India's Widest Range

Instrumentation Cable

 

 Shielded twisted pair, OSTP, IS+OS, armoured, FRLS and LSZH instrumentation cables — manufactured at our Bhiwadi, Rajasthan plant. Compliant with IS 1554, IS 8130 and IEC standards. Trusted by BPCL, NTPC, ONGC, BHEL and 500+ industrial plants across India.

Product Introduction

What Makes an Instrumentation Cable Different — and Why It Matters

Instrumentation cables are the signal highways of any industrial plant. Unlike standard power cables that carry high current at elevated voltages, instrumentation cables are designed to transmit low-level signals–4–20 mA current loops, millivolt thermocouple outputs, RTD resistance signals, HART, Fieldbus, and Modbus data from field instruments to control rooms and DCS panels.

The fundamental engineering challenge is maintaining signal accuracy across long cable runs in environments full of electrical interference motors, VFDs, high-voltage switchgear, and RF sources. This is why every properly engineered instrumentation cable uses twisted pair or twisted triad construction combined with EMI shielding (Al-Mylar tape screen + tinned copper drain wire) to achieve reliable, noise-free signal transmission.

BMI Cables manufactures the complete range of industrial instrumentation cables from simple 2 core twisted pair cable for single-loop field instruments, to complex 50-pair individually and overall screened armoured cables for large DCS and SCADA installations all tested to IS, IEC, and BS 5308 standards before leaving our Bhiwadi manufacturing facility.

Instrumentation Signal Cables - BMI Cables
Instrumentation Signal Cables 2 - BMI Cables
Complete Product Range

Types of Instrumentation Cables We Manufacture

From basic twisted cable for single-loop instruments to complex multi-triad IS+OS armoured designs — BMI supplies the complete spectrum of screened and shielded instrumentation cables, direct from our ISO-certified factory in Bhiwadi, Rajasthan.

Cable Type Shielding Configuration Armour Insulation Outer Sheath Typical Application
Overall Screened Unarmoured OS/UA Al-Mylar tape overall screen + tinned copper drain wire None PVC-GP / PVC-HR / PE / XLPE PVC-GP / PVC-FR / FRLS-H / LSZH General process control, indoor instrumentation runs
IS+OS Screened Unarmoured IS+OS/UA Individual pair/triad screen + overall screen (Al-Mylar / Cu tape) None PVC-GP / PVC-HR / PE / XLPE PVC-GP / PVC-FR / FRLS-H / LSZH Multi-pair signal cables, low-noise instrument loops, DCS panels
Overall Screened Armoured OS/A Al-Mylar tape / copper wire braid overall screen GI Wire / Strip / Tape PVC-GP / PVC-HR / PE / XLPE PVC-GP / PVC-FR / FRLS-H / LSZH Outdoor runs, underground trenches, mechanical protection
IS+OS Screened Armoured IS+OS/A Individual + overall screen (Al-Mylar / Cu tape / braid) GI Double Tape / Wire / Strip PVC-GP / PVC-HR / PE / XLPE PVC-GP / PVC-FR / FRLS-H / LSZH Oil & Gas, refineries, hazardous areas (IS loops)
Shielded Twisted Pair Cables 2P–50P Individual or overall screen (optional per spec) Armoured / Unarmoured PVC-GP / PVC-HR / PE / XLPE PVC-GP / PVC-FR / FRLS-H / LSZH Analog signal transmission, sensor-to-panel connections, SCADA
Triad Cables (3-Wire RTD) Individual triad screen + overall screen (optional) Armoured / Unarmoured PVC-GP / PVC-HR / PE / XLPE PVC-GP / PVC-FR / FRLS-H / LSZH Three-wire RTD, thermocouple extension, 4–20mA loops
Multi-Pair / Multi-Triad Up to 50 Pairs Individual pair/triad + overall screen (Al-Mylar + Cu braid) Armoured / Unarmoured PVC-GP / PVC-HR / PE / XLPE PVC-GP / PVC-FR / FRLS-H / LSZH DCS/SCADA systems, power plant control, marshalling cabinets

