Attaching to the Terminal Junction Attach the thermocouple wire to the terminal block by matching the wire polarity and/or color to the corresponding terminal (e.g. red wire to red wire). Use the Thermocouple Characteristics Table (see Table 1) if you are unfamiliar with thermocouple color coding. You can also determine polarity by checking to see if the wire from the thermocouple into the head is magnetic. In thermocouple pairs, usually one leg is magnetic and the other is not. The first name mentioned when naming the pairings indicates the positive leg (for example, copper in copper-constantan). One other point to keep in mind is that the color red in thermocouples indicates the negative leg, whereas in electronics, red generally indicates the positive. If you are using a shielded extension wire with a drain, connect the drain wire to the green grounding terminal. Shielded wire is typically used to protect the sensor signal from RF interference in environments where devices such as hand-held radios, welding equipment, circuit breakers, variable speed motors or fluorescent lighting come too close to the sensor leadwires. These devices produce electromagnetic fields that can be 5 www.conaxbuf .conaxbuff conaxbuf@conaxbuff 716-684-4500 Fax: 716-684-7 4-7433 1-800-223-2389 · www.conaxbuf falo.com · conaxbuf@conaxbuf falo.com · 716-684-4500 · Fax: 716-68 4-7433