National Instruments NI 1450 Series - Manual (Page 19)

Chapter 2 Setup and Configuration
© National Instruments Corporation 2-5 NI 1450 Series Compact Vision System User Manual
foreign matter—solid, liquid, or gas—that may reduce dielectric strength
or surface resistivity. Pollution degrees are listed below.
• Pollution Degree 1—No pollution or only dry, nonconductive
pollution occurs. The pollution has no effect.
• Pollution Degree 2—Normally only nonconductive pollution occurs.
Occasionally, nonconductive pollution becomes conductive because of
condensation.
• Pollution Degree 3—Conductive pollution or dry, nonconductive
pollution occurs. Nonconductive pollution becomes conductive
because of condensation.
Clean the device and accessories by brushing off light dust with a soft,
nonmetallic brush. Remove other contaminants with a stiff, nonmetallic
brush. The unit must be completely dry and free from contaminants before
returning it to service.
You must insulate signal connections for the maximum voltage for which
the device is rated. Do not exceed the maximum ratings for the device.
Remove power from signal lines before connection to or disconnection
from the device.
Caution National Instruments measurement products may be classified as either
Installation Category I or II. Operate products at or below the Installation Category level
specified in the hardware specifications.
Installation Category 1 : Measurement circuits are subjected to working
voltages 2 and transient stresses (overvoltage) from the circuit to which they
are connected during measurement or test. Installation Category establishes
standardized impulse withstand voltage levels that commonly occur in
electrical distribution systems. The following is a description of Installation
(Measurement
3 ) Categories:
• Installation Category I is for measurements performed on circuits not
directly connected to the electrical distribution system referred to as
MAINS
4 voltage. This category is for measurements of voltages from
specially protected secondary circuits. Such voltage measurements
include signal levels, special equipment, limited-energy parts of
1 Installation Categories as defined in electrical safety standard IEC 61010-1.
2 Working voltage is the highest rms value of an AC or DC voltage that can occur across any particular insulation.
3 Installation Category is also referred to as Measurement Category.
4 MAINS is defined as the (hazardous live) electrical supply system to which equipment is deisgned to be connected for the
purpose of powering the equipment. Suitably rated measuring circuits may be connected to the MAINS for measuring
purposes.