Overall Screened Unarmoured  OS/UA

Shielding Al-Mylar tape overall screen + tinned copper drain wire
Armour None
Insulation PVC-GP / PVC-HR / PE / XLPE
Outer Sheath PVC-GP / PVC-FR / FRLS-H / LSZH
Typical Application General process control, indoor instrumentation runs

IS+OS Screened Unarmoured  IS+OS/UA

Shielding Individual pair/triad screen + overall screen (Al-Mylar / Cu tape)
Armour None
Insulation PVC-GP / PVC-HR / PE / XLPE
Outer Sheath PVC-GP / PVC-FR / FRLS-H / LSZH
Typical Application Multi-pair signal cables, low-noise instrument loops, DCS panels

Overall Screened Armoured  OS/A

Shielding Al-Mylar tape / copper wire braid overall screen
Armour GI Wire / Strip / Tape
Insulation PVC-GP / PVC-HR / PE / XLPE
Outer Sheath PVC-GP / PVC-FR / FRLS-H / LSZH
Typical Application Outdoor runs, underground trenches, mechanical protection

IS+OS Screened Armoured  IS+OS/A

Shielding Individual + overall screen (Al-Mylar / Cu tape / braid)
Armour GI Double Tape / Wire / Strip
Insulation PVC-GP / PVC-HR / PE / XLPE
Outer Sheath PVC-GP / PVC-FR / FRLS-H / LSZH
Typical Application Oil & Gas, refineries, hazardous areas (IS loops)

Shielded Twisted Pair Cables  2P–50P

Shielding Individual or overall screen (optional per spec)
Armour Armoured / Unarmoured
Insulation PVC-GP / PVC-HR / PE / XLPE
Outer Sheath PVC-GP / PVC-FR / FRLS-H / LSZH
Typical Application Analog signal transmission, sensor-to-panel connections, SCADA

Triad Cables (3-Wire RTD)

Shielding Individual triad screen + overall screen (optional)
Armour Armoured / Unarmoured
Insulation PVC-GP / PVC-HR / PE / XLPE
Outer Sheath PVC-GP / PVC-FR / FRLS-H / LSZH
Typical Application Three-wire RTD, thermocouple extension, 4–20mA loops

Multi-Pair / Multi-Triad  Up to 50 Pairs

Shielding Individual pair/triad + overall screen (Al-Mylar + Cu braid)
Armour Armoured / Unarmoured
Insulation PVC-GP / PVC-HR / PE / XLPE
Outer Sheath PVC-GP / PVC-FR / FRLS-H / LSZH
Typical Application DCS/SCADA systems, power plant control, marshalling cabinets

Need a custom specification? We manufacture to your project datasheet, purchase order, or IS/IEC standard.

Industries We Serve

Instrumentation Cables for Every Critical Industry

Our shielded cables and screened signal cables are specified and installed in India’s most demanding industrial environments across five major sectors.

Oil & Gas - Refineries & Petrochemicals

BPCL, HPCL, ONGC, IOCL projects

Power Plants - Thermal, Nuclear & Hydro

NTPC, NPCIL, State DISCOMs

Steel & Metals Manufacturing

JSW, Tata Steel, SAIL projects

EPC & Infrastructure Projects

L&T, Tata Projects, Shapoorji

Fertilizers & Agrochemicals

Hazardous area IS loops

Railways & Metro Rail

Signalling & SCADA cables

Cement & Mining

Harsh-environment screened cables

Panel Manufacturers & OEMs

Control panels, MCC, VFD panels

OEM & Tender Supply

Dedicated Support for OEM Manufacturers & Tender-Based Procurement

Understanding how a Instrumentation Cables is constructed and what the abbreviations in its designation mean ensures the correct cable is specified for every installation type and environment.

