National Instruments Resources — Guides, Tutorials & Selection Tools

Free expert resources to help you choose, use, and maintain your test and measurement instruments. Written by engineers, for engineers.

Buyer Guides

Detailed comparison guides to help you make the right purchasing decision.

OTDR Buyer Guide

The Complete OTDR Buyer's Guide 2026

Dynamic range, dead zones, wavelengths, and event detection — everything you need to evaluate before purchasing an OTDR.

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Spectrum Analyzer Guide

Spectrum Analyzer Selection Guide

From phase noise to sweep speed — key specifications decoded for RF engineers and telecom technicians.

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Cable Tester Comparison

Cable & Antenna Tester Comparison

Side-by-side comparison of field testers for VSWR, DTF, PIM, and fiber measurements across leading brands.

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Video Tutorials

Step-by-step walkthroughs from our measurement engineers.

OTDR Trace Analysis Tutorial

Reading OTDR Traces: A Practical Walkthrough

Learn to identify events, measure splice loss, and locate faults on OTDR traces.

5G Signal Measurement Tutorial

Measuring 5G NR Signals with a Spectrum Analyzer

Configure channel power, ACLR, and OBW measurements for sub-6 GHz and mmWave bands.

Fiber Inspection Tutorial

Fiber End-Face Inspection Best Practices

How to properly inspect and clean fiber connectors to IEC 61300-3-35 standards.

Instrument Selection Assistant

Not sure which instrument fits your application? Answer a few questions about your measurement needs and we'll recommend the best options from our catalog.

  • Tell us your measurement type (fiber, RF, cable, general electronics)
  • Specify frequency range and accuracy requirements
  • Choose field-portable or bench-top form factor
  • Get up to 3 personalized instrument recommendations
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Instrument selection tool interface

OTDR Selection: Key Specification Trade-offs

Choosing an OTDR involves balancing dynamic range, dead zone performance, and portability. The table below summarizes how these specifications interact — no single instrument excels on every axis.

Specification Entry-Level OTDR Mid-Range OTDR High-Performance OTDR
Dynamic Range 24–30 dB 32–38 dB 40–50 dB
Event Dead Zone 1.5–3 m 0.8–1.5 m 0.5–0.8 m
Max Test Distance 80 km 160 km 240+ km
Wavelengths 1310/1550 nm 1310/1550/1625 nm 1310/1550/1625 nm + CWDM
Typical Use Case Access networks, FTTx drops (< 20 km) Metro rings, campus backbones (20–80 km) Long-haul, submarine, DWDM systems (> 80 km)
Weight 0.6–1.2 kg 1.5–3 kg 4–8 kg (bench-top modules)
Price Range (Approx.) $3,000–$8,000 $10,000–$25,000 $30,000–$80,000+

Trade-off note: Higher dynamic range requires longer pulse widths, which increase dead zones. For short-span testing in dense data centers (patch panels < 5 m apart), an entry-level OTDR with shorter dead zones often outperforms a high-end unit. Always match the OTDR class to your actual link lengths and splice density.

Technical Documentation

Application Notes

Measurement techniques for specific testing scenarios in telecom, manufacturing, and R&D.

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Product Datasheets

Complete specifications, measurement capabilities, and ordering information for all instruments.

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User Manuals

Detailed operating instructions, measurement setup procedures, and maintenance guidelines.

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Calibration Certs

Download calibration certificates and measurement uncertainty reports for your instruments.

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