Endress+Hauser Proline Promass E 300, Руководство по эксплуатации

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Proline Promass E 300 Modbus RS485 Technical data
Hauser 171
Calculation example for gas
• Sensor: Promass E, DN 50
• Gas: Air with a density of 60.3 kg/m³ (at 20 °C and 50 bar)
• Measuring range (liquid): 70 000 kg/h
• x = 125 kg/m³ (for Promass E, DN 50)
Maximum possible full scale value:

max(G)
= 
max(F)
· ρ
G
: x = 70 000 kg/h · 60.3 kg/m³ : 125 kg/m³ = 33 800 kg/h
Recommended measuring range
Flow limit →  186
Operable flow range Over 1000 : 1.
Flow rates above the preset full scale value do not override the electronics unit, with the
result that the totalizer values are registered correctly.
Input signal External measured values
To increase the accuracy of certain measured variables or to calculate the corrected volume
flow for gases, the automation system can continuously write different measured values to
the measuring device:
• Operating pressure to increase accuracy (Hauser recommends the use of a
pressure measuring device for absolute pressure, e.g. Cerabar M or Cerabar S)
• Medium temperature to increase accuracy (e.g. iTEMP)
• Reference density for calculating the corrected volume flow for gases
Various pressure and temperature measuring devices can be ordered from Endress
+Hauser: see "Accessories" section →  168
It is recommended to read in external measured values to calculate the corrected volume
flow.
Current input
The measured values are written from the automation system to the measuring device via
the current input →  171.
Digital communication
The measured values are written from the automation system to the measuring device via
Modbus RS485.
Current input 0/4 to 20 mA
Current input 0/4 to 20 mA (active/passive)
Current span • 4 to 20 mA (active)
• 0/4 to 20 mA (passive)
Resolution 1 µA
Voltage drop Typically: 0.6 to 2 V for 3.6 to 22 mA (passive)
Maximum input voltage ≤ 30 V (passive)
Open-circuit voltage ≤ 28.8 V (active)
Possible input variables • Pressure
• Temperature
• Density