A thermocouple is a temperature measuring device consisting of two conductors of dissimilar metals or alloys that are connected only at the ends. When the ends are at different temperatures a small voltage is produced in the wire that can be related directly to the temperature difference between the ends. If the temperature at one end is known, the temperature at the other end can be determined.
| Thermocouple Type | ANSI Color Code | Initial Calibration Tolerances | ||||
| Wire Alloys | Calibration | +/- Conductor | Overall | Temperature Range | Standard. Limits | Special Limits |
| Iron(+) vs. Constantan 1 TM(-) | J | White/Red | Brown | 0°C to + 285°C 285°C to +750°C |
±2.2°C ±.75% |
1.1°C ±4% |
| Chromel TM(+) vs. Alumerl TM(-) | K | Yellow / red | Brown | -20°C to + 110°C -110°C to 0°C +285°C to +1250°C |
±2% ±2.2°%C ±2.2°C to ±.75% |
±1.1°C% ±.4% |
| Copper(+) vs. Constantan TM .(-) | T | Blue/Red | Brown | -200°C to -65°C -65°C to +130°C 130°C to +230°C |
±1.5°C ±1°C ±.75% |
±.8°C ±.5% ±.4% |
| Chromel(+) vs. Constantan TM .(-) | E | Purple/Red | Brown | -200°C to -170°C -170°C to +250°C 250°C to +340°C 340°C to +900°C |
±1°C ±1.7°C ±1.7% ±.5% |
±1°C ±1°C% ±.4% ±.4% |
| Condwtor Type | J. K. T and E |
| Cote Insulation | PTEE Fibreglass. Asbestos. PVC Ceramic. SS Braided |
| Core Colour | ANSI Color Code |
| Max Temp | PTEE (260t). Fibre-Glass (400"C) |
| Size of Conductor | From AWG 10 to AWG 36 or As Per Customer |
| Shielding Material | SS, Bare Copper, SPC, NPC or as ner Customer |
| Jacket Insulation | PTFE, Fibre-glass, PVC Ceramic, SS Braided |
| Jacket Color | ANSI Color Code |