An Improved Noncatalytic Coating for Thermocouples

Abstract

We have developed an improved coating for Pt/Pt-13% Rh thermocouples using a commercially available high-temperature adhesive. This aluminum oxide/potassium silicate coating is non-toxic, easy to apply and more stable than the standard thermocouple coatings. Temperature profiles obtained using the coated thermocouple, corrected for radiation, and OH rotational temperatures obtained using Laser-Induced Fluorescence (LIF) are in excellent agreement, demonstrating that the coating removes the catalytic effects usually observed with uncoated thermocouples.

Keywords:

• Thermocouple coating
• temperature measurement
• low pressure flame