Glossary - Siemens 7MF4333 User Manual

UMSITRPDS-1

Glossary

10.0 GLOSSARY
Defined below are terms relevant to the SITRANS P DSIII transmitter, this User's Manual, pressure
measurement technology, and HART networks.
Absolute (abs) Pressure – A pressure measured against absolute zero or a total vacuum as a reference.
The units of measurement are called absolute pressure units. For example: psia = pounds per square inch
absolute.
Adjust - Zero and full scale are adjusted using a single reference pressure. See Set.
Analog Signaling – A low-current signal of 4 to 20 mAdc from a field instrument to a primary master or
non-signaling hardware.
ANSI – American National Standards Institute
Application Point or Switch Point - The point at which the output current characteristic changes from
linear to square root when a square root output characteristic is selected (Modes 11 and 12).
AWG – American Wire Gauge
Barrier – A device designed to limit the voltage and current in a hazardous area even if certain types of
faults occur on the non-hazardous side of the barrier.
Barrier Resistance – The maximum end-to-end resistance of a barrier, as specified by the barrier
manufacturer. If both supply and return barriers are used in a network, the barrier resistance is the sum of
the end-to-end resistance of both barriers. For active barriers that use resistance to limit current, the
barrier resistance is the internal resistance between the hazardous area terminal and the barrier internal
node where voltage is regulated.
Blind - No reference pressure is applied.
Commissioning – Testing of a transmitter and associated loop to verify transmitter configuration and
loop operation (piping, valving, wiring, control algorithm, data logging, etc.).
Configuration – A database (or archive) created using a HART Communicator and downloaded to a
transmitter to define transmitter operation.
Configure/Configuring – The entering of specific parameter data into a HART Communicator to be
downloaded to a transmitter to define that transmitter's operating characteristics.
Current Sense Resistor – The resistor in a network across which the field instrument (transmitter) signal
voltages are developed.
Damping – A user-selectable output characteristic that increases the response time of a transmitter to
smooth the output when the input signal contains rapid variations.
Digital Signaling – The high frequency HART signal.
Explosion-Proof Enclosure – An enclosure that can withstand the explosion of gases within it and
prevent the explosion of gases surrounding it due to sparks, flashes, or the explosion of the container
itself, and maintain an external temperature that will not ignite the surrounding gases.
10-1
November 2010