Instrumentation cables are designed to conduct or transmit low energy electrical signals. They can transmit electrical signals without any outside interference. This makes them ideal for controlling or monitoring electrical systems. They are used in manufacturing, processing and broadcasting industries as well as mass transit systems.
Some of the common applications are:
— Assembling Instruments,
— Digital / Analog Control
— Data Acquisition Systems
— PA Systems
— Computer Networking
— Measuring & Communication Systems.
Like other cables, the instrumentation cable too has a conducting wire or combination of wires that conduct electrical current or signals. Copper is usually used for its high thermal and corrosion resistance. Less frequent is the use of aluminium. Although less suitable than copper in almost every other capacity, aluminium has the singular advantage of being less dense. Hence, it is more suitable for power conduction. Steel is also used as conductor. It is wrapped in a copper or aluminium casing.
Insulation of the copper wire is important to stop the leakage of current. This is the role of the insulation jacket. In some instrumentation cables we also find an electromagnetic shielding layer that is wrapped around the wire, just below the insulation jacket.
This shielding layer is an added layer of security to the underlying wire, deducting the cable’s radiation, while cutting out electrical noise from reaching the signal carrying wire. The shielding material is usually a metal or foil braid. An assembly with shielding layered-instrumentation cables will usually also have an earthing wire.
There are different kinds of insulation jacket. The material is usually chosen according to the area of application for the cable. Some of the insulation materials used are Ethylene Propylene Diene EPDM, neoprene, silicon rubber,thermoplastic and mica tape.
Why is it important to Invest in High Quality Instrumentation Cable?
Instrumentation cables are often chosen for their efficiency in transmitting signals of high quality. For instance, musicians like guitarists use it for their equipment. It is the cable that is used in a computer network. These are all applications where a disturbance free transmission is of supreme importance and instrumentation cables do just that.
A high quality instrumentation promises the least dispersal of energy. In other words, the signal remains clear and disturbance free. This means that the guitarist will get a clear sound and the computer network will get a disturbance free transmission.
Different kinds of Instrumentation Cable are:
ARCNET cables: These are used inARCNET networks that form the local area network or LAN communications.These cable are ideal for high-speed, token-based communication between industrial computers.
AS-I cables: These two-core cables are used to interfaceAS-i devices like binary actuators and sensors. They are good at supplying power and transferring data.
CANbus cables: They are used in serial data networks that need high-speed, such as the automotive industry.They are designed to withstandhostile electrical environments.
CANopen cables: These cables have fieldbus protocol based on CANbus. They are widely used in industrial communications
DeviceNet cables: Although these cables use the controller area network or CAN protocol, they are typically used to connect devices such as photoelectric cells, motor starters, limit switches, valve manifolds, drives, and personal computers.
Fieldbus cables: These are used in various industries. They are used to connect devices like transducers, actuators, sensors, and controllers.
Foundation Fieldbus cables: Widely used in the local area network in all-digital, serial, two-way communications systems, especially for factory control and plant instrumentation.
HART cables: These cables allow a person to get multiple digital updates per second from a field device. Communication can take place without disturbing a 4-20mA signal.
PROFIBUS cables: use fieldbus standard that can be applied to both manufacturing and process automation applications.
P-Net cables: This is a European standard (EN 50 170 Vol. 1). It is also considered the International Fieldbus Standard (IEC 61558 Type 4).
Many people also choose instrumentation cables according to the shielding it carries. Where the quality of signal is of supreme importance, the shielding layer can be critical in maintaining the quality of the output. It also increases the efficiency, quality and durability of the cable. A prime example is computer network where such an instrumentation cable ensures a high quality are network.