Siemens 7MF4033 series, Руководство пользователя

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Glossary UMSITRPDS3-1
November 2010
10-2
Field Instrument
– A network element that uses current variation for digital signaling or digital plus
analog signaling.
Gauge Pressure
– A pressure measured against atmospheric or barometric pressure as a reference. The
units of measurement are called gauge pressure units. For example: psig = pounds per square inch gauge.
HART
– Highway Addressable Remote Transducer – A communication protocol that provides
simultaneous analog and digital signaling between master and slave devices. It is supported by the HART
Communications Foundation.
HART Network
– A single pair of cabled wires and the attached communicating HART elements.
Intrinsically Safe Instrument
– An instrument that will not produce any spark or thermal effects under
normal or abnormal conditions that will ignite a specified gas mixture.
Keyboard or Magnetic Pushbuttons -
Three pushbuttons or keys, located under a cover on the electrical
entrance portion of the transmitter enclosure and used for local configuration of the transmitter.
Leporello
- The condensed transmitter user’s manual found inside the field terminals enclosure cap. A
book that unfolds in accordion fashion.
Lower Range Limit (LRL)
– The lowest value of the measured variable that a transmitter or other
measurement device can be configured to measure.
Lower Range Value (LRV)
– Representing the 4 mA point in the transmitter’s output, the LRV is the
lowest value of the measured value that the transmitter can be configured to measure.
MA or p
min
-
Minimum operating input pressure.
Magnetic Pushbuttons -
See Keyboard.
Maximum Overrange
– The maximum pressure ( differential) that can be applied safely to a
transmitter.
ME or p
max
- Maximum operating input pressure.
Measuring Cell
- Sensor.
Multi-Drop Network
– A HART network having from 1 to 15 field instruments that are parallel
connected on a single 2-wire cable. This network uses digital signaling only.
Network
– A network includes the following items:
•
Transmitter(s)
•
Network element (controller, recorder, passive non-signaling element, or other device)
•
Cabling interconnecting these devices
•
Barriers for intrinsic safety, if installed
•
Current sense resistor