WATLOW'S TRUE SURFACE THERMOCOUPLE (TST) MEASURES SURFACE TEMPERATURES WITH UNMATCHED ACCURACY

ST. LOUIS – Watlow Electric Manufacturing Co. recently unveiled its new True Surface Thermocouple (TST). The innovative contact sensor offers surface temperature measurement accuracy that is unmatched in the industry.

The product, which is manufactured in an ISO-9001 certified facility, was developed as a highly accurate, low-cost thermocouple to measure flat surface temperatures in multiple locations. The TST was designed to reduce temperature-sensing errors associated with ambient airflow, while packaged in a small profile.

The technology features include:

• Isothermal measuring junction – The unit's large isothermal area for the measuring junction results in approximately 1/8 of the error of a common "washer" style thermocouple;
  
• Molded insulator – The removable molded cover insulates the isothermal measuring block from ambient flow. In such an environment, the insulated surface sensor exhibits approximately 1/16 the error of a common "washer" style thermocouple;
  
• Compact, universal package – The 0.44-inch wide by 0.25-inch high contoured sensor easily fits into corners and other tight locations. The molded insulator is field removable for applications where an even smaller package is needed; and
  
• Temperature rating of 200C – offers superior flexibility for applications including semiconductor chambers, platens, packaging, cleaning and food preparation.

The technology offers several options, including: dual, isolated thermocouples in the same sensor; ungrounded or grounded, Type J or Type K calibrations; and shielded lead wire with drain, either isolated from or connected to the sensor sheath.

Watlow developed a test to determine and compare the steady state error of the Watlow TST and a common "washer"- style thermocouple at several temperature settings with and without ambient airflow. In each case, the percentage of error was significantly less with the TST – less than two percent (temperature difference of surface and ambient) versus eight to 30 percent for the "washer" thermocouple.

Watlow is the world's largest custom designer and manufacturer of industrial heaters, sensors and controls. The firm's corporate headquarters are in St. Louis, Missouri with manufacturing facilities worldwide.

Watlow Electric Manufacturing Company, 12001 Lackland Road, St. Louis, MO 63146. Tel: 314-878-4600; Fax: 314-878-2360.