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Technical Selection Guide
Industrial Temperature Sensors

Advanced temperature measurement solutions

Conatec offers a complete range of temperature sensors designed to meet the demands of modern industry. With over four decades of experience, we provide precise and reliable solutions for critical applications in sectors such as chemical, petrochemical, food and metallurgical.

This technical guide will help you select the most suitable sensor for your specific application, considering factors such as temperature range, required precision, installation environment and available budget.

Precision Thermoresistances

RTD thermoresistances (Resistance Temperature Detector) base their operation on the predictable variation of electrical resistance with temperature. They are the preferred choice when maximum precision and long-term stability are required.

Available types and specifications

PT100 - International Standard

Temperature range: −200°C to +850°C
TCR: 0.00385 Ω/°C (IEC 60751)
Precision: Class A (±0.15°C), Class B (±0.3°C)
Ideal applications: General industry, laboratories, critical processes
Advantages: International standard, excellent stability, compatible with most instruments
Considerations: Higher cost than nickel sensors, lower sensitivity than PT1000

PT500 - Electrical Noise Reduction

Temperature range: −200°C to +650°C
TCR: 0.00385 Ω/°C
Ideal applications: HVAC, building automation, remote monitoring
Advantages: Lower electrical noise effect in long cables, compatible with modern transmitters
Considerations: Less standardized than PT100, lower availability of universal controllers

PT1000 - Minimum Self-heating

Temperature range: −200°C to +650°C
TCR: 0.00385 Ω/°C
Ideal applications: HVAC, energy efficiency, renewable energy, autonomous sensors
Advantages: Lower self-heating, ideal for battery-powered sensors
Considerations: Limited compatibility with some instruments, requires higher reading precision

Ni100 - Economical Solution

Temperature range: −60°C to +180°C
TCR: 0.00617 Ω/°C
Ideal applications: Appliances, economical applications, automotive
Advantages: Higher sensitivity than platinum, low cost
Considerations: Non-linear response, not internationally standardized, limited range

Cu100 - Excellent Linearity

Temperature range: −200°C to +260°C
TCR: 0.00427 Ω/°C
Ideal applications: Legacy systems, simple processes
Advantages: Excellent linearity, high thermal conductivity
Considerations: Rapid oxidation, little used in modern industry, no current regulations

  • Key advantages: Superior precision, long-term stability, linear response
  • Typical applications: Process control, laboratories, industrial air conditioning

Industrial Thermocouples

Thermocouples generate an electrical voltage proportional to temperature through the thermoelectric effect. They are the preferred choice for extreme temperature ranges and severe industrial environments where robustness is a priority.

Type T (Copper-Constantan)

Useful range: −200°C to +350°C (max. +400°C)
Precision: High (±0.5°C to ±1°C)
Ideal environment: Cryogenics, refrigeration, laboratories, mild oxidizing atmospheres
Advantages: Very stable at low temperature, excellent linearity, good moisture resistance
Limitations: Does not support high temperatures, copper oxidizes easily

Type J (Iron-Constantan)

Useful range: −40°C to +750°C
Precision: Good (±1°C typical)
Ideal environment: Electric furnaces, moderate industrial environments
Advantages: Low cost, good sensitivity
Limitations: Oxidizes in humid atmospheres, not suitable for prolonged use at high temperature

Type E (Chrome-Constantan)

Useful range: −200°C to +900°C
Precision: Very high (±0.5°C typical)
Ideal environment: Cryogenics, low temperature environments with high sensitivity required
Advantages: Highest sensitivity of all base metals, excellent for low temperature
Limitations: Limited resistance to chemical corrosion in some industrial environments

Type K (Chromel-Alumel)

Useful range: −200°C to +1,260°C
Precision: Medium (±1.5°C typical)
Ideal environment: General industrial, furnaces, engines, oxidizing or inert atmospheres
Advantages: Very versatile, economical, resistant, popular in automation
Limitations: Long-term sensitivity drift above 1000°C

Type S (Platinum-Rhodium 10%)

