Omega OMB-DAQSCAN-2000 Series 사용자 설명서

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 Glossary 

Differential mode voltage refers to a voltage difference between two signals that are referenced 

to a common point.  Example: Signal 1 is +5 VDC referenced to common.  Signal 2 is +6 VDC 

referenced to common. 

If the +5 VDC signal is used as the reference, the differential mode voltage is +1 VDC 

(+ 6 VDC - +5 VDC = +1 VDC). 

If the +6 VDC signal is used as the reference, the differential mode voltage is -1 VDC  

(+ 5 VDC - +6 VDC = -1 VDC). 

Electrostatic discharge (ESD) is the transfer of an electrostatic charge between bodies having 

different electrostatic potentials. This transfer occurs during direct contact of the bodies, or 

when induced by an electrostatic field.  ESD energy can damage an integrated circuit (IC). 

Some transducers  [e.g. strain gages, thermistors, and resistance temperature detectors 

(RTDs)] require a known voltage or current.  Typically, the variation of this signal through the 

transducer corresponds to the condition measured. 

The degree to which an input signal is amplified (or attenuated) to allow greater accuracy and 

resolution; can be expressed as ×n or ±dB. 

The arrangement or operation of a circuit so that signals from another circuit or device do not 

affect the isolated circuit. 

In reference to Daq devices, isolation usually refers to a separation of the direct link between 

the signal source and the analog-to-digital converter (ADC). Isolation is necessary when 

measuring high common-mode voltage. 

Some transducers produce a voltage in linear proportion to the condition measured.  Other 

transducers (e.g., thermocouples) have a nonlinear response.  To convert nonlinear signals 

into accurate readings requires software to calibrate several points in the range used and then 

interpolate values between these points.  

 A device that collects signals from several inputs and outputs them on a single channel. 

The value of a signal on a channel at an instant in time.  When triggered, the ADC reads the 

channel and converts the sampled value into a 12- or 16-bit value. 

A series of measurements across a pre-selected sequence of channels. 

A programmable device that manages channels and channel-specific settings. 

An operation that gathers samples from multiple channels at the same instant and holds these 

values until all are sequentially converted to digital values. 

The single-ended mode measures a voltage between a signal line and a common reference that 

may be shared with other channels.  (Also see differential mode). 

An event to start a scan or mark an instant during an acquisition.  The event can be defined in 

various ways; e.g., a TTL signal, a specified voltage level in a monitored channel, a button 

manually or mechanically engaged, a software command, etc.  Some applications may use 

pre- and post-triggers to gather data around an instant or based on signal counts. 

Transistor-Transistor Logic (TTL) is a circuit in which a multiple-emitter transistor has replaced 

the multiple diode cluster (of the diode-transistor logic circuit); typically used to communicate 

logic signals at 5 V. 

A range of analog signals that is always zero or positive (e.g., 0 to 10 V).  Evaluating a signal in 

the right range (unipolar or bipolar) allows greater resolution by using the full-range of the 

corresponding digital value. See bipolar.