All kinds of classification methods of electronic measuring instrument and measuring way

1 according to the measurements classification

1. 1 direct measurement: in the process of measurement, can will be measured directly comparing with similar standard quantity, or can directly use scale beforehand good measuring instrument to measure is measured directly obtain numerical measurement is called direct measurement.

　　1. Indirect measurement: when is measured for some reason can't direct measurement can be directly measured with have certain function relation of physical quantity is measured, and then according to the function relationship between measured value calculation, this indirect method called the indirect measurement of the measurement result.

　　1. 3 combination measurement: when a measurement results need to be expressed in multiple unknown parameters, but by changing the conditions of multiple measurement, listed according to the functional relation equation, and an unknown quantity measurement, called combined measurement.

2 according to measurement methods of classification

2. 1 straight law: with direct pointed out by measuring the size of the indicating instrument to measure, can directly from the meter dial, or read from the screen be measured numerical measuring method, referred to as the law.

　　2. 2 comparison method: will be measured with standard quantity direct comparison in comparison instrument, is measured to obtain the numerical method, called the comparison method.

3 according to the measurement property classification

3. 1 time domain measurement: also called instantaneous measurement, time domain is mainly measured by measuring the change rule of over time. If use the oscilloscope to observe the rise of the pulse signal along the falling edge, and flat land pulse parameters and dynamic circuit transient process. Vacuum gauge meter | | hardness flaw detector | | electronic scale thermal imager

3. 2 frequency domain measurements: also known as the steady state measurement frequency domain, the main purpose is to get to the measurement and the relationship between the frequency. Such as signal spectrum analysis of spectrum analyzer, measuring amplifier amplitude-frequency characteristic and phase frequency characteristics.

　　3. 3 data fields measurement: data fields is also called the logical volume measurement, mainly for digital signal, or logic state of the circuit measurement, such as logic analyzer and other equipment was used to measure the state of the counter.

　　3. 4 random measurement: random measurement also known as statistical measurement, mainly for all kinds of noise signal for dynamic measurement and statistical analysis. This is a new measurement technique, especially in the field of communications has a wide range of applications.