Comparison of resistance range between digital multimeter and analog multimeter
Features:
The digital type has special gears for measuring diodes, but the analog type does not. For parameters with unstable fluctuations, the digital type is not as good as the pointer type, but the digital type has higher accuracy and clear display. Unlike the pointer type, different scales must be selected according to different gears.
working principle:
The pointer meter is used by using electromagnetic induction and simple electronic circuits. The digital meter is used by digital circuit processing and adding digital display! The pointer resistance measurement type is convenient, economical, durable, afraid of falling, and inconvenient to read; the digital meter is intuitive, expensive, and has average protection functions!
1. The reading accuracy of the pointer meter is poor, but the process of the pointer swinging is relatively intuitive, and its swing speed can sometimes reflect the measured size more objectively (such as measuring the slightness of the TV data bus (SDL) when transmitting data). Jitter); the digital meter reading is intuitive, but the process of digital changes looks messy and not easy to watch.
2. There are generally two batteries in an analog watch, one with a low voltage of 1.5V and one with a high voltage of 9V or 15V. The black test lead is the positive terminal relative to the red test lead. Digital meters commonly use a 6V or 9V battery. In the resistance mode, the output current of the test pen of the pointer meter is much larger than that of the digital meter. Using the R×1Ω gear can make the speaker make a loud "click" sound, and using the R×10kΩ gear can even light up the light-emitting diode (LED).
3. In the voltage range, the internal resistance of the pointer meter is smaller than that of the digital meter, and the measurement accuracy is relatively poor. In some high-voltage and micro-current situations, it is even impossible to measure accurately because the internal resistance will affect the circuit under test (for example, when measuring the acceleration stage voltage of a TV picture tube, the measured value will be much lower than the actual value). The internal resistance of the voltage range of the digital meter is very large, at least in the megohm level, and has little impact on the circuit under test. However, the extremely high output impedance makes it susceptible to the influence of induced voltage, and the measured data may be false in some situations with strong electromagnetic interference.
4. Meter head: It is a highly sensitive magnetoelectric DC ammeter. The main performance indicators of the multimeter basically depend on the performance of the meter head. The sensitivity of the meter refers to the DC current value flowing through the meter when the meter pointer deflects at full scale. The smaller the value, the higher the sensitivity of the meter. The greater the internal resistance when measuring voltage, the better its performance. There are four scale lines on the meter head, and their functions are as follows: The first one (from top to bottom) is marked with R or Ω, indicating the resistance value. When the switch is in the ohm position, this scale line is read. The second bar is marked with ∽ and VA, indicating the AC and DC voltage and DC current values. When the transfer switch is in the AC, DC voltage or DC current position, and the range is in other positions except AC 10V, this scale is read. Wire. The third bar is marked 10V, which indicates the AC voltage value of 10V. When the transfer switch is in the AC and DC voltage range and the measurement range is AC 10V, this scale line is read. The fourth bar is marked in dB and indicates the audio level.
5. The digital meter must be powered on (usually a 9V laminated battery). When measuring voltage and current, the analog meter does not require battery power. 6. The digital meter reads directly, and the reading of the pointer meter is relatively not as direct as the digital meter. 7. In terms of dynamic measurement of voltage and current, digital meters (digital meters without oscilloscope function) are not as intuitive as pointer meters. 8. In terms of shock resistance and fall resistance, analog watches are far inferior to digital watches. 9. The digital meter function can be extended to measure frequency, capacitance, logic channel, triode amplification, etc. The analog meter usually only has three levels: resistance, voltage, and current. I hope the above answers can help you briefly understand the differences between digital watches and analog watches.
The analog multimeter directly drives the needle of the meter after rectifying, shunting, and voltage dividing the analog current and voltage, and makes corresponding indications on the dial. Only use the battery in the meter as a power source when measuring passive components (such as resistors, capacitors, transistors, etc.), and connect the red test lead to the negative pole of the battery. A digital multimeter is not just called a digital meter because it displays numbers. It converts the collected analog signals into digital signals through "digital-to-analog conversion" and then encodes them. The display drive circuit and display components display the measured values. At the same time, There are also integrated computing circuits such as sampling, comparison, and amplification. When using it, there must be a battery inside the meter to provide power for the circuit inside the meter. Different from the analog multimeter (also called an analog multimeter), the red pen is a high potential. The selection of gears during measurement is similar to the voltage and current gears of an analog multimeter. When measuring resistance, the reading of an analog multimeter is the multiple of the indicated value multiplied by the selected range. Generally, digital meters have smaller errors than analog multimeters.
