The global impact of COVID-19 on people and the economy is significant, and Watlow has taken a comprehensive approach to deal with the current crisis. Although the conditions are changing rapidly, we would like to share how the current situation is affecting Watlow, how we are protecting our team members, customers and partners, our business continuity plans and how we are maintaining the continuity of supply. 

We want to emphasize that Watlow remains open for business and committed to designing and manufacturing thermal solutions during this challenging time. Continue reading.

Temperature Sensor Comparison Guide  

Temperature Sensor Attributes

Criteria Thermocouple RTD Thermistor
Temperature Range Very wide
-450°F +4200°F
Wide
-400°F +1200°F
Narrow
-100°F +500°F
Interchangeability Good Excellent Poor to fair
Long-term Stability Poor to fair Good Poor
Accuracy Medium High Medium
Repeatability Fair Excellent Fair to good
Sensitivity (output) Low Medium Very high
Response Medium to fast Medium Medium to fast
Linearity Fair Good Poor
Self Heating No Very low to low High
Point (end) Sensitive Excellent Fair Good
Lead Effect High Medium Low
Size/Packaging Small to large Medium to small Small to medium

Temperature Sensor Advantages and Disadvantages

Sensor Advantages Disadvantages
Thermocouple
  • No resistance lead wire problems
  • Fastest response
  • Simple, rugged
  • Inexpensive
  • High temperature operation
  • Point temperature sensing
  • Non-linear
  • Low voltage
  • Least stable, repeatable
  • Least sensitive
RTD
  • Most stable, accurate
  • Contamination resistant
  • More linear than thermocouple
  • Area temperature sensing
  • Most repeatable temperature measurement
  • Current source required
  • Self-heating
  • Slow response time
  • Low sensitivity to small temperature changes
Thermistor
  • High output, fast
  • Two-wire ohms measurement
  • Economical
  • Point temperature sensing
  • Non-linear
  • Limited range
  • Fragile
  • Current source required
  • Self heating