DEWESOFT IOLITE, Technical Reference Manual

Page: 143 / 153

IOLITE®
TECHNICAL REFERENCE MANUAL
CJC
Cold junction compensation.
Thermocouples measure the temperature difference between two points, not absolute temperature. To
measure a single temperature one of the junctions - normally the cold junction - is maintained at a
known reference temperature, and the other junction is at the temperature to be sensed.
Having a junction of known temperature, while useful for laboratory calibration, is not convenient for
most measurement and control applications. Instead, they incorporate an artificial cold junction using a
thermally sensitive device such as a thermistor or diode to measure the temperature of the input
connections at the instrument, with special care being taken to minimize any temperature gradient
between terminals. Hence, the voltage from a known cold junction can be simulated, and the
appropriate correction applied. This is known as cold junction compensation.
dB
The decibel (dB) is a logarithmic unit that indicates the ratio of a physical quantity (usually power or
intensity) relative to a specified or implied reference level. A ratio in decibels is ten times the logarithm to
base 10 of the ratio of two power quantities.
Dewesoft
Dewesoft refers to the company.
DewesoftX® refers to the software suite for data acquisition, data processing, data analysis and much
more.
Dynamic Range
Dynamic Range is the ratio of a specified full scale input range to the minimum detectable value (peak
spurious signal). The value for dynamic range is expressed in decibels (dB).
DSP
A digital signal processor (DSP) is a specialized microprocessor with an optimized architecture for the
fast operational needs of digital signal processing.
The measurement modules use DSPs to process the measured data.
FFT
Fast Fourier transformation (FFT) can be used to show the frequency components of the acquired
signals in amplitude and frequency. DewesoftX® has a built-in visual control that makes FFT easy to use.
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