Comparison of Resistance Ranges between Digital Multimeters and Pointer Multimeters
Features:
The digital type has a dedicated range for measuring diodes, while the pointer type does not. For parameters with unstable fluctuations, the digital type is not as good as the pointer type, but the digital accuracy is higher and the display is clear. Unlike the pointer type, different scales need to be selected according to different gears.
Working principle:
The pointer table is used by using electromagnetic induction and simple electronic circuits, while the digital table is applied by processing and displaying words through digital circuits! The pointer resistance measurement type is convenient, economical, durable, and resistant to falling, making reading inconvenient; The digital watch is intuitive, expensive, and has average protection functions!
1. The reading accuracy of the pointer meter is poor, but the process of pointer oscillation is relatively intuitive, and the amplitude of its oscillation speed can sometimes objectively reflect the measured size (such as the slight jitter of the TV data bus (SDL) during data transmission); The reading on the digital meter is intuitive, but the process of changing the numbers looks messy and not easy to watch.
2. There are usually two batteries in a pointer meter, one with a low voltage of 1.5V and the other with a high voltage of 9V or 15V. The black pen is relatively positive compared to the red pen. A digital meter usually uses a 6V or 9V battery. In the resistance range, the output current of the pointer meter is much larger than that of a digital meter, using R × 1 Ω gear can make the speaker emit a loud "click" sound, using R × 10k Ω gear can even light up light-emitting diodes (LEDs).
3. In the voltage range, the internal resistance of a pointer meter is relatively small compared to a digital meter, and the measurement accuracy is relatively poor. In some situations where high voltage and micro current are present, it is even impossible to accurately measure them because their internal resistance can affect the circuit being tested (for example, when measuring the acceleration stage voltage of a television picture tube, the measured value may be much lower than the actual value). The internal resistance of the voltage range of the digital meter is very high, at least at the megaohm level, and has little impact on the circuit being tested. But the extremely high output impedance makes it susceptible to the influence of induced voltage, and the data measured in some places with strong electromagnetic interference may be false.
4. Meter head: It is a highly sensitive magnetoelectric DC ammeter, and the main performance indicators of the multimeter mainly depend on the performance of the meter head. The sensitivity of the meter head refers to the DC current value flowing through the meter head when the pointer of the meter head deflects at full scale. The smaller this value, the higher the sensitivity of the meter head. The greater the internal resistance during voltage measurement, the better its performance. There are four scale lines on the meter head, and their functions are as follows: the first line (from top to bottom) is marked with R or Ω, indicating the resistance value. When the conversion switch is in the ohm gear, this scale line is read. The second line is marked with Δ and VA, indicating the AC/DC voltage and DC current values. When the transfer switch is in the AC/DC voltage or DC current range, and the range is in other positions except for AC 10V, this scale line is read. The third line is marked with 10V, indicating the AC voltage value of 10V. When the transfer switch is in the AC/DC voltage range and the AC range is 10V, this scale line is read. The fourth item is marked with dB, indicating the audio level.
5. The digital meter must be powered on for operation (usually using a 9V stacked battery). The pointer meter does not require battery power when measuring voltage and current. 6. A digital meter reads directly, while a pointer meter does not read as directly as a digital meter. 7. In terms of dynamic measurement of voltage and current, digital meters (excluding oscilloscope functions) are not as intuitive as pointer meters. 8. In terms of seismic resistance and resistance to falling, pointer watches are far inferior to digital watches. 9. The digital meter function can be extended to measure frequency, capacitance, logic channel, transistor amplification, etc. A pointer meter usually only has three levels: resistance, voltage, and current. I hope the above answers can help you understand the difference between a digital table and a pointer table.
A pointer multimeter is an analog current and voltage that are directly driven by the meter needle after rectification, shunt, and voltage division, and are indicated on the dial accordingly. When measuring passive components (such as resistors, capacitors, transistors, etc.), only use the battery inside the meter as the power source, and connect the red lead to the negative electrode of the battery. A digital multimeter is not only called a digital meter because it displays numbers. It converts the collected analog signal into a digital signal through "digital to analog conversion", encodes it, and displays the measured values through the display driver circuit and display components. At the same time, it also has integrated operational circuits such as sampling, comparison, and amplification. When using, it is necessary to have a battery inside the meter to provide power for the circuit inside the meter. Unlike a pointer multimeter (also known as an analog multimeter), the red probe indicates a high potential. The selection of gear during measurement is similar to the voltage and current ranges of a pointer multimeter, while the reading of a pointer multimeter when measuring resistance is the multiplication of the indicated value by the selected range range. Generally, the error of a digital meter is smaller than that of a pointer multimeter.
