Glossary

Units of Measurement

AC

• The abbreviation for Alternating Current. An electric current that reverses its polarity at regular intervals.

• The abbreviation for Ampere and the unit of measurement of current. The symbol is "A"

• Measured in VA and is used in AC circuits when the load is not purely resistive having an inductive or capacative nature.

• The Ratio of the peak value divided by the r.m.s. value. With a true Sine Wave the Crest Factor is equal to the square root of 2 or 1.414

• The abbreviation for Direct Current. An electric current that has a constant polarity.

• The symbol of Kilo meaning 1000 (eg. 1KW = 1000 Watts)

• The highest instantaneous value found on any part of a waveform.

• The abbreviation for Power Factor. The Power Factor is defined as Real Power divided by Apparent Power.

• The difference of potential expressed in Volts measured between two points.

• The abbreviation of Root Mean Square. Defined as the square root of the arithmetic mean of the squares of a set of values of a waveform. This value is used to provide an effective value of any AC waveform that is compariable to a DC value. With a "true" sine wave the r.m.s. value is 0.707 of the peak (or the peak is 1.414 x the r.m.s.).

• Measured in Watts and is used in DC circuits and AC circuits when the load is resistive.

• The abbreviation for Volt Amp and is the product of multiplying Voltage and Ampage. See Apparent Power.

• The Voltage of an Alternating Current.

• The Electromotive Force (EMF) or Potential difference. The unit of measurement is the Volt. The symbol is 'V"

• The unit of measurement of power. One Watt occurs when the pottential difference in a circuit is one Volt and a current of one Amp flows. See Real Power.

• The Voltage of an Direct Current.