ADInstruments PowerLab 30 Series Owner's Manual page 42

connected across one diagonal, and the transducer output is taken across the
other.
bus. A data-carrying electrical pathway (cables and connectors).
connector. A plug, socket, jack or port used to connect one electronic device
to another (via a cable): a PowerLab to a computer, say.
CPU (central processing unit). A hardware device that performs logical and
arithmetical operations on data as specified in the instructions: the heart of
most computers.
DAC (digital-to-analog converter). A device that converts digital
information into some corresponding analog voltage or current.
DC offset. The amount of DC (direct current) voltage present at the output of
an amplifier when zero voltage is applied to the input; or the amount of DC
voltage present in a transducer in its equilibrium state.
differential input. Input using both positive and negative inputs on a
PowerLab. The recorded signal is the difference between the positive and
negative input voltages: if both were fed exactly the same signal, zero would
result. Can reduce the noise from long leads.
DIN (Deutsche Industrie Norm). A type of cable or connector; there are
various sorts with different numbers of pins.
envelope form. The overall shape of a signal, outlined by the minimum and
maximum recorded values. Often used to display quickly changing signals.
excitation voltage. The voltage supplied to a bridge circuit from which the
transducer output signal is derived. Manipulating the transducer changes the
measurement elements of the bridge circuit, producing a change in its output
voltage.
external trigger. The input connector on the front of the PowerLab marked
'Trigger' . This lets you start recording from an external source. The trigger
level (the voltage needed to have an effect) depends on the hardware and
cannot be changed. Recording can also be triggered by contact closure, if this
is set up in the software.
filter. An electronic device or a program that alters data in accordance with
specific criteria. Filters in hardware and software can be used to reduce or to
eliminate electronic noise or drift from data readings.
frequency. The number of complete cycles per second of a waveform.
Frequency is usually expressed in hertz: Hz (cycles per second), kilohertz:
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PowerLab Owner's Guide