Linearity - A measure of the departure from a straight-line response in the relationship between the primary and secondary quantities, where the change in one is directly proportional to a change in the other. Normally expressed as a maximum percentage
Loop Powered - The transducer uses the power supplied by the primary current measuring loop to power the transducer. An auxiliary power supply is not required.
Loop Resistance - The electrical resistance, in ohms, of a complete transducer circuit exclusive of an instrument's internal resistance.
m H2O - The amount of pressure exerted by a column of water 1 meter high. Commonly used as the unit of measure for liquid level sensors and depth sensors.
Magnetic Permeability - The degree of magnetization of a material that responds linearly to an applied magnetic field . (Wikipedia)
Magnetic Saturation - Magnetic saturation is the state when the material cannot absorb a stronger magnetic field, such that an increase of magnetization force produces no significant change in magnetic flux density in the material. (Wikipedia)
Nanocrystalline Magnetic Material - Iron based alloy magnetic core material which is treated to create a mixture of amorphous and crystalline structures in the material.
Non-Linearity - In an ideal system, the input-output relationship between variables is linear(i.e. straight line) Any departure from straight line is expressed as non-linearity.
Operating Voltage - A nominal operating voltage with a specified tolerance applied. The design voltage range to remain within the unit's operating tolerances.
Pa, kPa, mPa - “Pa” or Pascal is a unit of measure used in the measurement of pressure. A Pascal is one(1) Newton per square meter, where a Newton is the amount of force necessary to accelerate 1 kilogram to one(1) meter per second per second. kPA is 1000 Pascals and mPa is 1,000,000 Pascals. One(1) Psi (pounds per square inch) is equal to 6.896 kPa.
Permalloy - The trademark for any of several alloys of nickel and iron having high magnetic permeability . (Webster)
Phase Angle - The difference by which an alternating signal lags or leads another signal, typically expressed as degrees. Phase angle may be a measure of power factor when used to indicate the relationship of a voltage to current signal for a non-resistive load. Phase angle may also be used to measure the different in phase between the primary and secondary of a current or voltage transformer.
Polyphase Wattmeter - A wattmeter consisting of 2 or 3 single phase watt meters mounted in the same package. The watt sensing elements can be electronic transducers. A dual element wattmeter will measure power in a 3 phase system regardless of power factor, voltage or current variations between phases. Most common types are 2,2« or 3 element forms. In 4 wire circuits, with the 4th wire carrying current, the 2« or 3 element type is used. If there is voltage imbalance, only the 3 element units can be employed.
Power - A source or means of supplying energy. The unit of measurement is the watt. 1 Horsepower is equal to 745.7 Watts.
Power Factor - The RMS current of the fundamental harmonic divided by the Total RMS current multiplied by cosine (where is the phase angle between the current and voltage. A Power Factor of 1 implies all of the electrical energy is available as Active Power, a power factor of less than 1 implies losses due to Reactive Power.
Pulse Width Modulation (PWM) - Adjustment of the duty cycle of a signal or power source, to either convey information over a communications channel or control the amount of power sent to a load. http://en.wikipedia.org/wiki/Pulse_width_modulation
Range - Nominal operating limits, specified by the lowest calibration point to the highest calibration point.
Rated Output - The maximum output of a device at standard calibration
Ratios - The relationship between the primary input value divided by the secondary output value. For example: a current transformer that has a primary input value of 600 Amperes and a secondary value of 5 Amperes will have a Current Ratio of 600:5 and a Turns Ratio of 120:1. It is important to use the term Current Ratio for most applications because it defines the current handling capacity of wire used in the secondary winding. The Turns Ratio only refers to the winding ratio and does not define the current handling capacity of the either primary or secondary windings.
Real Power - Same as Effective Power.
Reactive Power - A component of apparent power (volt-amps/ VAR) which does not produce any real power (watt) transfer
Repeat Accuracy - The maximum deviation from one timing operation to the next.
RMS - The effective value of alternating current or voltage. The RMS (Root Mean Square) value equates an ac signal to a dc signal which provides the same power transfer.
Rogowski Coil - The Rogowski coil is an electrical device used for measuring alternating current (AC) or fluctuating current pulses.
It consists of a helical coil of wire wrapped around the primary conductor.
Effectively, each loop of the coil
is perpendicular to the magnetic flux generated by the fluctuating current pulses in the conductor. [Imagine a toy slinky wrapped around
the primary conductor. Using the "right-hand rule", the magnetic flux lines break the plane of each coil perpendicularly.]. A voltage is induced in the coils
that is proportional to the rate of change of current in the conductor. Integrating the resulting voltage provides a measurement of
the current in the conductor.
Advantages of a Rogowski coil sensor are;
RTD - Resistive Temperature Device or Resistive Temperature Detectors. These temperature sensing devices depend upon the relationship between the resistance of the sensor element and temperature to determine the ambient temperature. The most common industry sensor incorporates a platinum element, with a nominal resistance of 100 ohms at 0°C (commonly referred to as a Pt-100 sensor).