In order to measure the temperature, temperature sensors are used - primary converters. Resistance thermometers and thermocouples are commonly used in industry. There are several types of thermocouples. The most common are chromel-alumel and chromel-copel. A special program of a thermocouple thermometer is used for measurement.
It is necessary
for continuous monitoring of temperature changes the program "Multichannel recorder"
Instructions
Step 1
Before measuring, set the type of thermocouple you are using and the cold junction channel of the compensator. In multichannel measurements, channels can be connected to different types of thermocouples. According to the principle of operation, a thermocouple measures the temperature between the hot junction and the free ends of the thermoelectrodes.
Step 2
Connect the thermocouples to the device directly or using extension wires, which must be made of the same thermocouple materials.
Step 3
Measure the temperature of the free ends (cold junctions) in the thermocouple connection area (near the terminal block) using a special temperature sensor (cold junction compensator). It is taken into account when measuring the total temperature. To achieve maximum accuracy of readings and correct measurement of the temperature of the free ends, make sure that there are no large temperature gradients, convective flows (blowing, wind, draft) in the terminal block area, as well as radiant heating from hot bodies.
Step 4
Turn on the thermocouple thermometer program, but instead of the thermocouple, connect a jumper to the device input, i.e. short-circuit the input. In this case, the program will show the changed temperature of the terminal block. Adjust the cold junction compensator as needed according to the compensator calibration instructions.
Step 5
Immerse the thermocouple in boiling water to test the functionality of the program, thermocouple, device, compensation wire. Instrument readings should not differ from one hundred degrees by more than one or two degrees. Remember that the shorter the thermocouple wires are, the less electrical noise will be on them. In all cases, the length of the thermocouple wires should not exceed 50 meters. If you need to measure a long distance, use a distributed system with remote amplifiers.
