INSTRUMENTATION CABLES

UNIQUE provides a wide range of cables suitable for process control and signal transmission.In the industries related to power Generation & Distribution,Petrochemical,Fertilizers,Steel Plants,Oil Refineries,Aluminium Plants and other Engineering Industries,the process instrumentation plays a vital role in quality,productivity,economy and control of the entire plant.

Foil Shielding or Braid Screening is the most important part of instrumentation Cable which are provided by Aluminium Mylar tape with Copper drain wire or tinned copper simultaneously.Both the types have got their respective advantages.Armouring is provides to prevent the cables from mechanical stresses.

Shielding provides 100% Cables Coverage,necessary for electrostatic sheild protection.Because of their small size, foil Shields are commonly used to sheild individual pairs of multi-pair data cable to reduce crosstalk.They have less weight,bulk andcost less than screening and are generally more effective than screening in RF ranges.It is more flexible but have a shorter flex life span.Drain Wires are used along with this to make termination easier and to ground Electrostatic discharges.The shortcomings are higher DC Resistance and lower mechanical strength.Shielding is selected for protection against capacitive(electric field)coupling where shield coverage is more important than low DC resistance,When possible sources of interference include TV signals,crosstalk from other circuits,radio transmitters,flourescent lights or coupling equipment,for MATV,CATV,video,networking,computer I/O cable in office,industrial or commercial environment where ambient EMI levels are low.

Screening consists of groups of tinned or bare copper or aluminium strands,one set woven in a clockwise direction and interwoven with another set in a counter-clockwise direction.It provide superior structural integrity, while maintaining good flexibility and flex life. These are ideal for minimizing low frequency interference and have lower DC resistance than schilding.Screening is effective at audio,as well as RF ranges.Generally,the higher the braid caverage,the more effective the screening.However, the trade-off between cost and screen coverage must be considered.Typical Screen coverages are between 80% and 95% Coverage of 100% is unattainable.Other features to consider are the weave angle, strand diameter,number of carrier(strand groups) and the number of ends(strands).They are generally bulkier and heavier than selected for superior performance against diffusion coupling,where low DC resistance is important,and to a lesser extent, capacitive and inductive coupling,when possible sources of interference exhibit low impedance characteristics,such as motor control circuits and swithes which operate inductive loads,for computer to terminal interconnect for process,instrumentation or control applications.

Construction

Conductor

Solid/stranded,tinned/bare/silver-plated annealed high conductivity EC grade copper,size ranging from 0.5.sq.mm to 2.5 sq.mm.

Insulation

PVC/Solid PE/special thermoplastic materials,heat resistant PVC - 80C/105C operation.Halogen free polymeric or elastomeric insulation can be provided.Core identification by color-coding or printed numerals/letters.

Core-Wrap

One or more Plastic Tape

Screen

Cores/Pairs/Triad/Quads can be individually or overall screened or both.Screening by Cu/Al-Mylar Tape or copper braid or aluminium wire for reinforced armour types.

Drain Wire

Drain Wire or solid/stranded,bare/tinned copper wire normally provided with both individual and overall screen.

Mechanical protection

Cables can be armoured with galvanized steel wires & strips or double helical steel tape.

Inner and Outer Sheath

PVC Black/Grey,HR/FRLS PVC sheathing or Halogen free polymeric/elastomeric sheating also available.