How to use a digital multimeter to measure PT100 temperature sensor
A multimeter is a multi-purpose electronic measuring instrument that can have many special functions, but its main function is to measure voltage, resistance and current. Multimeters are divided into digital multimeters and traditional pointer electromagnetic deflection multimeters.
Measuring resistance with a digital multimeter is very simple, just set the range to the ohm range and take a reading. The resistance range is divided into seven levels: 200Ω, 2kΩ, 20kΩ, 200kΩ, 2MΩ, and 20MΩ. When measuring, set the range switch to the Ω range, insert the black test lead into the COM jack, and the red test lead into the V/Ω jack to read. However, it should be noted that when measuring resistance in a circuit, the power supply should be cut off.
For example, if the resistance value is 10K, set the digital multimeter to 20K (the one with the larger resistance and the closest resistance can get the greatest measurement accuracy), and then insert the black test lead into the COM hole (black ), insert the red test lead into the VΩ hole (red), and then touch the 2nd end of the resistor with the test lead.
It should be noted that if the resistance value is large, do not touch the 2nd terminal of the resistor with both hands, because the human body also has resistance. Touching the 2nd terminal means that the measured resistance and the human body resistance are connected in parallel, which will cause a test error. It does not matter if you touch one hand, so you can get Resistance reading.
How to use a digital multimeter to measure PT100 is to first adjust the digital multimeter to the 200 ohm range, and then use the two pens of the multimeter to touch the two pins of the PT100 respectively. If there is more than 100 ohms displayed on the digital display and the displayed data is stable , proving that the measured PT100 temperature sensor is a normal product. The above is the specific test method.
