Brochure/Catalogue

Glossary
RoHS The EC directive 2002/95/EC – concerning the restriction of the use of certain
hazardous substances in electrical and electronic equipment – regulates the use
of hazardous materials within devices and components. This directive, and it’s
various implementations into national laws, are referred to by the abbreviation
RoHS (Restriction of Hazardous Substances).
RTD/ PT100/ 1000 RTD sensors are temperature probes that operate based on the resistance
changes which take in metal as the temperature changes. They are resistance
thermometers based on PTC resistors. The electrical changes in resistance of a
platinum wire or platinum lm is often used for measuring temperatures ranging
from -200 °C to 850 °C. The platinum temperature sensors are characterised by
their nominal resistance R0 at a temperature of 0 °C. The standard types include:
• PT100 (R0= 100 Ohm)
• PT1000 (R0= 1 kOhm)
A two-wire, three-wire or four-wire electrical connection can be used to
electrically connect the PT/RTD sensor to the evaluative electronics. A three-wire
or four-wire method eliminates any errors caused by the inherent resistance of
the sensor connecting wires.
In the three-wire method, one end is equipped with two pigtail connectors. In the
four-wire method, both ends are equipped with two pigtail connectors.
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Self-heating Self-heating refers to the temperature increase in an operating device caused by
the internal power loss.
Sensor A sensor is a physical component capable of capturing certain physical or
chemical properties (such as thermal radiation, temperature, humidity, pressure,
noise, brightness or acceleration) as a measurement. It may also be able to
analyse the quality of the composition of the material surroundings. These
values are captured using physical or chemical phenomena and then converted
into another form (usually electrical signals) so they can be post-processed.
Signal distributorsplitter A signal isolator that accepts an analogue input signal and delivers at least two
signals on the output side. This permits the signal to be transmitted to a PLC/
DCS system and to a separate display. A signal multiplier is designed either as an
active isolator with an external power feed or as an output loop powered version.
SIL Safety Integrity Level.
The components must meet the requirements of IEC 61508 is order to reduce
risk. This standard provides general requirements for avoiding and minimising
device and equipment outages. It stipulates organization and technical
requirements concerning device development and operation. Four safety levels
are dened (from SIL1 for minimal risk to SIL4 for very high risk) for classifying
facilities and risk-reduction measures. Risk-reduction measures must be more
reliable when the classied risk level is higher.
Status indicator An LED that displays the operational status, such as operational (yellow),
switching (green), and alarm/malfunction (red).
Step response time This is the time delay in the output signal change when there is a signal jump
ranging from 10 to 90 % on the input side. The step response time is inversely
proportional to the limiting frequency
Storage temperature The permitted ambient temperature, related to a specic relative humidity level,
for which the product should be stored while in a current-free state.
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Technical appendix/Glossary
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