+32 … +104 °F)

< {0.0075 %/K x (T - 20 °C)} x

{0.5+0.5 x TD}

< {0.005 %/K x (T - 20 °C)} x

{0.5+0.5 x TD}

40 … 100 °C (+104 … +212 °F)

< {0.15 % } x {0.5+0.5 x TD}

< {0.005 %/K x (T - 20 °C)} x

{0.5+0.5 x TD}