Metal brought into the active field of a NAMUR type
proximity sensor causes its current consumption to change.
This change in current consumption or the change of the
sensor’s internal resistance is used as output signal. In
conjunction with properly homologated remote amplifiers
NAMUR sensors may be operated in hazardous areas (for more
information consult also ATEX).
A set of specifications devised for the safe application
and use of electric power and devices in the United States.
National Electrical Manufacturers Association (NEMA)
A United States association that establishes
specifications and ratings for the manufacture of electrical
components and apparatuses. Ratings of an enclosure's
ability to provide a degree of protection against contact
with equipment and against specified environmental
conditions. Conformance to these standards by manufacturers
A device with a direct point of access to a network.
Any unwanted electrical signals contaminating the signal to be measured and
obscuring the information content. May be electronic noise which is an artifact
of semiconductor construction techniques and is not reducible. Noise may also be
caused by environmental factors, as a result of poor positioning or screening of
signal wiring. This may result in mains frequency or RF pickup contaminating the
Noise results from the presence of undesirable electrical voltages or
current. It causes devices to operate erratically (if the noise is on the supply
line to a device), or produces false information on erratic operation if present
on wires carrying signals from the output of a device to the load. Noise can be
present in the supply or picked up on lines in many ways. Pick-up from noisy
adjacent wires or metal parts is possible. Good wiring practice and/or
additional parts can be used to diminish the effects of noise.
Nominal Sensing Distance
Approximate dimension value measured from the face of the sensor to the
nearest point of the target. It does not take into consideration manufacturer's
tolerance or operational variables. Also known as the operating point.
A product outside manufacturing limits but not necessarily defective.
Method of inspecting materials and products without affecting their
subsequent properties and performance. Abbreviation NDT.
Inability under normal operation to ignite a hazardous mixture.
Signifies that the relationship between output and input cannot be
represented by a single straight line.
Controls designed for indoor applications subject to neither bright ambient
light nor extreme vibration. Usually incandescent lamp controls, scanners and
light source-photoreceiver pairs.
Normal Contact Position
The position of a switch that exists when no force is applied to the
The state of a control in which the output is high (logic1) in voltage in
the rest (Off) condition.
Normal Mode Rejection
The ability of an electrical device to filter
out noise superimposed on the signal and applied
across the SIG HI to SIG LO input terminals.
Normally expressed in dB at 50/60 Hz.
Process of creating sensor interchangeability.
Normally Closed (NC)
During the conditions which are defined as "normal", the
output state of the sensor is conducting. For inductive,
capacitive and My-Com, normal is defined as no target
present. For photo-electric, normal is a "dark" receiver.
The state of a control in which the output is low (logic 0) in voltage in
the rest (Off) condition.
Normally Open (NO)
The opposite sense from Normally Closed.
A transistor consisting of two N-type regions separated by a P-type region.
NPN - Current Sinking
An output which supplies a path to ground. The
load is between the output and +Vs.
NPN - Output
An NPN output acts as an electronic switch from
the output to 0 Volt. The load is switched to +VS.
If the output is switched (if "light" is received in
a light operate mode or "no light" in a dark operate
mode) a current flows from +VS through the load and
via the output transistor and the reverse polarity
protection diode to 0 Volt. The voltage between the
output and 0 Volt is called the voltage drop. The
voltage protection prevents damage to the output if
Nicrosil-Nisil thermocouple with a temperature range of -200 to 1200 Degrees
The condition when the pressure on each side of the sensing diaphragm is
The electrical output present, when the pressure sensor is at null.
Null Temperature Shift
The change in null output value due to a change in temperature.