Your meter may also accept other thermocouple types such as type J or type T, and it may accept RTDs. The simplest thermocouple assembly consists of two thermocouple wires crimped or welded together at one end. Most thermocouple meters have a heat-conducting block to minimize any temperature difference between the wires at the meter. While using just unsheathed wires is certainly easy and inexpensive, the thermocouple is prone to damage unless you permanently mount it. And because the wires may not be shielded, they are susceptible to EMI from computers, machinery, electrical lines, and so forth.
Thermocouples generate a low-level voltage.
When you use a thermocouple to measure temperature on metal surfaces, check for possible ground loops or shorts. If the metal surface is grounded, contact with the sensor may ground the sensor, too. If you use a thermocouple enclosed in a sheath, verify if the sheath or the thermocouple wire is grounded. You might short out the sensor or introduce interference. Their temperature range isn't as wide as most thermocouples, but it well exceeds the range you need for measurements on electronic circuits or even on vehicle engines.