Useful range: 0°C to +1,480°C (max. 1,600°C)
Precision: Very high (±0.25°C to ±1°C depending on range)
Ideal environment: High temperature furnaces, laboratories, pharmaceutical, metallurgy
Advantages: Exceptional stability, resistant to high temperatures, critical applications
Limitations: High cost due to platinum content, lower sensitivity than base metals

Type N (Nicrosil-Nisil)

Useful range: −200°C to +1,280°C
Precision: Better than type K (±1°C typical)
Ideal environment: High temperature industrial environments, oxidizing and neutral atmospheres
Advantages: High thermal stability, drift resistant, modern alternative to type K
Limitations: Higher cost than type K, more limited availability

Performance Comparison Tables

The following tables provide a quick comparison of key characteristics to facilitate the selection of the most suitable sensor for each specific application.

RTD Thermoresistances

Type Material Range (°C) TCR (Ω/°C) Precision Ideal environment
PT100 Platinum −200 to +850 0.00385 ★★★★★ (±0.15°C) Industry, laboratory
PT500 Platinum −200 to +650 0.00385 ★★★★ HVAC, automation
PT1000 Platinum −200 to +650 0.00385 ★★★★ Energy, batteries
Ni100 Nickel −60 to +180 0.00617 ★★★ Appliances
Cu100 Copper −200 to +260 0.00427 ★★★ Legacy applications

Thermocouples

Type Materials Range (°C) Precision Ideal environment
T Cu-Constantan −200 to +350 ★★★★★ (±0.5°C) Cryogenics, refrigeration
J Fe-Constantan −40 to +750 ★★★★ Furnaces, general industry
E Cr-Constantan −200 to +900 ★★★★★ High sensitivity, laboratory
K Cr-Al −200 to +1260 ★★★ General industrial
S Pt-Rh (10%) 0 to +1480 ★★★★★ High temperature, pharmaceutical
N NiCr-NiSi −200 to +1280 ★★★★ High temperature, oxidizing
Download complete specifications table

Metallic and Ceramic Protections

Adequate protection is essential to ensure the durability and precision of sensors in severe industrial environments. Conatec offers a complete range of protections specifically designed for different operating conditions.

Metallic Protections

Material Max. oxidizing T. (°C) Max. reducing T. (°C) Diameters (mm) Main applications
AISI 304 900 600 4-6-8-10/12-15-21 Chemical, petrochemical industry
AISI 316 900 600 4-6-8-10/12-15-21 Acid resistant, seawater
AISI 446 1100 950 21, 30 Sulfurous atmospheres, furnaces
AISI 310 1150 650 18-21-26.9 Furnaces, corrosive processes
Inconel 600 1175 550 3-4-5-6-8 Chemical, thermal industries

Ceramic Protections

Type Max. T. (°C) Thermal shock Flexion (Kp/cm²) Applications
PYTHAGORAS KER 610 1600 Regular 1500 General use, halogen gases
ALSINT KER 710 1950 Good 3600 Aggressive atmospheres, HF
SILIMANTIN 60 1650 Very good 350 Double tube external protection
SILICON CARBIDE 1500 Excellent -- High thermal conductivity
SUPAMOR GM 1200 Good 2000 Molten aluminum

Extension and Compensation Cables

Compensation cables ensure precise signal transmission from the sensor to the measuring instrument. Correct selection is critical to maintain the accuracy of the complete system.

Color Coding by Standards

Type Standard Conductor + (Positive) Conductor - (Negative) Outer sheath
Type K ANSI Green White Green
IEC Green White Green
Type J ANSI White Red Black
IEC Black White Black
Type T ANSI Blue Red Blue
IEC Blue White Blue
Type S ANSI Black Red Black
IEC Orange White Orange

Selection Considerations

  • Material compatibility: Must exactly match the thermocouple type
  • Temperature range: Verify cable operating capacity
  • Insulation: PVC (up to 105°C), PTFE (up to 260°C), fiberglass (up to 482°C)
  • Length and gauge: Minimize resistance and signal attenuation

Key differences:

ANSI: Negative conductor generally red (except Type K)
IEC: Negative conductor always white

It is essential to follow the correct standard to avoid connection errors that affect precision.