OEM Supply Capability

For panel manufacturers, machine builders & industrial OEMs

Cable Designation Abbreviations

For EPC contractors, consultants & public sector procurement
Why Engineers Specify BMI

Why Engineers & Procurement Managers Specify BMI Instrumentation Cables

✓ Direct Manufacturer — Zero Distributor Markup

Buy directly from the ISO-certified factory. No dealer margin, no middleman, you get factory pricing with full quality accountability.

✓ Complete MTC & Third-Party Inspection Support

Manufacturer’s test certificates, batch test reports, and full TPI support from CEIL, RITES, and Bureau Veritas, free of charge on qualifying orders.

✓ Engineering Support — Cable Selection Assistance

Our technical team reviews your plant layout, instrument list, and environmental conditions and recommends the correct shielding, insulation, and armour specification before you commit to procurement.

✓ Approved Vendor — PSU & Private Sector

Already on approved vendor lists for BPCL, HPCL, NTPC, JSW, and 100+ industrial plants, with zero re-qualification delays on your project.

Instrumentation Cable — Technical & Commercial FAQs

Instrumentation cables carry low-level analogue or digital signals (4–20mA, 0–10V, RTD, thermocouple) and must have twisted pairs/triads with EMI shielding (Al-Mylar screen + drain wire) to prevent signal distortion from electrical interference.

Control cables carry switching signals at higher voltages (110V, 230V, 415V) and do not require shielding. Using a control cable in a DCS instrumentation loop causes signal noise, measurement errors, and loop calibration failures.

Individual Screened (IS): Each pair has its own Al-Mylar screen and drain wire. Eliminates cross-talk between signal loops in a multi-pair cable. Essential for DCS multi-loop systems.

Overall Screened (OS): One screen covers all pairs. More economical. Adequate for single-loop or where all pairs carry signals from the same instrument.

IS + OS: Double layer protection — required in high-EMI environments like refineries and near HV transformers.

0.5 sq mm — Short-distance wiring inside panels and marshalling cabinets (under 50m)
0.75 sq mm — Standard field runs up to 200–250m for 4–20mA loops
1.0 sq mm — General purpose field runs, medium distance
1.5 sq mm — Long-distance field wiring (300m+), intrinsically safe circuits
2.5 sq mm — Solenoid valve power, high-current field devices, very long runs
We can calculate the exact conductor size based on your loop resistance requirement. Contact us with your transmitter model and cable run length.

Yes. Every batch from our Bhiwadi factory comes with a Mill Test Certificate (MTC) covering conductor resistance, insulation resistance, spark test, and dimensional data as per the applicable IS/IEC standard.

For EPC and government project orders, we support third-party inspection by agencies such as RITES, Lloyd’s Register, Bureau Veritas, TÜV, or any client-nominated inspector. Pre-dispatch inspection can be arranged at our factory with advance notice.

Yes, we regularly manufacture custom OEM configurations including:

Non-standard core counts (e.g. 7-pair, 15-triad, mixed pair+triad)
Special insulation colour codes as per customer BOM or IEC standard
Custom reel lengths (100m, 250m, 500m, 1000m drums)
Private labelling with your brand/project name printed on sheath
Special sheath colours (grey, blue, black, red, orange)
Combined pair + triad cables in a single design

Standard PVC: Most economical. Adequate for general industrial use. Releases halogen gases when burned — not suitable for enclosed spaces.

FRLS-H: Flame Retardant Low Smoke — self-extinguishing, low smoke density. Required for buildings, metros, hospitals. Still contains halogens.

LSZH / ZHFR: Zero halogen gas emission. Mandatory in tunnels, ships, offshore platforms, pharma cleanrooms, nuclear facilities. Higher cost but critical for personnel safety in enclosed spaces.

A twisted pair cable simply twists two conductors together to cancel common-mode electromagnetic interference through balanced transmission — effective for low-noise environments. A shielded twisted pair (STP) cable adds an Al-Mylar tape or copper braid shield around the twisted pair, with a drain wire for grounding the shield. STP cables provide superior noise rejection in industrial environments where power cables, VFDs, and heavy machinery generate strong EMI fields. For most industrial plant instrumentation, shielded twisted pair cables are the correct specification.