Каталог Weidmuller: Electronics - Analogue Signal Conditioning

Technical appendix/Glossary
Glossary
G
Galvanic isolation
GOST-R
Potential-free isolation between electrical components.
Normally, the inputs circuit, output circuit and power supply are designed so that
they are electrically isolated from each other. The isolation can be achieved using
optical means (an optocoupler) or by using a transformer. The electrical isolation of
measurement signals ensures that the differences in earth potentials and commonmode
interference are suppressed
The Russian certification for products, materials and technical facilities.
H
Hall sensor current measurement
HART ®
Hall sensors can measure the magnetic field of a conducting wire. They then
generate a proportional voltage on the measurement output (the Hall voltage).
This can be converted to a standardised signal by means of an amplifier circuit.
Such a measurement is well suited for measuring high DC and AC currents with
frequencies up to 1 kHz. Start-up currents and current peaks cannot damage a Hall
sensor.
HART ® (Highway Addressable Remote Transducer) is a communications protocol
for bus-addressed field devices used in process automation. In HART ® -based
communications, field devices and controllers are connected together over 4–20 mA
current loops. This analogue signal is superimposed with a digital signal by using the
FSK process (Frequency Shift Keying). The process allows additional measurements,
configuration and device data to be transmitted without influencing the analogue
signal. HART ® Ex isolators can also be used in hazardous areas.
20 mA
Digital
signal
Analogue
signal
4 mA
Bit 1 Bit 0 Bit 0 Bit 1 Bit 1 Bit 0 Bit 1
Time
W
W.30