The detection methods of digital multimeters (i.e., digital multimeters) and electronic measuring instruments usually involve multiple aspects, including direct measurement, indirect measurement, combined measurement, etc., as well as specific operating steps and precautions. The following is a detailed summary of these detection methods:

1. Direct measurement method
The direct measurement method refers to directly reading the measured value through the measuring instrument. In the detection of digital multimeters and electronic measuring instruments, the direct measurement method is one of the most commonly used methods.

Select the range: Select the appropriate range according to the expected value of the measured value. If the digital multimeter supports automatic range, you can skip this step.
Connect the circuit: Connect the digital multimeter or electronic measuring instrument correctly to the circuit under test. For voltage and resistance measurement, it is usually necessary to connect the test leads in parallel at both ends of the circuit under test; for current measurement, it is necessary to connect the test leads in series in the circuit under test.
Read the value: Observe the display screen of the digital multimeter or electronic measuring instrument and directly read the measured value.
2. Indirect measurement method
The indirect measurement method refers to measuring a physical quantity that has a certain functional relationship with the measured value and then calculating the measured value based on the functional relationship. In the detection of digital multimeters and electronic measuring instruments, indirect measurement methods are usually used to measure parameters that are difficult to obtain directly.

Measure related physical quantities: First measure the physical quantities related to the measured quantity, such as time, current, voltage, etc.
Calculate the measured value: According to the known functional relationship, use the measured physical quantity to calculate the measured value. For example, when measuring capacitance, the capacitance value can be indirectly calculated by measuring the charging time or discharge time of the capacitor.
3. Combined measurement method
The combined measurement method refers to measuring different parameters multiple times and listing equations according to the functional relationship for solution, so as to obtain the measurement value of the unknown quantity. This method is more common in the complex detection of digital multimeters and electronic measuring instruments.

Set measurement conditions: According to the characteristics of the measured quantity, set appropriate measurement conditions, such as voltage, current, frequency, etc.
Perform multiple measurements: Perform multiple measurements under different measurement conditions and record the results of each measurement.
Solve unknown quantities: According to the measurement results and the known functional relationship, list equations for solutions to obtain the measurement value of the unknown quantity.
4. Specific detection steps and precautions
Check the instrument status: Before measuring, check the status of the digital multimeter or electronic measuring instrument to ensure that it is working properly and the range is selected correctly.
Connect the circuit: When connecting the circuit, pay attention to the polarity and correctness of the circuit to avoid a wrong connection or short circuit.
Read the value: When reading the value, pay attention to the resolution and accuracy of the display to avoid misreading or missing.
Record data: Record the results of each measurement on paper or in an electronic device for subsequent analysis and processing.
Pay attention to safety: When measuring, pay attention to safety to avoid dangerous situations such as electric shocks or short circuits. Especially when measuring high voltage or high current, appropriate protective measures should be taken.
5. Example analysis
Taking the measurement of capacitance by a digital multimeter as an example, the following steps can be used for detection:

Select the capacitance range: Set the function switch of the digital multimeter to the capacitance range.
Connect the capacitor: Connect the two pins of the capacitor to the two test pens of the digital multimeter respectively.
Read the value: Observe the display of the digital multimeter and read the measured value of the capacitor. If the measured value is close to the nominal value of the capacitor (considering the tolerance range), it indicates that the capacitor is in good condition; if the measured value is significantly different from the nominal value, the capacitor may need to be replaced.
In summary, the detection methods of digital multimeters/electronic measuring instruments involve many aspects, including direct measurement methods, indirect measurement methods, combined measurement methods, etc. In practical applications, the appropriate detection method should be selected according to the characteristics and requirements of the measured object, and attention should be paid to safety matters and precautions during the measurement process.